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            <h1>perldiag</h1>


  <!--    -->
<ul><li><a href="#NAME">NAME</a><li><a href="#DESCRIPTION">DESCRIPTION</a><li><a href="#SEE-ALSO">SEE ALSO</a></ul><a name="NAME"></a><h1>NAME</h1>
<p>perldiag - various Perl diagnostics</p>
<a name="DESCRIPTION"></a><h1>DESCRIPTION</h1>
<p>These messages are classified as follows (listed in increasing order of
desperation):</p>
<pre class="verbatim"><ol><li>    (W) A warning (optional).</li><li>    (D) A deprecation (enabled by default).</li><li>    (S) A severe warning (enabled by default).</li><li>    (F) A fatal error (trappable).</li><li>    (P) An internal error you should never see (trappable).</li><li>    (X) A very fatal error (nontrappable).</li><li>    (A) An alien error message (not generated by Perl).</li></ol></pre><p>The majority of messages from the first three classifications above
(W, D &amp; S) can be controlled using the <code class="inline"><span class="w">warnings</span></code>
 pragma.</p>
<p>If a message can be controlled by the <code class="inline"><span class="w">warnings</span></code>
 pragma, its warning
category is included with the classification letter in the description
below.  E.g. <code class="inline"><span class="s">(</span><span class="w">W</span> <span class="w">closed</span><span class="s">)</span></code>
 means a warning in the <code class="inline"><span class="w">closed</span></code>
 category.</p>
<p>Optional warnings are enabled by using the <code class="inline"><span class="w">warnings</span></code>
 pragma or the <b>-w</b>
and <b>-W</b> switches.  Warnings may be captured by setting <code class="inline"><span class="i">$SIG</span>{<span class="w">__WARN__</span>}</code>

to a reference to a routine that will be called on each warning instead
of printing it.  See <a href="perlvar.html">perlvar</a>.</p>
<p>Severe warnings are always enabled, unless they are explicitly disabled
with the <code class="inline"><span class="w">warnings</span></code>
 pragma or the <b>-X</b> switch.</p>
<p>Trappable errors may be trapped using the eval operator.  See
<a href="functions/eval.html">eval</a>.  In almost all cases, warnings may be selectively
disabled or promoted to fatal errors using the <code class="inline"><span class="w">warnings</span></code>
 pragma.
See <a href="warnings.html">warnings</a>.</p>
<p>The messages are in alphabetical order, without regard to upper or
lower-case.  Some of these messages are generic.  Spots that vary are
denoted with a %s or other printf-style escape.  These escapes are
ignored by the alphabetical order, as are all characters other than
letters.  To look up your message, just ignore anything that is not a
letter.</p>
<ul>
<li><a name="accept()-on-closed-socket-%25s"></a><b>accept() on closed socket %s</b>
<p>(W closed) You tried to do an accept on a closed socket.  Did you forget
to check the return value of your socket() call?  See
<a href="functions/accept.html">accept</a>.</p>
</li>
<li><a name="Aliasing-via-reference-is-experimental"></a><b>Aliasing via reference is experimental</b>
<p>(S experimental::refaliasing) This warning is emitted if you use
a reference constructor on the left-hand side of an assignment to
alias one variable to another.  Simply suppress the warning if you
want to use the feature, but know that in doing so you are taking
the risk of using an experimental feature which may change or be
removed in a future Perl version:</p>
<pre class="verbatim"><ol><li>    <a class="l_k" href="functions/no.html">no</a> <span class="w">warnings</span> <span class="q">&quot;experimental::refaliasing&quot;</span><span class="sc">;</span></li><li>    <a class="l_k" href="functions/use.html">use</a> <span class="w">feature</span> <span class="q">&quot;refaliasing&quot;</span><span class="sc">;</span></li><li>    \<span class="i">$x</span> = \<span class="i">$y</span><span class="sc">;</span></li></ol></pre></li>
<li><a name="Allocation-too-large%3a-%25x"></a><b>Allocation too large: %x</b>
<p>(X) You can't allocate more than 64K on an MS-DOS machine.</p>
</li>
<li><a name="'%25c'-allowed-only-after-types-%25s-in-%25s"></a><b>'%c' allowed only after types %s in %s</b>
<p>(F) The modifiers '!', '&lt;' and '&gt;' are allowed in pack() or unpack() only
after certain types.  See <a href="functions/pack.html">pack</a>.</p>
</li>
<li><a name="alpha-%3enumify()-is-lossy"></a><b>alpha-&gt;numify() is lossy</b>
<p>(W numeric) An alpha version can not be numified without losing
information.</p>
</li>
<li><a name="Ambiguous-call-resolved-as-CORE%3a%3a%25s()%2c-qualify-as-such-or-use-%26"></a><b>Ambiguous call resolved as CORE::%s(), qualify as such or use &amp;</b>
<p>(W ambiguous) A subroutine you have declared has the same name as a Perl
keyword, and you have used the name without qualification for calling
one or the other.  Perl decided to call the builtin because the
subroutine is not imported.</p>
<p>To force interpretation as a subroutine call, either put an ampersand
before the subroutine name, or qualify the name with its package.
Alternatively, you can import the subroutine (or pretend that it's
imported with the <code class="inline"><a class="l_k" href="functions/use.html">use</a> <span class="w">subs</span></code>
 pragma).</p>
<p>To silently interpret it as the Perl operator, use the <code class="inline"><span class="w">CORE::</span></code>
 prefix
on the operator (e.g. <code class="inline"><span class="i">CORE::log</span><span class="s">(</span><span class="i">$x</span><span class="s">)</span></code>
) or declare the subroutine
to be an object method (see <a href="perlsub.html#Subroutine-Attributes">Subroutine Attributes in perlsub</a> or
<a href="attributes.html">attributes</a>).</p>
</li>
<li><a name="Ambiguous-range-in-transliteration-operator"></a><b>Ambiguous range in transliteration operator</b>
<p>(F) You wrote something like <code class="inline"><a class="l_k" href="functions/tr.html">tr/a-z-0//</a></code> which doesn't mean anything at
all.  To include a <code class="inline">-</code>
 character in a transliteration, put it either
first or last.  (In the past, <code class="inline"><a class="l_k" href="functions/tr.html">tr/a-z-0//</a></code> was synonymous with
<code class="inline"><a class="l_k" href="functions/tr.html">tr/a-y//</a></code>, which was probably not what you would have expected.)</p>
</li>
<li><a name="Ambiguous-use-of-%25s-resolved-as-%25s"></a><b>Ambiguous use of %s resolved as %s</b>
<p>(S ambiguous) You said something that may not be interpreted the way
you thought.  Normally it's pretty easy to disambiguate it by supplying
a missing quote, operator, parenthesis pair or declaration.</p>
</li>
<li><a name="Ambiguous-use-of--%25s-resolved-as--%26%25s()"></a><b>Ambiguous use of -%s resolved as -&amp;%s()</b>
<p>(S ambiguous) You wrote something like <code class="inline">-<span class="w">foo</span></code>
, which might be the
string <code class="inline"><span class="q">&quot;-foo&quot;</span></code>
, or a call to the function <code class="inline"><span class="w">foo</span></code>
, negated.  If you meant
the string, just write <code class="inline"><span class="q">&quot;-foo&quot;</span></code>
.  If you meant the function call,
write <code class="inline">-<span class="i">foo</span><span class="s">(</span><span class="s">)</span></code>
.</p>
</li>
<li><a name="Ambiguous-use-of-%25c-resolved-as-operator-%25c"></a><b>Ambiguous use of %c resolved as operator %c</b>
<p>(S ambiguous) <code class="inline"><span class="i">%</span></code>
, <code class="inline"><span class="i">&amp;</span></code>
, and <code class="inline"><span class="i">*</span></code>
 are both infix operators (modulus,
bitwise and, and multiplication) <i>and</i> initial special characters
(denoting hashes, subroutines and typeglobs), and you said something
like <code class="inline"><span class="i">*foo</span> * <span class="w">foo</span></code>
 that might be interpreted as either of them.  We
assumed you meant the infix operator, but please try to make it more
clear -- in the example given, you might write <code class="inline"><span class="i">*foo</span> * <span class="i">foo</span><span class="s">(</span><span class="s">)</span></code>
 if you
really meant to multiply a glob by the result of calling a function.</p>
</li>
<li><a name="Ambiguous-use-of-%25c%7b%25s%7d-resolved-to-%25c%25s"></a><b>Ambiguous use of %c{%s} resolved to %c%s</b>
<p>(W ambiguous) You wrote something like <code class="inline"><span class="i">@</span>{<span class="w">foo</span>}</code>
, which might be
asking for the variable <code class="inline"><span class="i">@foo</span></code>
, or it might be calling a function
named foo, and dereferencing it as an array reference.  If you wanted
the variable, you can just write <code class="inline"><span class="i">@foo</span></code>
.  If you wanted to call the
function, write <code class="inline"><span class="i">@</span>{<span class="i">foo</span><span class="s">(</span><span class="s">)</span>}</code>
 ... or you could just not have a variable
and a function with the same name, and save yourself a lot of trouble.</p>
</li>
<li><a name="Ambiguous-use-of-%25c%7b%25s%5b...%5d%7d-resolved-to-%25c%25s%5b...%5d"></a><b>Ambiguous use of %c{%s[...]} resolved to %c%s[...]</b>
</li>
<li><a name="Ambiguous-use-of-%25c%7b%25s%7b...%7d%7d-resolved-to-%25c%25s%7b...%7d"></a><b>Ambiguous use of %c{%s{...}} resolved to %c%s{...}</b>
<p>(W ambiguous) You wrote something like <code class="inline"><span class="i">$</span>{<span class="w">foo</span><span class="s">[</span><span class="n">2</span><span class="s">]</span>}</code>
 (where foo represents
the name of a Perl keyword), which might be looking for element number
2 of the array named <code class="inline"><span class="i">@foo</span></code>
, in which case please write <code class="inline"><span class="i">$foo</span>[<span class="n">2</span>]</code>
, or you
might have meant to pass an anonymous arrayref to the function named
foo, and then do a scalar deref on the value it returns.  If you meant
that, write <code class="inline"><span class="i">$</span>{<span class="i">foo</span><span class="s">(</span><span class="s">[</span><span class="n">2</span><span class="s">]</span><span class="s">)</span>}</code>
.</p>
<p>In regular expressions, the <code class="inline"><span class="i">$</span>{<span class="w">foo</span><span class="s">[</span><span class="n">2</span><span class="s">]</span>}</code>
 syntax is sometimes necessary
to disambiguate between array subscripts and character classes.
<code class="inline"><span class="q">/$length[2345]/</span></code>
, for instance, will be interpreted as <code class="inline"><span class="i">$length</span></code>
 followed
by the character class <code class="inline"><span class="s">[</span><span class="n">2345</span><span class="s">]</span></code>
.  If an array subscript is what you
want, you can avoid the warning by changing <code class="inline"><span class="q">/${length[2345]}/</span></code>
 to the
unsightly <code class="inline"><span class="q">/${\$length[2345]}/</span></code>
, by renaming your array to something
that does not coincide with a built-in keyword, or by simply turning
off warnings with <code class="inline"><a class="l_k" href="functions/no.html">no</a> <span class="w">warnings</span> <span class="q">&#39;ambiguous&#39;</span><span class="sc">;</span></code>
.</p>
</li>
<li><a name="'%7c'-and-'%3c'-may-not-both-be-specified-on-command-line"></a><b>'|' and '&lt;' may not both be specified on command line</b>
<p>(F) An error peculiar to VMS.  Perl does its own command line
redirection, and found that STDIN was a pipe, and that you also tried to
redirect STDIN using '&lt;'.  Only one STDIN stream to a customer, please.</p>
</li>
<li><a name="'%7c'-and-'%3e'-may-not-both-be-specified-on-command-line"></a><b>'|' and '&gt;' may not both be specified on command line</b>
<p>(F) An error peculiar to VMS.  Perl does its own command line
redirection, and thinks you tried to redirect stdout both to a file and
into a pipe to another command.  You need to choose one or the other,
though nothing's stopping you from piping into a program or Perl script
which 'splits' output into two streams, such as</p>
<pre class="verbatim"><ol><li>    <a class="l_k" href="functions/open.html">open</a><span class="s">(</span><span class="w">OUT</span><span class="cm">,</span><span class="q">&quot;&gt;$ARGV[0]&quot;</span><span class="s">)</span> or <a class="l_k" href="functions/die.html">die</a> <span class="q">&quot;Can&#39;t write to $ARGV[0]: $!&quot;</span><span class="sc">;</span></li><li>    while <span class="s">(</span><span class="q">&lt;STDIN&gt;</span><span class="s">)</span> <span class="s">{</span></li><li>        <a class="l_k" href="functions/print.html">print</a><span class="sc">;</span></li><li>        <a class="l_k" href="functions/print.html">print</a> <span class="i">OUT</span><span class="sc">;</span></li><li>    <span class="s">}</span></li><li>    <a class="l_k" href="functions/close.html">close</a> <span class="w">OUT</span><span class="sc">;</span></li></ol></pre></li>
<li><a name="Applying-%25s-to-%25s-will-act-on-scalar(%25s)"></a><b>Applying %s to %s will act on scalar(%s)</b>
<p>(W misc) The pattern match (<code class="inline"><span class="q">//</span></code>
), substitution (<code class="inline"><a class="l_k" href="functions/s.html">s///</a></code>), and
transliteration (<code class="inline"><a class="l_k" href="functions/tr.html">tr///</a></code>) operators work on scalar values.  If you apply
one of them to an array or a hash, it will convert the array or hash to
a scalar value (the length of an array, or the population info of a
hash) and then work on that scalar value.  This is probably not what
you meant to do.  See <a href="functions/grep.html">grep</a> and <a href="functions/map.html">map</a> for
alternatives.</p>
</li>
<li><a name="Arg-too-short-for-msgsnd"></a><b>Arg too short for msgsnd</b>
<p>(F) msgsnd() requires a string at least as long as sizeof(long).</p>
</li>
<li><a name="Argument-%22%25s%22-isn't-numeric%25s"></a><b>Argument "%s" isn't numeric%s</b>
<p>(W numeric) The indicated string was fed as an argument to an operator
that expected a numeric value instead.  If you're fortunate the message
will identify which operator was so unfortunate.</p>
<p>Note that for the <code class="inline"><span class="w">Inf</span></code>
 and <code class="inline"><span class="w">NaN</span></code>
 (infinity and not-a-number) the
definition of "numeric" is somewhat unusual: the strings themselves
(like "Inf") are considered numeric, and anything following them is
considered non-numeric.</p>
</li>
<li><a name="Argument-list-not-closed-for-PerlIO-layer-%22%25s%22"></a><b>Argument list not closed for PerlIO layer "%s"</b>
<p>(W layer) When pushing a layer with arguments onto the Perl I/O
system you forgot the ) that closes the argument list.  (Layers
take care of transforming data between external and internal
representations.)  Perl stopped parsing the layer list at this
point and did not attempt to push this layer.  If your program
didn't explicitly request the failing operation, it may be the
result of the value of the environment variable PERLIO.</p>
</li>
<li><a name="Argument-%22%25s%22-treated-as-0-in-increment-(%2b%2b)"></a><b>Argument "%s" treated as 0 in increment (++)</b>
<p>(W numeric) The indicated string was fed as an argument to the <code class="inline">++</code>

operator which expects either a number or a string matching
<code class="inline"><span class="q">/^[a-zA-Z]*[0-9]*\z/</span></code>
.  See <a href="perlop.html#Auto-increment-and-Auto-decrement">Auto-increment and Auto-decrement in perlop</a> for details.</p>
</li>
<li><a name="Array-passed-to-stat-will-be-coerced-to-a-scalar%25s"></a><b>Array passed to stat will be coerced to a scalar%s</b>
<p>(W syntax) You called stat() on an array, but the array will be
coerced to a scalar - the number of elements in the array.</p>
</li>
<li><a name="A-signature-parameter-must-start-with-'%24'%2c-'%40'-or-'%25'"></a><b>A signature parameter must start with '$', '@' or '%'</b>
<p>(F) Each subroutine signature parameter declaration must start with a valid
sigil; for example:</p>
<pre class="verbatim"><ol><li><a name="foo"></a>    sub <span class="m">foo ($a, $, $b = 1, @c)</span> <span class="s">{</span><span class="s">}</span></li></ol></pre></li>
<li><a name="A-slurpy-parameter-may-not-have-a-default-value"></a><b>A slurpy parameter may not have a default value</b>
<p>(F) Only scalar subroutine signature parameters may have a default value;
for example:</p>
<pre class="verbatim"><ol><li><a name="foo"></a>    sub <span class="m">foo ($a = 1)</span>        <span class="s">{</span><span class="s">}</span> <span class="c"># legal</span></li><li><a name="foo-1"></a>    sub <span class="m">foo (@a = (1)</span><span class="p">)</span>      <span class="s">{</span><span class="s">}</span> <span class="c"># invalid</span></li><li><a name="foo-2"></a>    sub <span class="m">foo (%a = (a =&gt; b)</span><span class="p">)</span> <span class="s">{</span><span class="s">}</span> <span class="c"># invalid</span></li></ol></pre></li>
<li><a name="assertion-botched%3a-%25s"></a><b>assertion botched: %s</b>
<p>(X) The malloc package that comes with Perl had an internal failure.</p>
</li>
<li><a name="Assertion-%25s-failed%3a-file-%22%25s%22%2c-line-%25d"></a><b>Assertion %s failed: file "%s", line %d</b>
<p>(X) A general assertion failed.  The file in question must be examined.</p>
</li>
<li><a name="Assigned-value-is-not-a-reference"></a><b>Assigned value is not a reference</b>
<p>(F) You tried to assign something that was not a reference to an lvalue
reference (e.g., <code class="inline">\<span class="i">$x</span> = <span class="i">$y</span></code>
).  If you meant to make $x an alias to $y, use
<code class="inline">\<span class="i">$x</span> = \<span class="i">$y</span></code>
.</p>
</li>
<li><a name="Assigned-value-is-not-%25s-reference"></a><b>Assigned value is not %s reference</b>
<p>(F) You tried to assign a reference to a reference constructor, but the
two references were not of the same type.  You cannot alias a scalar to
an array, or an array to a hash; the two types must match.</p>
<pre class="verbatim"><ol><li>    \<span class="i">$x</span> = \<span class="i">@y</span><span class="sc">;</span>  <span class="c"># error</span></li><li>    \<span class="i">@x</span> = \<span class="i">%y</span><span class="sc">;</span>  <span class="c"># error</span></li><li>     <span class="i">$y</span> = <span class="s">[</span><span class="s">]</span><span class="sc">;</span></li><li>    \<span class="i">$x</span> = <span class="i">$y</span><span class="sc">;</span>   <span class="c"># error; did you mean \$y?</span></li></ol></pre></li>
<li><a name="Assigning-non-zero-to-%24%5b-is-no-longer-possible"></a><b>Assigning non-zero to $[ is no longer possible</b>
<p>(F) When the "array_base" feature is disabled (e.g., under <code class="inline"><a class="l_k" href="functions/use.html">use</a> <span class="v">v5.16</span><span class="sc">;</span></code>
)
the special variable <code class="inline"><span class="i">$[</span></code>
, which is deprecated, is now a fixed zero value.</p>
</li>
<li><a name="Assignment-to-both-a-list-and-a-scalar"></a><b>Assignment to both a list and a scalar</b>
<p>(F) If you assign to a conditional operator, the 2nd and 3rd arguments
must either both be scalars or both be lists.  Otherwise Perl won't
know which context to supply to the right side.</p>
</li>
<li><a name="Assuming-NOT-a-POSIX-class-since-%25s-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>Assuming NOT a POSIX class since %s in regex; marked by &lt;-- HERE in m/%s/</b>
<p>(W regexp) You had something like these:</p>
<pre class="verbatim"><ol><li> <span class="s">[</span><span class="s">[</span><span class="co">:</span><span class="w">alnum</span><span class="s">]</span><span class="s">]</span></li><li> <span class="s">[</span><span class="s">[</span><span class="co">:</span><span class="w">digit</span><span class="co">:</span><span class="w">xyz</span><span class="s">]</span></li></ol></pre><p>They look like they might have been meant to be the POSIX classes
<code class="inline"><span class="s">[</span><span class="co">:</span><span class="w">alnum</span><span class="co">:</span><span class="s">]</span></code>
 or <code class="inline">[:digit:]</code>.  If so, they should be written:</p>
<pre class="verbatim"><ol><li> <span class="s">[</span><span class="s">[</span><span class="co">:</span><span class="w">alnum</span><span class="co">:</span><span class="s">]</span><span class="s">]</span></li><li> <span class="s">[</span><span class="s">[</span><span class="co">:</span><span class="w">digit</span><span class="co">:</span><span class="s">]</span><span class="w">xyz</span><span class="s">]</span></li></ol></pre><p>Since these aren't legal POSIX class specifications, but are legal
bracketed character classes, Perl treats them as the latter.  In the
first example, it matches the characters <code class="inline"><span class="q">&quot;:&quot;</span></code>
, <code class="inline"><span class="q">&quot;[&quot;</span></code>
, <code class="inline"><span class="q">&quot;a&quot;</span></code>
, <code class="inline"><span class="q">&quot;l&quot;</span></code>
,
<code class="inline"><span class="q">&quot;m&quot;</span></code>
, <code class="inline"><span class="q">&quot;n&quot;</span></code>
, and <code class="inline"><span class="q">&quot;u&quot;</span></code>
.</p>
<p>If these weren't meant to be POSIX classes, this warning message is
spurious, and can be suppressed by reordering things, such as</p>
<pre class="verbatim"><ol><li> <span class="s">[</span><span class="s">[</span><span class="w">al</span><span class="co">:</span><span class="w">num</span><span class="s">]</span><span class="s">]</span></li></ol></pre><p>or</p>
<pre class="verbatim"><ol><li> <span class="s">[</span><span class="s">[</span><span class="co">:</span><span class="w">munla</span><span class="s">]</span><span class="s">]</span></li></ol></pre></li>
<li><a name="%3c%3e-at-require-statement-should-be-quotes"></a><b>&lt;&gt; at require-statement should be quotes</b>
<p>(F) You wrote <code class="inline"><a class="l_k" href="functions/require.html">require</a> <span class="q">&lt;file&gt;</span></code>
 when you should have written
<code class="inline"><a class="l_k" href="functions/require.html">require</a> <span class="q">&#39;file&#39;</span></code>
.</p>
</li>
<li><a name="Attempt-to-access-disallowed-key-'%25s'-in-a-restricted-hash"></a><b>Attempt to access disallowed key '%s' in a restricted hash</b>
<p>(F) The failing code has attempted to get or set a key which is not in
the current set of allowed keys of a restricted hash.</p>
</li>
<li><a name="Attempt-to-bless-into-a-freed-package"></a><b>Attempt to bless into a freed package</b>
<p>(F) You wrote <code class="inline"><a class="l_k" href="functions/bless.html">bless</a> <span class="i">$foo</span></code>
 with one argument after somehow causing
the current package to be freed.  Perl cannot figure out what to
do, so it throws up in hands in despair.</p>
</li>
<li><a name="Attempt-to-bless-into-a-reference"></a><b>Attempt to bless into a reference</b>
<p>(F) The CLASSNAME argument to the bless() operator is expected to be
the name of the package to bless the resulting object into.  You've
supplied instead a reference to something: perhaps you wrote</p>
<pre class="verbatim"><ol><li>    <a class="l_k" href="functions/bless.html">bless</a> <span class="i">$self</span><span class="cm">,</span> <span class="i">$proto</span><span class="sc">;</span></li></ol></pre><p>when you intended</p>
<pre class="verbatim"><ol><li>    <a class="l_k" href="functions/bless.html">bless</a> <span class="i">$self</span><span class="cm">,</span> <a class="l_k" href="functions/ref.html">ref</a><span class="s">(</span><span class="i">$proto</span><span class="s">)</span> || <span class="i">$proto</span><span class="sc">;</span></li></ol></pre><p>If you actually want to bless into the stringified version
of the reference supplied, you need to stringify it yourself, for
example by:</p>
<pre class="verbatim"><ol><li>    <a class="l_k" href="functions/bless.html">bless</a> <span class="i">$self</span><span class="cm">,</span> <span class="q">&quot;$proto&quot;</span><span class="sc">;</span></li></ol></pre></li>
<li><a name="Attempt-to-clear-deleted-array"></a><b>Attempt to clear deleted array</b>
<p>(S debugging) An array was assigned to when it was being freed.
Freed values are not supposed to be visible to Perl code.  This
can also happen if XS code calls <code class="inline"><span class="w">av_clear</span></code>
 from a custom magic
callback on the array.</p>
</li>
<li><a name="Attempt-to-delete-disallowed-key-'%25s'-from-a-restricted-hash"></a><b>Attempt to delete disallowed key '%s' from a restricted hash</b>
<p>(F) The failing code attempted to delete from a restricted hash a key
which is not in its key set.</p>
</li>
<li><a name="Attempt-to-delete-readonly-key-'%25s'-from-a-restricted-hash"></a><b>Attempt to delete readonly key '%s' from a restricted hash</b>
<p>(F) The failing code attempted to delete a key whose value has been
declared readonly from a restricted hash.</p>
</li>
<li><a name="Attempt-to-free-non-arena-SV%3a-0x%25x"></a><b>Attempt to free non-arena SV: 0x%x</b>
<p>(S internal) All SV objects are supposed to be allocated from arenas
that will be garbage collected on exit.  An SV was discovered to be
outside any of those arenas.</p>
</li>
<li><a name="Attempt-to-free-nonexistent-shared-string-'%25s'%25s"></a><b>Attempt to free nonexistent shared string '%s'%s</b>
<p>(S internal) Perl maintains a reference-counted internal table of
strings to optimize the storage and access of hash keys and other
strings.  This indicates someone tried to decrement the reference count
of a string that can no longer be found in the table.</p>
</li>
<li><a name="Attempt-to-free-temp-prematurely%3a-SV-0x%25x"></a><b>Attempt to free temp prematurely: SV 0x%x</b>
<p>(S debugging) Mortalized values are supposed to be freed by the
free_tmps() routine.  This indicates that something else is freeing the
SV before the free_tmps() routine gets a chance, which means that the
free_tmps() routine will be freeing an unreferenced scalar when it does
try to free it.</p>
</li>
<li><a name="Attempt-to-free-unreferenced-glob-pointers"></a><b>Attempt to free unreferenced glob pointers</b>
<p>(S internal) The reference counts got screwed up on symbol aliases.</p>
</li>
<li><a name="Attempt-to-free-unreferenced-scalar%3a-SV-0x%25x"></a><b>Attempt to free unreferenced scalar: SV 0x%x</b>
<p>(S internal) Perl went to decrement the reference count of a scalar to
see if it would go to 0, and discovered that it had already gone to 0
earlier, and should have been freed, and in fact, probably was freed.
This could indicate that SvREFCNT_dec() was called too many times, or
that SvREFCNT_inc() was called too few times, or that the SV was
mortalized when it shouldn't have been, or that memory has been
corrupted.</p>
</li>
<li><a name="Attempt-to-pack-pointer-to-temporary-value"></a><b>Attempt to pack pointer to temporary value</b>
<p>(W pack) You tried to pass a temporary value (like the result of a
function, or a computed expression) to the "p" pack() template.  This
means the result contains a pointer to a location that could become
invalid anytime, even before the end of the current statement.  Use
literals or global values as arguments to the "p" pack() template to
avoid this warning.</p>
</li>
<li><a name="Attempt-to-reload-%25s-aborted."></a><b>Attempt to reload %s aborted.</b>
<p>(F) You tried to load a file with <code class="inline"><a class="l_k" href="functions/use.html">use</a></code> or <code class="inline"><a class="l_k" href="functions/require.html">require</a></code> that failed to
compile once already.  Perl will not try to compile this file again
unless you delete its entry from %INC.  See <a href="functions/require.html">require</a> and
<a href="perlvar.html#%25INC">%INC in perlvar</a>.</p>
</li>
<li><a name="Attempt-to-set-length-of-freed-array"></a><b>Attempt to set length of freed array</b>
<p>(W misc) You tried to set the length of an array which has
been freed.  You can do this by storing a reference to the
scalar representing the last index of an array and later
assigning through that reference.  For example</p>
<pre class="verbatim"><ol><li>    <span class="i">$r</span> = <a class="l_k" href="functions/do.html">do</a> <span class="s">{</span><a class="l_k" href="functions/my.html">my</a> <span class="i">@a</span><span class="sc">;</span> \<span class="i">$#a</span><span class="s">}</span><span class="sc">;</span></li><li>    <span class="i">$$r</span> = <span class="n">503</span></li></ol></pre></li>
<li><a name="Attempt-to-use-reference-as-lvalue-in-substr"></a><b>Attempt to use reference as lvalue in substr</b>
<p>(W substr) You supplied a reference as the first argument to substr()
used as an lvalue, which is pretty strange.  Perhaps you forgot to
dereference it first.  See <a href="functions/substr.html">substr</a>.</p>
</li>
<li><a name="Attribute-%22locked%22-is-deprecated%2c-and-will-disappear-in-Perl-5.28"></a><b>Attribute "locked" is deprecated, and will disappear in Perl 5.28</b>
<p>(D deprecated) You have used the attributes pragma to modify the
"locked" attribute on a code reference.  The :locked attribute is
obsolete, has had no effect since 5005 threads were removed, and
will be removed in a Perl 5.28.</p>
</li>
<li><a name="Attribute-prototype(%25s)-discards-earlier-prototype-attribute-in-same-sub"></a><b>Attribute prototype(%s) discards earlier prototype attribute in same sub</b>
<p>(W misc) A sub was declared as sub foo : prototype(A) : prototype(B) {}, for
example.  Since each sub can only have one prototype, the earlier
declaration(s) are discarded while the last one is applied.</p>
</li>
<li><a name="Attribute-%22unique%22-is-deprecated%2c-and-will-disappear-in-Perl-5.28"></a><b>Attribute "unique" is deprecated, and will disappear in Perl 5.28</b>
<p>(D deprecated) You have used the attributes pragma to modify
the "unique" attribute on an array, hash or scalar reference.
The :unique attribute has had no effect since Perl 5.8.8, and
will be removed in a Perl 5.28.</p>
</li>
<li><a name="av_reify-called-on-tied-array"></a><b>av_reify called on tied array</b>
<p>(S debugging) This indicates that something went wrong and Perl got <i>very</i>
confused about <code class="inline"><span class="i">@_</span></code>
 or <code class="inline"><span class="i">@DB::args</span></code>
 being tied.</p>
</li>
<li><a name="Bad-arg-length-for-%25s%2c-is-%25u%2c-should-be-%25d"></a><b>Bad arg length for %s, is %u, should be %d</b>
<p>(F) You passed a buffer of the wrong size to one of msgctl(), semctl()
or shmctl().  In C parlance, the correct sizes are, respectively,
sizeof(struct msqid_ds *), sizeof(struct semid_ds *), and
sizeof(struct shmid_ds *).</p>
</li>
<li><a name="Bad-evalled-substitution-pattern"></a><b>Bad evalled substitution pattern</b>
<p>(F) You've used the <code class="inline">/e</code> switch to evaluate the replacement for a
substitution, but perl found a syntax error in the code to evaluate,
most likely an unexpected right brace '}'.</p>
</li>
<li><a name="Bad-filehandle%3a-%25s"></a><b>Bad filehandle: %s</b>
<p>(F) A symbol was passed to something wanting a filehandle, but the
symbol has no filehandle associated with it.  Perhaps you didn't do an
open(), or did it in another package.</p>
</li>
<li><a name="Bad-free()-ignored"></a><b>Bad free() ignored</b>
<p>(S malloc) An internal routine called free() on something that had never
been malloc()ed in the first place.  Mandatory, but can be disabled by
setting environment variable <code class="inline"><span class="w">PERL_BADFREE</span></code>
 to 0.</p>
<p>This message can be seen quite often with DB_File on systems with "hard"
dynamic linking, like <code class="inline"><span class="w">AIX</span></code>
 and <code class="inline"><span class="w">OS</span>/<span class="n">2</span></code>
.  It is a bug of <code class="inline"><span class="w">Berkeley</span> <span class="w">DB</span></code>

which is left unnoticed if <code class="inline"><span class="w">DB</span></code>
 uses <i>forgiving</i> system malloc().</p>
</li>
<li><a name="Bad-hash"></a><b>Bad hash</b>
<p>(P) One of the internal hash routines was passed a null HV pointer.</p>
</li>
<li><a name="Badly-placed-()'s"></a><b>Badly placed ()'s</b>
<p>(A) You've accidentally run your script through <b>csh</b> instead
of Perl.  Check the #! line, or manually feed your script into
Perl yourself.</p>
</li>
<li><a name="Bad-name-after-%25s"></a><b>Bad name after %s</b>
<p>(F) You started to name a symbol by using a package prefix, and then
didn't finish the symbol.  In particular, you can't interpolate outside
of quotes, so</p>
<pre class="verbatim"><ol><li>    <span class="i">$var</span> = <span class="q">&#39;myvar&#39;</span><span class="sc">;</span></li><li>    <span class="i">$sym</span> = <span class="w">mypack::</span><span class="i">$var</span><span class="sc">;</span></li></ol></pre><p>is not the same as</p>
<pre class="verbatim"><ol><li>    <span class="i">$var</span> = <span class="q">&#39;myvar&#39;</span><span class="sc">;</span></li><li>    <span class="i">$sym</span> = <span class="q">&quot;mypack::$var&quot;</span><span class="sc">;</span></li></ol></pre></li>
<li><a name="Bad-plugin-affecting-keyword-'%25s'"></a><b>Bad plugin affecting keyword '%s'</b>
<p>(F) An extension using the keyword plugin mechanism violated the
plugin API.</p>
</li>
<li><a name="Bad-realloc()-ignored"></a><b>Bad realloc() ignored</b>
<p>(S malloc) An internal routine called realloc() on something that
had never been malloc()ed in the first place.  Mandatory, but can
be disabled by setting the environment variable <code class="inline"><span class="w">PERL_BADFREE</span></code>
 to 1.</p>
</li>
<li><a name="Bad-symbol-for-array"></a><b>Bad symbol for array</b>
<p>(P) An internal request asked to add an array entry to something that
wasn't a symbol table entry.</p>
</li>
<li><a name="Bad-symbol-for-dirhandle"></a><b>Bad symbol for dirhandle</b>
<p>(P) An internal request asked to add a dirhandle entry to something
that wasn't a symbol table entry.</p>
</li>
<li><a name="Bad-symbol-for-filehandle"></a><b>Bad symbol for filehandle</b>
<p>(P) An internal request asked to add a filehandle entry to something
that wasn't a symbol table entry.</p>
</li>
<li><a name="Bad-symbol-for-hash"></a><b>Bad symbol for hash</b>
<p>(P) An internal request asked to add a hash entry to something that
wasn't a symbol table entry.</p>
</li>
<li><a name="Bad-symbol-for-scalar"></a><b>Bad symbol for scalar</b>
<p>(P) An internal request asked to add a scalar entry to something that
wasn't a symbol table entry.</p>
</li>
<li><a name="Bareword-found-in-conditional"></a><b>Bareword found in conditional</b>
<p>(W bareword) The compiler found a bareword where it expected a
conditional, which often indicates that an || or &amp;&amp; was parsed as part
of the last argument of the previous construct, for example:</p>
<pre class="verbatim"><ol><li>    <a class="l_k" href="functions/open.html">open</a> <span class="w">FOO</span> || <a class="l_k" href="functions/die.html">die</a><span class="sc">;</span></li></ol></pre><p>It may also indicate a misspelled constant that has been interpreted as
a bareword:</p>
<pre class="verbatim"><ol><li>    <a class="l_k" href="functions/use.html">use</a> <span class="w">constant</span> <span class="i">TYPO</span> <span class="cm">=&gt;</span> <span class="n">1</span><span class="sc">;</span></li><li>    if <span class="s">(</span><span class="w">TYOP</span><span class="s">)</span> <span class="s">{</span> <a class="l_k" href="functions/print.html">print</a> <span class="q">&quot;foo&quot;</span> <span class="s">}</span></li></ol></pre><p>The <code class="inline"><span class="w">strict</span></code>
 pragma is useful in avoiding such errors.</p>
</li>
<li><a name="Bareword-in-require-contains-%22%25s%22"></a><b>Bareword in require contains "%s"</b>
</li>
<li><a name="Bareword-in-require-maps-to-disallowed-filename-%22%25s%22"></a><b>Bareword in require maps to disallowed filename "%s"</b>
</li>
<li><a name="Bareword-in-require-maps-to-empty-filename"></a><b>Bareword in require maps to empty filename</b>
<p>(F) The bareword form of require has been invoked with a filename which could
not have been generated by a valid bareword permitted by the parser.  You
shouldn't be able to get this error from Perl code, but XS code may throw it
if it passes an invalid module name to <code class="inline"><span class="w">Perl_load_module</span></code>
.</p>
</li>
<li><a name="Bareword-in-require-must-not-start-with-a-double-colon%3a-%22%25s%22"></a><b>Bareword in require must not start with a double-colon: "%s"</b>
<p>(F) In <code class="inline"><a class="l_k" href="functions/require.html">require</a> <span class="w">Bare::Word</span></code>
, the bareword is not allowed to start with a
double-colon.  Write <code class="inline"><a class="l_k" href="functions/require.html">require</a> <span class="w">::Foo::Bar</span></code>
 as  <code class="inline"><a class="l_k" href="functions/require.html">require</a> <span class="w">Foo::Bar</span></code>
 instead.</p>
</li>
<li><a name="Bareword-%22%25s%22-not-allowed-while-%22strict-subs%22-in-use"></a><b>Bareword "%s" not allowed while "strict subs" in use</b>
<p>(F) With "strict subs" in use, a bareword is only allowed as a
subroutine identifier, in curly brackets or to the left of the "=&gt;"
symbol.  Perhaps you need to predeclare a subroutine?</p>
</li>
<li><a name="Bareword-%22%25s%22-refers-to-nonexistent-package"></a><b>Bareword "%s" refers to nonexistent package</b>
<p>(W bareword) You used a qualified bareword of the form <code class="inline"><span class="w">Foo::</span></code>
, but the
compiler saw no other uses of that namespace before that point.  Perhaps
you need to predeclare a package?</p>
</li>
<li><a name="BEGIN-failed--compilation-aborted"></a><b>BEGIN failed--compilation aborted</b>
<p>(F) An untrapped exception was raised while executing a BEGIN
subroutine.  Compilation stops immediately and the interpreter is
exited.</p>
</li>
<li><a name="BEGIN-not-safe-after-errors--compilation-aborted"></a><b>BEGIN not safe after errors--compilation aborted</b>
<p>(F) Perl found a <code class="inline">BEGIN <span class="s">{</span><span class="s">}</span></code>
 subroutine (or a <code class="inline"><a class="l_k" href="functions/use.html">use</a></code> directive, which
implies a <code class="inline">BEGIN <span class="s">{</span><span class="s">}</span></code>
) after one or more compilation errors had already
occurred.  Since the intended environment for the <code class="inline">BEGIN <span class="s">{</span><span class="s">}</span></code>
 could not
be guaranteed (due to the errors), and since subsequent code likely
depends on its correct operation, Perl just gave up.</p>
</li>
<li><a name="%5c%25d-better-written-as-%24%25d"></a><b>\%d better written as $%d</b>
<p>(W syntax) Outside of patterns, backreferences live on as variables.
The use of backslashes is grandfathered on the right-hand side of a
substitution, but stylistically it's better to use the variable form
because other Perl programmers will expect it, and it works better if
there are more than 9 backreferences.</p>
</li>
<li><a name="Binary-number-%3e-0b11111111111111111111111111111111-non-portable"></a><b>Binary number &gt; 0b11111111111111111111111111111111 non-portable</b>
<p>(W portable) The binary number you specified is larger than 2**32-1
(4294967295) and therefore non-portable between systems.  See
<a href="perlport.html">perlport</a> for more on portability concerns.</p>
</li>
<li><a name="bind()-on-closed-socket-%25s"></a><b>bind() on closed socket %s</b>
<p>(W closed) You tried to do a bind on a closed socket.  Did you forget to
check the return value of your socket() call?  See <a href="functions/bind.html">bind</a>.</p>
</li>
<li><a name="binmode()-on-closed-filehandle-%25s"></a><b>binmode() on closed filehandle %s</b>
<p>(W unopened) You tried binmode() on a filehandle that was never opened.
Check your control flow and number of arguments.</p>
</li>
<li><a name="Bit-vector-size-%3e-32-non-portable"></a><b>Bit vector size &gt; 32 non-portable</b>
<p>(W portable) Using bit vector sizes larger than 32 is non-portable.</p>
</li>
<li><a name="Bizarre-copy-of-%25s"></a><b>Bizarre copy of %s</b>
<p>(P) Perl detected an attempt to copy an internal value that is not
copiable.</p>
</li>
<li><a name="Bizarre-SvTYPE-%5b%25d%5d"></a><b>Bizarre SvTYPE [%d]</b>
<p>(P) When starting a new thread or returning values from a thread, Perl
encountered an invalid data type.</p>
</li>
<li><a name="Both-or-neither-range-ends-should-be-Unicode-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>Both or neither range ends should be Unicode in regex; marked by
&lt;-- HERE in m/%s/</b>
<p>(W regexp) (only under <code class="inline"><a class="l_k" href="functions/use.html">use</a> <span class="w">re</span> <span class="q">&#39;strict&#39;</span></code>
 or within <code class="inline"><span class="s">(</span><span class="q">?[...])</span></code>
)</p>
<p>In a bracketed character class in a regular expression pattern, you
had a range which has exactly one end of it specified using <code class="inline">\<span class="w">N</span><span class="s">{</span><span class="s">}</span></code>
, and
the other end is specified using a non-portable mechanism.  Perl treats
the range as a Unicode range, that is, all the characters in it are
considered to be the Unicode characters, and which may be different code
points on some platforms Perl runs on.  For example, <code class="inline"><span class="s">[</span>\<span class="i">N</span><span class="s">{</span><span class="w">U</span>+<span class="n">06</span><span class="s">}</span>-\<span class="w">x08</span><span class="s">]</span></code>

is treated as if you had instead said <code class="inline"><span class="s">[</span>\<span class="i">N</span><span class="s">{</span><span class="w">U</span>+<span class="n">06</span><span class="s">}</span>-\<span class="i">N</span><span class="s">{</span><span class="w">U</span>+<span class="n">08</span><span class="s">}</span><span class="s">]</span></code>
, that is it
matches the characters whose code points in Unicode are 6, 7, and 8.
But that <code class="inline">\<span class="w">x08</span></code>
 might indicate that you meant something different, so
the warning gets raised.</p>
</li>
<li><a name="Buffer-overflow-in-prime_env_iter%3a-%25s"></a><b>Buffer overflow in prime_env_iter: %s</b>
<p>(W internal) A warning peculiar to VMS.  While Perl was preparing to
iterate over %ENV, it encountered a logical name or symbol definition
which was too long, so it was truncated to the string shown.</p>
</li>
<li><a name="Callback-called-exit"></a><b>Callback called exit</b>
<p>(F) A subroutine invoked from an external package via call_sv()
exited by calling exit.</p>
</li>
<li><a name="%25s()-called-too-early-to-check-prototype"></a><b>%s() called too early to check prototype</b>
<p>(W prototype) You've called a function that has a prototype before the
parser saw a definition or declaration for it, and Perl could not check
that the call conforms to the prototype.  You need to either add an
early prototype declaration for the subroutine in question, or move the
subroutine definition ahead of the call to get proper prototype
checking.  Alternatively, if you are certain that you're calling the
function correctly, you may put an ampersand before the name to avoid
the warning.  See <a href="perlsub.html">perlsub</a>.</p>
</li>
<li><a name="Cannot-chr-%25f"></a><b>Cannot chr %f</b>
<p>(F) You passed an invalid number (like an infinity or not-a-number) to <code class="inline"><a class="l_k" href="functions/chr.html">chr</a></code>.</p>
</li>
<li><a name="Cannot-compress-%25f-in-pack"></a><b>Cannot compress %f in pack</b>
<p>(F) You tried compressing an infinity or not-a-number as an unsigned
integer with BER, which makes no sense.</p>
</li>
<li><a name="Cannot-compress-integer-in-pack"></a><b>Cannot compress integer in pack</b>
<p>(F) An argument to pack("w",...) was too large to compress.
The BER compressed integer format can only be used with positive
integers, and you attempted to compress a very large number (&gt; 1e308).
See <a href="functions/pack.html">pack</a>.</p>
</li>
<li><a name="Cannot-compress-negative-numbers-in-pack"></a><b>Cannot compress negative numbers in pack</b>
<p>(F) An argument to pack("w",...) was negative.  The BER compressed integer
format can only be used with positive integers.  See <a href="functions/pack.html">pack</a>.</p>
</li>
<li><a name="Cannot-convert-a-reference-to-%25s-to-typeglob"></a><b>Cannot convert a reference to %s to typeglob</b>
<p>(F) You manipulated Perl's symbol table directly, stored a reference
in it, then tried to access that symbol via conventional Perl syntax.
The access triggers Perl to autovivify that typeglob, but it there is
no legal conversion from that type of reference to a typeglob.</p>
</li>
<li><a name="Cannot-copy-to-%25s"></a><b>Cannot copy to %s</b>
<p>(P) Perl detected an attempt to copy a value to an internal type that cannot
be directly assigned to.</p>
</li>
<li><a name="Cannot-find-encoding-%22%25s%22"></a><b>Cannot find encoding "%s"</b>
<p>(S io) You tried to apply an encoding that did not exist to a filehandle,
either with open() or binmode().</p>
</li>
<li><a name="Cannot-pack-%25f-with-'%25c'"></a><b>Cannot pack %f with '%c'</b>
<p>(F) You tried converting an infinity or not-a-number to an integer,
which makes no sense.</p>
</li>
<li><a name="Cannot-printf-%25f-with-'%25c'"></a><b>Cannot printf %f with '%c'</b>
<p>(F) You tried printing an infinity or not-a-number as a character (%c),
which makes no sense.  Maybe you meant '%s', or just stringifying it?</p>
</li>
<li><a name="Cannot-set-tied-%40DB%3a%3aargs"></a><b>Cannot set tied @DB::args</b>
<p>(F) <code class="inline"><a class="l_k" href="functions/caller.html">caller</a></code> tried to set <code class="inline"><span class="i">@DB::args</span></code>
, but found it tied.  Tying <code class="inline"><span class="i">@DB::args</span></code>

is not supported.  (Before this error was added, it used to crash.)</p>
</li>
<li><a name="Cannot-tie-unreifiable-array"></a><b>Cannot tie unreifiable array</b>
<p>(P) You somehow managed to call <code class="inline"><a class="l_k" href="functions/tie.html">tie</a></code> on an array that does not
keep a reference count on its arguments and cannot be made to
do so.  Such arrays are not even supposed to be accessible to
Perl code, but are only used internally.</p>
</li>
<li><a name="Cannot-yet-reorder-sv_catpvfn()-arguments-from-va_list"></a><b>Cannot yet reorder sv_catpvfn() arguments from va_list</b>
<p>(F) Some XS code tried to use <code class="inline"><span class="i">sv_catpvfn</span><span class="s">(</span><span class="s">)</span></code>
 or a related function with a
format string that specifies explicit indexes for some of the elements, and
using a C-style variable-argument list (a <code class="inline"><span class="w">va_list</span></code>
).  This is not currently
supported.  XS authors wanting to do this must instead construct a C array
of <code class="inline"><span class="w">SV</span>*</code>
 scalars containing the arguments.</p>
</li>
<li><a name="Can-only-compress-unsigned-integers-in-pack"></a><b>Can only compress unsigned integers in pack</b>
<p>(F) An argument to pack("w",...) was not an integer.  The BER compressed
integer format can only be used with positive integers, and you attempted
to compress something else.  See <a href="functions/pack.html">pack</a>.</p>
</li>
<li><a name="Can't-bless-non-reference-value"></a><b>Can't bless non-reference value</b>
<p>(F) Only hard references may be blessed.  This is how Perl "enforces"
encapsulation of objects.  See <a href="perlobj.html">perlobj</a>.</p>
</li>
<li><a name="Can't-%22break%22-in-a-loop-topicalizer"></a><b>Can't "break" in a loop topicalizer</b>
<p>(F) You called <code class="inline"><span class="w">break</span></code>
, but you're in a <code class="inline">foreach</code>
 block rather than
a <code class="inline">given</code>
 block.  You probably meant to use <code class="inline"><a class="l_k" href="functions/next.html">next</a></code> or <code class="inline"><a class="l_k" href="functions/last.html">last</a></code>.</p>
</li>
<li><a name="Can't-%22break%22-outside-a-given-block"></a><b>Can't "break" outside a given block</b>
<p>(F) You called <code class="inline"><span class="w">break</span></code>
, but you're not inside a <code class="inline">given</code>
 block.</p>
</li>
<li><a name="Can't-call-method-%22%25s%22-on-an-undefined-value"></a><b>Can't call method "%s" on an undefined value</b>
<p>(F) You used the syntax of a method call, but the slot filled by the
object reference or package name contains an undefined value.  Something
like this will reproduce the error:</p>
<pre class="verbatim"><ol><li>    <span class="i">$BADREF</span> = <a class="l_k" href="functions/undef.html">undef</a><span class="sc">;</span></li><li>    <span class="w">process</span> <span class="i">$BADREF</span> <span class="n">1</span><span class="cm">,</span><span class="n">2</span><span class="cm">,</span><span class="n">3</span><span class="sc">;</span></li><li>    <span class="i">$BADREF</span><span class="i">-&gt;process</span><span class="s">(</span><span class="n">1</span><span class="cm">,</span><span class="n">2</span><span class="cm">,</span><span class="n">3</span><span class="s">)</span><span class="sc">;</span></li></ol></pre></li>
<li><a name="Can't-call-method-%22%25s%22-on-unblessed-reference"></a><b>Can't call method "%s" on unblessed reference</b>
<p>(F) A method call must know in what package it's supposed to run.  It
ordinarily finds this out from the object reference you supply, but you
didn't supply an object reference in this case.  A reference isn't an
object reference until it has been blessed.  See <a href="perlobj.html">perlobj</a>.</p>
</li>
<li><a name="Can't-call-method-%22%25s%22-without-a-package-or-object-reference"></a><b>Can't call method "%s" without a package or object reference</b>
<p>(F) You used the syntax of a method call, but the slot filled by the
object reference or package name contains an expression that returns a
defined value which is neither an object reference nor a package name.
Something like this will reproduce the error:</p>
<pre class="verbatim"><ol><li>    <span class="i">$BADREF</span> = <span class="n">42</span><span class="sc">;</span></li><li>    <span class="w">process</span> <span class="i">$BADREF</span> <span class="n">1</span><span class="cm">,</span><span class="n">2</span><span class="cm">,</span><span class="n">3</span><span class="sc">;</span></li><li>    <span class="i">$BADREF</span><span class="i">-&gt;process</span><span class="s">(</span><span class="n">1</span><span class="cm">,</span><span class="n">2</span><span class="cm">,</span><span class="n">3</span><span class="s">)</span><span class="sc">;</span></li></ol></pre></li>
<li><a name="Can't-call-mro_isa_changed_in()-on-anonymous-symbol-table"></a><b>Can't call mro_isa_changed_in() on anonymous symbol table</b>
<p>(P) Perl got confused as to whether a hash was a plain hash or a
symbol table hash when trying to update @ISA caches.</p>
</li>
<li><a name="Can't-call-mro_method_changed_in()-on-anonymous-symbol-table"></a><b>Can't call mro_method_changed_in() on anonymous symbol table</b>
<p>(F) An XS module tried to call <code class="inline"><span class="w">mro_method_changed_in</span></code>
 on a hash that was
not attached to the symbol table.</p>
</li>
<li><a name="Can't-chdir-to-%25s"></a><b>Can't chdir to %s</b>
<p>(F) You called <code class="inline">perl -x/foo/bar</code>, but <i>/foo/bar</i> is not a directory
that you can chdir to, possibly because it doesn't exist.</p>
</li>
<li><a name="Can't-check-filesystem-of-script-%22%25s%22-for-nosuid"></a><b>Can't check filesystem of script "%s" for nosuid</b>
<p>(P) For some reason you can't check the filesystem of the script for
nosuid.</p>
</li>
<li><a name="Can't-coerce-%25s-to-%25s-in-%25s"></a><b>Can't coerce %s to %s in %s</b>
<p>(F) Certain types of SVs, in particular real symbol table entries
(typeglobs), can't be forced to stop being what they are.  So you can't
say things like:</p>
<pre class="verbatim"><ol><li>    <span class="i">*foo</span> += <span class="n">1</span><span class="sc">;</span></li></ol></pre><p>You CAN say</p>
<pre class="verbatim"><ol><li>    <span class="i">$foo</span> = <span class="i">*foo</span><span class="sc">;</span></li><li>    <span class="i">$foo</span> += <span class="n">1</span><span class="sc">;</span></li></ol></pre><p>but then $foo no longer contains a glob.</p>
</li>
<li><a name="Can't-%22continue%22-outside-a-when-block"></a><b>Can't "continue" outside a when block</b>
<p>(F) You called <code class="inline"><a class="l_k" href="functions/continue.html">continue</a></code>, but you're not inside a <code class="inline">when</code>

or <code class="inline"><span class="w">default</span></code>
 block.</p>
</li>
<li><a name="Can't-create-pipe-mailbox"></a><b>Can't create pipe mailbox</b>
<p>(P) An error peculiar to VMS.  The process is suffering from exhausted
quotas or other plumbing problems.</p>
</li>
<li><a name="Can't-declare-%25s-in-%22%25s%22"></a><b>Can't declare %s in "%s"</b>
<p>(F) Only scalar, array, and hash variables may be declared as "my", "our" or
"state" variables.  They must have ordinary identifiers as names.</p>
</li>
<li><a name="Can't-%22default%22-outside-a-topicalizer"></a><b>Can't "default" outside a topicalizer</b>
<p>(F) You have used a <code class="inline"><span class="w">default</span></code>
 block that is neither inside a
<code class="inline">foreach</code>
 loop nor a <code class="inline">given</code>
 block.  (Note that this error is
issued on exit from the <code class="inline"><span class="w">default</span></code>
 block, so you won't get the
error if you use an explicit <code class="inline"><a class="l_k" href="functions/continue.html">continue</a></code>.)</p>
</li>
<li><a name="Can't-determine-class-of-operator-%25s%2c-assuming-BASEOP"></a><b>Can't determine class of operator %s, assuming BASEOP</b>
<p>(S) This warning indicates something wrong in the internals of perl.
Perl was trying to find the class (e.g. LISTOP) of a particular OP,
and was unable to do so. This is likely to be due to a bug in the perl
internals, or due to a bug in XS code which manipulates perl optrees.</p>
</li>
<li><a name="Can't-do-inplace-edit%3a-%25s-is-not-a-regular-file"></a><b>Can't do inplace edit: %s is not a regular file</b>
<p>(S inplace) You tried to use the <b>-i</b> switch on a special file, such as
a file in /dev, a FIFO or an uneditable directory.  The file was ignored.</p>
</li>
<li><a name="Can't-do-inplace-edit-on-%25s%3a-%25s"></a><b>Can't do inplace edit on %s: %s</b>
<p>(S inplace) The creation of the new file failed for the indicated
reason.</p>
</li>
<li><a name="Can't-do-inplace-edit-without-backup"></a><b>Can't do inplace edit without backup</b>
<p>(F) You're on a system such as MS-DOS that gets confused if you try
reading from a deleted (but still opened) file.  You have to say
<code class="inline">-<span class="w">i</span>.<span class="w">bak</span></code>
, or some such.</p>
</li>
<li><a name="Can't-do-inplace-edit%3a-%25s-would-not-be-unique"></a><b>Can't do inplace edit: %s would not be unique</b>
<p>(S inplace) Your filesystem does not support filenames longer than 14
characters and Perl was unable to create a unique filename during
inplace editing with the <b>-i</b> switch.  The file was ignored.</p>
</li>
<li><a name="Can't-do-%25s(%22%25s%22)-on-non-UTF-8-locale%3b-resolved-to-%22%25s%22."></a><b>Can't do %s("%s") on non-UTF-8 locale; resolved to "%s".</b>
<p>(W locale) You are 1) running under "<code class="inline"><a class="l_k" href="functions/use.html">use</a> <span class="w">locale</span></code>
"; 2) the current
locale is not a UTF-8 one; 3) you tried to do the designated case-change
operation on the specified Unicode character; and 4) the result of this
operation would mix Unicode and locale rules, which likely conflict.
Mixing of different rule types is forbidden, so the operation was not
done; instead the result is the indicated value, which is the best
available that uses entirely Unicode rules.  That turns out to almost
always be the original character, unchanged.</p>
<p>It is generally a bad idea to mix non-UTF-8 locales and Unicode, and
this issue is one of the reasons why.  This warning is raised when
Unicode rules would normally cause the result of this operation to
contain a character that is in the range specified by the locale,
0..255, and hence is subject to the locale's rules, not Unicode's.</p>
<p>If you are using locale purely for its characteristics related to things
like its numeric and time formatting (and not <code class="inline"><span class="w">LC_CTYPE</span></code>
), consider
using a restricted form of the locale pragma (see <a href="perllocale.html#The-%22use-locale%22-pragma">The use locale pragma in perllocale</a>) like "<code class="inline"><a class="l_k" href="functions/use.html">use</a> <span class="w">locale</span> <span class="q">&#39;:not_characters&#39;</span></code>
".</p>
<p>Note that failed case-changing operations done as a result of
case-insensitive <code class="inline">/i</code> regular expression matching will show up in this
warning as having the <code class="inline"><a class="l_k" href="functions/fc.html">fc</a></code> operation (as that is what the regular
expression engine calls behind the scenes.)</p>
</li>
<li><a name="Can't-do-waitpid-with-flags"></a><b>Can't do waitpid with flags</b>
<p>(F) This machine doesn't have either waitpid() or wait4(), so only
waitpid() without flags is emulated.</p>
</li>
<li><a name="Can't-emulate--%25s-on-%23!-line"></a><b>Can't emulate -%s on #! line</b>
<p>(F) The #! line specifies a switch that doesn't make sense at this
point.  For example, it'd be kind of silly to put a <b>-x</b> on the #!
line.</p>
</li>
<li><a name="Can't-%25s-%25s-endian-%25ss-on-this-platform"></a><b>Can't %s %s-endian %ss on this platform</b>
<p>(F) Your platform's byte-order is neither big-endian nor little-endian,
or it has a very strange pointer size.  Packing and unpacking big- or
little-endian floating point values and pointers may not be possible.
See <a href="functions/pack.html">pack</a>.</p>
</li>
<li><a name="Can't-exec-%22%25s%22%3a-%25s"></a><b>Can't exec "%s": %s</b>
<p>(W exec) A system(), exec(), or piped open call could not execute the
named program for the indicated reason.  Typical reasons include: the
permissions were wrong on the file, the file wasn't found in
<code class="inline"><span class="i">$ENV</span>{<span class="w">PATH</span>}</code>
, the executable in question was compiled for another
architecture, or the #! line in a script points to an interpreter that
can't be run for similar reasons.  (Or maybe your system doesn't support
#! at all.)</p>
</li>
<li><a name="Can't-exec-%25s"></a><b>Can't exec %s</b>
<p>(F) Perl was trying to execute the indicated program for you because
that's what the #! line said.  If that's not what you wanted, you may
need to mention "perl" on the #! line somewhere.</p>
</li>
<li><a name="Can't-execute-%25s"></a><b>Can't execute %s</b>
<p>(F) You used the <b>-S</b> switch, but the copies of the script to execute
found in the PATH did not have correct permissions.</p>
</li>
<li><a name="Can't-find-an-opnumber-for-%22%25s%22"></a><b>Can't find an opnumber for "%s"</b>
<p>(F) A string of a form <code class="inline"><span class="w">CORE::word</span></code>
 was given to prototype(), but there
is no builtin with the name <code class="inline"><span class="w">word</span></code>
.</p>
</li>
<li><a name="Can't-find-label-%25s"></a><b>Can't find label %s</b>
<p>(F) You said to goto a label that isn't mentioned anywhere that it's
possible for us to go to.  See <a href="functions/goto.html">goto</a>.</p>
</li>
<li><a name="Can't-find-%25s-on-PATH"></a><b>Can't find %s on PATH</b>
<p>(F) You used the <b>-S</b> switch, but the script to execute could not be
found in the PATH.</p>
</li>
<li><a name="Can't-find-%25s-on-PATH%2c-'.'-not-in-PATH"></a><b>Can't find %s on PATH, '.' not in PATH</b>
<p>(F) You used the <b>-S</b> switch, but the script to execute could not be
found in the PATH, or at least not with the correct permissions.  The
script exists in the current directory, but PATH prohibits running it.</p>
</li>
<li><a name="Can't-find-string-terminator-%25s-anywhere-before-EOF"></a><b>Can't find string terminator %s anywhere before EOF</b>
<p>(F) Perl strings can stretch over multiple lines.  This message means
that the closing delimiter was omitted.  Because bracketed quotes count
nesting levels, the following is missing its final parenthesis:</p>
<pre class="verbatim"><ol><li>    print q(The character '(' starts a side comment.);</li></ol></pre><p>If you're getting this error from a here-document, you may have
included unseen whitespace before or after your closing tag or there
may not be a linebreak after it.  A good programmer's editor will have
a way to help you find these characters (or lack of characters).  See
<a href="perlop.html">perlop</a> for the full details on here-documents.</p>
</li>
<li><a name="Can't-find-Unicode-property-definition-%22%25s%22"></a><b>Can't find Unicode property definition "%s"</b>
</li>
<li><a name="Can't-find-Unicode-property-definition-%22%25s%22-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>Can't find Unicode property definition "%s" in regex; marked by &lt;-- HERE in m/%s/</b>
<p>(F) The named property which you specified via <code class="inline">\<span class="w">p</span></code>
 or <code class="inline">\<span class="w">P</span></code>
 is not one
known to Perl.  Perhaps you misspelled the name?  See
<a href="perluniprops.html#Properties-accessible-through-%5cp%7b%7d-and-%5cP%7b%7d">Properties accessible through \p{} and \P{} in perluniprops</a>
for a complete list of available official
properties.  If it is a
<a href="perlunicode.html#User-Defined-Character-Properties">user-defined property</a>
it must have been defined by the time the regular expression is
matched.</p>
<p>If you didn't mean to use a Unicode property, escape the <code class="inline">\<span class="w">p</span></code>
, either
by <code class="inline">\\<span class="w">p</span></code>
 (just the <code class="inline">\<span class="w">p</span></code>
) or by <code class="inline">\<span class="w">Q</span>\<span class="w">p</span></code>
 (the rest of the string, or
until <code class="inline">\<span class="w">E</span></code>
).</p>
</li>
<li><a name="Can't-fork%3a-%25s"></a><b>Can't fork: %s</b>
<p>(F) A fatal error occurred while trying to fork while opening a
pipeline.</p>
</li>
<li><a name="Can't-fork%2c-trying-again-in-5-seconds"></a><b>Can't fork, trying again in 5 seconds</b>
<p>(W pipe) A fork in a piped open failed with EAGAIN and will be retried
after five seconds.</p>
</li>
<li><a name="Can't-get-filespec---stale-stat-buffer%3f"></a><b>Can't get filespec - stale stat buffer?</b>
<p>(S) A warning peculiar to VMS.  This arises because of the difference
between access checks under VMS and under the Unix model Perl assumes.
Under VMS, access checks are done by filename, rather than by bits in
the stat buffer, so that ACLs and other protections can be taken into
account.  Unfortunately, Perl assumes that the stat buffer contains all
the necessary information, and passes it, instead of the filespec, to
the access-checking routine.  It will try to retrieve the filespec using
the device name and FID present in the stat buffer, but this works only
if you haven't made a subsequent call to the CRTL stat() routine,
because the device name is overwritten with each call.  If this warning
appears, the name lookup failed, and the access-checking routine gave up
and returned FALSE, just to be conservative.  (Note: The access-checking
routine knows about the Perl <code class="inline"><a class="l_k" href="functions/stat.html">stat</a></code> operator and file tests, so you
shouldn't ever see this warning in response to a Perl command; it arises
only if some internal code takes stat buffers lightly.)</p>
</li>
<li><a name="Can't-get-pipe-mailbox-device-name"></a><b>Can't get pipe mailbox device name</b>
<p>(P) An error peculiar to VMS.  After creating a mailbox to act as a
pipe, Perl can't retrieve its name for later use.</p>
</li>
<li><a name="Can't-get-SYSGEN-parameter-value-for-MAXBUF"></a><b>Can't get SYSGEN parameter value for MAXBUF</b>
<p>(P) An error peculiar to VMS.  Perl asked $GETSYI how big you want your
mailbox buffers to be, and didn't get an answer.</p>
</li>
<li><a name="Can't-%22goto%22-into-the-middle-of-a-foreach-loop"></a><b>Can't "goto" into the middle of a foreach loop</b>
<p>(F) A "goto" statement was executed to jump into the middle of a foreach
loop.  You can't get there from here.  See <a href="functions/goto.html">goto</a>.</p>
</li>
<li><a name="Can't-%22goto%22-out-of-a-pseudo-block"></a><b>Can't "goto" out of a pseudo block</b>
<p>(F) A "goto" statement was executed to jump out of what might look like
a block, except that it isn't a proper block.  This usually occurs if
you tried to jump out of a sort() block or subroutine, which is a no-no.
See <a href="functions/goto.html">goto</a>.</p>
</li>
<li><a name="Can't-goto-subroutine-from-an-eval-%25s"></a><b>Can't goto subroutine from an eval-%s</b>
<p>(F) The "goto subroutine" call can't be used to jump out of an eval
"string" or block.</p>
</li>
<li><a name="Can't-goto-subroutine-from-a-sort-sub-(or-similar-callback)"></a><b>Can't goto subroutine from a sort sub (or similar callback)</b>
<p>(F) The "goto subroutine" call can't be used to jump out of the
comparison sub for a sort(), or from a similar callback (such
as the reduce() function in List::Util).</p>
</li>
<li><a name="Can't-goto-subroutine-outside-a-subroutine"></a><b>Can't goto subroutine outside a subroutine</b>
<p>(F) The deeply magical "goto subroutine" call can only replace one
subroutine call for another.  It can't manufacture one out of whole
cloth.  In general you should be calling it out of only an AUTOLOAD
routine anyway.  See <a href="functions/goto.html">goto</a>.</p>
</li>
<li><a name="Can't-ignore-signal-CHLD%2c-forcing-to-default"></a><b>Can't ignore signal CHLD, forcing to default</b>
<p>(W signal) Perl has detected that it is being run with the SIGCHLD
signal (sometimes known as SIGCLD) disabled.  Since disabling this
signal will interfere with proper determination of exit status of child
processes, Perl has reset the signal to its default value.  This
situation typically indicates that the parent program under which Perl
may be running (e.g. cron) is being very careless.</p>
</li>
<li><a name="Can't-kill-a-non-numeric-process-ID"></a><b>Can't kill a non-numeric process ID</b>
<p>(F) Process identifiers must be (signed) integers.  It is a fatal error to
attempt to kill() an undefined, empty-string or otherwise non-numeric
process identifier.</p>
</li>
<li><a name="Can't-%22last%22-outside-a-loop-block"></a><b>Can't "last" outside a loop block</b>
<p>(F) A "last" statement was executed to break out of the current block,
except that there's this itty bitty problem called there isn't a current
block.  Note that an "if" or "else" block doesn't count as a "loopish"
block, as doesn't a block given to sort(), map() or grep().  You can
usually double the curlies to get the same effect though, because the
inner curlies will be considered a block that loops once.  See
<a href="functions/last.html">last</a>.</p>
</li>
<li><a name="Can't-linearize-anonymous-symbol-table"></a><b>Can't linearize anonymous symbol table</b>
<p>(F) Perl tried to calculate the method resolution order (MRO) of a
package, but failed because the package stash has no name.</p>
</li>
<li><a name="Can't-load-'%25s'-for-module-%25s"></a><b>Can't load '%s' for module %s</b>
<p>(F) The module you tried to load failed to load a dynamic extension.
This may either mean that you upgraded your version of perl to one
that is incompatible with your old dynamic extensions (which is known
to happen between major versions of perl), or (more likely) that your
dynamic extension was built against an older version of the library
that is installed on your system.  You may need to rebuild your old
dynamic extensions.</p>
</li>
<li><a name="Can't-localize-lexical-variable-%25s"></a><b>Can't localize lexical variable %s</b>
<p>(F) You used local on a variable name that was previously declared as a
lexical variable using "my" or "state".  This is not allowed.  If you
want to localize a package variable of the same name, qualify it with
the package name.</p>
</li>
<li><a name="Can't-localize-through-a-reference"></a><b>Can't localize through a reference</b>
<p>(F) You said something like <code class="inline"><a class="l_k" href="functions/local.html">local</a> <span class="i">$$ref</span></code>
, which Perl can't currently
handle, because when it goes to restore the old value of whatever $ref
pointed to after the scope of the local() is finished, it can't be sure
that $ref will still be a reference.</p>
</li>
<li><a name="Can't-locate-%25s"></a><b>Can't locate %s</b>
<p>(F) You said to <code class="inline"><a class="l_k" href="functions/do.html">do</a></code> (or <code class="inline"><a class="l_k" href="functions/require.html">require</a></code>, or <code class="inline"><a class="l_k" href="functions/use.html">use</a></code>) a file that couldn't be found.
Perl looks for the file in all the locations mentioned in @INC, unless
the file name included the full path to the file.  Perhaps you need
to set the PERL5LIB or PERL5OPT environment variable to say where the
extra library is, or maybe the script needs to add the library name
to @INC.  Or maybe you just misspelled the name of the file.  See
<a href="functions/require.html">require</a> and <a href="lib.html">lib</a>.</p>
</li>
<li><a name="Can't-locate-auto%2f%25s.al-in-%40INC"></a><b>Can't locate auto/%s.al in @INC</b>
<p>(F) A function (or method) was called in a package which allows
autoload, but there is no function to autoload.  Most probable causes
are a misprint in a function/method name or a failure to <code class="inline"><span class="w">AutoSplit</span></code>

the file, say, by doing <code class="inline"><span class="w">make</span> <span class="w">install</span></code>
.</p>
</li>
<li><a name="Can't-locate-loadable-object-for-module-%25s-in-%40INC"></a><b>Can't locate loadable object for module %s in @INC</b>
<p>(F) The module you loaded is trying to load an external library, like
for example, <i>foo.so</i> or <i>bar.dll</i>, but the <a href="DynaLoader.html">DynaLoader</a> module was
unable to locate this library.  See <a href="DynaLoader.html">DynaLoader</a>.</p>
</li>
<li><a name="Can't-locate-object-method-%22%25s%22-via-package-%22%25s%22"></a><b>Can't locate object method "%s" via package "%s"</b>
<p>(F) You called a method correctly, and it correctly indicated a package
functioning as a class, but that package doesn't define that particular
method, nor does any of its base classes.  See <a href="perlobj.html">perlobj</a>.</p>
</li>
<li><a name="Can't-locate-object-method-%22%25s%22-via-package-%22%25s%22-(perhaps-you-forgot-to-load-%22%25s%22%3f)"></a><b>Can't locate object method "%s" via package "%s" (perhaps you forgot
to load "%s"?)</b>
<p>(F) You called a method on a class that did not exist, and the method
could not be found in UNIVERSAL.  This often means that a method
requires a package that has not been loaded.</p>
</li>
<li><a name="Can't-locate-package-%25s-for-%40%25s%3a%3aISA"></a><b>Can't locate package %s for @%s::ISA</b>
<p>(W syntax) The @ISA array contained the name of another package that
doesn't seem to exist.</p>
</li>
<li><a name="Can't-locate-PerlIO%25s"></a><b>Can't locate PerlIO%s</b>
<p>(F) You tried to use in open() a PerlIO layer that does not exist,
e.g. open(FH, "&gt;:nosuchlayer", "somefile").</p>
</li>
<li><a name="Can't-make-list-assignment-to-%25ENV-on-this-system"></a><b>Can't make list assignment to %ENV on this system</b>
<p>(F) List assignment to %ENV is not supported on some systems, notably
VMS.</p>
</li>
<li><a name="Can't-make-loaded-symbols-global-on-this-platform-while-loading-%25s"></a><b>Can't make loaded symbols global on this platform while loading %s</b>
<p>(S) A module passed the flag 0x01 to DynaLoader::dl_load_file() to request
that symbols from the stated file are made available globally within the
process, but that functionality is not available on this platform.  Whilst
the module likely will still work, this may prevent the perl interpreter
from loading other XS-based extensions which need to link directly to
functions defined in the C or XS code in the stated file.</p>
</li>
<li><a name="Can't-modify-%25s-in-%25s"></a><b>Can't modify %s in %s</b>
<p>(F) You aren't allowed to assign to the item indicated, or otherwise try
to change it, such as with an auto-increment.</p>
</li>
<li><a name="Can't-modify-nonexistent-substring"></a><b>Can't modify nonexistent substring</b>
<p>(P) The internal routine that does assignment to a substr() was handed
a NULL.</p>
</li>
<li><a name="Can't-modify-non-lvalue-subroutine-call-of-%26%25s"></a><b>Can't modify non-lvalue subroutine call of &amp;%s</b>
<p>(F) Subroutines meant to be used in lvalue context should be declared as
such.  See <a href="perlsub.html#Lvalue-subroutines">Lvalue subroutines in perlsub</a>.</p>
</li>
<li><a name="Can't-modify-reference-to-%25s-in-%25s-assignment"></a><b>Can't modify reference to %s in %s assignment</b>
<p>(F) Only a limited number of constructs can be used as the argument to a
reference constructor on the left-hand side of an assignment, and what
you used was not one of them.  See <a href="perlref.html#Assigning-to-References">Assigning to References in perlref</a>.</p>
</li>
<li><a name="Can't-modify-reference-to-localized-parenthesized-array-in-list-assignment"></a><b>Can't modify reference to localized parenthesized array in list
assignment</b>
<p>(F) Assigning to <code class="inline">\<a class="l_k" href="functions/local.html">local</a><span class="s">(</span><span class="i">@array</span><span class="s">)</span></code>
 or <code class="inline">\<span class="s">(</span><a class="l_k" href="functions/local.html">local</a> <span class="i">@array</span><span class="s">)</span></code>
 is not supported, as
it is not clear exactly what it should do.  If you meant to make @array
refer to some other array, use <code class="inline">\<span class="i">@array</span> = \<span class="i">@other_array</span></code>
.  If you want to
make the elements of @array aliases of the scalars referenced on the
right-hand side, use <code class="inline">\<span class="s">(</span><span class="i">@array</span><span class="s">)</span> = <span class="i">@scalar_refs</span></code>
.</p>
</li>
<li><a name="Can't-modify-reference-to-parenthesized-hash-in-list-assignment"></a><b>Can't modify reference to parenthesized hash in list assignment</b>
<p>(F) Assigning to <code class="inline">\<span class="s">(</span><span class="i">%hash</span><span class="s">)</span></code>
 is not supported.  If you meant to make %hash
refer to some other hash, use <code class="inline">\<span class="i">%hash</span> = \<span class="i">%other_hash</span></code>
.  If you want to
make the elements of %hash into aliases of the scalars referenced on the
right-hand side, use a hash slice: <code class="inline">\<span class="i">@hash</span>{<span class="i">@keys</span>} = <span class="i">@those_scalar_refs</span></code>
.</p>
</li>
<li><a name="Can't-msgrcv-to-read-only-var"></a><b>Can't msgrcv to read-only var</b>
<p>(F) The target of a msgrcv must be modifiable to be used as a receive
buffer.</p>
</li>
<li><a name="Can't-%22next%22-outside-a-loop-block"></a><b>Can't "next" outside a loop block</b>
<p>(F) A "next" statement was executed to reiterate the current block, but
there isn't a current block.  Note that an "if" or "else" block doesn't
count as a "loopish" block, as doesn't a block given to sort(), map() or
grep().  You can usually double the curlies to get the same effect
though, because the inner curlies will be considered a block that loops
once.  See <a href="functions/next.html">next</a>.</p>
</li>
<li><a name="Can't-open-%25s%3a-%25s"></a><b>Can't open %s: %s</b>
<p>(S inplace) The implicit opening of a file through use of the <code class="inline">&lt;&gt;</code>

filehandle, either implicitly under the <code class="inline">-<span class="w">n</span></code>
 or <code class="inline">-p</code>
 command-line
switches, or explicitly, failed for the indicated reason.  Usually
this is because you don't have read permission for a file which
you named on the command line.</p>
<p>(F) You tried to call perl with the <b>-e</b> switch, but <i>/dev/null</i> (or
your operating system's equivalent) could not be opened.</p>
</li>
<li><a name="Can't-open-a-reference"></a><b>Can't open a reference</b>
<p>(W io) You tried to open a scalar reference for reading or writing,
using the 3-arg open() syntax:</p>
<pre class="verbatim"><ol><li>    <a class="l_k" href="functions/open.html">open</a> <span class="w">FH</span><span class="cm">,</span> <span class="q">&#39;&gt;&#39;</span><span class="cm">,</span> <span class="i">$ref</span><span class="sc">;</span></li></ol></pre><p>but your version of perl is compiled without perlio, and this form of
open is not supported.</p>
</li>
<li><a name="Can't-open-bidirectional-pipe"></a><b>Can't open bidirectional pipe</b>
<p>(W pipe) You tried to say <code class="inline"><a class="l_k" href="functions/open.html">open</a><span class="s">(</span><span class="w">CMD</span><span class="cm">,</span> <span class="q">&quot;|cmd|&quot;</span><span class="s">)</span></code>
, which is not supported.
You can try any of several modules in the Perl library to do this, such
as IPC::Open2.  Alternately, direct the pipe's output to a file using
"&gt;", and then read it in under a different file handle.</p>
</li>
<li><a name="Can't-open-error-file-%25s-as-stderr"></a><b>Can't open error file %s as stderr</b>
<p>(F) An error peculiar to VMS.  Perl does its own command line
redirection, and couldn't open the file specified after '2&gt;' or '2&gt;&gt;' on
the command line for writing.</p>
</li>
<li><a name="Can't-open-input-file-%25s-as-stdin"></a><b>Can't open input file %s as stdin</b>
<p>(F) An error peculiar to VMS.  Perl does its own command line
redirection, and couldn't open the file specified after '&lt;' on the
command line for reading.</p>
</li>
<li><a name="Can't-open-output-file-%25s-as-stdout"></a><b>Can't open output file %s as stdout</b>
<p>(F) An error peculiar to VMS.  Perl does its own command line
redirection, and couldn't open the file specified after '&gt;' or '&gt;&gt;' on
the command line for writing.</p>
</li>
<li><a name="Can't-open-output-pipe-(name%3a-%25s)"></a><b>Can't open output pipe (name: %s)</b>
<p>(P) An error peculiar to VMS.  Perl does its own command line
redirection, and couldn't open the pipe into which to send data destined
for stdout.</p>
</li>
<li><a name="Can't-open-perl-script-%22%25s%22%3a-%25s"></a><b>Can't open perl script "%s": %s</b>
<p>(F) The script you specified can't be opened for the indicated reason.</p>
<p>If you're debugging a script that uses #!, and normally relies on the
shell's $PATH search, the -S option causes perl to do that search, so
you don't have to type the path or <code class="inline"><span class="q">`which $scriptname`</span></code>
.</p>
</li>
<li><a name="Can't-read-CRTL-environ"></a><b>Can't read CRTL environ</b>
<p>(S) A warning peculiar to VMS.  Perl tried to read an element of %ENV
from the CRTL's internal environment array and discovered the array was
missing.  You need to figure out where your CRTL misplaced its environ
or define <i>PERL_ENV_TABLES</i> (see <a href="perlvms.html">perlvms</a>) so that environ is not
searched.</p>
</li>
<li><a name="Can't-redeclare-%22%25s%22-in-%22%25s%22"></a><b>Can't redeclare "%s" in "%s"</b>
<p>(F) A "my", "our" or "state" declaration was found within another declaration,
such as <code class="inline"><a class="l_k" href="functions/my.html">my</a> <span class="s">(</span><span class="i">$x</span><span class="cm">,</span> <a class="l_k" href="functions/my.html">my</a><span class="s">(</span><span class="i">$y</span><span class="s">)</span><span class="cm">,</span> <span class="i">$z</span><span class="s">)</span></code>
 or <code class="inline"><a class="l_k" href="functions/our.html">our</a> <span class="s">(</span><a class="l_k" href="functions/my.html">my</a> <span class="i">$x</span><span class="s">)</span></code>
.</p>
</li>
<li><a name="Can't-%22redo%22-outside-a-loop-block"></a><b>Can't "redo" outside a loop block</b>
<p>(F) A "redo" statement was executed to restart the current block, but
there isn't a current block.  Note that an "if" or "else" block doesn't
count as a "loopish" block, as doesn't a block given to sort(), map()
or grep().  You can usually double the curlies to get the same effect
though, because the inner curlies will be considered a block that
loops once.  See <a href="functions/redo.html">redo</a>.</p>
</li>
<li><a name="Can't-remove-%25s%3a-%25s%2c-skipping-file"></a><b>Can't remove %s: %s, skipping file</b>
<p>(S inplace) You requested an inplace edit without creating a backup
file.  Perl was unable to remove the original file to replace it with
the modified file.  The file was left unmodified.</p>
</li>
<li><a name="Can't-rename-%25s-to-%25s%3a-%25s%2c-skipping-file"></a><b>Can't rename %s to %s: %s, skipping file</b>
<p>(S inplace) The rename done by the <b>-i</b> switch failed for some reason,
probably because you don't have write permission to the directory.</p>
</li>
<li><a name="Can't-reopen-input-pipe-(name%3a-%25s)-in-binary-mode"></a><b>Can't reopen input pipe (name: %s) in binary mode</b>
<p>(P) An error peculiar to VMS.  Perl thought stdin was a pipe, and tried
to reopen it to accept binary data.  Alas, it failed.</p>
</li>
<li><a name="Can't-represent-character-for-Ox%25X-on-this-platform"></a><b>Can't represent character for Ox%X on this platform</b>
<p>(F) There is a hard limit to how big a character code point can be due
to the fundamental properties of UTF-8, especially on EBCDIC
platforms.  The given code point exceeds that.  The only work-around is
to not use such a large code point.</p>
</li>
<li><a name="Can't-reset-%25ENV-on-this-system"></a><b>Can't reset %ENV on this system</b>
<p>(F) You called <code class="inline"><a class="l_k" href="functions/reset.html">reset('E')</a></code> or similar, which tried to reset
all variables in the current package beginning with "E".  In
the main package, that includes %ENV.  Resetting %ENV is not
supported on some systems, notably VMS.</p>
</li>
<li><a name="Can't-resolve-method-%22%25s%22-overloading-%22%25s%22-in-package-%22%25s%22"></a><b>Can't resolve method "%s" overloading "%s" in package "%s"</b>
<p>(F)(P) Error resolving overloading specified by a method name (as
opposed to a subroutine reference): no such method callable via the
package.  If the method name is <code class="inline">???</code>, this is an internal error.</p>
</li>
<li><a name="Can't-return-%25s-from-lvalue-subroutine"></a><b>Can't return %s from lvalue subroutine</b>
<p>(F) Perl detected an attempt to return illegal lvalues (such as
temporary or readonly values) from a subroutine used as an lvalue.  This
is not allowed.</p>
</li>
<li><a name="Can't-return-outside-a-subroutine"></a><b>Can't return outside a subroutine</b>
<p>(F) The return statement was executed in mainline code, that is, where
there was no subroutine call to return out of.  See <a href="perlsub.html">perlsub</a>.</p>
</li>
<li><a name="Can't-return-%25s-to-lvalue-scalar-context"></a><b>Can't return %s to lvalue scalar context</b>
<p>(F) You tried to return a complete array or hash from an lvalue
subroutine, but you called the subroutine in a way that made Perl
think you meant to return only one value.  You probably meant to
write parentheses around the call to the subroutine, which tell
Perl that the call should be in list context.</p>
</li>
<li><a name="Can't-stat-script-%22%25s%22"></a><b>Can't stat script "%s"</b>
<p>(P) For some reason you can't fstat() the script even though you have it
open already.  Bizarre.</p>
</li>
<li><a name="Can't-take-log-of-%25g"></a><b>Can't take log of %g</b>
<p>(F) For ordinary real numbers, you can't take the logarithm of a
negative number or zero.  There's a Math::Complex package that comes
standard with Perl, though, if you really want to do that for the
negative numbers.</p>
</li>
<li><a name="Can't-take-sqrt-of-%25g"></a><b>Can't take sqrt of %g</b>
<p>(F) For ordinary real numbers, you can't take the square root of a
negative number.  There's a Math::Complex package that comes standard
with Perl, though, if you really want to do that.</p>
</li>
<li><a name="Can't-undef-active-subroutine"></a><b>Can't undef active subroutine</b>
<p>(F) You can't undefine a routine that's currently running.  You can,
however, redefine it while it's running, and you can even undef the
redefined subroutine while the old routine is running.  Go figure.</p>
</li>
<li><a name="Can't-upgrade-%25s-(%25d)-to-%25d"></a><b>Can't upgrade %s (%d) to %d</b>
<p>(P) The internal sv_upgrade routine adds "members" to an SV, making it
into a more specialized kind of SV.  The top several SV types are so
specialized, however, that they cannot be interconverted.  This message
indicates that such a conversion was attempted.</p>
</li>
<li><a name="Can't-use-'%25c'-after--mname"></a><b>Can't use '%c' after -mname</b>
<p>(F) You tried to call perl with the <b>-m</b> switch, but you put something
other than "=" after the module name.</p>
</li>
<li><a name="Can't-use-a-hash-as-a-reference"></a><b>Can't use a hash as a reference</b>
<p>(F) You tried to use a hash as a reference, as in
<code class="inline"><span class="i">%foo</span>-&gt;{<span class="q">&quot;bar&quot;</span>}</code>
 or <code class="inline"><span class="i">%$ref</span>-&gt;{<span class="q">&quot;hello&quot;</span>}</code>
.  Versions of perl
&lt;= 5.22.0 used to allow this syntax, but shouldn't
have.  This was deprecated in perl 5.6.1.</p>
</li>
<li><a name="Can't-use-an-array-as-a-reference"></a><b>Can't use an array as a reference</b>
<p>(F) You tried to use an array as a reference, as in
<code class="inline"><span class="i">@foo</span>-&gt;[<span class="n">23</span>]</code>
 or <code class="inline"><span class="i">@$ref</span>-&gt;[<span class="n">99</span>]</code>
.  Versions of perl &lt;= 5.22.0
used to allow this syntax, but shouldn't have.  This
was deprecated in perl 5.6.1.</p>
</li>
<li><a name="Can't-use-anonymous-symbol-table-for-method-lookup"></a><b>Can't use anonymous symbol table for method lookup</b>
<p>(F) The internal routine that does method lookup was handed a symbol
table that doesn't have a name.  Symbol tables can become anonymous
for example by undefining stashes: <code class="inline"><a class="l_k" href="functions/undef.html">undef</a> <span class="i">%Some::Package::</span></code>
.</p>
</li>
<li><a name="Can't-use-an-undefined-value-as-%25s-reference"></a><b>Can't use an undefined value as %s reference</b>
<p>(F) A value used as either a hard reference or a symbolic reference must
be a defined value.  This helps to delurk some insidious errors.</p>
</li>
<li><a name="Can't-use-bareword-(%22%25s%22)-as-%25s-ref-while-%22strict-refs%22-in-use"></a><b>Can't use bareword ("%s") as %s ref while "strict refs" in use</b>
<p>(F) Only hard references are allowed by "strict refs".  Symbolic
references are disallowed.  See <a href="perlref.html">perlref</a>.</p>
</li>
<li><a name="Can't-use-%25!-because-Errno.pm-is-not-available"></a><b>Can't use %! because Errno.pm is not available</b>
<p>(F) The first time the <code class="inline"><span class="i">%!</span></code>
 hash is used, perl automatically loads the
Errno.pm module.  The Errno module is expected to tie the %! hash to
provide symbolic names for <code class="inline"><span class="i">$!</span></code>
 errno values.</p>
</li>
<li><a name="Can't-use-both-'%3c'-and-'%3e'-after-type-'%25c'-in-%25s"></a><b>Can't use both '&lt;' and '&gt;' after type '%c' in %s</b>
<p>(F) A type cannot be forced to have both big-endian and little-endian
byte-order at the same time, so this combination of modifiers is not
allowed.  See <a href="functions/pack.html">pack</a>.</p>
</li>
<li><a name="Can't-use-'defined(%40array)'-(Maybe-you-should-just-omit-the-defined()%3f)"></a><b>Can't use 'defined(@array)' (Maybe you should just omit the defined()?)</b>
<p>(F) defined() is not useful on arrays because it
checks for an undefined <i>scalar</i> value.  If you want to see if the
array is empty, just use <code class="inline">if (@array) { # not empty }</code> for example.</p>
</li>
<li><a name="Can't-use-'defined(%25hash)'-(Maybe-you-should-just-omit-the-defined()%3f)"></a><b>Can't use 'defined(%hash)' (Maybe you should just omit the defined()?)</b>
<p>(F) <code class="inline"><a class="l_k" href="functions/defined.html">defined()</a></code> is not usually right on hashes.</p>
<p>Although <code class="inline"><a class="l_k" href="functions/defined.html">defined</a> <span class="i">%hash</span></code>
 is false on a plain not-yet-used hash, it
becomes true in several non-obvious circumstances, including iterators,
weak references, stash names, even remaining true after <code class="inline"><a class="l_k" href="functions/undef.html">undef</a> <span class="i">%hash</span></code>
.
These things make <code class="inline"><a class="l_k" href="functions/defined.html">defined</a> <span class="i">%hash</span></code>
 fairly useless in practice, so it now
generates a fatal error.</p>
<p>If a check for non-empty is what you wanted then just put it in boolean
context (see <a href="perldata.html#Scalar-values">Scalar values in perldata</a>):</p>
<pre class="verbatim"><ol><li>    <a class="l_k" href="functions/if.html">if</a> <span class="s">(</span><span class="i">%hash</span><span class="s">)</span> <span class="s">{</span></li><li>       <span class="c"># not empty</span></li><li>    <span class="s">}</span></li></ol></pre><p>If you had <code class="inline"><a class="l_k" href="functions/defined.html">defined</a> <span class="i">%Foo::Bar::QUUX</span></code>
 to check whether such a package
variable exists then that's never really been reliable, and isn't
a good way to enquire about the features of a package, or whether
it's loaded, etc.</p>
</li>
<li><a name="Can't-use-%25s-for-loop-variable"></a><b>Can't use %s for loop variable</b>
<p>(P) The parser got confused when trying to parse a <code class="inline">foreach</code>
 loop.</p>
</li>
<li><a name="Can't-use-global-%25s-in-%22%25s%22"></a><b>Can't use global %s in "%s"</b>
<p>(F) You tried to declare a magical variable as a lexical variable.  This
is not allowed, because the magic can be tied to only one location
(namely the global variable) and it would be incredibly confusing to
have variables in your program that looked like magical variables but
weren't.</p>
</li>
<li><a name="Can't-use-'%25c'-in-a-group-with-different-byte-order-in-%25s"></a><b>Can't use '%c' in a group with different byte-order in %s</b>
<p>(F) You attempted to force a different byte-order on a type
that is already inside a group with a byte-order modifier.
For example you cannot force little-endianness on a type that
is inside a big-endian group.</p>
</li>
<li><a name="Can't-use-%22my-%25s%22-in-sort-comparison"></a><b>Can't use "my %s" in sort comparison</b>
<p>(F) The global variables $a and $b are reserved for sort comparisons.
You mentioned $a or $b in the same line as the &lt;=&gt; or cmp operator,
and the variable had earlier been declared as a lexical variable.
Either qualify the sort variable with the package name, or rename the
lexical variable.</p>
</li>
<li><a name="Can't-use-%25s-ref-as-%25s-ref"></a><b>Can't use %s ref as %s ref</b>
<p>(F) You've mixed up your reference types.  You have to dereference a
reference of the type needed.  You can use the ref() function to
test the type of the reference, if need be.</p>
</li>
<li><a name="Can't-use-string-(%22%25s%22)-as-%25s-ref-while-%22strict-refs%22-in-use"></a><b>Can't use string ("%s") as %s ref while "strict refs" in use</b>
</li>
<li><a name="Can't-use-string-(%22%25s%22...)-as-%25s-ref-while-%22strict-refs%22-in-use"></a><b>Can't use string ("%s"...) as %s ref while "strict refs" in use</b>
<p>(F) You've told Perl to dereference a string, something which
<code class="inline"><a class="l_k" href="functions/use.html">use</a> <span class="w">strict</span></code>
 blocks to prevent it happening accidentally.  See
<a href="perlref.html#Symbolic-references">Symbolic references in perlref</a>.  This can be triggered by an <code class="inline"><span class="i">@</span></code>
 or <code class="inline"><span class="i">$</span></code>

in a double-quoted string immediately before interpolating a variable,
for example in <code class="inline"><span class="q">&quot;user @$twitter_id&quot;</span></code>
, which says to treat the contents
of <code class="inline"><span class="i">$twitter_id</span></code>
 as an array reference; use a <code class="inline">\</code>
 to have a literal <code class="inline"><span class="i">@</span></code>

symbol followed by the contents of <code class="inline"><span class="i">$twitter_id</span></code>
: <code class="inline"><span class="q">&quot;user \@$twitter_id&quot;</span></code>
.</p>
</li>
<li><a name="Can't-use-subscript-on-%25s"></a><b>Can't use subscript on %s</b>
<p>(F) The compiler tried to interpret a bracketed expression as a
subscript.  But to the left of the brackets was an expression that
didn't look like a hash or array reference, or anything else subscriptable.</p>
</li>
<li><a name="Can't-use-%5c%25c-to-mean-%24%25c-in-expression"></a><b>Can't use \%c to mean $%c in expression</b>
<p>(W syntax) In an ordinary expression, backslash is a unary operator that
creates a reference to its argument.  The use of backslash to indicate a
backreference to a matched substring is valid only as part of a regular
expression pattern.  Trying to do this in ordinary Perl code produces a
value that prints out looking like SCALAR(0xdecaf).  Use the $1 form
instead.</p>
</li>
<li><a name="Can't-weaken-a-nonreference"></a><b>Can't weaken a nonreference</b>
<p>(F) You attempted to weaken something that was not a reference.  Only
references can be weakened.</p>
</li>
<li><a name="Can't-%22when%22-outside-a-topicalizer"></a><b>Can't "when" outside a topicalizer</b>
<p>(F) You have used a when() block that is neither inside a <code class="inline">foreach</code>

loop nor a <code class="inline">given</code>
 block.  (Note that this error is issued on exit
from the <code class="inline">when</code>
 block, so you won't get the error if the match fails,
or if you use an explicit <code class="inline"><a class="l_k" href="functions/continue.html">continue</a></code>.)</p>
</li>
<li><a name="Can't-x%3d-to-read-only-value"></a><b>Can't x= to read-only value</b>
<p>(F) You tried to repeat a constant value (often the undefined value)
with an assignment operator, which implies modifying the value itself.
Perhaps you need to copy the value to a temporary, and repeat that.</p>
</li>
<li><a name="Character-following-%22%5cc%22-must-be-printable-ASCII"></a><b>Character following "\c" must be printable ASCII</b>
<p>(F) In <code class="inline">\c<i>X</i></code>, <i>X</i> must be a printable (non-control) ASCII character.</p>
<p>Note that ASCII characters that don't map to control characters are
discouraged, and will generate the warning (when enabled)
<a href="#%5cc%25c%22-is-more-clearly-written-simply-as-%22%25s">\c%c is more clearly written simply as %s</a>.</p>
</li>
<li><a name="Character-following-%5c%25c-must-be-'%7b'-or-a-single-character-Unicode-property-name-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>Character following \%c must be '{' or a single-character Unicode property name in regex; marked by &lt;-- HERE in m/%s/</b>
<p>(F) (In the above the <code class="inline"><span class="i">%c</span></code>
 is replaced by either <code class="inline"><span class="w">p</span></code>
 or <code class="inline"><span class="w">P</span></code>
.)  You
specified something that isn't a legal Unicode property name.  Most
Unicode properties are specified by <code class="inline">\<span class="i">p</span><span class="s">{</span>...<span class="s">}</span></code>
.  But if the name is a
single character one, the braces may be omitted.</p>
</li>
<li><a name="Character-in-'C'-format-wrapped-in-pack"></a><b>Character in 'C' format wrapped in pack</b>
<p>(W pack) You said</p>
<pre class="verbatim"><ol><li>    <a class="l_k" href="functions/pack.html">pack</a><span class="s">(</span><span class="q">&quot;C&quot;</span><span class="cm">,</span> <span class="i">$x</span><span class="s">)</span></li></ol></pre><p>where $x is either less than 0 or more than 255; the <code class="inline"><span class="q">&quot;C&quot;</span></code>
 format is
only for encoding native operating system characters (ASCII, EBCDIC,
and so on) and not for Unicode characters, so Perl behaved as if you meant</p>
<pre class="verbatim"><ol><li>    <a class="l_k" href="functions/pack.html">pack</a><span class="s">(</span><span class="q">&quot;C&quot;</span><span class="cm">,</span> <span class="i">$x</span> &amp; <span class="n">255</span><span class="s">)</span></li></ol></pre><p>If you actually want to pack Unicode codepoints, use the <code class="inline"><span class="q">&quot;U&quot;</span></code>
 format
instead.</p>
</li>
<li><a name="Character-in-'c'-format-wrapped-in-pack"></a><b>Character in 'c' format wrapped in pack</b>
<p>(W pack) You said</p>
<pre class="verbatim"><ol><li>    <a class="l_k" href="functions/pack.html">pack</a><span class="s">(</span><span class="q">&quot;c&quot;</span><span class="cm">,</span> <span class="i">$x</span><span class="s">)</span></li></ol></pre><p>where $x is either less than -128 or more than 127; the <code class="inline"><span class="q">&quot;c&quot;</span></code>
 format
is only for encoding native operating system characters (ASCII, EBCDIC,
and so on) and not for Unicode characters, so Perl behaved as if you meant</p>
<pre class="verbatim"><ol><li>    <a class="l_k" href="functions/pack.html">pack</a><span class="s">(</span><span class="q">&quot;c&quot;</span><span class="cm">,</span> <span class="i">$x</span> &amp; <span class="n">255</span><span class="s">)</span><span class="sc">;</span></li></ol></pre><p>If you actually want to pack Unicode codepoints, use the <code class="inline"><span class="q">&quot;U&quot;</span></code>
 format
instead.</p>
</li>
<li><a name="Character-in-'%25c'-format-wrapped-in-unpack"></a><b>Character in '%c' format wrapped in unpack</b>
<p>(W unpack) You tried something like</p>
<pre class="verbatim"><ol><li>   <a class="l_k" href="functions/unpack.html">unpack</a><span class="s">(</span><span class="q">&quot;H&quot;</span><span class="cm">,</span> <span class="q">&quot;\x{2a1}&quot;</span><span class="s">)</span></li></ol></pre><p>where the format expects to process a byte (a character with a value
below 256), but a higher value was provided instead.  Perl uses the
value modulus 256 instead, as if you had provided:</p>
<pre class="verbatim"><ol><li>   <a class="l_k" href="functions/unpack.html">unpack</a><span class="s">(</span><span class="q">&quot;H&quot;</span><span class="cm">,</span> <span class="q">&quot;\x{a1}&quot;</span><span class="s">)</span></li></ol></pre></li>
<li><a name="Character-in-'W'-format-wrapped-in-pack"></a><b>Character in 'W' format wrapped in pack</b>
<p>(W pack) You said</p>
<pre class="verbatim"><ol><li>    <a class="l_k" href="functions/pack.html">pack</a><span class="s">(</span><span class="q">&quot;U0W&quot;</span><span class="cm">,</span> <span class="i">$x</span><span class="s">)</span></li></ol></pre><p>where $x is either less than 0 or more than 255.  However, <code class="inline"><span class="w">U0</span></code>
-mode
expects all values to fall in the interval [0, 255], so Perl behaved
as if you meant:</p>
<pre class="verbatim"><ol><li>    <a class="l_k" href="functions/pack.html">pack</a><span class="s">(</span><span class="q">&quot;U0W&quot;</span><span class="cm">,</span> <span class="i">$x</span> &amp; <span class="n">255</span><span class="s">)</span></li></ol></pre></li>
<li><a name="Character(s)-in-'%25c'-format-wrapped-in-pack"></a><b>Character(s) in '%c' format wrapped in pack</b>
<p>(W pack) You tried something like</p>
<pre class="verbatim"><ol><li>   <a class="l_k" href="functions/pack.html">pack</a><span class="s">(</span><span class="q">&quot;u&quot;</span><span class="cm">,</span> <span class="q">&quot;\x{1f3}b&quot;</span><span class="s">)</span></li></ol></pre><p>where the format expects to process a sequence of bytes (character with a
value below 256), but some of the characters had a higher value.  Perl
uses the character values modulus 256 instead, as if you had provided:</p>
<pre class="verbatim"><ol><li>   <a class="l_k" href="functions/pack.html">pack</a><span class="s">(</span><span class="q">&quot;u&quot;</span><span class="cm">,</span> <span class="q">&quot;\x{f3}b&quot;</span><span class="s">)</span></li></ol></pre></li>
<li><a name="Character(s)-in-'%25c'-format-wrapped-in-unpack"></a><b>Character(s) in '%c' format wrapped in unpack</b>
<p>(W unpack) You tried something like</p>
<pre class="verbatim"><ol><li>   <a class="l_k" href="functions/unpack.html">unpack</a><span class="s">(</span><span class="q">&quot;s&quot;</span><span class="cm">,</span> <span class="q">&quot;\x{1f3}b&quot;</span><span class="s">)</span></li></ol></pre><p>where the format expects to process a sequence of bytes (character with a
value below 256), but some of the characters had a higher value.  Perl
uses the character values modulus 256 instead, as if you had provided:</p>
<pre class="verbatim"><ol><li>   <a class="l_k" href="functions/unpack.html">unpack</a><span class="s">(</span><span class="q">&quot;s&quot;</span><span class="cm">,</span> <span class="q">&quot;\x{f3}b&quot;</span><span class="s">)</span></li></ol></pre></li>
<li><a name="charnames-alias-definitions-may-not-contain-a-sequence-of-multiple-spaces"></a><b>charnames alias definitions may not contain a sequence of multiple spaces</b>
<p>(F) You defined a character name which had multiple space characters
in a row.  Change them to single spaces.  Usually these names are
defined in the <code class="inline"><span class="j">:</span><span class="w">alias</span></code>
 import argument to <code class="inline"><a class="l_k" href="functions/use.html">use</a> <span class="w">charnames</span></code>
, but they
could be defined by a translator installed into <code class="inline"><span class="i">$^H</span>{<span class="w">charnames</span>}</code>
.  See
<a href="charnames.html#CUSTOM-ALIASES">CUSTOM ALIASES in charnames</a>.</p>
</li>
<li><a name="charnames-alias-definitions-may-not-contain-trailing-white-space"></a><b>charnames alias definitions may not contain trailing white-space</b>
<p>(F) You defined a character name which ended in a space
character.  Remove the trailing space(s).  Usually these names are
defined in the <code class="inline"><span class="j">:</span><span class="w">alias</span></code>
 import argument to <code class="inline"><a class="l_k" href="functions/use.html">use</a> <span class="w">charnames</span></code>
, but they
could be defined by a translator installed into <code class="inline"><span class="i">$^H</span>{<span class="w">charnames</span>}</code>
.
See <a href="charnames.html#CUSTOM-ALIASES">CUSTOM ALIASES in charnames</a>.</p>
</li>
<li><a name="chdir()-on-unopened-filehandle-%25s"></a><b>chdir() on unopened filehandle %s</b>
<p>(W unopened) You tried chdir() on a filehandle that was never opened.</p>
</li>
<li><a name="%22%5cc%25c%22-is-more-clearly-written-simply-as-%22%25s%22"></a><b>"\c%c" is more clearly written simply as "%s"</b>
<p>(W syntax) The <code class="inline">\c<i>X</i></code> construct is intended to be a way to specify
non-printable characters.  You used it for a printable one, which
is better written as simply itself, perhaps preceded by a backslash
for non-word characters.  Doing it the way you did is not portable
between ASCII and EBCDIC platforms.</p>
</li>
<li><a name="Cloning-substitution-context-is-unimplemented"></a><b>Cloning substitution context is unimplemented</b>
<p>(F) Creating a new thread inside the <code class="inline"><a class="l_k" href="functions/s.html">s///</a></code> operator is not supported.</p>
</li>
<li><a name="closedir()-attempted-on-invalid-dirhandle-%25s"></a><b>closedir() attempted on invalid dirhandle %s</b>
<p>(W io) The dirhandle you tried to close is either closed or not really
a dirhandle.  Check your control flow.</p>
</li>
<li><a name="close()-on-unopened-filehandle-%25s"></a><b>close() on unopened filehandle %s</b>
<p>(W unopened) You tried to close a filehandle that was never opened.</p>
</li>
<li><a name="Closure-prototype-called"></a><b>Closure prototype called</b>
<p>(F) If a closure has attributes, the subroutine passed to an attribute
handler is the prototype that is cloned when a new closure is created.
This subroutine cannot be called.</p>
</li>
<li><a name="%5cC-no-longer-supported-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>\C no longer supported in regex; marked by &lt;-- HERE in m/%s/</b>
<p>(F) The \C character class used to allow a match of single byte
within a multi-byte utf-8 character, but was removed in v5.24 as
it broke encapsulation and its implementation was extremely buggy.
If you really need to process the individual bytes, you probably
want to convert your string to one where each underlying byte is
stored as a character, with utf8::encode().</p>
</li>
<li><a name="Code-missing-after-'%2f'"></a><b>Code missing after '/'</b>
<p>(F) You had a (sub-)template that ends with a '/'.  There must be
another template code following the slash.  See <a href="functions/pack.html">pack</a>.</p>
</li>
<li><a name="Code-point-0x%25X-is-not-Unicode%2c-and-not-portable"></a><b>Code point 0x%X is not Unicode, and not portable</b>
<p>(S non_unicode) You had a code point that has never been in any
standard, so it is likely that languages other than Perl will NOT
understand it.  At one time, it was legal in some standards to have code
points up to 0x7FFF_FFFF, but not higher, and this code point is higher.</p>
<p>Acceptance of these code points is a Perl extension, and you should
expect that nothing other than Perl can handle them; Perl itself on
EBCDIC platforms before v5.24 does not handle them.</p>
<p>Code points above 0xFFFF_FFFF require larger than a 32 bit word.</p>
<p>Perl also makes no guarantees that the representation of these code
points won't change at some point in the future, say when machines
become available that have larger than a 64-bit word.  At that time,
files written by an older Perl would require conversion before being
readable by a newer Perl.</p>
</li>
<li><a name="Code-point-0x%25X-is-not-Unicode%2c-may-not-be-portable"></a><b>Code point 0x%X is not Unicode, may not be portable</b>
<p>(S non_unicode) You had a code point above the Unicode maximum
of U+10FFFF.</p>
<p>Perl allows strings to contain a superset of Unicode code points, but
these may not be accepted by other languages/systems.  Further, even if
these languages/systems accept these large code points, they may have
chosen a different representation for them than the UTF-8-like one that
Perl has, which would mean files are not exchangeable between them and
Perl.</p>
<p>On EBCDIC platforms, code points above 0x3FFF_FFFF have a different
representation in Perl v5.24 than before, so any file containing these
that was written before that version will require conversion before
being readable by a later Perl.</p>
</li>
<li><a name="%25s%3a-Command-not-found"></a><b>%s: Command not found</b>
<p>(A) You've accidentally run your script through <b>csh</b> or another shell
instead of Perl.  Check the #! line, or manually feed your script into
Perl yourself.  The #! line at the top of your file could look like</p>
<pre class="verbatim"><ol><li>  <span class="c">#!/usr/bin/perl</span></li></ol></pre></li>
<li><a name="%25s%3a-command-not-found"></a><b>%s: command not found</b>
<p>(A) You've accidentally run your script through <b>bash</b> or another shell
instead of Perl.  Check the #! line, or manually feed your script into
Perl yourself.  The #! line at the top of your file could look like</p>
<pre class="verbatim"><ol><li>  <span class="c">#!/usr/bin/perl</span></li></ol></pre></li>
<li><a name="%25s%3a-command-not-found%3a-%25s"></a><b>%s: command not found: %s</b>
<p>(A) You've accidentally run your script through <b>zsh</b> or another shell
instead of Perl.  Check the #! line, or manually feed your script into
Perl yourself.  The #! line at the top of your file could look like</p>
<pre class="verbatim"><ol><li>  <span class="c">#!/usr/bin/perl</span></li></ol></pre></li>
<li><a name="Compilation-failed-in-require"></a><b>Compilation failed in require</b>
<p>(F) Perl could not compile a file specified in a <code class="inline"><a class="l_k" href="functions/require.html">require</a></code> statement.
Perl uses this generic message when none of the errors that it
encountered were severe enough to halt compilation immediately.</p>
</li>
<li><a name="Complex-regular-subexpression-recursion-limit-(%25d)-exceeded"></a><b>Complex regular subexpression recursion limit (%d) exceeded</b>
<p>(W regexp) The regular expression engine uses recursion in complex
situations where back-tracking is required.  Recursion depth is limited
to 32766, or perhaps less in architectures where the stack cannot grow
arbitrarily.  ("Simple" and "medium" situations are handled without
recursion and are not subject to a limit.)  Try shortening the string
under examination; looping in Perl code (e.g. with <code class="inline">while</code>
) rather than
in the regular expression engine; or rewriting the regular expression so
that it is simpler or backtracks less.  (See <a href="perlfaq2.html">perlfaq2</a> for information
on <i>Mastering Regular Expressions</i>.)</p>
</li>
<li><a name="connect()-on-closed-socket-%25s"></a><b>connect() on closed socket %s</b>
<p>(W closed) You tried to do a connect on a closed socket.  Did you forget
to check the return value of your socket() call?  See
<a href="functions/connect.html">connect</a>.</p>
</li>
<li><a name="Constant(%25s)%3a-Call-to-%26%7b%24%5eH%7b%25s%7d%7d-did-not-return-a-defined-value"></a><b>Constant(%s): Call to &amp;{$^H{%s}} did not return a defined value</b>
<p>(F) The subroutine registered to handle constant overloading
(see <a href="overload.html">overload</a>) or a custom charnames handler (see
<a href="charnames.html#CUSTOM-TRANSLATORS">CUSTOM TRANSLATORS in charnames</a>) returned an undefined value.</p>
</li>
<li><a name="Constant(%25s)%3a-%24%5eH%7b%25s%7d-is-not-defined"></a><b>Constant(%s): $^H{%s} is not defined</b>
<p>(F) The parser found inconsistencies while attempting to define an
overloaded constant.  Perhaps you forgot to load the corresponding
<a href="overload.html">overload</a> pragma?</p>
</li>
<li><a name="Constant-is-not-%25s-reference"></a><b>Constant is not %s reference</b>
<p>(F) A constant value (perhaps declared using the <code class="inline"><a class="l_k" href="functions/use.html">use</a> <span class="w">constant</span></code>
 pragma)
is being dereferenced, but it amounts to the wrong type of reference.
The message indicates the type of reference that was expected.  This
usually indicates a syntax error in dereferencing the constant value.
See <a href="perlsub.html#Constant-Functions">Constant Functions in perlsub</a> and <a href="constant.html">constant</a>.</p>
</li>
<li><a name="Constants-from-lexical-variables-potentially-modified-elsewhere-are-deprecated.-This-will-not-be-allowed-in-Perl-5.32"></a><b>Constants from lexical variables potentially modified elsewhere are
deprecated. This will not be allowed in Perl 5.32</b>
<p>(D deprecated) You wrote something like</p>
<pre class="verbatim"><ol><li>    <a class="l_k" href="functions/my.html">my</a> <span class="i">$var</span><span class="sc">;</span></li><li>    <span class="i">$sub</span> = <span class="i">sub ()</span> <span class="s">{</span> <span class="i">$var</span> <span class="s">}</span><span class="sc">;</span></li></ol></pre><p>but $var is referenced elsewhere and could be modified after the <code class="inline"><a class="l_k" href="functions/sub.html">sub</a></code>
expression is evaluated.  Either it is explicitly modified elsewhere
(<code class="inline"><span class="i">$var</span> = <span class="n">3</span></code>
) or it is passed to a subroutine or to an operator like
<code class="inline"><a class="l_k" href="functions/printf.html">printf</a></code> or <code class="inline"><a class="l_k" href="functions/map.html">map</a></code>, which may or may not modify the variable.</p>
<p>Traditionally, Perl has captured the value of the variable at that
point and turned the subroutine into a constant eligible for inlining.
In those cases where the variable can be modified elsewhere, this
breaks the behavior of closures, in which the subroutine captures
the variable itself, rather than its value, so future changes to the
variable are reflected in the subroutine's return value.</p>
<p>This usage is deprecated, and will no longer be allowed in Perl 5.32,
making it possible to change the behavior in the future.</p>
<p>If you intended for the subroutine to be eligible for inlining, then
make sure the variable is not referenced elsewhere, possibly by
copying it:</p>
<pre class="verbatim"><ol><li>    <a class="l_k" href="functions/my.html">my</a> <span class="i">$var2</span> = <span class="i">$var</span><span class="sc">;</span></li><li>    <span class="i">$sub</span> = <span class="i">sub ()</span> <span class="s">{</span> <span class="i">$var2</span> <span class="s">}</span><span class="sc">;</span></li></ol></pre><p>If you do want this subroutine to be a closure that reflects future
changes to the variable that it closes over, add an explicit <code class="inline"><a class="l_k" href="functions/return.html">return</a></code>:</p>
<pre class="verbatim"><ol><li>    <a class="l_k" href="functions/my.html">my</a> <span class="i">$var</span><span class="sc">;</span></li><li>    <span class="i">$sub</span> = <span class="i">sub ()</span> <span class="s">{</span> <a class="l_k" href="functions/return.html">return</a> <span class="i">$var</span> <span class="s">}</span><span class="sc">;</span></li></ol></pre></li>
<li><a name="Constant-subroutine-%25s-redefined"></a><b>Constant subroutine %s redefined</b>
<p>(W redefine)(S) You redefined a subroutine which had previously
been eligible for inlining.  See <a href="perlsub.html#Constant-Functions">Constant Functions in perlsub</a>
for commentary and workarounds.</p>
</li>
<li><a name="Constant-subroutine-%25s-undefined"></a><b>Constant subroutine %s undefined</b>
<p>(W misc) You undefined a subroutine which had previously been eligible
for inlining.  See <a href="perlsub.html#Constant-Functions">Constant Functions in perlsub</a> for commentary and
workarounds.</p>
</li>
<li><a name="Constant(%25s)-unknown"></a><b>Constant(%s) unknown</b>
<p>(F) The parser found inconsistencies either while attempting
to define an overloaded constant, or when trying to find the
character name specified in the <code class="inline">\<span class="i">N</span><span class="s">{</span>...<span class="s">}</span></code>
 escape.  Perhaps you
forgot to load the corresponding <a href="overload.html">overload</a> pragma?</p>
</li>
<li><a name="%3aconst-is-experimental"></a><b>:const is experimental</b>
<p>(S experimental::const_attr) The "const" attribute is experimental.
If you want to use the feature, disable the warning with <code class="inline"><a class="l_k" href="functions/no.html">no</a> <span class="w">warnings</span>
<span class="q">&#39;experimental::const_attr&#39;</span></code>
, but know that in doing so you are taking
the risk that your code may break in a future Perl version.</p>
</li>
<li><a name="%3aconst-is-not-permitted-on-named-subroutines"></a><b>:const is not permitted on named subroutines</b>
<p>(F) The "const" attribute causes an anonymous subroutine to be run and
its value captured at the time that it is cloned.  Named subroutines are
not cloned like this, so the attribute does not make sense on them.</p>
</li>
<li><a name="Copy-method-did-not-return-a-reference"></a><b>Copy method did not return a reference</b>
<p>(F) The method which overloads "=" is buggy.  See
<a href="overload.html#Copy-Constructor">Copy Constructor in overload</a>.</p>
</li>
<li><a name="%26CORE%3a%3a%25s-cannot-be-called-directly"></a><b>&amp;CORE::%s cannot be called directly</b>
<p>(F) You tried to call a subroutine in the <code class="inline"><span class="w">CORE::</span></code>
 namespace
with <code class="inline"><span class="i">&amp;foo</span></code>
 syntax or through a reference.  Some subroutines
in this package cannot yet be called that way, but must be
called as barewords.  Something like this will work:</p>
<pre class="verbatim"><ol><li>    <a class="l_k" href="functions/BEGIN.html">BEGIN</a> <span class="s">{</span> <span class="i">*shove</span> = \<span class="i">&amp;CORE::push</span><span class="sc">;</span> <span class="s">}</span></li><li>    <span class="w">shove</span> <span class="i">@array</span><span class="cm">,</span> <span class="n">1</span><span class="cm">,</span><span class="n">2</span><span class="cm">,</span><span class="n">3</span><span class="sc">;</span> <span class="c"># pushes on to @array</span></li></ol></pre></li>
<li><a name="CORE%3a%3a%25s-is-not-a-keyword"></a><b>CORE::%s is not a keyword</b>
<p>(F) The CORE:: namespace is reserved for Perl keywords.</p>
</li>
<li><a name="Corrupted-regexp-opcode-%25d-%3e-%25d"></a><b>Corrupted regexp opcode %d &gt; %d</b>
<p>(P) This is either an error in Perl, or, if you're using
one, your <a href="perlreapi.html">custom regular expression engine</a>.  If not the
latter, report the problem through the <a href="perlbug.html">perlbug</a> utility.</p>
</li>
<li><a name="corrupted-regexp-pointers"></a><b>corrupted regexp pointers</b>
<p>(P) The regular expression engine got confused by what the regular
expression compiler gave it.</p>
</li>
<li><a name="corrupted-regexp-program"></a><b>corrupted regexp program</b>
<p>(P) The regular expression engine got passed a regexp program without a
valid magic number.</p>
</li>
<li><a name="Corrupt-malloc-ptr-0x%25x-at-0x%25x"></a><b>Corrupt malloc ptr 0x%x at 0x%x</b>
<p>(P) The malloc package that comes with Perl had an internal failure.</p>
</li>
<li><a name="Count-after-length%2fcode-in-unpack"></a><b>Count after length/code in unpack</b>
<p>(F) You had an unpack template indicating a counted-length string, but
you have also specified an explicit size for the string.  See
<a href="functions/pack.html">pack</a>.</p>
</li>
<li><a name="Declaring-references-is-experimental"></a><b>Declaring references is experimental</b>
<p>(S experimental::declared_refs) This warning is emitted if you use
a reference constructor on the right-hand side of <code class="inline"><a class="l_k" href="functions/my.html">my</a></code>, <code class="inline"><a class="l_k" href="functions/state.html">state</a></code>, <code class="inline"><a class="l_k" href="functions/our.html">our</a></code>, or
<code class="inline"><a class="l_k" href="functions/local.html">local</a></code>.  Simply suppress the warning if you want to use the feature, but
know that in doing so you are taking the risk of using an experimental
feature which may change or be removed in a future Perl version:</p>
<pre class="verbatim"><ol><li>    <a class="l_k" href="functions/no.html">no</a> <span class="w">warnings</span> <span class="q">&quot;experimental::declared_refs&quot;</span><span class="sc">;</span></li><li>    <a class="l_k" href="functions/use.html">use</a> <span class="w">feature</span> <span class="q">&quot;declared_refs&quot;</span><span class="sc">;</span></li><li>    <span class="i">$fooref</span> = <a class="l_k" href="functions/my.html">my</a> \<span class="i">$foo</span><span class="sc">;</span></li></ol></pre></li>
<li><a name="Deep-recursion-on-anonymous-subroutine"></a><b>Deep recursion on anonymous subroutine</b>
</li>
<li><a name="Deep-recursion-on-subroutine-%22%25s%22"></a><b>Deep recursion on subroutine "%s"</b>
<p>(W recursion) This subroutine has called itself (directly or indirectly)
100 times more than it has returned.  This probably indicates an
infinite recursion, unless you're writing strange benchmark programs, in
which case it indicates something else.</p>
<p>This threshold can be changed from 100, by recompiling the <i>perl</i> binary,
setting the C pre-processor macro <code class="inline"><span class="w">PERL_SUB_DEPTH_WARN</span></code>
 to the desired value.</p>
</li>
<li><a name="(%3f(DEFINE)....)-does-not-allow-branches-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>(?(DEFINE)....) does not allow branches in regex; marked by
&lt;-- HERE in m/%s/</b>
<p>(F) You used something like <code class="inline">(?(DEFINE)...|..)</code> which is illegal.  The
most likely cause of this error is that you left out a parenthesis inside
of the <code class="inline">....</code> part.</p>
<p>The &lt;-- HERE shows whereabouts in the regular expression the problem was
discovered.</p>
</li>
<li><a name="%25s-defines-neither-package-nor-VERSION--version-check-failed"></a><b>%s defines neither package nor VERSION--version check failed</b>
<p>(F) You said something like "use Module 42" but in the Module file
there are neither package declarations nor a <code class="inline"><span class="i">$VERSION</span></code>
.</p>
</li>
<li><a name="delete-argument-is-index%2fvalue-array-slice%2c-use-array-slice"></a><b>delete argument is index/value array slice, use array slice</b>
<p>(F) You used index/value array slice syntax (<code class="inline"><span class="i">%array</span>[...]</code>
) as
the argument to <code class="inline"><a class="l_k" href="functions/delete.html">delete</a></code>.  You probably meant <code class="inline"><span class="i">@array</span>[...]</code>
 with
an @ symbol instead.</p>
</li>
<li><a name="delete-argument-is-key%2fvalue-hash-slice%2c-use-hash-slice"></a><b>delete argument is key/value hash slice, use hash slice</b>
<p>(F) You used key/value hash slice syntax (<code class="inline"><span class="i">%hash</span>{...}</code>
) as the argument to
<code class="inline"><a class="l_k" href="functions/delete.html">delete</a></code>.  You probably meant <code class="inline"><span class="i">@hash</span>{...}</code>
 with an @ symbol instead.</p>
</li>
<li><a name="delete-argument-is-not-a-HASH-or-ARRAY-element-or-slice"></a><b>delete argument is not a HASH or ARRAY element or slice</b>
<p>(F) The argument to <code class="inline"><a class="l_k" href="functions/delete.html">delete</a></code> must be either a hash or array element,
such as:</p>
<pre class="verbatim"><ol><li>    $foo{$bar}</li><li>    $ref-&gt;{"susie"}[12]</li></ol></pre><p>or a hash or array slice, such as:</p>
<pre class="verbatim"><ol><li>    @foo[$bar, $baz, $xyzzy]</li><li>    @{$ref-&gt;[12]}{"susie", "queue"}</li></ol></pre></li>
<li><a name="Delimiter-for-here-document-is-too-long"></a><b>Delimiter for here document is too long</b>
<p>(F) In a here document construct like <code class="inline">&lt;&lt;FOO</code>, the label <code class="inline"><span class="w">FOO</span></code>
 is too
long for Perl to handle.  You have to be seriously twisted to write code
that triggers this error.</p>
</li>
<li><a name="Deprecated-use-of-my()-in-false-conditional.-This-will-be-a-fatal-error-in-Perl-5.30"></a><b>Deprecated use of my() in false conditional. This will be a fatal error in Perl 5.30</b>
<p>(D deprecated) You used a declaration similar to <code class="inline"><a class="l_k" href="functions/my.html">my</a> <span class="i">$x</span> if <span class="n">0</span></code>
.  There
has been a long-standing bug in Perl that causes a lexical variable
not to be cleared at scope exit when its declaration includes a false
conditional.  Some people have exploited this bug to achieve a kind of
static variable.  Since we intend to fix this bug, we don't want people
relying on this behavior.  You can achieve a similar static effect by
declaring the variable in a separate block outside the function, eg</p>
<pre class="verbatim"><ol><li><a name="f"></a>    sub <span class="m">f</span> <span class="s">{</span> <a class="l_k" href="functions/my.html">my</a> <span class="i">$x</span> if <span class="n">0</span><span class="sc">;</span> <a class="l_k" href="functions/return.html">return</a> <span class="i">$x</span>++ <span class="s">}</span></li></ol></pre><p>becomes</p>
<pre class="verbatim"><ol><li><a name="f"></a>    <span class="s">{</span> <a class="l_k" href="functions/my.html">my</a> <span class="i">$x</span><span class="sc">;</span> sub <span class="m">f</span> <span class="s">{</span> <a class="l_k" href="functions/return.html">return</a> <span class="i">$x</span>++ <span class="s">}</span> <span class="s">}</span></li></ol></pre><p>Beginning with perl 5.10.0, you can also use <code class="inline"><a class="l_k" href="functions/state.html">state</a></code> variables to have
lexicals that are initialized only once (see <a href="feature.html">feature</a>):</p>
<pre class="verbatim"><ol><li><a name="f"></a>    sub <span class="m">f</span> <span class="s">{</span> <span class="w">state</span> <span class="i">$x</span><span class="sc">;</span> <a class="l_k" href="functions/return.html">return</a> <span class="i">$x</span>++ <span class="s">}</span></li></ol></pre><p>This use of <code class="inline"><a class="l_k" href="functions/my.html">my()</a></code> in a false conditional has been deprecated since
Perl 5.10, and it will become a fatal error in Perl 5.30.</p>
</li>
<li><a name="DESTROY-created-new-reference-to-dead-object-'%25s'"></a><b>DESTROY created new reference to dead object '%s'</b>
<p>(F) A DESTROY() method created a new reference to the object which is
just being DESTROYed.  Perl is confused, and prefers to abort rather
than to create a dangling reference.</p>
</li>
<li><a name="Did-not-produce-a-valid-header"></a><b>Did not produce a valid header</b>
<p>See <a href="#500-Server-error">500 Server error</a>.</p>
</li>
<li><a name="%25s-did-not-return-a-true-value"></a><b>%s did not return a true value</b>
<p>(F) A required (or used) file must return a true value to indicate that
it compiled correctly and ran its initialization code correctly.  It's
traditional to end such a file with a "1;", though any true value would
do.  See <a href="functions/require.html">require</a>.</p>
</li>
<li><a name="(Did-you-mean-%26%25s-instead%3f)"></a><b>(Did you mean &amp;%s instead?)</b>
<p>(W misc) You probably referred to an imported subroutine &amp;FOO as $FOO or
some such.</p>
</li>
<li><a name="(Did-you-mean-%22local%22-instead-of-%22our%22%3f)"></a><b>(Did you mean "local" instead of "our"?)</b>
<p>(W misc) Remember that "our" does not localize the declared global
variable.  You have declared it again in the same lexical scope, which
seems superfluous.</p>
</li>
<li><a name="(Did-you-mean-%24-or-%40-instead-of-%25%3f)"></a><b>(Did you mean $ or @ instead of %?)</b>
<p>(W) You probably said %hash{$key} when you meant $hash{$key} or
@hash{@keys}.  On the other hand, maybe you just meant %hash and got
carried away.</p>
</li>
<li><a name="Died"></a><b>Died</b>
<p>(F) You passed die() an empty string (the equivalent of <code class="inline"><a class="l_k" href="functions/die.html">die</a> <span class="q">&quot;&quot;</span></code>
) or
you called it with no args and <code class="inline"><span class="i">$@</span></code>
 was empty.</p>
</li>
<li><a name="Document-contains-no-data"></a><b>Document contains no data</b>
<p>See <a href="#500-Server-error">500 Server error</a>.</p>
</li>
<li><a name="%25s-does-not-define-%25s%3a%3aVERSION--version-check-failed"></a><b>%s does not define %s::VERSION--version check failed</b>
<p>(F) You said something like "use Module 42" but the Module did not
define a <code class="inline"><span class="i">$VERSION</span></code>
.</p>
</li>
<li><a name="'%2f'-does-not-take-a-repeat-count"></a><b>'/' does not take a repeat count</b>
<p>(F) You cannot put a repeat count of any kind right after the '/' code.
See <a href="functions/pack.html">pack</a>.</p>
</li>
<li><a name="do-%22%25s%22-failed%2c-'.'-is-no-longer-in-%40INC%3b-did-you-mean-do-%22.%2f%25s%22%3f"></a><b>do "%s" failed, '.' is no longer in @INC; did you mean do "./%s"?</b>
<p>(D deprecated) Previously <code class="inline"> <a class="l_k" href="functions/do.html">do</a> <span class="q">&quot;somefile&quot;</span><span class="sc">;</span> </code>
 would search the current
directory for the specified file.  Since perl v5.26.0, <i>.</i> has been
removed from <code class="inline"><span class="i">@INC</span></code>
 by default, so this is no longer true.  To search the
current directory (and only the current directory) you can write
<code class="inline"> <a class="l_k" href="functions/do.html">do</a> <span class="q">&quot;./somefile&quot;</span><span class="sc">;</span> </code>
.</p>
</li>
<li><a name="Don't-know-how-to-get-file-name"></a><b>Don't know how to get file name</b>
<p>(P) <code class="inline"><span class="w">PerlIO_getname</span></code>
, a perl internal I/O function specific to VMS, was
somehow called on another platform.  This should not happen.</p>
</li>
<li><a name="Don't-know-how-to-handle-magic-of-type-%5c%25o"></a><b>Don't know how to handle magic of type \%o</b>
<p>(P) The internal handling of magical variables has been cursed.</p>
</li>
<li><a name="do_study%3a-out-of-memory"></a><b>do_study: out of memory</b>
<p>(P) This should have been caught by safemalloc() instead.</p>
</li>
<li><a name="(Do-you-need-to-predeclare-%25s%3f)"></a><b>(Do you need to predeclare %s?)</b>
<p>(S syntax) This is an educated guess made in conjunction with the message
"%s found where operator expected".  It often means a subroutine or module
name is being referenced that hasn't been declared yet.  This may be
because of ordering problems in your file, or because of a missing
"sub", "package", "require", or "use" statement.  If you're referencing
something that isn't defined yet, you don't actually have to define the
subroutine or package before the current location.  You can use an empty
"sub foo;" or "package FOO;" to enter a "forward" declaration.</p>
</li>
<li><a name="dump()-better-written-as-CORE%3a%3adump().-dump()-will-no-longer-be-available-in-Perl-5.30"></a><b>dump() better written as CORE::dump(). dump() will no longer be available in Perl 5.30</b>
<p>(D deprecated, misc) You used the obsolescent <code class="inline"><a class="l_k" href="functions/dump.html">dump()</a></code> built-in function,
without fully qualifying it as <code class="inline"><span class="i">CORE::dump</span><span class="s">(</span><span class="s">)</span></code>
. Maybe it's a typo.</p>
<p>Use of a unqualified <code class="inline"><a class="l_k" href="functions/dump.html">dump()</a></code> was deprecated in Perl 5.8.0, and this
will not be available in Perl 5.30.</p>
<p>See <a href="functions/dump.html">dump</a>.</p>
</li>
<li><a name="dump-is-not-supported"></a><b>dump is not supported</b>
<p>(F) Your machine doesn't support dump/undump.</p>
</li>
<li><a name="Duplicate-free()-ignored"></a><b>Duplicate free() ignored</b>
<p>(S malloc) An internal routine called free() on something that had
already been freed.</p>
</li>
<li><a name="Duplicate-modifier-'%25c'-after-'%25c'-in-%25s"></a><b>Duplicate modifier '%c' after '%c' in %s</b>
<p>(W unpack) You have applied the same modifier more than once after a
type in a pack template.  See <a href="functions/pack.html">pack</a>.</p>
</li>
<li><a name="elseif-should-be-elsif"></a><b>elseif should be elsif</b>
<p>(S syntax) There is no keyword "elseif" in Perl because Larry thinks
it's ugly.  Your code will be interpreted as an attempt to call a method
named "elseif" for the class returned by the following block.  This is
unlikely to be what you want.</p>
</li>
<li><a name="Empty-%5c%25c-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>Empty \%c in regex; marked by &lt;-- HERE in m/%s/</b>
</li>
<li><a name="Empty-%5c%25c%7b%7d-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>Empty \%c{} in regex; marked by &lt;-- HERE in m/%s/</b>
<p>(F) <code class="inline">\<span class="w">p</span></code>
 and <code class="inline">\<span class="w">P</span></code>
 are used to introduce a named Unicode property, as
described in <a href="perlunicode.html">perlunicode</a> and <a href="perlre.html">perlre</a>.  You used <code class="inline">\<span class="w">p</span></code>
 or <code class="inline">\<span class="w">P</span></code>
 in
a regular expression without specifying the property name.</p>
</li>
<li><a name="%24%7b%5eENCODING%7d-is-no-longer-supported.-Its-use-will-be-fatal-in-Perl-5.28"></a><b>${^ENCODING} is no longer supported. Its use will be fatal in Perl 5.28</b>
<p>(D deprecated) The special variable <code class="inline"><span class="i">$</span>{<span class="w">^ENCODING</span>}</code>
, formerly used to implement
the <code class="inline"><span class="w">encoding</span></code>
 pragma, is no longer supported as of Perl 5.26.0.</p>
<p>Setting this variable will become a fatal error in Perl 5.28.</p>
</li>
<li><a name="entering-effective-%25s-failed"></a><b>entering effective %s failed</b>
<p>(F) While under the <code class="inline"><a class="l_k" href="functions/use.html">use</a> <span class="w">filetest</span></code>
 pragma, switching the real and
effective uids or gids failed.</p>
</li>
<li><a name="%25ENV-is-aliased-to-%25s"></a><b>%ENV is aliased to %s</b>
<p>(F) You're running under taint mode, and the <code class="inline"><span class="i">%ENV</span></code>
 variable has been
aliased to another hash, so it doesn't reflect anymore the state of the
program's environment.  This is potentially insecure.</p>
</li>
<li><a name="Error-converting-file-specification-%25s"></a><b>Error converting file specification %s</b>
<p>(F) An error peculiar to VMS.  Because Perl may have to deal with file
specifications in either VMS or Unix syntax, it converts them to a
single form when it must operate on them directly.  Either you've passed
an invalid file specification to Perl, or you've found a case the
conversion routines don't handle.  Drat.</p>
</li>
<li><a name="Eval-group-in-insecure-regular-expression"></a><b>Eval-group in insecure regular expression</b>
<p>(F) Perl detected tainted data when trying to compile a regular
expression that contains the <code class="inline">(?{ ... })</code> zero-width assertion, which
is unsafe.  See <a href="perlre.html#(%3f%7b-code-%7d)">(?{ code }) in perlre</a>, and <a href="perlsec.html">perlsec</a>.</p>
</li>
<li><a name="Eval-group-not-allowed-at-runtime%2c-use-re-'eval'-in-regex-m%2f%25s%2f"></a><b>Eval-group not allowed at runtime, use re 'eval' in regex m/%s/</b>
<p>(F) Perl tried to compile a regular expression containing the
<code class="inline">(?{ ... })</code> zero-width assertion at run time, as it would when the
pattern contains interpolated values.  Since that is a security risk,
it is not allowed.  If you insist, you may still do this by using the
<code class="inline"><span class="w">re</span> <span class="q">&#39;eval&#39;</span></code>
 pragma or by explicitly building the pattern from an
interpolated string at run time and using that in an eval().  See
<a href="perlre.html#(%3f%7b-code-%7d)">(?{ code }) in perlre</a>.</p>
</li>
<li><a name="Eval-group-not-allowed%2c-use-re-'eval'-in-regex-m%2f%25s%2f"></a><b>Eval-group not allowed, use re 'eval' in regex m/%s/</b>
<p>(F) A regular expression contained the <code class="inline">(?{ ... })</code> zero-width
assertion, but that construct is only allowed when the <code class="inline"><a class="l_k" href="functions/use.html">use</a> <span class="w">re</span> <span class="q">&#39;eval&#39;</span></code>

pragma is in effect.  See <a href="perlre.html#(%3f%7b-code-%7d)">(?{ code }) in perlre</a>.</p>
</li>
<li><a name="EVAL-without-pos-change-exceeded-limit-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>EVAL without pos change exceeded limit in regex; marked by
&lt;-- HERE in m/%s/</b>
<p>(F) You used a pattern that nested too many EVAL calls without consuming
any text.  Restructure the pattern so that text is consumed.</p>
<p>The &lt;-- HERE shows whereabouts in the regular expression the problem was
discovered.</p>
</li>
<li><a name="Excessively-long-%3c%3e-operator"></a><b>Excessively long &lt;&gt; operator</b>
<p>(F) The contents of a &lt;&gt; operator may not exceed the maximum size of a
Perl identifier.  If you're just trying to glob a long list of
filenames, try using the glob() operator, or put the filenames into a
variable and glob that.</p>
</li>
<li><a name="exec%3f-I'm-not-*that*-kind-of-operating-system"></a><b>exec? I'm not *that* kind of operating system</b>
<p>(F) The <code class="inline"><a class="l_k" href="functions/exec.html">exec</a></code> function is not implemented on some systems, e.g., Symbian
OS.  See <a href="perlport.html">perlport</a>.</p>
</li>
<li><a name="%25sExecution-of-%25s-aborted-due-to-compilation-errors."></a><b>%sExecution of %s aborted due to compilation errors.</b>
<p>(F) The final summary message when a Perl compilation fails.</p>
</li>
<li><a name="exists-argument-is-not-a-HASH-or-ARRAY-element-or-a-subroutine"></a><b>exists argument is not a HASH or ARRAY element or a subroutine</b>
<p>(F) The argument to <code class="inline"><a class="l_k" href="functions/exists.html">exists</a></code> must be a hash or array element or a
subroutine with an ampersand, such as:</p>
<pre class="verbatim"><ol><li>    $foo{$bar}</li><li>    $ref-&gt;{"susie"}[12]</li><li>    &amp;do_something</li></ol></pre></li>
<li><a name="exists-argument-is-not-a-subroutine-name"></a><b>exists argument is not a subroutine name</b>
<p>(F) The argument to <code class="inline"><a class="l_k" href="functions/exists.html">exists</a></code> for <code class="inline"><a class="l_k" href="functions/exists.html">exists</a> <span class="i">&amp;sub</span></code>
 must be a subroutine name,
and not a subroutine call.  <code class="inline"><a class="l_k" href="functions/exists.html">exists</a> <span class="i">&amp;sub</span><span class="s">(</span><span class="s">)</span></code>
 will generate this error.</p>
</li>
<li><a name="Exiting-eval-via-%25s"></a><b>Exiting eval via %s</b>
<p>(W exiting) You are exiting an eval by unconventional means, such as a
goto, or a loop control statement.</p>
</li>
<li><a name="Exiting-format-via-%25s"></a><b>Exiting format via %s</b>
<p>(W exiting) You are exiting a format by unconventional means, such as a
goto, or a loop control statement.</p>
</li>
<li><a name="Exiting-pseudo-block-via-%25s"></a><b>Exiting pseudo-block via %s</b>
<p>(W exiting) You are exiting a rather special block construct (like a
sort block or subroutine) by unconventional means, such as a goto, or a
loop control statement.  See <a href="functions/sort.html">sort</a>.</p>
</li>
<li><a name="Exiting-subroutine-via-%25s"></a><b>Exiting subroutine via %s</b>
<p>(W exiting) You are exiting a subroutine by unconventional means, such
as a goto, or a loop control statement.</p>
</li>
<li><a name="Exiting-substitution-via-%25s"></a><b>Exiting substitution via %s</b>
<p>(W exiting) You are exiting a substitution by unconventional means, such
as a return, a goto, or a loop control statement.</p>
</li>
<li><a name="Expecting-close-bracket-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>Expecting close bracket in regex; marked by &lt;-- HERE in m/%s/</b>
<p>(F) You wrote something like</p>
<pre class="verbatim"><ol><li> <span class="s">(</span><span class="q">?13</span></li></ol></pre><p>to denote a capturing group of the form
<a href="perlre.html#(%3fPARNO)-(%3f-PARNO)-(%3f%2bPARNO)-(%3fR)-(%3f0)">(?PARNO)</a>,
but omitted the <code class="inline"><span class="q">&quot;)&quot;</span></code>
.</p>
</li>
<li><a name="Expecting-'(%3fflags%3a(%3f%5b...'-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>Expecting '(?flags:(?[...' in regex; marked by &lt;-- HERE in m/%s/</b>
<p>(F) The <code class="inline"><span class="s">(</span><span class="q">?[...])</span></code>
 extended character class regular expression construct
only allows character classes (including character class escapes like
<code class="inline">\<span class="w">d</span></code>
), operators, and parentheses.  The one exception is <code class="inline"><span class="s">(</span><span class="q">?flags:...)</span></code>

containing at least one flag and exactly one <code class="inline"><span class="s">(</span><span class="q">?[...])</span></code>
 construct.
This allows a regular expression containing just <code class="inline"><span class="s">(</span><span class="q">?[...])</span></code>
 to be
interpolated.  If you see this error message, then you probably
have some other <code class="inline">(?...)</code> construct inside your character class.  See
<a href="perlrecharclass.html#Extended-Bracketed-Character-Classes">Extended Bracketed Character Classes in perlrecharclass</a>.</p>
</li>
<li><a name="Experimental-aliasing-via-reference-not-enabled"></a><b>Experimental aliasing via reference not enabled</b>
<p>(F) To do aliasing via references, you must first enable the feature:</p>
<pre class="verbatim"><ol><li>    <a class="l_k" href="functions/no.html">no</a> <span class="w">warnings</span> <span class="q">&quot;experimental::refaliasing&quot;</span><span class="sc">;</span></li><li>    <a class="l_k" href="functions/use.html">use</a> <span class="w">feature</span> <span class="q">&quot;refaliasing&quot;</span><span class="sc">;</span></li><li>    \<span class="i">$x</span> = \<span class="i">$y</span><span class="sc">;</span></li></ol></pre></li>
<li><a name="Experimental-%25s-on-scalar-is-now-forbidden"></a><b>Experimental %s on scalar is now forbidden</b>
<p>(F) An experimental feature added in Perl 5.14 allowed <code class="inline"><a class="l_k" href="functions/each.html">each</a></code>, <code class="inline"><a class="l_k" href="functions/keys.html">keys</a></code>,
<code class="inline"><a class="l_k" href="functions/push.html">push</a></code>, <code class="inline"><a class="l_k" href="functions/pop.html">pop</a></code>, <code class="inline"><a class="l_k" href="functions/shift.html">shift</a></code>, <code class="inline"><a class="l_k" href="functions/splice.html">splice</a></code>, <code class="inline"><a class="l_k" href="functions/unshift.html">unshift</a></code>, and <code class="inline"><a class="l_k" href="functions/values.html">values</a></code> to be called with a
scalar argument.  This experiment is considered unsuccessful, and
has been removed.  The <code class="inline"><span class="w">postderef</span></code>
 feature may meet your needs better.</p>
</li>
<li><a name="Experimental-subroutine-signatures-not-enabled"></a><b>Experimental subroutine signatures not enabled</b>
<p>(F) To use subroutine signatures, you must first enable them:</p>
<pre class="verbatim"><ol><li>    <a class="l_k" href="functions/no.html">no</a> <span class="w">warnings</span> <span class="q">&quot;experimental::signatures&quot;</span><span class="sc">;</span></li><li>    <a class="l_k" href="functions/use.html">use</a> <span class="w">feature</span> <span class="q">&quot;signatures&quot;</span><span class="sc">;</span></li><li><a name="foo"></a>    sub <span class="m">foo ($left, $right)</span> <span class="s">{</span> ... <span class="s">}</span></li></ol></pre></li>
<li><a name="Explicit-blessing-to-''-(assuming-package-main)"></a><b>Explicit blessing to '' (assuming package main)</b>
<p>(W misc) You are blessing a reference to a zero length string.  This has
the effect of blessing the reference into the package main.  This is
usually not what you want.  Consider providing a default target package,
e.g. bless($ref, $p || 'MyPackage');</p>
</li>
<li><a name="%25s%3a-Expression-syntax"></a><b>%s: Expression syntax</b>
<p>(A) You've accidentally run your script through <b>csh</b> instead of Perl.
Check the #! line, or manually feed your script into Perl yourself.</p>
</li>
<li><a name="%25s-failed--call-queue-aborted"></a><b>%s failed--call queue aborted</b>
<p>(F) An untrapped exception was raised while executing a UNITCHECK,
CHECK, INIT, or END subroutine.  Processing of the remainder of the
queue of such routines has been prematurely ended.</p>
</li>
<li><a name="Failed-to-close-in-place-edit-file-%25s%3a-%25s"></a><b>Failed to close in-place edit file %s: %s</b>
<p>(F) Closing an output file from in-place editing, as with the <code class="inline">-<span class="w">i</span></code>

command-line switch, failed.</p>
</li>
<li><a name="False-%5b%5d-range-%22%25s%22-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>False [] range "%s" in regex; marked by &lt;-- HERE in m/%s/</b>
<p>(W regexp)(F) A character class range must start and end at a literal
character, not another character class like <code class="inline">\<span class="w">d</span></code>
 or <code class="inline">[:alpha:]</code>.  The "-"
in your false range is interpreted as a literal "-".  In a <code class="inline"><span class="s">(</span><span class="q">?[...])</span></code>

construct, this is an error, rather than a warning.  Consider quoting
the "-", "\-".  The &lt;-- HERE shows whereabouts in the regular expression
the problem was discovered.  See <a href="perlre.html">perlre</a>.</p>
</li>
<li><a name="Fatal-VMS-error-(status%3d%25d)-at-%25s%2c-line-%25d"></a><b>Fatal VMS error (status=%d) at %s, line %d</b>
<p>(P) An error peculiar to VMS.  Something untoward happened in a VMS
system service or RTL routine; Perl's exit status should provide more
details.  The filename in "at %s" and the line number in "line %d" tell
you which section of the Perl source code is distressed.</p>
</li>
<li><a name="fcntl-is-not-implemented"></a><b>fcntl is not implemented</b>
<p>(F) Your machine apparently doesn't implement fcntl().  What is this, a
PDP-11 or something?</p>
</li>
<li><a name="FETCHSIZE-returned-a-negative-value"></a><b>FETCHSIZE returned a negative value</b>
<p>(F) A tied array claimed to have a negative number of elements, which
is not possible.</p>
</li>
<li><a name="Field-too-wide-in-'u'-format-in-pack"></a><b>Field too wide in 'u' format in pack</b>
<p>(W pack) Each line in an uuencoded string starts with a length indicator
which can't encode values above 63.  So there is no point in asking for
a line length bigger than that.  Perl will behave as if you specified
<code class="inline"><span class="w">u63</span></code>
 as the format.</p>
</li>
<li><a name="File%3a%3aGlob%3a%3aglob()-will-disappear-in-perl-5.30.-Use-File%3a%3aGlob%3a%3absd_glob()-instead."></a><b>File::Glob::glob() will disappear in perl 5.30. Use File::Glob::bsd_glob() instead.</b>
<p>(D deprecated) <code class="inline"><span class="w">File::Glob</span></code>
 has a function called <code class="inline"><a class="l_k" href="functions/glob.html">glob</a></code>, which
just calls <code class="inline"><span class="w">bsd_glob</span></code>
. However, its prototype is different from the
prototype of <code class="inline"><span class="w">CORE::glob</span></code>
, and hence, <code class="inline"><span class="w">File::Glob::glob</span></code>
 should
not be used.</p>
<p><code class="inline"><span class="i">File::Glob::glob</span><span class="s">(</span><span class="s">)</span></code>
 was deprecated in perl 5.8.0. A deprecation
message was issued from perl 5.26.0 onwards, and the function will
disappear in perl 5.30.0.</p>
<p>Code using <code class="inline"><span class="i">File::Glob::glob</span><span class="s">(</span><span class="s">)</span></code>
 should call
<code class="inline"><span class="i">File::Glob::bsd_glob</span><span class="s">(</span><span class="s">)</span></code>
 instead.</p>
</li>
<li><a name="Filehandle-%25s-opened-only-for-input"></a><b>Filehandle %s opened only for input</b>
<p>(W io) You tried to write on a read-only filehandle.  If you intended
it to be a read-write filehandle, you needed to open it with "+&lt;" or
"+&gt;" or "+&gt;&gt;" instead of with "&lt;" or nothing.  If you intended only to
write the file, use "&gt;" or "&gt;&gt;".  See <a href="functions/open.html">open</a>.</p>
</li>
<li><a name="Filehandle-%25s-opened-only-for-output"></a><b>Filehandle %s opened only for output</b>
<p>(W io) You tried to read from a filehandle opened only for writing, If
you intended it to be a read/write filehandle, you needed to open it
with "+&lt;" or "+&gt;" or "+&gt;&gt;" instead of with "&gt;".  If you intended only to
read from the file, use "&lt;".  See <a href="functions/open.html">open</a>.  Another possibility
is that you attempted to open filedescriptor 0 (also known as STDIN) for
output (maybe you closed STDIN earlier?).</p>
</li>
<li><a name="Filehandle-%25s-reopened-as-%25s-only-for-input"></a><b>Filehandle %s reopened as %s only for input</b>
<p>(W io) You opened for reading a filehandle that got the same filehandle id
as STDOUT or STDERR.  This occurred because you closed STDOUT or STDERR
previously.</p>
</li>
<li><a name="Filehandle-STDIN-reopened-as-%25s-only-for-output"></a><b>Filehandle STDIN reopened as %s only for output</b>
<p>(W io) You opened for writing a filehandle that got the same filehandle id
as STDIN.  This occurred because you closed STDIN previously.</p>
</li>
<li><a name="Final-%24-should-be-%5c%24-or-%24name"></a><b>Final $ should be \$ or $name</b>
<p>(F) You must now decide whether the final $ in a string was meant to be
a literal dollar sign, or was meant to introduce a variable name that
happens to be missing.  So you have to put either the backslash or the
name.</p>
</li>
<li><a name="flock()-on-closed-filehandle-%25s"></a><b>flock() on closed filehandle %s</b>
<p>(W closed) The filehandle you're attempting to flock() got itself closed
some time before now.  Check your control flow.  flock() operates on
filehandles.  Are you attempting to call flock() on a dirhandle by the
same name?</p>
</li>
<li><a name="Format-not-terminated"></a><b>Format not terminated</b>
<p>(F) A format must be terminated by a line with a solitary dot.  Perl got
to the end of your file without finding such a line.</p>
</li>
<li><a name="Format-%25s-redefined"></a><b>Format %s redefined</b>
<p>(W redefine) You redefined a format.  To suppress this warning, say</p>
<pre class="verbatim"><ol><li>    <span class="s">{</span></li><li>	<a class="l_k" href="functions/no.html">no</a> <span class="w">warnings</span> <span class="q">&#39;redefine&#39;</span><span class="sc">;</span></li><li>	<a class="l_k" href="functions/eval.html">eval</a> <span class="q">&quot;format NAME =...&quot;</span><span class="sc">;</span></li><li>    <span class="s">}</span></li></ol></pre></li>
<li><a name="Found-%3d-in-conditional%2c-should-be-%3d%3d"></a><b>Found = in conditional, should be ==</b>
<p>(W syntax) You said</p>
<pre class="verbatim"><ol><li>    if <span class="s">(</span><span class="i">$foo</span> = <span class="n">123</span><span class="s">)</span></li></ol></pre><p>when you meant</p>
<pre class="verbatim"><ol><li>    if <span class="s">(</span><span class="i">$foo</span> == <span class="n">123</span><span class="s">)</span></li></ol></pre><p>(or something like that).</p>
</li>
<li><a name="%25s-found-where-operator-expected"></a><b>%s found where operator expected</b>
<p>(S syntax) The Perl lexer knows whether to expect a term or an operator.
If it sees what it knows to be a term when it was expecting to see an
operator, it gives you this warning.  Usually it indicates that an
operator or delimiter was omitted, such as a semicolon.</p>
</li>
<li><a name="gdbm-store-returned-%25d%2c-errno-%25d%2c-key-%22%25s%22"></a><b>gdbm store returned %d, errno %d, key "%s"</b>
<p>(S) A warning from the GDBM_File extension that a store failed.</p>
</li>
<li><a name="gethostent-not-implemented"></a><b>gethostent not implemented</b>
<p>(F) Your C library apparently doesn't implement gethostent(), probably
because if it did, it'd feel morally obligated to return every hostname
on the Internet.</p>
</li>
<li><a name="get%25sname()-on-closed-socket-%25s"></a><b>get%sname() on closed socket %s</b>
<p>(W closed) You tried to get a socket or peer socket name on a closed
socket.  Did you forget to check the return value of your socket() call?</p>
</li>
<li><a name="getpwnam-returned-invalid-UIC-%25%23o-for-user-%22%25s%22"></a><b>getpwnam returned invalid UIC %#o for user "%s"</b>
<p>(S) A warning peculiar to VMS.  The call to <code class="inline"><span class="w">sys</span><span class="i">$getuai</span></code>
 underlying the
<code class="inline"><a class="l_k" href="functions/getpwnam.html">getpwnam</a></code> operator returned an invalid UIC.</p>
</li>
<li><a name="getsockopt()-on-closed-socket-%25s"></a><b>getsockopt() on closed socket %s</b>
<p>(W closed) You tried to get a socket option on a closed socket.  Did you
forget to check the return value of your socket() call?  See
<a href="functions/getsockopt.html">getsockopt</a>.</p>
</li>
<li><a name="given-is-experimental"></a><b>given is experimental</b>
<p>(S experimental::smartmatch) <code class="inline">given</code>
 depends on smartmatch, which
is experimental, so its behavior may change or even be removed
in any future release of perl.  See the explanation under
<a href="perlsyn.html#Experimental-Details-on-given-and-when">Experimental Details on given and when in perlsyn</a>.</p>
</li>
<li><a name="Global-symbol-%22%25s%22-requires-explicit-package-name-(did-you-forget-to-declare-%22my-%25s%22%3f)"></a><b>Global symbol "%s" requires explicit package name (did you forget to
declare "my %s"?)</b>
<p>(F) You've said "use strict" or "use strict vars", which indicates 
that all variables must either be lexically scoped (using "my" or "state"), 
declared beforehand using "our", or explicitly qualified to say 
which package the global variable is in (using "::").</p>
</li>
<li><a name="glob-failed-(%25s)"></a><b>glob failed (%s)</b>
<p>(S glob) Something went wrong with the external program(s) used
for <code class="inline"><a class="l_k" href="functions/glob.html">glob</a></code> and <code class="inline"><span class="q">&lt;*.c&gt;</span></code>
.  Usually, this means that you supplied a <code class="inline"><a class="l_k" href="functions/glob.html">glob</a></code>
pattern that caused the external program to fail and exit with a
nonzero status.  If the message indicates that the abnormal exit
resulted in a coredump, this may also mean that your csh (C shell)
is broken.  If so, you should change all of the csh-related variables
in config.sh:  If you have tcsh, make the variables refer to it as
if it were csh (e.g. <code class="inline"><span class="w">full_csh</span>=<span class="q">&#39;/usr/bin/tcsh&#39;</span></code>
); otherwise, make them
all empty (except that <code class="inline"><span class="w">d_csh</span></code>
 should be <code class="inline"><span class="q">&#39;undef&#39;</span></code>
) so that Perl will
think csh is missing.  In either case, after editing config.sh, run
<code class="inline">./Configure -S</code> and rebuild Perl.</p>
</li>
<li><a name="Glob-not-terminated"></a><b>Glob not terminated</b>
<p>(F) The lexer saw a left angle bracket in a place where it was expecting
a term, so it's looking for the corresponding right angle bracket, and
not finding it.  Chances are you left some needed parentheses out
earlier in the line, and you really meant a "less than".</p>
</li>
<li><a name="gmtime(%25f)-failed"></a><b>gmtime(%f) failed</b>
<p>(W overflow) You called <code class="inline"><a class="l_k" href="functions/gmtime.html">gmtime</a></code> with a number that it could not handle:
too large, too small, or NaN.  The returned value is <code class="inline"><a class="l_k" href="functions/undef.html">undef</a></code>.</p>
</li>
<li><a name="gmtime(%25f)-too-large"></a><b>gmtime(%f) too large</b>
<p>(W overflow) You called <code class="inline"><a class="l_k" href="functions/gmtime.html">gmtime</a></code> with a number that was larger than
it can reliably handle and <code class="inline"><a class="l_k" href="functions/gmtime.html">gmtime</a></code> probably returned the wrong
date.  This warning is also triggered with NaN (the special
not-a-number value).</p>
</li>
<li><a name="gmtime(%25f)-too-small"></a><b>gmtime(%f) too small</b>
<p>(W overflow) You called <code class="inline"><a class="l_k" href="functions/gmtime.html">gmtime</a></code> with a number that was smaller than
it can reliably handle and <code class="inline"><a class="l_k" href="functions/gmtime.html">gmtime</a></code> probably returned the wrong date.</p>
</li>
<li><a name="Got-an-error-from-DosAllocMem"></a><b>Got an error from DosAllocMem</b>
<p>(P) An error peculiar to OS/2.  Most probably you're using an obsolete
version of Perl, and this should not happen anyway.</p>
</li>
<li><a name="goto-must-have-label"></a><b>goto must have label</b>
<p>(F) Unlike with "next" or "last", you're not allowed to goto an
unspecified destination.  See <a href="functions/goto.html">goto</a>.</p>
</li>
<li><a name="Goto-undefined-subroutine%25s"></a><b>Goto undefined subroutine%s</b>
<p>(F) You tried to call a subroutine with <code class="inline"><a class="l_k" href="functions/goto.html">goto</a> <span class="i">&amp;sub</span></code>
 syntax, but
the indicated subroutine hasn't been defined, or if it was, it
has since been undefined.</p>
</li>
<li><a name="Group-name-must-start-with-a-non-digit-word-character-in-regex%3b-marked-by--%3c---HERE-in-m%2f%25s%2f"></a><b>Group name must start with a non-digit word character in regex; marked by 
&lt;-- HERE in m/%s/</b>
<p>(F) Group names must follow the rules for perl identifiers, meaning
they must start with a non-digit word character.  A common cause of
this error is using (?&amp;0) instead of (?0).  See <a href="perlre.html">perlre</a>.</p>
</li>
<li><a name="()-group-starts-with-a-count"></a><b>()-group starts with a count</b>
<p>(F) A ()-group started with a count.  A count is supposed to follow
something: a template character or a ()-group.  See <a href="functions/pack.html">pack</a>.</p>
</li>
<li><a name="%25s-had-compilation-errors."></a><b>%s had compilation errors.</b>
<p>(F) The final summary message when a <code class="inline"><span class="w">perl</span> -c</code>
 fails.</p>
</li>
<li><a name="Had-to-create-%25s-unexpectedly"></a><b>Had to create %s unexpectedly</b>
<p>(S internal) A routine asked for a symbol from a symbol table that ought
to have existed already, but for some reason it didn't, and had to be
created on an emergency basis to prevent a core dump.</p>
</li>
<li><a name="%25s-has-too-many-errors"></a><b>%s has too many errors</b>
<p>(F) The parser has given up trying to parse the program after 10 errors.
Further error messages would likely be uninformative.</p>
</li>
<li><a name="Hexadecimal-float%3a-exponent-overflow"></a><b>Hexadecimal float: exponent overflow</b>
<p>(W overflow) The hexadecimal floating point has a larger exponent
than the floating point supports.</p>
</li>
<li><a name="Hexadecimal-float%3a-exponent-underflow"></a><b>Hexadecimal float: exponent underflow</b>
<p>(W overflow) The hexadecimal floating point has a smaller exponent
than the floating point supports.  With the IEEE 754 floating point,
this may also mean that the subnormals (formerly known as denormals)
are being used, which may or may not be an error.</p>
</li>
<li><a name="Hexadecimal-float%3a-internal-error-(%25s)"></a><b>Hexadecimal float: internal error (%s)</b>
<p>(F) Something went horribly bad in hexadecimal float handling.</p>
</li>
<li><a name="Hexadecimal-float%3a-mantissa-overflow"></a><b>Hexadecimal float: mantissa overflow</b>
<p>(W overflow) The hexadecimal floating point literal had more bits in
the mantissa (the part between the 0x and the exponent, also known as
the fraction or the significand) than the floating point supports.</p>
</li>
<li><a name="Hexadecimal-float%3a-precision-loss"></a><b>Hexadecimal float: precision loss</b>
<p>(W overflow) The hexadecimal floating point had internally more
digits than could be output.  This can be caused by unsupported
long double formats, or by 64-bit integers not being available
(needed to retrieve the digits under some configurations).</p>
</li>
<li><a name="Hexadecimal-float%3a-unsupported-long-double-format"></a><b>Hexadecimal float: unsupported long double format</b>
<p>(F) You have configured Perl to use long doubles but
the internals of the long double format are unknown;
therefore the hexadecimal float output is impossible.</p>
</li>
<li><a name="Hexadecimal-number-%3e-0xffffffff-non-portable"></a><b>Hexadecimal number &gt; 0xffffffff non-portable</b>
<p>(W portable) The hexadecimal number you specified is larger than 2**32-1
(4294967295) and therefore non-portable between systems.  See
<a href="perlport.html">perlport</a> for more on portability concerns.</p>
</li>
<li><a name="Identifier-too-long"></a><b>Identifier too long</b>
<p>(F) Perl limits identifiers (names for variables, functions, etc.) to
about 250 characters for simple names, and somewhat more for compound
names (like <code class="inline"><span class="i">$A::B</span></code>
).  You've exceeded Perl's limits.  Future versions
of Perl are likely to eliminate these arbitrary limitations.</p>
</li>
<li><a name="Ignoring-zero-length-%5cN%7b%7d-in-character-class-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>Ignoring zero length \N{} in character class in regex; marked by
&lt;-- HERE in m/%s/</b>
<p>(W regexp) Named Unicode character escapes (<code class="inline">\<span class="i">N</span><span class="s">{</span>...<span class="s">}</span></code>
) may return a
zero-length sequence.  When such an escape is used in a character
class its behavior is not well defined.  Check that the correct
escape has been used, and the correct charname handler is in scope.</p>
</li>
<li><a name="Illegal-binary-digit-%25s"></a><b>Illegal binary digit %s</b>
<p>(F) You used a digit other than 0 or 1 in a binary number.</p>
</li>
<li><a name="Illegal-binary-digit-%25s-ignored"></a><b>Illegal binary digit %s ignored</b>
<p>(W digit) You may have tried to use a digit other than 0 or 1 in a
binary number.  Interpretation of the binary number stopped before the
offending digit.</p>
</li>
<li><a name="Illegal-character-after-'_'-in-prototype-for-%25s-%3a-%25s"></a><b>Illegal character after '_' in prototype for %s : %s</b>
<p>(W illegalproto) An illegal character was found in a prototype
declaration.  The '_' in a prototype must be followed by a ';',
indicating the rest of the parameters are optional, or one of '@'
or '%', since those two will accept 0 or more final parameters.</p>
</li>
<li><a name="Illegal-character-%5c%25o-(carriage-return)"></a><b>Illegal character \%o (carriage return)</b>
<p>(F) Perl normally treats carriage returns in the program text as
it would any other whitespace, which means you should never see
this error when Perl was built using standard options.  For some
reason, your version of Perl appears to have been built without
this support.  Talk to your Perl administrator.</p>
</li>
<li><a name="Illegal-character-following-sigil-in-a-subroutine-signature"></a><b>Illegal character following sigil in a subroutine signature</b>
<p>(F) A parameter in a subroutine signature contained an unexpected character
following the <code class="inline"><span class="i">$</span></code>
, <code class="inline"><span class="i">@</span></code>
 or <code class="inline"><span class="i">%</span></code>
 sigil character.  Normally the sigil
should be followed by the variable name or <code class="inline">=</code>
 etc.  Perhaps you are
trying use a prototype while in the scope of <code class="inline"><a class="l_k" href="functions/use.html">use</a> <span class="w">feature</span> <span class="q">&#39;signatures&#39;</span></code>
?
For example:</p>
<pre class="verbatim"><ol><li><a name="foo"></a>    sub <span class="m">foo ($$)</span> <span class="s">{</span><span class="s">}</span>            <span class="c"># legal - a prototype</span></li><li></li><li>    <a class="l_k" href="functions/use.html">use</a> <span class="w">feature</span> <span class="q">&#39;signatures;</span></li><li>    <span class="q">    sub foo ($$) {}            # illegal - was expecting a signature</span></li><li>    <span class="q">    sub foo ($a, $b)</span></li><li>            <span class="q">            :prototype($$) {}  # legal</span></li></ol></pre></li>
<li><a name="Illegal-character-in-prototype-for-%25s-%3a-%25s"></a><b>Illegal character in prototype for %s : %s</b>
<p>(W illegalproto) An illegal character was found in a prototype declaration.
Legal characters in prototypes are $, @, %, *, ;, [, ], &amp;, \, and +.
Perhaps you were trying to write a subroutine signature but didn't enable
that feature first (<code class="inline"><a class="l_k" href="functions/use.html">use</a> <span class="w">feature</span> <span class="q">&#39;signatures&#39;</span></code>
), so your signature was
instead interpreted as a bad prototype.</p>
</li>
<li><a name="Illegal-declaration-of-anonymous-subroutine"></a><b>Illegal declaration of anonymous subroutine</b>
<p>(F) When using the <code class="inline"><a class="l_k" href="functions/sub.html">sub</a></code> keyword to construct an anonymous subroutine,
you must always specify a block of code.  See <a href="perlsub.html">perlsub</a>.</p>
</li>
<li><a name="Illegal-declaration-of-subroutine-%25s"></a><b>Illegal declaration of subroutine %s</b>
<p>(F) A subroutine was not declared correctly.  See <a href="perlsub.html">perlsub</a>.</p>
</li>
<li><a name="Illegal-division-by-zero"></a><b>Illegal division by zero</b>
<p>(F) You tried to divide a number by 0.  Either something was wrong in
your logic, or you need to put a conditional in to guard against
meaningless input.</p>
</li>
<li><a name="Illegal-hexadecimal-digit-%25s-ignored"></a><b>Illegal hexadecimal digit %s ignored</b>
<p>(W digit) You may have tried to use a character other than 0 - 9 or
A - F, a - f in a hexadecimal number.  Interpretation of the hexadecimal
number stopped before the illegal character.</p>
</li>
<li><a name="Illegal-modulus-zero"></a><b>Illegal modulus zero</b>
<p>(F) You tried to divide a number by 0 to get the remainder.  Most
numbers don't take to this kindly.</p>
</li>
<li><a name="Illegal-number-of-bits-in-vec"></a><b>Illegal number of bits in vec</b>
<p>(F) The number of bits in vec() (the third argument) must be a power of
two from 1 to 32 (or 64, if your platform supports that).</p>
</li>
<li><a name="Illegal-octal-digit-%25s"></a><b>Illegal octal digit %s</b>
<p>(F) You used an 8 or 9 in an octal number.</p>
</li>
<li><a name="Illegal-octal-digit-%25s-ignored"></a><b>Illegal octal digit %s ignored</b>
<p>(W digit) You may have tried to use an 8 or 9 in an octal number.
Interpretation of the octal number stopped before the 8 or 9.</p>
</li>
<li><a name="Illegal-pattern-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>Illegal pattern in regex; marked by &lt;-- HERE in m/%s/</b>
<p>(F) You wrote something like</p>
<pre class="verbatim"><ol><li> <span class="s">(</span><span class="q">?+foo)</span></li></ol></pre><p>The <code class="inline"><span class="q">&quot;+&quot;</span></code>
 is valid only when followed by digits, indicating a
capturing group.  See
<a href="perlre.html#(%3fPARNO)-(%3f-PARNO)-(%3f%2bPARNO)-(%3fR)-(%3f0)">(?PARNO)</a>.</p>
</li>
<li><a name="Illegal-suidscript"></a><b>Illegal suidscript</b>
<p>(F) The script run under suidperl was somehow illegal.</p>
</li>
<li><a name="Illegal-switch-in-PERL5OPT%3a--%25c"></a><b>Illegal switch in PERL5OPT: -%c</b>
<p>(X) The PERL5OPT environment variable may only be used to set the
following switches: <b>-[CDIMUdmtw]</b>.</p>
</li>
<li><a name="Illegal-user-defined-property-name"></a><b>Illegal user-defined property name</b>
<p>(F) You specified a Unicode-like property name in a regular expression
pattern (using <code class="inline">\<span class="w">p</span><span class="s">{</span><span class="s">}</span></code>
 or <code class="inline">\<span class="w">P</span><span class="s">{</span><span class="s">}</span></code>
) that Perl knows isn't an official
Unicode property, and was likely meant to be a user-defined property
name, but it can't be one of those, as they must begin with either <code class="inline"><span class="w">In</span></code>

or <code class="inline"><span class="w">Is</span></code>
.  Check the spelling.  See also
<a href="#Can't-find-Unicode-property-definition-%22%25s%22">Can't find Unicode property definition %s</a>.</p>
</li>
<li><a name="Ill-formed-CRTL-environ-value-%22%25s%22"></a><b>Ill-formed CRTL environ value "%s"</b>
<p>(W internal) A warning peculiar to VMS.  Perl tried to read the CRTL's
internal environ array, and encountered an element without the <code class="inline">=</code>

delimiter used to separate keys from values.  The element is ignored.</p>
</li>
<li><a name="Ill-formed-message-in-prime_env_iter%3a-%7c%25s%7c"></a><b>Ill-formed message in prime_env_iter: |%s|</b>
<p>(W internal) A warning peculiar to VMS.  Perl tried to read a logical
name or CLI symbol definition when preparing to iterate over %ENV, and
didn't see the expected delimiter between key and value, so the line was
ignored.</p>
</li>
<li><a name="(in-cleanup)-%25s"></a><b>(in cleanup) %s</b>
<p>(W misc) This prefix usually indicates that a DESTROY() method raised
the indicated exception.  Since destructors are usually called by the
system at arbitrary points during execution, and often a vast number of
times, the warning is issued only once for any number of failures that
would otherwise result in the same message being repeated.</p>
<p>Failure of user callbacks dispatched using the <code class="inline"><span class="w">G_KEEPERR</span></code>
 flag could
also result in this warning.  See <a href="perlcall.html#G_KEEPERR">G_KEEPERR in perlcall</a>.</p>
</li>
<li><a name="Incomplete-expression-within-'(%3f%5b-%5d)'-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>Incomplete expression within '(?[ ])' in regex; marked by &lt;-- HERE
in m/%s/</b>
<p>(F) There was a syntax error within the <code class="inline"><span class="s">(</span><span class="q">?[ ])</span></code>
.  This can happen if the
expression inside the construct was completely empty, or if there are
too many or few operands for the number of operators.  Perl is not smart
enough to give you a more precise indication as to what is wrong.</p>
</li>
<li><a name="Inconsistent-hierarchy-during-C3-merge-of-class-'%25s'%3a-merging-failed-on--parent-'%25s'"></a><b>Inconsistent hierarchy during C3 merge of class '%s': merging failed on 
parent '%s'</b>
<p>(F) The method resolution order (MRO) of the given class is not
C3-consistent, and you have enabled the C3 MRO for this class.  See the C3
documentation in <a href="mro.html">mro</a> for more information.</p>
</li>
<li><a name="Indentation-on-line-%25d-of-here-doc-doesn't-match-delimiter"></a><b>Indentation on line %d of here-doc doesn't match delimiter</b>
<p>(F) You have an indented here-document where one or more of its lines
have whitespace at the beginning that does not match the closing
delimiter.</p>
<p>For example, line 2 below is wrong because it does not have at least
2 spaces, but lines 1 and 3 are fine because they have at least 2:</p>
<pre class="verbatim"><ol><li>    <a class="l_k" href="functions/if.html">if</a> <span class="s">(</span><span class="i">$something</span><span class="s">)</span> <span class="s">{</span></li><li>      <a class="l_k" href="functions/print.html">print</a> <span class="h">&lt;&lt;</span>~<span class="w">EOF</span><span class="sc">;</span></li><li><span class="hh">        Line 1</span></li><li><span class="hh">       Line 2 not</span></li><li><span class="hh">          Line 3</span></li><li><span class="hh">        EOF</span></li><li><span class="hh">    }</span></li></ol></pre><p>Note that tabs and spaces are compared strictly, meaning 1 tab will
not match 8 spaces.</p>
</li>
<li><a name="Infinite-recursion-in-regex"></a><b>Infinite recursion in regex</b>
<p>(F) You used a pattern that references itself without consuming any input
text.  You should check the pattern to ensure that recursive patterns
either consume text or fail.</p>
</li>
<li><a name="Initialization-of-state-variables-in-list-context-currently-forbidden"></a><b>Initialization of state variables in list context currently forbidden</b>
<p>(F) <code class="inline"><a class="l_k" href="functions/state.html">state</a></code> only permits initializing a single scalar variable, in scalar
context.  So <code class="inline"><span class="w">state</span> <span class="i">$a</span> = <span class="n">42</span></code>
 is allowed, but not <code class="inline"><span class="w">state</span> <span class="s">(</span><span class="i">$a</span><span class="s">)</span> = <span class="n">42</span></code>
.  To apply
state semantics to a hash or array, store a hash or array reference in a
scalar variable.</p>
</li>
<li><a name="%25%25s%5b%25s%5d-in-scalar-context-better-written-as-%24%25s%5b%25s%5d"></a><b>%%s[%s] in scalar context better written as $%s[%s]</b>
<p>(W syntax) In scalar context, you've used an array index/value slice
(indicated by %) to select a single element of an array.  Generally
it's better to ask for a scalar value (indicated by $).  The difference
is that <code class="inline"><span class="i">$foo</span>[<span class="i">&amp;bar</span>]</code>
 always behaves like a scalar, both in the value it
returns and when evaluating its argument, while <code class="inline"><span class="i">%foo</span>[<span class="i">&amp;bar</span>]</code>
 provides
a list context to its subscript, which can do weird things if you're
expecting only one subscript.  When called in list context, it also
returns the index (what <code class="inline"><span class="i">&amp;bar</span></code>
 returns) in addition to the value.</p>
</li>
<li><a name="%25%25s%7b%25s%7d-in-scalar-context-better-written-as-%24%25s%7b%25s%7d"></a><b>%%s{%s} in scalar context better written as $%s{%s}</b>
<p>(W syntax) In scalar context, you've used a hash key/value slice
(indicated by %) to select a single element of a hash.  Generally it's
better to ask for a scalar value (indicated by $).  The difference
is that <code class="inline"><span class="i">$foo</span>{<span class="i">&amp;bar</span>}</code>
 always behaves like a scalar, both in the value
it returns and when evaluating its argument, while <code class="inline"><span class="i">@foo</span>{<span class="i">&amp;bar</span>}</code>
 and
provides a list context to its subscript, which can do weird things
if you're expecting only one subscript.  When called in list context,
it also returns the key in addition to the value.</p>
</li>
<li><a name="Insecure-dependency-in-%25s"></a><b>Insecure dependency in %s</b>
<p>(F) You tried to do something that the tainting mechanism didn't like.
The tainting mechanism is turned on when you're running setuid or
setgid, or when you specify <b>-T</b> to turn it on explicitly.  The
tainting mechanism labels all data that's derived directly or indirectly
from the user, who is considered to be unworthy of your trust.  If any
such data is used in a "dangerous" operation, you get this error.  See
<a href="perlsec.html">perlsec</a> for more information.</p>
</li>
<li><a name="Insecure-directory-in-%25s"></a><b>Insecure directory in %s</b>
<p>(F) You can't use system(), exec(), or a piped open in a setuid or
setgid script if <code class="inline"><span class="i">$ENV</span>{<span class="w">PATH</span>}</code>
 contains a directory that is writable by
the world.  Also, the PATH must not contain any relative directory.
See <a href="perlsec.html">perlsec</a>.</p>
</li>
<li><a name="Insecure-%24ENV%7b%25s%7d-while-running-%25s"></a><b>Insecure $ENV{%s} while running %s</b>
<p>(F) You can't use system(), exec(), or a piped open in a setuid or
setgid script if any of <code class="inline"><span class="i">$ENV</span>{<span class="w">PATH</span>}</code>
, <code class="inline"><span class="i">$ENV</span>{<span class="w">IFS</span>}</code>
, <code class="inline"><span class="i">$ENV</span>{<span class="w">CDPATH</span>}</code>
,
<code class="inline"><span class="i">$ENV</span>{<span class="w">ENV</span>}</code>
, <code class="inline"><span class="i">$ENV</span>{<span class="w">BASH_ENV</span>}</code>
 or <code class="inline"><span class="i">$ENV</span>{<span class="w">TERM</span>}</code>
 are derived from data
supplied (or potentially supplied) by the user.  The script must set
the path to a known value, using trustworthy data.  See <a href="perlsec.html">perlsec</a>.</p>
</li>
<li><a name="Insecure-user-defined-property-%25s"></a><b>Insecure user-defined property %s</b>
<p>(F) Perl detected tainted data when trying to compile a regular
expression that contains a call to a user-defined character property
function, i.e. <code class="inline">\<span class="i">p</span><span class="s">{</span><span class="w">IsFoo</span><span class="s">}</span></code>
 or <code class="inline">\<span class="i">p</span><span class="s">{</span><span class="w">InFoo</span><span class="s">}</span></code>
.
See <a href="perlunicode.html#User-Defined-Character-Properties">User-Defined Character Properties in perlunicode</a> and <a href="perlsec.html">perlsec</a>.</p>
</li>
<li><a name="Integer-overflow-in-format-string-for-%25s"></a><b>Integer overflow in format string for %s</b>
<p>(F) The indexes and widths specified in the format string of <code class="inline"><a class="l_k" href="functions/printf.html">printf()</a></code>
or <code class="inline"><a class="l_k" href="functions/sprintf.html">sprintf()</a></code> are too large.  The numbers must not overflow the size of
integers for your architecture.</p>
</li>
<li><a name="Integer-overflow-in-%25s-number"></a><b>Integer overflow in %s number</b>
<p>(S overflow) The hexadecimal, octal or binary number you have specified
either as a literal or as an argument to hex() or oct() is too big for
your architecture, and has been converted to a floating point number.
On a 32-bit architecture the largest hexadecimal, octal or binary number
representable without overflow is 0xFFFFFFFF, 037777777777, or
0b11111111111111111111111111111111 respectively.  Note that Perl
transparently promotes all numbers to a floating point representation
internally--subject to loss of precision errors in subsequent
operations.</p>
</li>
<li><a name="Integer-overflow-in-srand"></a><b>Integer overflow in srand</b>
<p>(S overflow) The number you have passed to srand is too big to fit
in your architecture's integer representation.  The number has been
replaced with the largest integer supported (0xFFFFFFFF on 32-bit
architectures).  This means you may be getting less randomness than
you expect, because different random seeds above the maximum will
return the same sequence of random numbers.</p>
</li>
<li><a name="Integer-overflow-in-version"></a><b>Integer overflow in version</b>
</li>
<li><a name="Integer-overflow-in-version-%25d"></a><b>Integer overflow in version %d</b>
<p>(W overflow) Some portion of a version initialization is too large for
the size of integers for your architecture.  This is not a warning
because there is no rational reason for a version to try and use an
element larger than typically 2**32.  This is usually caused by trying
to use some odd mathematical operation as a version, like 100/9.</p>
</li>
<li><a name="Internal-disaster-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>Internal disaster in regex; marked by &lt;-- HERE in m/%s/</b>
<p>(P) Something went badly wrong in the regular expression parser.
The &lt;-- HERE shows whereabouts in the regular expression the problem was
discovered.</p>
</li>
<li><a name="Internal-inconsistency-in-tracking-vforks"></a><b>Internal inconsistency in tracking vforks</b>
<p>(S) A warning peculiar to VMS.  Perl keeps track of the number of times
you've called <code class="inline"><a class="l_k" href="functions/fork.html">fork</a></code> and <code class="inline"><a class="l_k" href="functions/exec.html">exec</a></code>, to determine whether the current call
to <code class="inline"><a class="l_k" href="functions/exec.html">exec</a></code> should affect the current script or a subprocess (see
<a href="perlvms.html#exec-LIST">exec LIST in perlvms</a>).  Somehow, this count has become scrambled, so
Perl is making a guess and treating this <code class="inline"><a class="l_k" href="functions/exec.html">exec</a></code> as a request to
terminate the Perl script and execute the specified command.</p>
</li>
<li><a name="internal-%25%3cnum%3ep-might-conflict-with-future-printf-extensions"></a><b>internal %&lt;num&gt;p might conflict with future printf extensions</b>
<p>(S internal) Perl's internal routine that handles <code class="inline"><a class="l_k" href="functions/printf.html">printf</a></code> and <code class="inline"><a class="l_k" href="functions/sprintf.html">sprintf</a></code>
formatting follows a slightly different set of rules when called from
C or XS code.  Specifically, formats consisting of digits followed
by "p" (e.g., "%7p") are reserved for future use.  If you see this
message, then an XS module tried to call that routine with one such
reserved format.</p>
</li>
<li><a name="Internal-urp-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>Internal urp in regex; marked by &lt;-- HERE in m/%s/</b>
<p>(P) Something went badly awry in the regular expression parser.  The
&lt;-- HERE shows whereabouts in the regular expression the problem was
discovered.</p>
</li>
<li><a name="%25s-(...)-interpreted-as-function"></a><b>%s (...) interpreted as function</b>
<p>(W syntax) You've run afoul of the rule that says that any list operator
followed by parentheses turns into a function, with all the list
operators arguments found inside the parentheses.  See
<a href="perlop.html#Terms-and-List-Operators-(Leftward)">Terms and List Operators (Leftward) in perlop</a>.</p>
</li>
<li><a name="In-'(%3f...)'%2c-the-'('-and-'%3f'-must-be-adjacent-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>In '(?...)', the '(' and '?' must be adjacent in regex;
marked by &lt;-- HERE in m/%s/</b>
<p>(F) The two-character sequence <code class="inline"><span class="q">&quot;(?&quot;</span></code>
 in this context in a regular
expression pattern should be an indivisible token, with nothing
intervening between the <code class="inline"><span class="q">&quot;(&quot;</span></code>
 and the <code class="inline"><span class="q">&quot;?&quot;</span></code>
, but you separated them
with whitespace.</p>
</li>
<li><a name="Invalid-%25s-attribute%3a-%25s"></a><b>Invalid %s attribute: %s</b>
<p>(F) The indicated attribute for a subroutine or variable was not recognized
by Perl or by a user-supplied handler.  See <a href="attributes.html">attributes</a>.</p>
</li>
<li><a name="Invalid-%25s-attributes%3a-%25s"></a><b>Invalid %s attributes: %s</b>
<p>(F) The indicated attributes for a subroutine or variable were not
recognized by Perl or by a user-supplied handler.  See <a href="attributes.html">attributes</a>.</p>
</li>
<li><a name="Invalid-character-in-charnames-alias-definition%3b-marked-by-%3c---HERE-in-'%25s"></a><b>Invalid character in charnames alias definition; marked by
&lt;-- HERE in '%s</b>
<p>(F) You tried to create a custom alias for a character name, with
the <code class="inline"><span class="j">:</span><span class="w">alias</span></code>
 option to <code class="inline"><a class="l_k" href="functions/use.html">use</a> <span class="w">charnames</span></code>
 and the specified character in
the indicated name isn't valid.  See <a href="charnames.html#CUSTOM-ALIASES">CUSTOM ALIASES in charnames</a>.</p>
</li>
<li><a name="Invalid-%5c0-character-in-%25s-for-%25s%3a-%25s%5c0%25s"></a><b>Invalid \0 character in %s for %s: %s\0%s</b>
<p>(W syscalls) Embedded \0 characters in pathnames or other system call
arguments produce a warning as of 5.20.  The parts after the \0 were
formerly ignored by system calls.</p>
</li>
<li><a name="Invalid-character-in-%5cN%7b...%7d%3b-marked-by-%3c---HERE-in-%5cN%7b%25s%7d"></a><b>Invalid character in \N{...}; marked by &lt;-- HERE in \N{%s}</b>
<p>(F) Only certain characters are valid for character names.  The
indicated one isn't.  See <a href="charnames.html#CUSTOM-ALIASES">CUSTOM ALIASES in charnames</a>.</p>
</li>
<li><a name="Invalid-conversion-in-%25s%3a-%22%25s%22"></a><b>Invalid conversion in %s: "%s"</b>
<p>(W printf) Perl does not understand the given format conversion.  See
<a href="functions/sprintf.html">sprintf</a>.</p>
</li>
<li><a name="Invalid-escape-in-the-specified-encoding-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>Invalid escape in the specified encoding in regex; marked by
&lt;-- HERE in m/%s/</b>
<p>(W regexp)(F) The numeric escape (for example <code class="inline">\<span class="w">xHH</span></code>
) of value &lt; 256
didn't correspond to a single character through the conversion
from the encoding specified by the encoding pragma.
The escape was replaced with REPLACEMENT CHARACTER (U+FFFD)
instead, except within <code class="inline"><span class="s">(</span><span class="q">?[   ])</span></code>
, where it is a fatal error.
The &lt;-- HERE shows whereabouts in the regular expression the
escape was discovered.</p>
</li>
<li><a name="Invalid-hexadecimal-number-in-%5cN%7bU%2b...%7d"></a><b>Invalid hexadecimal number in \N{U+...}</b>
</li>
<li><a name="Invalid-hexadecimal-number-in-%5cN%7bU%2b...%7d-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>Invalid hexadecimal number in \N{U+...} in regex; marked by
&lt;-- HERE in m/%s/</b>
<p>(F) The character constant represented by <code class="inline">...</code>
 is not a valid hexadecimal
number.  Either it is empty, or you tried to use a character other than
0 - 9 or A - F, a - f in a hexadecimal number.</p>
</li>
<li><a name="Invalid-module-name-%25s-with--%25c-option%3a-contains-single-'%3a'"></a><b>Invalid module name %s with -%c option: contains single ':'</b>
<p>(F) The module argument to perl's <b>-m</b> and <b>-M</b> command-line options
cannot contain single colons in the module name, but only in the
arguments after "=".  In other words, <b>-MFoo::Bar=:baz</b> is ok, but
<b>-MFoo:Bar=baz</b> is not.</p>
</li>
<li><a name="Invalid-mro-name%3a-'%25s'"></a><b>Invalid mro name: '%s'</b>
<p>(F) You tried to <code class="inline"><span class="i">mro::set_mro</span><span class="s">(</span><span class="q">&quot;classname&quot;</span><span class="cm">,</span> <span class="q">&quot;foo&quot;</span><span class="s">)</span></code>
 or <code class="inline"><a class="l_k" href="functions/use.html">use</a> <span class="w">mro</span> <span class="q">'foo'</span></code>
,
where <code class="inline"><span class="w">foo</span></code>
 is not a valid method resolution order (MRO).  Currently,
the only valid ones supported are <code class="inline"><span class="w">dfs</span></code>
 and <code class="inline"><span class="w">c3</span></code>
, unless you have loaded
a module that is a MRO plugin.  See <a href="mro.html">mro</a> and <a href="perlmroapi.html">perlmroapi</a>.</p>
</li>
<li><a name="Invalid-negative-number-(%25s)-in-chr"></a><b>Invalid negative number (%s) in chr</b>
<p>(W utf8) You passed a negative number to <code class="inline"><a class="l_k" href="functions/chr.html">chr</a></code>.  Negative numbers are
not valid character numbers, so it returns the Unicode replacement
character (U+FFFD).</p>
</li>
<li><a name="Invalid-number-'%25s'-for--C-option."></a><b>Invalid number '%s' for -C option.</b>
<p>(F) You supplied a number to the -C option that either has extra leading
zeroes or overflows perl's unsigned integer representation.</p>
</li>
<li><a name="invalid-option--D%25c%2c-use--D''-to-see-choices"></a><b>invalid option -D%c, use -D'' to see choices</b>
<p>(S debugging) Perl was called with invalid debugger flags.  Call perl
with the <b>-D</b> option with no flags to see the list of acceptable values.
See also <a href="perlrun.html#-Dletters">-Dletters in perlrun</a>.</p>
</li>
<li><a name="Invalid-quantifier-in-%7b%2c%7d-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>Invalid quantifier in {,} in regex; marked by &lt;-- HERE in m/%s/</b>
<p>(F) The pattern looks like a {min,max} quantifier, but the min or max
could not be parsed as a valid number - either it has leading zeroes,
or it represents too big a number to cope with.  The &lt;-- HERE shows
where in the regular expression the problem was discovered.  See <a href="perlre.html">perlre</a>.</p>
</li>
<li><a name="Invalid-%5b%5d-range-%22%25s%22-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>Invalid [] range "%s" in regex; marked by &lt;-- HERE in m/%s/</b>
<p>(F) The range specified in a character class had a minimum character
greater than the maximum character.  One possibility is that you forgot the
<code class="inline"><span class="s">{</span><span class="s">}</span></code>
 from your ending <code class="inline">\<span class="w">x</span><span class="s">{</span><span class="s">}</span></code>
 - <code class="inline">\<span class="w">x</span></code>
 without the curly braces can go only
up to <code class="inline"><span class="w">ff</span></code>
.  The &lt;-- HERE shows whereabouts in the regular expression the
problem was discovered.  See <a href="perlre.html">perlre</a>.</p>
</li>
<li><a name="Invalid-range-%22%25s%22-in-transliteration-operator"></a><b>Invalid range "%s" in transliteration operator</b>
<p>(F) The range specified in the tr/// or y/// operator had a minimum
character greater than the maximum character.  See <a href="perlop.html">perlop</a>.</p>
</li>
<li><a name="Invalid-separator-character-%25s-in-attribute-list"></a><b>Invalid separator character %s in attribute list</b>
<p>(F) Something other than a colon or whitespace was seen between the
elements of an attribute list.  If the previous attribute had a
parenthesised parameter list, perhaps that list was terminated too soon.
See <a href="attributes.html">attributes</a>.</p>
</li>
<li><a name="Invalid-separator-character-%25s-in-PerlIO-layer-specification-%25s"></a><b>Invalid separator character %s in PerlIO layer specification %s</b>
<p>(W layer) When pushing layers onto the Perl I/O system, something other
than a colon or whitespace was seen between the elements of a layer list.
If the previous attribute had a parenthesised parameter list, perhaps that
list was terminated too soon.</p>
</li>
<li><a name="Invalid-strict-version-format-(%25s)"></a><b>Invalid strict version format (%s)</b>
<p>(F) A version number did not meet the "strict" criteria for versions.
A "strict" version number is a positive decimal number (integer or
decimal-fraction) without exponentiation or else a dotted-decimal
v-string with a leading 'v' character and at least three components.
The parenthesized text indicates which criteria were not met.
See the <a href="version.html">version</a> module for more details on allowed version formats.</p>
</li>
<li><a name="Invalid-type-'%25s'-in-%25s"></a><b>Invalid type '%s' in %s</b>
<p>(F) The given character is not a valid pack or unpack type.
See <a href="functions/pack.html">pack</a>.</p>
<p>(W) The given character is not a valid pack or unpack type but used to be
silently ignored.</p>
</li>
<li><a name="Invalid-version-format-(%25s)"></a><b>Invalid version format (%s)</b>
<p>(F) A version number did not meet the "lax" criteria for versions.
A "lax" version number is a positive decimal number (integer or
decimal-fraction) without exponentiation or else a dotted-decimal
v-string.  If the v-string has fewer than three components, it
must have a leading 'v' character.  Otherwise, the leading 'v' is
optional.  Both decimal and dotted-decimal versions may have a
trailing "alpha" component separated by an underscore character
after a fractional or dotted-decimal component.  The parenthesized
text indicates which criteria were not met.  See the <a href="version.html">version</a> module
for more details on allowed version formats.</p>
</li>
<li><a name="Invalid-version-object"></a><b>Invalid version object</b>
<p>(F) The internal structure of the version object was invalid.
Perhaps the internals were modified directly in some way or
an arbitrary reference was blessed into the "version" class.</p>
</li>
<li><a name="In-'(*VERB...)'%2c-the-'('-and-'*'-must-be-adjacent-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>In '(*VERB...)', the '(' and '*' must be adjacent in regex;
marked by &lt;-- HERE in m/%s/</b>
<p>(F) The two-character sequence <code class="inline"><span class="q">&quot;(*&quot;</span></code>
 in
this context in a regular expression pattern should be an
indivisible token, with nothing intervening between the <code class="inline"><span class="q">&quot;(&quot;</span></code>

and the <code class="inline"><span class="q">&quot;*&quot;</span></code>
, but you separated them.</p>
</li>
<li><a name="ioctl-is-not-implemented"></a><b>ioctl is not implemented</b>
<p>(F) Your machine apparently doesn't implement ioctl(), which is pretty
strange for a machine that supports C.</p>
</li>
<li><a name="ioctl()-on-unopened-%25s"></a><b>ioctl() on unopened %s</b>
<p>(W unopened) You tried ioctl() on a filehandle that was never opened.
Check your control flow and number of arguments.</p>
</li>
<li><a name="IO-layers-(like-'%25s')-unavailable"></a><b>IO layers (like '%s') unavailable</b>
<p>(F) Your Perl has not been configured to have PerlIO, and therefore
you cannot use IO layers.  To have PerlIO, Perl must be configured
with 'useperlio'.</p>
</li>
<li><a name="IO%3a%3aSocket%3a%3aatmark-not-implemented-on-this-architecture"></a><b>IO::Socket::atmark not implemented on this architecture</b>
<p>(F) Your machine doesn't implement the sockatmark() functionality,
neither as a system call nor an ioctl call (SIOCATMARK).</p>
</li>
<li><a name="'%25s'-is-an-unknown-bound-type-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>'%s' is an unknown bound type in regex; marked by &lt;-- HERE in m/%s/</b>
<p>(F) You used <code class="inline">\<span class="i">b</span><span class="s">{</span>...<span class="s">}</span></code>
 or <code class="inline">\<span class="i">B</span><span class="s">{</span>...<span class="s">}</span></code>
 and the <code class="inline">...</code>
 is not known to
Perl.  The current valid ones are given in
<a href="perlrebackslash.html#%5cb%7b%7d%2c-%5cb%2c-%5cB%7b%7d%2c-%5cB">\b{}, \b, \B{}, \B in perlrebackslash</a>.</p>
</li>
<li><a name="%25s()-is-deprecated-on-%3autf8-handles.-This-will-be-a-fatal-error-in-Perl-5.30"></a><b>%s() is deprecated on :utf8 handles. This will be a fatal error in Perl 5.30</b>
<p>(D deprecated) The sysread(), recv(), syswrite() and send() operators are
deprecated on handles that have the <code class="inline"><span class="j">:</span><span class="w">utf8</span></code>
 layer, either explicitly, or
implicitly, eg., with the <code class="inline"><span class="j">:</span><span class="i">encoding</span><span class="s">(</span><span class="w">UTF</span>-<span class="n">16</span>LE<span class="s">)</span></code>
 layer.</p>
<p>Both sysread() and recv() currently use only the <code class="inline"><span class="j">:</span><span class="w">utf8</span></code>
 flag for the stream,
ignoring the actual layers.  Since sysread() and recv() do no UTF-8
validation they can end up creating invalidly encoded scalars.</p>
<p>Similarly, syswrite() and send() use only the <code class="inline"><span class="j">:</span><span class="w">utf8</span></code>
 flag, otherwise ignoring
any layers.  If the flag is set, both write the value UTF-8 encoded, even if
the layer is some different encoding, such as the example above.</p>
<p>Ideally, all of these operators would completely ignore the <code class="inline"><span class="j">:</span><span class="w">utf8</span></code>
 state,
working only with bytes, but this would result in silently breaking existing
code.</p>
<p>In Perl 5.30, it will no longer be possible to use sysread(), recv(),
syswrite() or send() to read or send bytes from/to :utf8 handles.</p>
</li>
<li><a name="%22%25s%22-is-more-clearly-written-simply-as-%22%25s%22-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>"%s" is more clearly written simply as "%s" in regex; marked by &lt;-- HERE in m/%s/</b>
<p>(W regexp) (only under <code class="inline"><a class="l_k" href="functions/use.html">use</a> <span class="w">re</span> <span class="q">&#39;strict&#39;</span></code>
 or within <code class="inline"><span class="s">(</span><span class="q">?[...])</span></code>
)</p>
<p>You specified a character that has the given plainer way of writing it,
and which is also portable to platforms running with different character
sets.</p>
</li>
<li><a name="%24*-is-no-longer-supported.-Its-use-will-be-fatal-in-Perl-5.30"></a><b>$* is no longer supported. Its use will be fatal in Perl 5.30</b>
<p>(D deprecated, syntax) The special variable <code class="inline"><span class="i">$*</span></code>
, deprecated in older
perls, has been removed as of 5.10.0 and is no longer supported.  In
previous versions of perl the use of <code class="inline"><span class="i">$*</span></code>
 enabled or disabled multi-line
matching within a string.</p>
<p>Instead of using <code class="inline"><span class="i">$*</span></code>
 you should use the <code class="inline">/m</code> (and maybe <code class="inline">/s</code>) regexp
modifiers.  You can enable <code class="inline">/m</code> for a lexical scope (even a whole file)
with <code class="inline"><a class="l_k" href="functions/use.html">use</a> <span class="w">re</span> <span class="q">&#39;/m&#39;</span></code>
.  (In older versions: when <code class="inline"><span class="i">$*</span></code>
 was set to a true value
then all regular expressions behaved as if they were written using <code class="inline">/m</code>.)</p>
<p>Use of this variable will be a fatal error in Perl 5.30.</p>
</li>
<li><a name="%24%23-is-no-longer-supported.-Its-use-will-be-fatal-in-Perl-5.30"></a><b>$# is no longer supported. Its use will be fatal in Perl 5.30</b>
<p>(D deprecated, syntax) The special variable <code class="inline"><span class="i">$#</span></code>
, deprecated in older
perls, has been removed as of 5.10.0 and is no longer supported.  You
should use the printf/sprintf functions instead.</p>
<p>Use of this variable will be a fatal error in Perl 5.30.</p>
</li>
<li><a name="'%25s'-is-not-a-code-reference"></a><b>'%s' is not a code reference</b>
<p>(W overload) The second (fourth, sixth, ...) argument of
overload::constant needs to be a code reference.  Either
an anonymous subroutine, or a reference to a subroutine.</p>
</li>
<li><a name="'%25s'-is-not-an-overloadable-type"></a><b>'%s' is not an overloadable type</b>
<p>(W overload) You tried to overload a constant type the overload package is
unaware of.</p>
</li>
<li><a name="-i-used-with-no-filenames-on-the-command-line%2c-reading-from-STDIN"></a><b>-i used with no filenames on the command line, reading from STDIN</b>
<p>(S inplace) The <code class="inline">-<span class="w">i</span></code>
 option was passed on the command line, indicating
that the script is intended to edit files in place, but no files were
given.  This is usually a mistake, since editing STDIN in place doesn't
make sense, and can be confusing because it can make perl look like
it is hanging when it is really just trying to read from STDIN.  You
should either pass a filename to edit, or remove <code class="inline">-<span class="w">i</span></code>
 from the command
line.  See <a href="perlrun.html">perlrun</a> for more details.</p>
</li>
<li><a name="Junk-on-end-of-regexp-in-regex-m%2f%25s%2f"></a><b>Junk on end of regexp in regex m/%s/</b>
<p>(P) The regular expression parser is confused.</p>
</li>
<li><a name="Label-not-found-for-%22last-%25s%22"></a><b>Label not found for "last %s"</b>
<p>(F) You named a loop to break out of, but you're not currently in a loop
of that name, not even if you count where you were called from.  See
<a href="functions/last.html">last</a>.</p>
</li>
<li><a name="Label-not-found-for-%22next-%25s%22"></a><b>Label not found for "next %s"</b>
<p>(F) You named a loop to continue, but you're not currently in a loop of
that name, not even if you count where you were called from.  See
<a href="functions/last.html">last</a>.</p>
</li>
<li><a name="Label-not-found-for-%22redo-%25s%22"></a><b>Label not found for "redo %s"</b>
<p>(F) You named a loop to restart, but you're not currently in a loop of
that name, not even if you count where you were called from.  See
<a href="functions/last.html">last</a>.</p>
</li>
<li><a name="leaving-effective-%25s-failed"></a><b>leaving effective %s failed</b>
<p>(F) While under the <code class="inline"><a class="l_k" href="functions/use.html">use</a> <span class="w">filetest</span></code>
 pragma, switching the real and
effective uids or gids failed.</p>
</li>
<li><a name="length%2fcode-after-end-of-string-in-unpack"></a><b>length/code after end of string in unpack</b>
<p>(F) While unpacking, the string buffer was already used up when an unpack
length/code combination tried to obtain more data.  This results in
an undefined value for the length.  See <a href="functions/pack.html">pack</a>.</p>
</li>
<li><a name="length()-used-on-%25s-(did-you-mean-%22scalar(%25s)%22%3f)"></a><b>length() used on %s (did you mean "scalar(%s)"?)</b>
<p>(W syntax) You used length() on either an array or a hash when you
probably wanted a count of the items.</p>
<p>Array size can be obtained by doing:</p>
<pre class="verbatim"><ol><li>    <a class="l_k" href="functions/scalar.html">scalar</a><span class="s">(</span><span class="i">@array</span><span class="s">)</span><span class="sc">;</span></li></ol></pre><p>The number of items in a hash can be obtained by doing:</p>
<pre class="verbatim"><ol><li>    <a class="l_k" href="functions/scalar.html">scalar</a><span class="s">(</span><a class="l_k" href="functions/keys.html">keys</a> <span class="i">%hash</span><span class="s">)</span><span class="sc">;</span></li></ol></pre></li>
<li><a name="Lexing-code-attempted-to-stuff-non-Latin-1-character-into-Latin-1-input"></a><b>Lexing code attempted to stuff non-Latin-1 character into Latin-1 input</b>
<p>(F) An extension is attempting to insert text into the current parse
(using <a href="perlapi.html#lex_stuff_pvn">lex_stuff_pvn</a> or similar), but tried to insert a character that
couldn't be part of the current input.  This is an inherent pitfall
of the stuffing mechanism, and one of the reasons to avoid it.  Where
it is necessary to stuff, stuffing only plain ASCII is recommended.</p>
</li>
<li><a name="Lexing-code-internal-error-(%25s)"></a><b>Lexing code internal error (%s)</b>
<p>(F) Lexing code supplied by an extension violated the lexer's API in a
detectable way.</p>
</li>
<li><a name="listen()-on-closed-socket-%25s"></a><b>listen() on closed socket %s</b>
<p>(W closed) You tried to do a listen on a closed socket.  Did you forget
to check the return value of your socket() call?  See
<a href="functions/listen.html">listen</a>.</p>
</li>
<li><a name="List-form-of-piped-open-not-implemented"></a><b>List form of piped open not implemented</b>
<p>(F) On some platforms, notably Windows, the three-or-more-arguments
form of <code class="inline"><a class="l_k" href="functions/open.html">open</a></code> does not support pipes, such as <code class="inline"><a class="l_k" href="functions/open.html">open</a><span class="s">(</span><span class="i">$pipe</span><span class="cm">,</span> <span class="q">&#39;|-&#39;</span><span class="cm">,</span> <span class="i">@args</span><span class="s">)</span></code>
.
Use the two-argument <code class="inline"><a class="l_k" href="functions/open.html">open</a><span class="s">(</span><span class="i">$pipe</span><span class="cm">,</span> <span class="q">&#39;|prog arg1 arg2...&#39;</span><span class="s">)</span></code>
 form instead.</p>
</li>
<li><a name="%25s%3a-loadable-library-and-perl-binaries-are-mismatched-(got-handshake-key-%25p%2c-needed-%25p)"></a><b>%s: loadable library and perl binaries are mismatched (got handshake key %p, needed %p)</b>
<p>(P) A dynamic loading library <code class="inline">.<span class="w">so</span></code>
 or <code class="inline">.<span class="w">dll</span></code>
 was being loaded into the
process that was built against a different build of perl than the
said library was compiled against.  Reinstalling the XS module will
likely fix this error.</p>
</li>
<li><a name="Locale-'%25s'-may-not-work-well.%25s"></a><b>Locale '%s' may not work well.%s</b>
<p>(W locale) You are using the named locale, which is a non-UTF-8 one, and
which perl has determined is not fully compatible with what it can
handle.  The second <code class="inline"><span class="i">%s</span></code>
 gives a reason.</p>
<p>By far the most common reason is that the locale has characters in it
that are represented by more than one byte.  The only such locales that
Perl can handle are the UTF-8 locales.  Most likely the specified locale
is a non-UTF-8 one for an East Asian language such as Chinese or
Japanese.  If the locale is a superset of ASCII, the ASCII portion of it
may work in Perl.</p>
<p>Some essentially obsolete locales that aren't supersets of ASCII, mainly
those in ISO 646 or other 7-bit locales, such as ASMO 449, can also have
problems, depending on what portions of the ASCII character set get
changed by the locale and are also used by the program.
The warning message lists the determinable conflicting characters.</p>
<p>Note that not all incompatibilities are found.</p>
<p>If this happens to you, there's not much you can do except switch to use a
different locale or use <a href="Encode.html">Encode</a> to translate from the locale into
UTF-8; if that's impracticable, you have been warned that some things
may break.</p>
<p>This message is output once each time a bad locale is switched into
within the scope of <code class="inline"><a class="l_k" href="functions/use.html">use</a> <span class="w">locale</span></code>
, or on the first possibly-affected
operation if the <code class="inline"><a class="l_k" href="functions/use.html">use</a> <span class="w">locale</span></code>
 inherits a bad one.  It is not raised
for any operations from the <a href="POSIX.html">POSIX</a> module.</p>
</li>
<li><a name="localtime(%25f)-failed"></a><b>localtime(%f) failed</b>
<p>(W overflow) You called <code class="inline"><a class="l_k" href="functions/localtime.html">localtime</a></code> with a number that it could not handle:
too large, too small, or NaN.  The returned value is <code class="inline"><a class="l_k" href="functions/undef.html">undef</a></code>.</p>
</li>
<li><a name="localtime(%25f)-too-large"></a><b>localtime(%f) too large</b>
<p>(W overflow) You called <code class="inline"><a class="l_k" href="functions/localtime.html">localtime</a></code> with a number that was larger
than it can reliably handle and <code class="inline"><a class="l_k" href="functions/localtime.html">localtime</a></code> probably returned the
wrong date.  This warning is also triggered with NaN (the special
not-a-number value).</p>
</li>
<li><a name="localtime(%25f)-too-small"></a><b>localtime(%f) too small</b>
<p>(W overflow) You called <code class="inline"><a class="l_k" href="functions/localtime.html">localtime</a></code> with a number that was smaller
than it can reliably handle and <code class="inline"><a class="l_k" href="functions/localtime.html">localtime</a></code> probably returned the
wrong date.</p>
</li>
<li><a name="Lookbehind-longer-than-%25d-not-implemented-in-regex-m%2f%25s%2f"></a><b>Lookbehind longer than %d not implemented in regex m/%s/</b>
<p>(F) There is currently a limit on the length of string which lookbehind can
handle.  This restriction may be eased in a future release.</p>
</li>
<li><a name="Lost-precision-when-%25s-%25f-by-1"></a><b>Lost precision when %s %f by 1</b>
<p>(W imprecision) The value you attempted to increment or decrement by one
is too large for the underlying floating point representation to store
accurately, hence the target of <code class="inline">++</code>
 or <code class="inline">--</code>
 is unchanged.  Perl issues this
warning because it has already switched from integers to floating point
when values are too large for integers, and now even floating point is
insufficient.  You may wish to switch to using <a href="Math/BigInt.html">Math::BigInt</a> explicitly.</p>
</li>
<li><a name="lstat()-on-filehandle%25s"></a><b>lstat() on filehandle%s</b>
<p>(W io) You tried to do an lstat on a filehandle.  What did you mean
by that?  lstat() makes sense only on filenames.  (Perl did a fstat()
instead on the filehandle.)</p>
</li>
<li><a name="lvalue-attribute-%25s-already-defined-subroutine"></a><b>lvalue attribute %s already-defined subroutine</b>
<p>(W misc) Although <a href="attributes.html">attributes.pm</a> allows this, turning the lvalue
attribute on or off on a Perl subroutine that is already defined
does not always work properly.  It may or may not do what you
want, depending on what code is inside the subroutine, with exact
details subject to change between Perl versions.  Only do this
if you really know what you are doing.</p>
</li>
<li><a name="lvalue-attribute-ignored-after-the-subroutine-has-been-defined"></a><b>lvalue attribute ignored after the subroutine has been defined</b>
<p>(W misc) Using the <code class="inline"><span class="j">:</span><span class="w">lvalue</span></code>
 declarative syntax to make a Perl
subroutine an lvalue subroutine after it has been defined is
not permitted.  To make the subroutine an lvalue subroutine,
add the lvalue attribute to the definition, or put the <code class="inline"><a class="l_k" href="functions/sub.html">sub</a>
<span class="i">foo</span> <span class="co">:</span><span class="w">lvalue</span><span class="sc">;</span></code>
 declaration before the definition.</p>
<p>See also <a href="attributes.html">attributes.pm</a>.</p>
</li>
<li><a name="Magical-list-constants-are-not-supported"></a><b>Magical list constants are not supported</b>
<p>(F) You assigned a magical array to a stash element, and then tried
to use the subroutine from the same slot.  You are asking Perl to do
something it cannot do, details subject to change between Perl versions.</p>
</li>
<li><a name="Malformed-integer-in-%5b%5d-in-pack"></a><b>Malformed integer in [] in pack</b>
<p>(F) Between the brackets enclosing a numeric repeat count only digits
are permitted.  See <a href="functions/pack.html">pack</a>.</p>
</li>
<li><a name="Malformed-integer-in-%5b%5d-in-unpack"></a><b>Malformed integer in [] in unpack</b>
<p>(F) Between the brackets enclosing a numeric repeat count only digits
are permitted.  See <a href="functions/pack.html">pack</a>.</p>
</li>
<li><a name="Malformed-PERLLIB_PREFIX"></a><b>Malformed PERLLIB_PREFIX</b>
<p>(F) An error peculiar to OS/2.  PERLLIB_PREFIX should be of the form</p>
<pre class="verbatim"><ol><li>    <span class="w">prefix1</span><span class="sc">;</span><span class="w">prefix2</span></li></ol></pre><p>or
    prefix1 prefix2</p>
<p>with nonempty prefix1 and prefix2.  If <code class="inline"><span class="w">prefix1</span></code>
 is indeed a prefix of
a builtin library search path, prefix2 is substituted.  The error may
appear if components are not found, or are too long.  See
"PERLLIB_PREFIX" in <a href="perlos2.html">perlos2</a>.</p>
</li>
<li><a name="Malformed-prototype-for-%25s%3a-%25s"></a><b>Malformed prototype for %s: %s</b>
<p>(F) You tried to use a function with a malformed prototype.  The
syntax of function prototypes is given a brief compile-time check for
obvious errors like invalid characters.  A more rigorous check is run
when the function is called.
Perhaps the function's author was trying to write a subroutine signature
but didn't enable that feature first (<code class="inline"><a class="l_k" href="functions/use.html">use</a> <span class="w">feature</span> <span class="q">&#39;signatures&#39;</span></code>
),
so the signature was instead interpreted as a bad prototype.</p>
</li>
<li><a name="Malformed-UTF-8-character%25s"></a><b>Malformed UTF-8 character%s</b>
<p>(S utf8)(F) Perl detected a string that should be UTF-8, but didn't
comply with UTF-8 encoding rules, or represents a code point whose
ordinal integer value doesn't fit into the word size of the current
platform (overflows).  Details as to the exact malformation are given in
the variable, <code class="inline"><span class="i">%s</span></code>
, part of the message.</p>
<p>One possible cause is that you set the UTF8 flag yourself for data that
you thought to be in UTF-8 but it wasn't (it was for example legacy
8-bit data).  To guard against this, you can use <code class="inline"><span class="i">Encode::decode</span><span class="s">(</span><span class="q">&#39;UTF-8&#39;</span><span class="cm">,</span> ...<span class="s">)</span></code>
.</p>
<p>If you use the <code class="inline"><span class="j">:</span><span class="i">encoding</span><span class="s">(</span><span class="w">UTF</span>-<span class="n">8</span><span class="s">)</span></code>
 PerlIO layer for input, invalid byte
sequences are handled gracefully, but if you use <code class="inline"><span class="j">:</span><span class="w">utf8</span></code>
, the flag is
set without validating the data, possibly resulting in this error
message.</p>
<p>See also <a href="Encode.html#Handling-Malformed-Data">Handling Malformed Data in Encode</a>.</p>
</li>
<li><a name="Malformed-UTF-8-returned-by-%5cN%7b%25s%7d-immediately-after-'%25s'"></a><b>Malformed UTF-8 returned by \N{%s} immediately after '%s'</b>
<p>(F) The charnames handler returned malformed UTF-8.</p>
</li>
<li><a name="Malformed-UTF-8-string-in-'%25c'-format-in-unpack"></a><b>Malformed UTF-8 string in '%c' format in unpack</b>
<p>(F) You tried to unpack something that didn't comply with UTF-8 encoding
rules and perl was unable to guess how to make more progress.</p>
</li>
<li><a name="Malformed-UTF-8-string-in-pack"></a><b>Malformed UTF-8 string in pack</b>
<p>(F) You tried to pack something that didn't comply with UTF-8 encoding
rules and perl was unable to guess how to make more progress.</p>
</li>
<li><a name="Malformed-UTF-8-string-in-unpack"></a><b>Malformed UTF-8 string in unpack</b>
<p>(F) You tried to unpack something that didn't comply with UTF-8 encoding
rules and perl was unable to guess how to make more progress.</p>
</li>
<li><a name="Malformed-UTF-8-string-in-%22%25s%22"></a><b>Malformed UTF-8 string in "%s"</b>
<p>(F) This message indicates a bug either in the Perl core or in XS
code. Such code was trying to find out if a character, allegedly
stored internally encoded as UTF-8, was of a given type, such as
being punctuation or a digit.  But the character was not encoded
in legal UTF-8.  The <code class="inline"><span class="i">%s</span></code>
 is replaced by a string that can be used
by knowledgeable people to determine what the type being checked
against was.</p>
<p>Passing malformed strings was deprecated in Perl 5.18, and
became fatal in Perl 5.26.</p>
</li>
<li><a name="Malformed-UTF-16-surrogate"></a><b>Malformed UTF-16 surrogate</b>
<p>(F) Perl thought it was reading UTF-16 encoded character data but while
doing it Perl met a malformed Unicode surrogate.</p>
</li>
<li><a name="Mandatory-parameter-follows-optional-parameter"></a><b>Mandatory parameter follows optional parameter</b>
<p>(F) In a subroutine signature, you wrote something like "$a = undef,
$b", making an earlier parameter optional and a later one mandatory.
Parameters are filled from left to right, so it's impossible for the
caller to omit an earlier one and pass a later one.  If you want to act
as if the parameters are filled from right to left, declare the rightmost
optional and then shuffle the parameters around in the subroutine's body.</p>
</li>
<li><a name="Matched-non-Unicode-code-point-0x%25X-against-Unicode-property%3b-may-not-be-portable"></a><b>Matched non-Unicode code point 0x%X against Unicode property; may
not be portable</b>
<p>(S non_unicode) Perl allows strings to contain a superset of
Unicode code points; each code point may be as large as what is storable
in an unsigned integer on your system, but these may not be accepted by
other languages/systems.  This message occurs when you matched a string
containing such a code point against a regular expression pattern, and
the code point was matched against a Unicode property, <code class="inline">\<span class="i">p</span><span class="s">{</span>...<span class="s">}</span></code>
 or
<code class="inline">\<span class="i">P</span><span class="s">{</span>...<span class="s">}</span></code>
.  Unicode properties are only defined on Unicode code points,
so the result of this match is undefined by Unicode, but Perl (starting
in v5.20) treats non-Unicode code points as if they were typical
unassigned Unicode ones, and matched this one accordingly.  Whether a
given property matches these code points or not is specified in
<a href="perluniprops.html#Properties-accessible-through-%5cp%7b%7d-and-%5cP%7b%7d">Properties accessible through \p{} and \P{} in perluniprops</a>.</p>
<p>This message is suppressed (unless it has been made fatal) if it is
immaterial to the results of the match if the code point is Unicode or
not.  For example, the property <code class="inline">\<span class="i">p</span><span class="s">{</span><span class="w">ASCII_Hex_Digit</span><span class="s">}</span></code>
 only can match
the 22 characters <code class="inline"><span class="s">[</span><span class="n">0</span>-<span class="n">9</span><span class="w">A</span>-<span class="w">Fa</span>-f<span class="s">]</span></code>
, so obviously all other code points,
Unicode or not, won't match it.  (And <code class="inline">\<span class="i">P</span><span class="s">{</span><span class="w">ASCII_Hex_Digit</span><span class="s">}</span></code>
 will match
every code point except these 22.)</p>
<p>Getting this message indicates that the outcome of the match arguably
should have been the opposite of what actually happened.  If you think
that is the case, you may wish to make the <code class="inline"><span class="w">non_unicode</span></code>
 warnings
category fatal; if you agree with Perl's decision, you may wish to turn
off this category.</p>
<p>See <a href="perlunicode.html#Beyond-Unicode-code-points">Beyond Unicode code points in perlunicode</a> for more information.</p>
</li>
<li><a name="%25s-matches-null-string-many-times-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>%s matches null string many times in regex; marked by &lt;-- HERE in
m/%s/</b>
<p>(W regexp) The pattern you've specified would be an infinite loop if the
regular expression engine didn't specifically check for that.  The &lt;-- HERE
shows whereabouts in the regular expression the problem was discovered.
See <a href="perlre.html">perlre</a>.</p>
</li>
<li><a name="Maximal-count-of-pending-signals-(%25u)-exceeded"></a><b>Maximal count of pending signals (%u) exceeded</b>
<p>(F) Perl aborted due to too high a number of signals pending.  This
usually indicates that your operating system tried to deliver signals
too fast (with a very high priority), starving the perl process from
resources it would need to reach a point where it can process signals
safely.  (See <a href="perlipc.html#Deferred-Signals-(Safe-Signals)">Deferred Signals (Safe Signals) in perlipc</a>.)</p>
</li>
<li><a name="%22%25s%22-may-clash-with-future-reserved-word"></a><b>"%s" may clash with future reserved word</b>
<p>(W) This warning may be due to running a perl5 script through a perl4
interpreter, especially if the word that is being warned about is
"use" or "my".</p>
</li>
<li><a name="'%25'-may-not-be-used-in-pack"></a><b>'%' may not be used in pack</b>
<p>(F) You can't pack a string by supplying a checksum, because the
checksumming process loses information, and you can't go the other way.
See <a href="functions/unpack.html">unpack</a>.</p>
</li>
<li><a name="Method-for-operation-%25s-not-found-in-package-%25s-during-blessing"></a><b>Method for operation %s not found in package %s during blessing</b>
<p>(F) An attempt was made to specify an entry in an overloading table that
doesn't resolve to a valid subroutine.  See <a href="overload.html">overload</a>.</p>
</li>
<li><a name="Method-%25s-not-permitted"></a><b>Method %s not permitted</b>
<p>See <a href="#500-Server-error">500 Server error</a>.</p>
</li>
<li><a name="Might-be-a-runaway-multi-line-%25s-string-starting-on-line-%25d"></a><b>Might be a runaway multi-line %s string starting on line %d</b>
<p>(S) An advisory indicating that the previous error may have been caused
by a missing delimiter on a string or pattern, because it eventually
ended earlier on the current line.</p>
</li>
<li><a name="Misplaced-_-in-number"></a><b>Misplaced _ in number</b>
<p>(W syntax) An underscore (underbar) in a numeric constant did not
separate two digits.</p>
</li>
<li><a name="Missing-argument-in-%25s"></a><b>Missing argument in %s</b>
<p>(W missing) You called a function with fewer arguments than other
arguments you supplied indicated would be needed.</p>
<p>Currently only emitted when a printf-type format required more
arguments than were supplied, but might be used in the future for
other cases where we can statically determine that arguments to
functions are missing, e.g. for the <a href="functions/pack.html">pack</a> function.</p>
</li>
<li><a name="Missing-argument-to--%25c"></a><b>Missing argument to -%c</b>
<p>(F) The argument to the indicated command line switch must follow
immediately after the switch, without intervening spaces.</p>
</li>
<li><a name="Missing-braces-on-%5cN%7b%7d"></a><b>Missing braces on \N{}</b>
</li>
<li><a name="Missing-braces-on-%5cN%7b%7d-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>Missing braces on \N{} in regex; marked by &lt;-- HERE in m/%s/</b>
<p>(F) Wrong syntax of character name literal <code class="inline">\<span class="i">N</span><span class="s">{</span><span class="w">charname</span><span class="s">}</span></code>
 within
double-quotish context.  This can also happen when there is a space
(or comment) between the <code class="inline">\<span class="w">N</span></code>
 and the <code class="inline">{</code> in a regex with the <code class="inline">/x</code> modifier.
This modifier does not change the requirement that the brace immediately
follow the <code class="inline">\<span class="w">N</span></code>
.</p>
</li>
<li><a name="Missing-braces-on-%5co%7b%7d"></a><b>Missing braces on \o{}</b>
<p>(F) A <code class="inline">\<span class="w">o</span></code>
 must be followed immediately by a <code class="inline">{</code> in double-quotish context.</p>
</li>
<li><a name="Missing-comma-after-first-argument-to-%25s-function"></a><b>Missing comma after first argument to %s function</b>
<p>(F) While certain functions allow you to specify a filehandle or an
"indirect object" before the argument list, this ain't one of them.</p>
</li>
<li><a name="Missing-command-in-piped-open"></a><b>Missing command in piped open</b>
<p>(W pipe) You used the <code class="inline"><a class="l_k" href="functions/open.html">open</a><span class="s">(</span><span class="w">FH</span><span class="cm">,</span> <span class="q">&quot;| command&quot;</span><span class="s">)</span></code>
 or
<code class="inline"><a class="l_k" href="functions/open.html">open</a><span class="s">(</span><span class="w">FH</span><span class="cm">,</span> <span class="q">&quot;command |&quot;</span><span class="s">)</span></code>
 construction, but the command was missing or
blank.</p>
</li>
<li><a name="Missing-control-char-name-in-%5cc"></a><b>Missing control char name in \c</b>
<p>(F) A double-quoted string ended with "\c", without the required control
character name.</p>
</li>
<li><a name="Missing-'%5d'-in-prototype-for-%25s-%3a-%25s"></a><b>Missing ']' in prototype for %s : %s</b>
<p>(W illegalproto) A grouping was started with <code class="inline">[</code> but never closed with <code class="inline">]</code>.</p>
</li>
<li><a name="Missing-name-in-%22%25s-sub%22"></a><b>Missing name in "%s sub"</b>
<p>(F) The syntax for lexically scoped subroutines requires that
they have a name with which they can be found.</p>
</li>
<li><a name="Missing-%24-on-loop-variable"></a><b>Missing $ on loop variable</b>
<p>(F) Apparently you've been programming in <b>csh</b> too much.  Variables
are always mentioned with the $ in Perl, unlike in the shells, where it
can vary from one line to the next.</p>
</li>
<li><a name="(Missing-operator-before-%25s%3f)"></a><b>(Missing operator before %s?)</b>
<p>(S syntax) This is an educated guess made in conjunction with the message
"%s found where operator expected".  Often the missing operator is a comma.</p>
</li>
<li><a name="Missing-or-undefined-argument-to-%25s"></a><b>Missing or undefined argument to %s</b>
<p>(F) You tried to call require or do with no argument or with an undefined
value as an argument.  Require expects either a package name or a
file-specification as an argument; do expects a filename.  See
<a href="functions/require.html">require EXPR</a> and <a href="functions/do.html">do EXPR</a>.</p>
</li>
<li><a name="Missing-right-brace-on-%5c%25c%7b%7d-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>Missing right brace on \%c{} in regex; marked by &lt;-- HERE in m/%s/</b>
<p>(F) Missing right brace in <code class="inline">\<span class="i">x</span><span class="s">{</span>...<span class="s">}</span></code>
, <code class="inline">\<span class="i">p</span><span class="s">{</span>...<span class="s">}</span></code>
, <code class="inline">\<span class="i">P</span><span class="s">{</span>...<span class="s">}</span></code>
, or <code class="inline">\<span class="i">N</span><span class="s">{</span>...<span class="s">}</span></code>
.</p>
</li>
<li><a name="Missing-right-brace-on-%5cN%7b%7d"></a><b>Missing right brace on \N{}</b>
</li>
<li><a name="Missing-right-brace-on-%5cN%7b%7d-or-unescaped-left-brace-after-%5cN"></a><b>Missing right brace on \N{} or unescaped left brace after \N</b>
<p>(F) <code class="inline">\<span class="w">N</span></code>
 has two meanings.</p>
<p>The traditional one has it followed by a name enclosed in braces,
meaning the character (or sequence of characters) given by that
name.  Thus <code class="inline">\<span class="i">N</span><span class="s">{</span><span class="w">ASTERISK</span><span class="s">}</span></code>
 is another way of writing <code class="inline"><span class="i">*</span></code>
, valid in both
double-quoted strings and regular expression patterns.  In patterns,
it doesn't have the meaning an unescaped <code class="inline"><span class="i">*</span></code>
 does.</p>
<p>Starting in Perl 5.12.0, <code class="inline">\<span class="w">N</span></code>
 also can have an additional meaning (only)
in patterns, namely to match a non-newline character.  (This is short
for <code class="inline">[^\n]</code>, and like <code class="inline">.</code> but is not affected by the <code class="inline">/s</code> regex modifier.)</p>
<p>This can lead to some ambiguities.  When <code class="inline">\<span class="w">N</span></code>
 is not followed immediately
by a left brace, Perl assumes the <code class="inline">[^\n]</code> meaning.  Also, if the braces
form a valid quantifier such as <code class="inline">\<span class="i">N</span><span class="s">{</span><span class="n">3</span><span class="s">}</span></code>
 or <code class="inline">\<span class="w">N</span><span class="s">{</span><span class="n">5</span><span class="cm">,</span><span class="s">}</span></code>
, Perl assumes that this
means to match the given quantity of non-newlines (in these examples,
3; and 5 or more, respectively).  In all other case, where there is a
<code class="inline">\N{</code> and a matching <code class="inline">}</code>, Perl assumes that a character name is desired.</p>
<p>However, if there is no matching <code class="inline">}</code>, Perl doesn't know if it was
mistakenly omitted, or if <code class="inline">[^\n]{</code> was desired, and raises this error.
If you meant the former, add the right brace; if you meant the latter,
escape the brace with a backslash, like so: <code class="inline">\N\{</code></p>
</li>
<li><a name="Missing-right-curly-or-square-bracket"></a><b>Missing right curly or square bracket</b>
<p>(F) The lexer counted more opening curly or square brackets than closing
ones.  As a general rule, you'll find it's missing near the place you
were last editing.</p>
</li>
<li><a name="(Missing-semicolon-on-previous-line%3f)"></a><b>(Missing semicolon on previous line?)</b>
<p>(S syntax) This is an educated guess made in conjunction with the message
"%s found where operator expected".  Don't automatically put a semicolon on
the previous line just because you saw this message.</p>
</li>
<li><a name="Modification-of-a-read-only-value-attempted"></a><b>Modification of a read-only value attempted</b>
<p>(F) You tried, directly or indirectly, to change the value of a
constant.  You didn't, of course, try "2 = 1", because the compiler
catches that.  But an easy way to do the same thing is:</p>
<pre class="verbatim"><ol><li><a name="mod"></a>    sub <span class="m">mod</span> <span class="s">{</span> <span class="i">$_</span>[<span class="n">0</span>] = <span class="n">1</span> <span class="s">}</span></li><li>    <span class="i">mod</span><span class="s">(</span><span class="n">2</span><span class="s">)</span><span class="sc">;</span></li></ol></pre><p>Another way is to assign to a substr() that's off the end of the string.</p>
<p>Yet another way is to assign to a <code class="inline">foreach</code>
 loop <i>VAR</i> when <i>VAR</i>
is aliased to a constant in the look <i>LIST</i>:</p>
<pre class="verbatim"><ol><li>    <span class="i">$x</span> = <span class="n">1</span><span class="sc">;</span></li><li>    <a class="l_k" href="functions/foreach.html">foreach</a> <a class="l_k" href="functions/my.html">my</a> <span class="i">$n</span> <span class="s">(</span><span class="i">$x</span><span class="cm">,</span> <span class="n">2</span><span class="s">)</span> <span class="s">{</span></li><li>        <span class="i">$n</span> *= <span class="n">2</span><span class="sc">;</span> <span class="c"># modifies the $x, but fails on attempt to</span></li><li>    <span class="s">}</span>            <span class="c"># modify the 2</span></li></ol></pre></li>
<li><a name="Modification-of-non-creatable-array-value-attempted%2c-%25s"></a><b>Modification of non-creatable array value attempted, %s</b>
<p>(F) You tried to make an array value spring into existence, and the
subscript was probably negative, even counting from end of the array
backwards.</p>
</li>
<li><a name="Modification-of-non-creatable-hash-value-attempted%2c-%25s"></a><b>Modification of non-creatable hash value attempted, %s</b>
<p>(P) You tried to make a hash value spring into existence, and it
couldn't be created for some peculiar reason.</p>
</li>
<li><a name="Module-name-must-be-constant"></a><b>Module name must be constant</b>
<p>(F) Only a bare module name is allowed as the first argument to a "use".</p>
</li>
<li><a name="Module-name-required-with--%25c-option"></a><b>Module name required with -%c option</b>
<p>(F) The <code class="inline">-M</code>
 or <code class="inline">-m</code> options say that Perl should load some module, but
you omitted the name of the module.  Consult <a href="perlrun.html">perlrun</a> for full details
about <code class="inline">-M</code>
 and <code class="inline">-m</code>.</p>
</li>
<li><a name="More-than-one-argument-to-'%25s'-open"></a><b>More than one argument to '%s' open</b>
<p>(F) The <code class="inline"><a class="l_k" href="functions/open.html">open</a></code> function has been asked to open multiple files.  This
can happen if you are trying to open a pipe to a command that takes a
list of arguments, but have forgotten to specify a piped open mode.
See <a href="functions/open.html">open</a> for details.</p>
</li>
<li><a name="mprotect-for-COW-string-%25p-%25u-failed-with-%25d"></a><b>mprotect for COW string %p %u failed with %d</b>
<p>(S) You compiled perl with <b>-D</b>PERL_DEBUG_READONLY_COW (see
<a href="perlguts.html#Copy-on-Write">Copy on Write in perlguts</a>), but a shared string buffer
could not be made read-only.</p>
</li>
<li><a name="mprotect-for-%25p-%25u-failed-with-%25d"></a><b>mprotect for %p %u failed with %d</b>
<p>(S) You compiled perl with <b>-D</b>PERL_DEBUG_READONLY_OPS (see <a href="perlhacktips.html">perlhacktips</a>),
but an op tree could not be made read-only.</p>
</li>
<li><a name="mprotect-RW-for-COW-string-%25p-%25u-failed-with-%25d"></a><b>mprotect RW for COW string %p %u failed with %d</b>
<p>(S) You compiled perl with <b>-D</b>PERL_DEBUG_READONLY_COW (see
<a href="perlguts.html#Copy-on-Write">Copy on Write in perlguts</a>), but a read-only shared string
buffer could not be made mutable.</p>
</li>
<li><a name="mprotect-RW-for-%25p-%25u-failed-with-%25d"></a><b>mprotect RW for %p %u failed with %d</b>
<p>(S) You compiled perl with <b>-D</b>PERL_DEBUG_READONLY_OPS (see
<a href="perlhacktips.html">perlhacktips</a>), but a read-only op tree could not be made
mutable before freeing the ops.</p>
</li>
<li><a name="msg%25s-not-implemented"></a><b>msg%s not implemented</b>
<p>(F) You don't have System V message IPC on your system.</p>
</li>
<li><a name="Multidimensional-syntax-%25s-not-supported"></a><b>Multidimensional syntax %s not supported</b>
<p>(W syntax) Multidimensional arrays aren't written like <code class="inline"><span class="i">$foo</span>[<span class="n">1</span><span class="cm">,</span><span class="n">2</span><span class="cm">,</span><span class="n">3</span>]</code>
.
They're written like <code class="inline"><span class="i">$foo</span>[<span class="n">1</span>][<span class="n">2</span>][<span class="n">3</span>]</code>
, as in C.</p>
</li>
<li><a name="Multiple-slurpy-parameters-not-allowed"></a><b>Multiple slurpy parameters not allowed</b>
<p>(F) In subroutine signatures, a slurpy parameter (<code class="inline"><span class="i">@</span></code>
 or <code class="inline"><span class="i">%</span></code>
) must be
the last parameter, and there must not be more than one of them; for
example:</p>
<pre class="verbatim"><ol><li><a name="foo"></a>    sub <span class="m">foo ($a, @b)</span>    <span class="s">{</span><span class="s">}</span> <span class="c"># legal</span></li><li><a name="foo-1"></a>    sub <span class="m">foo ($a, @b, %)</span> <span class="s">{</span><span class="s">}</span> <span class="c"># invalid</span></li></ol></pre></li>
<li><a name="'%2f'-must-follow-a-numeric-type-in-unpack"></a><b>'/' must follow a numeric type in unpack</b>
<p>(F) You had an unpack template that contained a '/', but this did not
follow some unpack specification producing a numeric value.
See <a href="functions/pack.html">pack</a>.</p>
</li>
<li><a name="%25s-must-not-be-a-named-sequence-in-transliteration-operator"></a><b>%s must not be a named sequence in transliteration operator</b>
<p>(F) Transliteration (<code class="inline"><a class="l_k" href="functions/tr.html">tr///</a></code> and <code class="inline"><a class="l_k" href="functions/y.html">y///</a></code>) transliterates individual
characters.  But a named sequence by definition is more than an
individual charater, and hence doing this operation on it doesn't make
sense.</p>
</li>
<li><a name="%22my-sub%22-not-yet-implemented"></a><b>"my sub" not yet implemented</b>
<p>(F) Lexically scoped subroutines are not yet implemented.  Don't try
that yet.</p>
</li>
<li><a name="%22my%22-subroutine-%25s-can't-be-in-a-package"></a><b>"my" subroutine %s can't be in a package</b>
<p>(F) Lexically scoped subroutines aren't in a package, so it doesn't make
sense to try to declare one with a package qualifier on the front.</p>
</li>
<li><a name="%22my-%25s%22-used-in-sort-comparison"></a><b>"my %s" used in sort comparison</b>
<p>(W syntax) The package variables $a and $b are used for sort comparisons.
You used $a or $b in as an operand to the <code class="inline">&lt;=&gt;</code>
 or <code class="inline">cmp</code>
 operator inside a
sort comparison block, and the variable had earlier been declared as a
lexical variable.  Either qualify the sort variable with the package
name, or rename the lexical variable.</p>
</li>
<li><a name="%22my%22-variable-%25s-can't-be-in-a-package"></a><b>"my" variable %s can't be in a package</b>
<p>(F) Lexically scoped variables aren't in a package, so it doesn't make
sense to try to declare one with a package qualifier on the front.  Use
local() if you want to localize a package variable.</p>
</li>
<li><a name="Name-%22%25s%3a%3a%25s%22-used-only-once%3a-possible-typo"></a><b>Name "%s::%s" used only once: possible typo</b>
<p>(W once) Typographical errors often show up as unique variable
names.  If you had a good reason for having a unique name, then
just mention it again somehow to suppress the message.  The <code class="inline"><a class="l_k" href="functions/our.html">our</a></code>
declaration is also provided for this purpose.</p>
<p>NOTE: This warning detects package symbols that have been used
only once.  This means lexical variables will never trigger this
warning.  It also means that all of the package variables $c, @c,
%c, as well as *c, &amp;c, sub c{}, c(), and c (the filehandle or
format) are considered the same; if a program uses $c only once
but also uses any of the others it will not trigger this warning.
Symbols beginning with an underscore and symbols using special
identifiers (q.v. <a href="perldata.html">perldata</a>) are exempt from this warning.</p>
</li>
<li><a name="Need-exactly-3-octal-digits-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>Need exactly 3 octal digits in regex; marked by &lt;-- HERE in m/%s/</b>
<p>(F) Within <code class="inline"><span class="s">(</span><span class="q">?[   ])</span></code>
, all constants interpreted as octal need to be
exactly 3 digits long.  This helps catch some ambiguities.  If your
constant is too short, add leading zeros, like</p>
<pre class="verbatim"><ol><li> <span class="s">(</span><span class="q">?[ [ \078 ] ])     # Syntax error!</span></li><li> <span class="q"> (?</span><span class="s">[</span> <span class="s">[</span> \<span class="n">0078</span> <span class="s">]</span> <span class="s">]</span><span class="s">)</span>    <span class="c"># Works</span></li><li> <span class="s">(</span><span class="q">?[ [ \007 8 ] ])   # Clearer</span></li></ol></pre><p>The maximum number this construct can express is <code class="inline">\<span class="n">777</span></code>
.  If you
need a larger one, you need to use <a href="perlrebackslash.html#Octal-escapes">\o{}</a> instead.  If you meant
two separate things, you need to separate them:</p>
<pre class="verbatim"><ol><li> <span class="s">(</span><span class="q">?[ [ \7776 ] ])        # Syntax error!</span></li><li> <span class="q"> (?</span><span class="s">[</span> <span class="s">[</span> \<span class="i">o</span><span class="s">{</span><span class="n">7776</span><span class="s">}</span> <span class="s">]</span> <span class="s">]</span><span class="s">)</span>     <span class="c"># One meaning</span></li><li> <span class="s">(</span><span class="q">?[ [ \777 6 ] ])       # Another meaning</span></li><li> <span class="q"> (?</span><span class="s">[</span> <span class="s">[</span> \<span class="n">777</span> \<span class="n">006</span> <span class="s">]</span> <span class="s">]</span><span class="s">)</span>    <span class="c"># Still another</span></li></ol></pre></li>
<li><a name="Negative-'%2f'-count-in-unpack"></a><b>Negative '/' count in unpack</b>
<p>(F) The length count obtained from a length/code unpack operation was
negative.  See <a href="functions/pack.html">pack</a>.</p>
</li>
<li><a name="Negative-length"></a><b>Negative length</b>
<p>(F) You tried to do a read/write/send/recv operation with a buffer
length that is less than 0.  This is difficult to imagine.</p>
</li>
<li><a name="Negative-offset-to-vec-in-lvalue-context"></a><b>Negative offset to vec in lvalue context</b>
<p>(F) When <code class="inline"><a class="l_k" href="functions/vec.html">vec</a></code> is called in an lvalue context, the second argument must be
greater than or equal to zero.</p>
</li>
<li><a name="Negative-repeat-count-does-nothing"></a><b>Negative repeat count does nothing</b>
<p>(W numeric) You tried to execute the
<a href="perlop.html#Multiplicative-Operators">x </a> repetition operator fewer than 0
times, which doesn't make sense.</p>
</li>
<li><a name="Nested-quantifiers-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>Nested quantifiers in regex; marked by &lt;-- HERE in m/%s/</b>
<p>(F) You can't quantify a quantifier without intervening parentheses.
So things like ** or +* or ?* are illegal.  The &lt;-- HERE shows
whereabouts in the regular expression the problem was discovered.</p>
<p>Note that the minimal matching quantifiers, <code class="inline"><span class="i">*?</span></code>
, <code class="inline">+?</code>, and
<code class="inline"><span class="q">??</span></code>
 appear to be nested quantifiers, but aren't.  See <a href="perlre.html">perlre</a>.</p>
</li>
<li><a name="%25s-never-introduced"></a><b>%s never introduced</b>
<p>(S internal) The symbol in question was declared but somehow went out of
scope before it could possibly have been used.</p>
</li>
<li><a name="next%3a%3amethod%2fnext%3a%3acan%2fmaybe%3a%3anext%3a%3amethod-cannot-find-enclosing-method"></a><b>next::method/next::can/maybe::next::method cannot find enclosing method</b>
<p>(F) <code class="inline"><a class="l_k" href="functions/next.html">next::method</a></code> needs to be called within the context of a
real method in a real package, and it could not find such a context.
See <a href="mro.html">mro</a>.</p>
</li>
<li><a name="%5cN-in-a-character-class-must-be-a-named-character%3a-%5cN%7b...%7d-in-regex%3b--marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>\N in a character class must be a named character: \N{...} in regex; 
marked by &lt;-- HERE in m/%s/</b>
<p>(F) The new (as of Perl 5.12) meaning of <code class="inline">\<span class="w">N</span></code>
 as <code class="inline">[^\n]</code> is not valid in a
bracketed character class, for the same reason that <code class="inline">.</code> in a character
class loses its specialness: it matches almost everything, which is
probably not what you want.</p>
</li>
<li><a name="%5cN%7b%7d-in-inverted-character-class-or-as-a-range-end-point-is-restricted-to-one-character-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>\N{} in inverted character class or as a range end-point is restricted to one character in regex; marked by &lt;-- HERE in m/%s/</b>
<p>(F) Named Unicode character escapes (<code class="inline">\<span class="i">N</span><span class="s">{</span>...<span class="s">}</span></code>
) may return a
multi-character sequence.  Even though a character class is
supposed to match just one character of input, perl will match the
whole thing correctly, except when the class is inverted (<code class="inline">[^...]</code>),
or the escape is the beginning or final end point of a range.  The
mathematically logical behavior for what matches when inverting
is very different from what people expect, so we have decided to
forbid it.  Similarly unclear is what should be generated when the
<code class="inline">\<span class="i">N</span><span class="s">{</span>...<span class="s">}</span></code>
 is used as one of the end points of the range, such as in</p>
<pre class="verbatim"><ol><li> <span class="s">[</span>\<span class="i">x</span><span class="s">{</span><span class="n">41</span><span class="s">}</span>-\<span class="i">N</span><span class="s">{</span><span class="w">ARABIC</span> <span class="w">SEQUENCE</span> <span class="w">YEH</span> <span class="w">WITH</span> <span class="w">HAMZA</span> <span class="w">ABOVE</span> <span class="w">WITH</span> <span class="w">AE</span><span class="s">}</span><span class="s">]</span></li></ol></pre><p>What is meant here is unclear, as the <code class="inline">\<span class="i">N</span><span class="s">{</span>...<span class="s">}</span></code>
 escape is a sequence
of code points, so this is made an error.</p>
</li>
<li><a name="%5cN%7bNAME%7d-must-be-resolved-by-the-lexer-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>\N{NAME} must be resolved by the lexer in regex; marked by
&lt;-- HERE in m/%s/</b>
<p>(F) When compiling a regex pattern, an unresolved named character or
sequence was encountered.  This can happen in any of several ways that
bypass the lexer, such as using single-quotish context, or an extra
backslash in double-quotish:</p>
<pre class="verbatim"><ol><li>    <span class="i">$re</span> = <span class="q">&#39;\N{SPACE}&#39;</span><span class="sc">;</span>	<span class="c"># Wrong!</span></li><li>    <span class="i">$re</span> = <span class="q">&quot;\\N{SPACE}&quot;</span><span class="sc">;</span>	<span class="c"># Wrong!</span></li><li>    <span class="q">/$re/</span><span class="sc">;</span></li></ol></pre><p>Instead, use double-quotes with a single backslash:</p>
<pre class="verbatim"><ol><li>    <span class="i">$re</span> = <span class="q">&quot;\N{SPACE}&quot;</span><span class="sc">;</span>	<span class="c"># ok</span></li><li>    <span class="q">/$re/</span><span class="sc">;</span></li></ol></pre><p>The lexer can be bypassed as well by creating the pattern from smaller
components:</p>
<pre class="verbatim"><ol><li>    <span class="i">$re</span> = <span class="q">&#39;\N&#39;</span><span class="sc">;</span></li><li>    <span class="q">/${re}{SPACE}/</span><span class="sc">;</span>	<span class="c"># Wrong!</span></li></ol></pre><p>It's not a good idea to split a construct in the middle like this, and
it doesn't work here.  Instead use the solution above.</p>
<p>Finally, the message also can happen under the <code class="inline">/x</code> regex modifier when the
<code class="inline">\<span class="w">N</span></code>
 is separated by spaces from the <code class="inline">{</code>, in which case, remove the spaces.</p>
<pre class="verbatim"><ol><li>    <span class="q">/\N {SPACE}/x</span><span class="sc">;</span>	<span class="c"># Wrong!</span></li><li>    <span class="q">/\N{SPACE}/x</span><span class="sc">;</span>	<span class="c"># ok</span></li></ol></pre></li>
<li><a name="No-%25s-allowed-while-running-setuid"></a><b>No %s allowed while running setuid</b>
<p>(F) Certain operations are deemed to be too insecure for a setuid or
setgid script to even be allowed to attempt.  Generally speaking there
will be another way to do what you want that is, if not secure, at least
securable.  See <a href="perlsec.html">perlsec</a>.</p>
</li>
<li><a name="No-code-specified-for--%25c"></a><b>No code specified for -%c</b>
<p>(F) Perl's <b>-e</b> and <b>-E</b> command-line options require an argument.  If
you want to run an empty program, pass the empty string as a separate
argument or run a program consisting of a single 0 or 1:</p>
<pre class="verbatim"><ol><li>    <span class="w">perl</span> -e <span class="q">&quot;&quot;</span></li><li>    <span class="w">perl</span> -<span class="w">e0</span></li><li>    <span class="w">perl</span> -<span class="w">e1</span></li></ol></pre></li>
<li><a name="No-comma-allowed-after-%25s"></a><b>No comma allowed after %s</b>
<p>(F) A list operator that has a filehandle or "indirect object" is
not allowed to have a comma between that and the following arguments.
Otherwise it'd be just another one of the arguments.</p>
<p>One possible cause for this is that you expected to have imported
a constant to your name space with <b>use</b> or <b>import</b> while no such
importing took place, it may for example be that your operating
system does not support that particular constant.  Hopefully you did
use an explicit import list for the constants you expect to see;
please see <a href="functions/use.html">use</a> and <a href="functions/import.html">import</a>.  While an
explicit import list would probably have caught this error earlier
it naturally does not remedy the fact that your operating system
still does not support that constant.  Maybe you have a typo in
the constants of the symbol import list of <b>use</b> or <b>import</b> or in the
constant name at the line where this error was triggered?</p>
</li>
<li><a name="No-command-into-which-to-pipe-on-command-line"></a><b>No command into which to pipe on command line</b>
<p>(F) An error peculiar to VMS.  Perl handles its own command line
redirection, and found a '|' at the end of the command line, so it
doesn't know where you want to pipe the output from this command.</p>
</li>
<li><a name="No-DB%3a%3aDB-routine-defined"></a><b>No DB::DB routine defined</b>
<p>(F) The currently executing code was compiled with the <b>-d</b> switch, but
for some reason the current debugger (e.g. <i>perl5db.pl</i> or a <code class="inline"><span class="w">Devel::</span></code>

module) didn't define a routine to be called at the beginning of each
statement.</p>
</li>
<li><a name="No-dbm-on-this-machine"></a><b>No dbm on this machine</b>
<p>(P) This is counted as an internal error, because every machine should
supply dbm nowadays, because Perl comes with SDBM.  See <a href="SDBM_File.html">SDBM_File</a>.</p>
</li>
<li><a name="No-DB%3a%3asub-routine-defined"></a><b>No DB::sub routine defined</b>
<p>(F) The currently executing code was compiled with the <b>-d</b> switch, but
for some reason the current debugger (e.g. <i>perl5db.pl</i> or a <code class="inline"><span class="w">Devel::</span></code>

module) didn't define a <code class="inline"><span class="w">DB::sub</span></code>
 routine to be called at the beginning
of each ordinary subroutine call.</p>
</li>
<li><a name="No-directory-specified-for--I"></a><b>No directory specified for -I</b>
<p>(F) The <b>-I</b> command-line switch requires a directory name as part of the
<i>same</i> argument.  Use <b>-Ilib</b>, for instance.  <b>-I lib</b> won't work.</p>
</li>
<li><a name="No-error-file-after-2%3e-or-2%3e%3e-on-command-line"></a><b>No error file after 2&gt; or 2&gt;&gt; on command line</b>
<p>(F) An error peculiar to VMS.  Perl handles its own command line
redirection, and found a '2&gt;' or a '2&gt;&gt;' on the command line, but can't
find the name of the file to which to write data destined for stderr.</p>
</li>
<li><a name="No-group-ending-character-'%25c'-found-in-template"></a><b>No group ending character '%c' found in template</b>
<p>(F) A pack or unpack template has an opening '(' or '[' without its
matching counterpart.  See <a href="functions/pack.html">pack</a>.</p>
</li>
<li><a name="No-input-file-after-%3c-on-command-line"></a><b>No input file after &lt; on command line</b>
<p>(F) An error peculiar to VMS.  Perl handles its own command line
redirection, and found a '&lt;' on the command line, but can't find the
name of the file from which to read data for stdin.</p>
</li>
<li><a name="No-next%3a%3amethod-'%25s'-found-for-%25s"></a><b>No next::method '%s' found for %s</b>
<p>(F) <code class="inline"><a class="l_k" href="functions/next.html">next::method</a></code> found no further instances of this method name
in the remaining packages of the MRO of this class.  If you don't want
it throwing an exception, use <code class="inline"><span class="w">maybe::next::method</span></code>

or <code class="inline"><a class="l_k" href="functions/next.html">next::can</a></code>.  See <a href="mro.html">mro</a>.</p>
</li>
<li><a name="Non-finite-repeat-count-does-nothing"></a><b>Non-finite repeat count does nothing</b>
<p>(W numeric) You tried to execute the
<a href="perlop.html#Multiplicative-Operators">x </a> repetition operator <code class="inline"><span class="w">Inf</span></code>
 (or
<code class="inline">-<span class="w">Inf</span></code>
) or <code class="inline"><span class="w">NaN</span></code>
 times, which doesn't make sense.</p>
</li>
<li><a name="Non-hex-character-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>Non-hex character in regex; marked by &lt;-- HERE in m/%s/</b>
<p>(F) In a regular expression, there was a non-hexadecimal character where
a hex one was expected, like</p>
<pre class="verbatim"><ol><li> <span class="s">(</span><span class="q">?[ [ \xDG ] ])</span></li><li> <span class="q"> (?</span><span class="s">[</span> <span class="s">[</span> \<span class="i">x</span><span class="s">{</span><span class="w">DEKA</span><span class="s">}</span> <span class="s">]</span> <span class="s">]</span><span class="s">)</span></li></ol></pre></li>
<li><a name="Non-octal-character-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>Non-octal character in regex; marked by &lt;-- HERE in m/%s/</b>
<p>(F) In a regular expression, there was a non-octal character where
an octal one was expected, like</p>
<pre class="verbatim"><ol><li> <span class="s">(</span><span class="q">?[ [ \o{1278} ] ])</span></li></ol></pre></li>
<li><a name="Non-octal-character-'%25c'.--Resolved-as-%22%25s%22"></a><b>Non-octal character '%c'.  Resolved as "%s"</b>
<p>(W digit) In parsing an octal numeric constant, a character was
unexpectedly encountered that isn't octal.  The resulting value
is as indicated.</p>
</li>
<li><a name="%22no%22-not-allowed-in-expression"></a><b>"no" not allowed in expression</b>
<p>(F) The "no" keyword is recognized and executed at compile time, and
returns no useful value.  See <a href="perlmod.html">perlmod</a>.</p>
</li>
<li><a name="Non-string-passed-as-bitmask"></a><b>Non-string passed as bitmask</b>
<p>(W misc) A number has been passed as a bitmask argument to select().
Use the vec() function to construct the file descriptor bitmasks for
select.  See <a href="functions/select.html">select</a>.</p>
</li>
<li><a name="No-output-file-after-%3e-on-command-line"></a><b>No output file after &gt; on command line</b>
<p>(F) An error peculiar to VMS.  Perl handles its own command line
redirection, and found a lone '&gt;' at the end of the command line, so it
doesn't know where you wanted to redirect stdout.</p>
</li>
<li><a name="No-output-file-after-%3e-or%3e%3e-on-command-line"></a><b>No output file after &gt; or&gt;&gt; on command line</b>
<p>(F) An error peculiar to VMS.  Perl handles its own command line
redirection, and found a '&gt;' or a '&gt;&gt;' on the command line, but can't
find the name of the file to which to write data destined for stdout.</p>
</li>
<li><a name="No-package-name-allowed-for-variable-%25s-in-%22our%22"></a><b>No package name allowed for variable %s in "our"</b>
<p>(F) Fully qualified variable names are not allowed in "our"
declarations, because that doesn't make much sense under existing
rules.  Such syntax is reserved for future extensions.</p>
</li>
<li><a name="No-Perl-script-found-in-input"></a><b>No Perl script found in input</b>
<p>(F) You called <code class="inline"><span class="w">perl</span> -x</code>
, but no line was found in the file beginning
with #! and containing the word "perl".</p>
</li>
<li><a name="No-setregid-available"></a><b>No setregid available</b>
<p>(F) Configure didn't find anything resembling the setregid() call for
your system.</p>
</li>
<li><a name="No-setreuid-available"></a><b>No setreuid available</b>
<p>(F) Configure didn't find anything resembling the setreuid() call for
your system.</p>
</li>
<li><a name="No-such-class-%25s"></a><b>No such class %s</b>
<p>(F) You provided a class qualifier in a "my", "our" or "state"
declaration, but this class doesn't exist at this point in your program.</p>
</li>
<li><a name="No-such-class-field-%22%25s%22-in-variable-%25s-of-type-%25s"></a><b>No such class field "%s" in variable %s of type %s</b>
<p>(F) You tried to access a key from a hash through the indicated typed
variable but that key is not allowed by the package of the same type.
The indicated package has restricted the set of allowed keys using the
<a href="fields.html">fields</a> pragma.</p>
</li>
<li><a name="No-such-hook%3a-%25s"></a><b>No such hook: %s</b>
<p>(F) You specified a signal hook that was not recognized by Perl.
Currently, Perl accepts <code class="inline"><span class="w">__DIE__</span></code>
 and <code class="inline"><span class="w">__WARN__</span></code>
 as valid signal hooks.</p>
</li>
<li><a name="No-such-pipe-open"></a><b>No such pipe open</b>
<p>(P) An error peculiar to VMS.  The internal routine my_pclose() tried to
close a pipe which hadn't been opened.  This should have been caught
earlier as an attempt to close an unopened filehandle.</p>
</li>
<li><a name="No-such-signal%3a-SIG%25s"></a><b>No such signal: SIG%s</b>
<p>(W signal) You specified a signal name as a subscript to %SIG that was
not recognized.  Say <code class="inline"><a class="l_k" href="functions/kill.html">kill</a> -l</code>
 in your shell to see the valid signal
names on your system.</p>
</li>
<li><a name="Not-a-CODE-reference"></a><b>Not a CODE reference</b>
<p>(F) Perl was trying to evaluate a reference to a code value (that is, a
subroutine), but found a reference to something else instead.  You can
use the ref() function to find out what kind of ref it really was.  See
also <a href="perlref.html">perlref</a>.</p>
</li>
<li><a name="Not-a-GLOB-reference"></a><b>Not a GLOB reference</b>
<p>(F) Perl was trying to evaluate a reference to a "typeglob" (that is, a
symbol table entry that looks like <code class="inline"><span class="i">*foo</span></code>
), but found a reference to
something else instead.  You can use the ref() function to find out what
kind of ref it really was.  See <a href="perlref.html">perlref</a>.</p>
</li>
<li><a name="Not-a-HASH-reference"></a><b>Not a HASH reference</b>
<p>(F) Perl was trying to evaluate a reference to a hash value, but found a
reference to something else instead.  You can use the ref() function to
find out what kind of ref it really was.  See <a href="perlref.html">perlref</a>.</p>
</li>
<li><a name="'%23'-not-allowed-immediately-following-a-sigil-in-a-subroutine-signature"></a><b>'#' not allowed immediately following a sigil in a subroutine signature</b>
<p>(F) In a subroutine signature definition, a comment following a sigil
(<code class="inline"><span class="i">$</span></code>
, <code class="inline"><span class="i">@</span></code>
 or <code class="inline"><span class="i">%</span></code>
), needs to be separated by whitespace or a commma etc., in
particular to avoid confusion with the <code class="inline"><span class="i">$#</span></code>
 variable.  For example:</p>
<pre class="verbatim"><ol><li>    <span class="c"># bad</span></li><li><span class="q">    sub f ($# ignore first arg</span></li><li><span class="q">           , $b) {}</span></li><li><span class="q">    # good</span></li><li><span class="q">    sub f ($, # ignore first arg</span></li><li><span class="q">           $b) {}</span></li></ol></pre></li>
<li><a name="Not-an-ARRAY-reference"></a><b>Not an ARRAY reference</b>
<p>(F) Perl was trying to evaluate a reference to an array value, but found
a reference to something else instead.  You can use the ref() function
to find out what kind of ref it really was.  See <a href="perlref.html">perlref</a>.</p>
</li>
<li><a name="Not-a-SCALAR-reference"></a><b>Not a SCALAR reference</b>
<p>(F) Perl was trying to evaluate a reference to a scalar value, but found
a reference to something else instead.  You can use the ref() function
to find out what kind of ref it really was.  See <a href="perlref.html">perlref</a>.</p>
</li>
<li><a name="Not-a-subroutine-reference"></a><b>Not a subroutine reference</b>
<p>(F) Perl was trying to evaluate a reference to a code value (that is, a
subroutine), but found a reference to something else instead.  You can
use the ref() function to find out what kind of ref it really was.  See
also <a href="perlref.html">perlref</a>.</p>
</li>
<li><a name="Not-a-subroutine-reference-in-overload-table"></a><b>Not a subroutine reference in overload table</b>
<p>(F) An attempt was made to specify an entry in an overloading table that
doesn't somehow point to a valid subroutine.  See <a href="overload.html">overload</a>.</p>
</li>
<li><a name="Not-enough-arguments-for-%25s"></a><b>Not enough arguments for %s</b>
<p>(F) The function requires more arguments than you specified.</p>
</li>
<li><a name="Not-enough-format-arguments"></a><b>Not enough format arguments</b>
<p>(W syntax) A format specified more picture fields than the next line
supplied.  See <a href="perlform.html">perlform</a>.</p>
</li>
<li><a name="%25s%3a-not-found"></a><b>%s: not found</b>
<p>(A) You've accidentally run your script through the Bourne shell instead
of Perl.  Check the #! line, or manually feed your script into Perl
yourself.</p>
</li>
<li><a name="(%3f%5b...%5d)-not-valid-in-locale-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>(?[...]) not valid in locale in regex; marked by &lt;-- HERE in m/%s/</b>
<p>(F) <code class="inline"><span class="s">(</span><span class="q">?[...])</span></code>
 cannot be used within the scope of a <code class="inline"><a class="l_k" href="functions/use.html">use</a> <span class="w">locale</span></code>
 or with
an <code class="inline"><span class="q">/l</span></code>
 regular expression modifier, as that would require deferring
to run-time the calculation of what it should evaluate to, and it is
regex compile-time only.</p>
</li>
<li><a name="no-UTC-offset-information%3b-assuming-local-time-is-UTC"></a><b>no UTC offset information; assuming local time is UTC</b>
<p>(S) A warning peculiar to VMS.  Perl was unable to find the local
timezone offset, so it's assuming that local system time is equivalent
to UTC.  If it's not, define the logical name
<i>SYS$TIMEZONE_DIFFERENTIAL</i> to translate to the number of seconds which
need to be added to UTC to get local time.</p>
</li>
<li><a name="NULL-OP-IN-RUN"></a><b>NULL OP IN RUN</b>
<p>(S debugging) Some internal routine called run() with a null opcode
pointer.</p>
</li>
<li><a name="Null-picture-in-formline"></a><b>Null picture in formline</b>
<p>(F) The first argument to formline must be a valid format picture
specification.  It was found to be empty, which probably means you
supplied it an uninitialized value.  See <a href="perlform.html">perlform</a>.</p>
</li>
<li><a name="Null-realloc"></a><b>Null realloc</b>
<p>(P) An attempt was made to realloc NULL.</p>
</li>
<li><a name="NULL-regexp-argument"></a><b>NULL regexp argument</b>
<p>(P) The internal pattern matching routines blew it big time.</p>
</li>
<li><a name="NULL-regexp-parameter"></a><b>NULL regexp parameter</b>
<p>(P) The internal pattern matching routines are out of their gourd.</p>
</li>
<li><a name="Number-too-long"></a><b>Number too long</b>
<p>(F) Perl limits the representation of decimal numbers in programs to
about 250 characters.  You've exceeded that length.  Future
versions of Perl are likely to eliminate this arbitrary limitation.  In
the meantime, try using scientific notation (e.g. "1e6" instead of
"1_000_000").</p>
</li>
<li><a name="Number-with-no-digits"></a><b>Number with no digits</b>
<p>(F) Perl was looking for a number but found nothing that looked like
a number.  This happens, for example with <code class="inline">\<span class="w">o</span><span class="s">{</span><span class="s">}</span></code>
, with no number between
the braces.</p>
</li>
<li><a name="Octal-number-%3e-037777777777-non-portable"></a><b>Octal number &gt; 037777777777 non-portable</b>
<p>(W portable) The octal number you specified is larger than 2**32-1
(4294967295) and therefore non-portable between systems.  See
<a href="perlport.html">perlport</a> for more on portability concerns.</p>
</li>
<li><a name="Odd-name%2fvalue-argument-for-subroutine-'%25s'"></a><b>Odd name/value argument for subroutine '%s'</b>
<p>(F) A subroutine using a slurpy hash parameter in its signature
received an odd number of arguments to populate the hash.  It requires
the arguments to be paired, with the same number of keys as values.
The caller of the subroutine is presumably at fault.</p>
<p>The message attempts to include the name of the called subroutine. If the
subroutine has been aliased, the subroutine's original name will be shown,
regardless of what name the caller used.</p>
</li>
<li><a name="Odd-number-of-arguments-for-overload%3a%3aconstant"></a><b>Odd number of arguments for overload::constant</b>
<p>(W overload) The call to overload::constant contained an odd number of
arguments.  The arguments should come in pairs.</p>
</li>
<li><a name="Odd-number-of-elements-in-anonymous-hash"></a><b>Odd number of elements in anonymous hash</b>
<p>(W misc) You specified an odd number of elements to initialize a hash,
which is odd, because hashes come in key/value pairs.</p>
</li>
<li><a name="Odd-number-of-elements-in-hash-assignment"></a><b>Odd number of elements in hash assignment</b>
<p>(W misc) You specified an odd number of elements to initialize a hash,
which is odd, because hashes come in key/value pairs.</p>
</li>
<li><a name="Offset-outside-string"></a><b>Offset outside string</b>
<p>(F)(W layer) You tried to do a read/write/send/recv/seek operation
with an offset pointing outside the buffer.  This is difficult to
imagine.  The sole exceptions to this are that zero padding will
take place when going past the end of the string when either
<code class="inline"><a class="l_k" href="functions/sysread.html">sysread()</a></code>ing a file, or when seeking past the end of a scalar opened
for I/O (in anticipation of future reads and to imitate the behavior
with real files).</p>
</li>
<li><a name="%25s()-on-unopened-%25s"></a><b>%s() on unopened %s</b>
<p>(W unopened) An I/O operation was attempted on a filehandle that was
never initialized.  You need to do an open(), a sysopen(), or a socket()
call, or call a constructor from the FileHandle package.</p>
</li>
<li><a name="-%25s-on-unopened-filehandle-%25s"></a><b>-%s on unopened filehandle %s</b>
<p>(W unopened) You tried to invoke a file test operator on a filehandle
that isn't open.  Check your control flow.  See also <a href="functions/-X.html">-X</a>.</p>
</li>
<li><a name="oops%3a-oopsAV"></a><b>oops: oopsAV</b>
<p>(S internal) An internal warning that the grammar is screwed up.</p>
</li>
<li><a name="oops%3a-oopsHV"></a><b>oops: oopsHV</b>
<p>(S internal) An internal warning that the grammar is screwed up.</p>
</li>
<li><a name="Opening-dirhandle-%25s-also-as-a-file.-This-will-be-a-fatal-error-in-Perl-5.28"></a><b>Opening dirhandle %s also as a file. This will be a fatal error in Perl 5.28</b>
<p>(D io, deprecated) You used open() to associate a filehandle to
a symbol (glob or scalar) that already holds a dirhandle.
Although legal, this idiom might render your code confusing
and this was deprecated in Perl 5.10. In Perl 5.28, this 
will be a fatal error.</p>
</li>
<li><a name="Opening-filehandle-%25s-also-as-a-directory.-This-will-be-a-fatal-error-in-Perl-5.28"></a><b>Opening filehandle %s also as a directory. This will be a fatal error in Perl 5.28</b>
<p>(D io, deprecated) You used opendir() to associate a dirhandle to
a symbol (glob or scalar) that already holds a filehandle.
Although legal, this idiom might render your code confusing
and this was deprecated in Perl 5.10. In Perl 5.28, this 
will be a fatal error.</p>
</li>
<li><a name="Operand-with-no-preceding-operator-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>Operand with no preceding operator in regex; marked by &lt;-- HERE in
m/%s/</b>
<p>(F) You wrote something like</p>
<pre class="verbatim"><ol><li> <span class="s">(</span><span class="q">?[ \p{Digit} \p{Thai} ])</span></li></ol></pre><p>There are two operands, but no operator giving how you want to combine
them.</p>
</li>
<li><a name="Operation-%22%25s%22%3a-no-method-found%2c-%25s"></a><b>Operation "%s": no method found, %s</b>
<p>(F) An attempt was made to perform an overloaded operation for which no
handler was defined.  While some handlers can be autogenerated in terms
of other handlers, there is no default handler for any operation, unless
the <code class="inline"><span class="w">fallback</span></code>
 overloading key is specified to be true.  See <a href="overload.html">overload</a>.</p>
</li>
<li><a name="Operation-%22%25s%22-returns-its-argument-for-non-Unicode-code-point-0x%25X"></a><b>Operation "%s" returns its argument for non-Unicode code point 0x%X</b>
<p>(S non_unicode) You performed an operation requiring Unicode rules
on a code point that is not in Unicode, so what it should do is not
defined.  Perl has chosen to have it do nothing, and warn you.</p>
<p>If the operation shown is "ToFold", it means that case-insensitive
matching in a regular expression was done on the code point.</p>
<p>If you know what you are doing you can turn off this warning by
<code class="inline"><a class="l_k" href="functions/no.html">no</a> <span class="w">warnings</span> <span class="q">&#39;non_unicode&#39;</span><span class="sc">;</span></code>
.</p>
</li>
<li><a name="Operation-%22%25s%22-returns-its-argument-for-UTF-16-surrogate-U%2b%25X"></a><b>Operation "%s" returns its argument for UTF-16 surrogate U+%X</b>
<p>(S surrogate) You performed an operation requiring Unicode
rules on a Unicode surrogate.  Unicode frowns upon the use
of surrogates for anything but storing strings in UTF-16, but
rules are (reluctantly) defined for the surrogates, and
they are to do nothing for this operation.  Because the use of
surrogates can be dangerous, Perl warns.</p>
<p>If the operation shown is "ToFold", it means that case-insensitive
matching in a regular expression was done on the code point.</p>
<p>If you know what you are doing you can turn off this warning by
<code class="inline"><a class="l_k" href="functions/no.html">no</a> <span class="w">warnings</span> <span class="q">&#39;surrogate&#39;</span><span class="sc">;</span></code>
.</p>
</li>
<li><a name="Operator-or-semicolon-missing-before-%25s"></a><b>Operator or semicolon missing before %s</b>
<p>(S ambiguous) You used a variable or subroutine call where the parser
was expecting an operator.  The parser has assumed you really meant to
use an operator, but this is highly likely to be incorrect.  For
example, if you say "*foo *foo" it will be interpreted as if you said
"*foo * 'foo'".</p>
</li>
<li><a name="Optional-parameter-lacks-default-expression"></a><b>Optional parameter lacks default expression</b>
<p>(F) In a subroutine signature, you wrote something like "$a =", making a
named optional parameter without a default value.  A nameless optional
parameter is permitted to have no default value, but a named one must
have a specific default.  You probably want "$a = undef".</p>
</li>
<li><a name="%22our%22-variable-%25s-redeclared"></a><b>"our" variable %s redeclared</b>
<p>(W misc) You seem to have already declared the same global once before
in the current lexical scope.</p>
</li>
<li><a name="Out-of-memory!"></a><b>Out of memory!</b>
<p>(X) The malloc() function returned 0, indicating there was insufficient
remaining memory (or virtual memory) to satisfy the request.  Perl has
no option but to exit immediately.</p>
<p>At least in Unix you may be able to get past this by increasing your
process datasize limits: in csh/tcsh use <code class="inline"><span class="w">limit</span></code>
 and
<code class="inline"><span class="w">limit</span> <span class="w">datasize</span> <span class="w">n</span></code>
 (where <code class="inline"><span class="w">n</span></code>
 is the number of kilobytes) to check
the current limits and change them, and in ksh/bash/zsh use <code class="inline"><span class="w">ulimit</span> -<span class="w">a</span></code>

and <code class="inline"><span class="w">ulimit</span> -d <span class="w">n</span></code>
, respectively.</p>
</li>
<li><a name="Out-of-memory-during-%25s-extend"></a><b>Out of memory during %s extend</b>
<p>(X) An attempt was made to extend an array, a list, or a string beyond
the largest possible memory allocation.</p>
</li>
<li><a name="Out-of-memory-during-%22large%22-request-for-%25s"></a><b>Out of memory during "large" request for %s</b>
<p>(F) The malloc() function returned 0, indicating there was insufficient
remaining memory (or virtual memory) to satisfy the request.  However,
the request was judged large enough (compile-time default is 64K), so a
possibility to shut down by trapping this error is granted.</p>
</li>
<li><a name="Out-of-memory-during-request-for-%25s"></a><b>Out of memory during request for %s</b>
<p>(X)(F) The malloc() function returned 0, indicating there was
insufficient remaining memory (or virtual memory) to satisfy the
request.</p>
<p>The request was judged to be small, so the possibility to trap it
depends on the way perl was compiled.  By default it is not trappable.
However, if compiled for this, Perl may use the contents of <code class="inline"><span class="i">$^M</span></code>
 as an
emergency pool after die()ing with this message.  In this case the error
is trappable <i>once</i>, and the error message will include the line and file
where the failed request happened.</p>
</li>
<li><a name="Out-of-memory-during-ridiculously-large-request"></a><b>Out of memory during ridiculously large request</b>
<p>(F) You can't allocate more than 2^31+"small amount" bytes.  This error
is most likely to be caused by a typo in the Perl program. e.g.,
<code class="inline"><span class="i">$arr</span>[<a class="l_k" href="functions/time.html">time</a>]</code>
 instead of <code class="inline"><span class="i">$arr</span>[<span class="i">$time</span>]</code>
.</p>
</li>
<li><a name="Out-of-memory-for-yacc-stack"></a><b>Out of memory for yacc stack</b>
<p>(F) The yacc parser wanted to grow its stack so it could continue
parsing, but realloc() wouldn't give it more memory, virtual or
otherwise.</p>
</li>
<li><a name="'.'-outside-of-string-in-pack"></a><b>'.' outside of string in pack</b>
<p>(F) The argument to a '.' in your template tried to move the working
position to before the start of the packed string being built.</p>
</li>
<li><a name="'%40'-outside-of-string-in-unpack"></a><b>'@' outside of string in unpack</b>
<p>(F) You had a template that specified an absolute position outside
the string being unpacked.  See <a href="functions/pack.html">pack</a>.</p>
</li>
<li><a name="'%40'-outside-of-string-with-malformed-UTF-8-in-unpack"></a><b>'@' outside of string with malformed UTF-8 in unpack</b>
<p>(F) You had a template that specified an absolute position outside
the string being unpacked.  The string being unpacked was also invalid
UTF-8.  See <a href="functions/pack.html">pack</a>.</p>
</li>
<li><a name="overload-arg-'%25s'-is-invalid"></a><b>overload arg '%s' is invalid</b>
<p>(W overload) The <a href="overload.html">overload</a> pragma was passed an argument it did not
recognize.  Did you mistype an operator?</p>
</li>
<li><a name="Overloaded-dereference-did-not-return-a-reference"></a><b>Overloaded dereference did not return a reference</b>
<p>(F) An object with an overloaded dereference operator was dereferenced,
but the overloaded operation did not return a reference.  See
<a href="overload.html">overload</a>.</p>
</li>
<li><a name="Overloaded-qr-did-not-return-a-REGEXP"></a><b>Overloaded qr did not return a REGEXP</b>
<p>(F) An object with a <code class="inline"><a class="l_k" href="functions/qr.html">qr</a></code> overload was used as part of a match, but the
overloaded operation didn't return a compiled regexp.  See <a href="overload.html">overload</a>.</p>
</li>
<li><a name="%25s-package-attribute-may-clash-with-future-reserved-word%3a-%25s"></a><b>%s package attribute may clash with future reserved word: %s</b>
<p>(W reserved) A lowercase attribute name was used that had a
package-specific handler.  That name might have a meaning to Perl itself
some day, even though it doesn't yet.  Perhaps you should use a
mixed-case attribute name, instead.  See <a href="attributes.html">attributes</a>.</p>
</li>
<li><a name="pack%2funpack-repeat-count-overflow"></a><b>pack/unpack repeat count overflow</b>
<p>(F) You can't specify a repeat count so large that it overflows your
signed integers.  See <a href="functions/pack.html">pack</a>.</p>
</li>
<li><a name="page-overflow"></a><b>page overflow</b>
<p>(W io) A single call to write() produced more lines than can fit on a
page.  See <a href="perlform.html">perlform</a>.</p>
</li>
<li><a name="panic%3a-%25s"></a><b>panic: %s</b>
<p>(P) An internal error.</p>
</li>
<li><a name="panic%3a-attempt-to-call-%25s-in-%25s"></a><b>panic: attempt to call %s in %s</b>
<p>(P) One of the file test operators entered a code branch that calls
an ACL related-function, but that function is not available on this
platform.  Earlier checks mean that it should not be possible to
enter this branch on this platform.</p>
</li>
<li><a name="panic%3a-child-pseudo-process-was-never-scheduled"></a><b>panic: child pseudo-process was never scheduled</b>
<p>(P) A child pseudo-process in the ithreads implementation on Windows
was not scheduled within the time period allowed and therefore was not
able to initialize properly.</p>
</li>
<li><a name="panic%3a-ck_grep%2c-type%3d%25u"></a><b>panic: ck_grep, type=%u</b>
<p>(P) Failed an internal consistency check trying to compile a grep.</p>
</li>
<li><a name="panic%3a-corrupt-saved-stack-index-%25ld"></a><b>panic: corrupt saved stack index %ld</b>
<p>(P) The savestack was requested to restore more localized values than
there are in the savestack.</p>
</li>
<li><a name="panic%3a-del_backref"></a><b>panic: del_backref</b>
<p>(P) Failed an internal consistency check while trying to reset a weak
reference.</p>
</li>
<li><a name="panic%3a-do_subst"></a><b>panic: do_subst</b>
<p>(P) The internal pp_subst() routine was called with invalid operational
data.</p>
</li>
<li><a name="panic%3a-do_trans_%25s"></a><b>panic: do_trans_%s</b>
<p>(P) The internal do_trans routines were called with invalid operational
data.</p>
</li>
<li><a name="panic%3a-fold_constants-JMPENV_PUSH-returned-%25d"></a><b>panic: fold_constants JMPENV_PUSH returned %d</b>
<p>(P) While attempting folding constants an exception other than an <code class="inline"><a class="l_k" href="functions/eval.html">eval</a></code>
failure was caught.</p>
</li>
<li><a name="panic%3a-frexp%3a-%25f"></a><b>panic: frexp: %f</b>
<p>(P) The library function frexp() failed, making printf("%f") impossible.</p>
</li>
<li><a name="panic%3a-goto%2c-type%3d%25u%2c-ix%3d%25ld"></a><b>panic: goto, type=%u, ix=%ld</b>
<p>(P) We popped the context stack to a context with the specified label,
and then discovered it wasn't a context we know how to do a goto in.</p>
</li>
<li><a name="panic%3a-gp_free-failed-to-free-glob-pointer"></a><b>panic: gp_free failed to free glob pointer</b>
<p>(P) The internal routine used to clear a typeglob's entries tried
repeatedly, but each time something re-created entries in the glob.
Most likely the glob contains an object with a reference back to
the glob and a destructor that adds a new object to the glob.</p>
</li>
<li><a name="panic%3a-INTERPCASEMOD%2c-%25s"></a><b>panic: INTERPCASEMOD, %s</b>
<p>(P) The lexer got into a bad state at a case modifier.</p>
</li>
<li><a name="panic%3a-INTERPCONCAT%2c-%25s"></a><b>panic: INTERPCONCAT, %s</b>
<p>(P) The lexer got into a bad state parsing a string with brackets.</p>
</li>
<li><a name="panic%3a-kid-popen-errno-read"></a><b>panic: kid popen errno read</b>
<p>(F) A forked child returned an incomprehensible message about its errno.</p>
</li>
<li><a name="panic%3a-last%2c-type%3d%25u"></a><b>panic: last, type=%u</b>
<p>(P) We popped the context stack to a block context, and then discovered
it wasn't a block context.</p>
</li>
<li><a name="panic%3a-leave_scope-clearsv"></a><b>panic: leave_scope clearsv</b>
<p>(P) A writable lexical variable became read-only somehow within the
scope.</p>
</li>
<li><a name="panic%3a-leave_scope-inconsistency-%25u"></a><b>panic: leave_scope inconsistency %u</b>
<p>(P) The savestack probably got out of sync.  At least, there was an
invalid enum on the top of it.</p>
</li>
<li><a name="panic%3a-magic_killbackrefs"></a><b>panic: magic_killbackrefs</b>
<p>(P) Failed an internal consistency check while trying to reset all weak
references to an object.</p>
</li>
<li><a name="panic%3a-malloc%2c-%25s"></a><b>panic: malloc, %s</b>
<p>(P) Something requested a negative number of bytes of malloc.</p>
</li>
<li><a name="panic%3a-memory-wrap"></a><b>panic: memory wrap</b>
<p>(P) Something tried to allocate either more memory than possible or a
negative amount.</p>
</li>
<li><a name="panic%3a-pad_alloc%2c-%25p!%3d%25p"></a><b>panic: pad_alloc, %p!=%p</b>
<p>(P) The compiler got confused about which scratch pad it was allocating
and freeing temporaries and lexicals from.</p>
</li>
<li><a name="panic%3a-pad_free-curpad%2c-%25p!%3d%25p"></a><b>panic: pad_free curpad, %p!=%p</b>
<p>(P) The compiler got confused about which scratch pad it was allocating
and freeing temporaries and lexicals from.</p>
</li>
<li><a name="panic%3a-pad_free-po"></a><b>panic: pad_free po</b>
<p>(P) A zero scratch pad offset was detected internally.  An attempt was
made to free a target that had not been allocated to begin with.</p>
</li>
<li><a name="panic%3a-pad_reset-curpad%2c-%25p!%3d%25p"></a><b>panic: pad_reset curpad, %p!=%p</b>
<p>(P) The compiler got confused about which scratch pad it was allocating
and freeing temporaries and lexicals from.</p>
</li>
<li><a name="panic%3a-pad_sv-po"></a><b>panic: pad_sv po</b>
<p>(P) A zero scratch pad offset was detected internally.  Most likely
an operator needed a target but that target had not been allocated
for whatever reason.</p>
</li>
<li><a name="panic%3a-pad_swipe-curpad%2c-%25p!%3d%25p"></a><b>panic: pad_swipe curpad, %p!=%p</b>
<p>(P) The compiler got confused about which scratch pad it was allocating
and freeing temporaries and lexicals from.</p>
</li>
<li><a name="panic%3a-pad_swipe-po"></a><b>panic: pad_swipe po</b>
<p>(P) An invalid scratch pad offset was detected internally.</p>
</li>
<li><a name="panic%3a-pp_iter%2c-type%3d%25u"></a><b>panic: pp_iter, type=%u</b>
<p>(P) The foreach iterator got called in a non-loop context frame.</p>
</li>
<li><a name="panic%3a-pp_match%25s"></a><b>panic: pp_match%s</b>
<p>(P) The internal pp_match() routine was called with invalid operational
data.</p>
</li>
<li><a name="panic%3a-realloc%2c-%25s"></a><b>panic: realloc, %s</b>
<p>(P) Something requested a negative number of bytes of realloc.</p>
</li>
<li><a name="panic%3a-reference-miscount-on-nsv-in-sv_replace()-(%25d-!%3d-1)"></a><b>panic: reference miscount on nsv in sv_replace() (%d != 1)</b>
<p>(P) The internal sv_replace() function was handed a new SV with a
reference count other than 1.</p>
</li>
<li><a name="panic%3a-restartop-in-%25s"></a><b>panic: restartop in %s</b>
<p>(P) Some internal routine requested a goto (or something like it), and
didn't supply the destination.</p>
</li>
<li><a name="panic%3a-return%2c-type%3d%25u"></a><b>panic: return, type=%u</b>
<p>(P) We popped the context stack to a subroutine or eval context, and
then discovered it wasn't a subroutine or eval context.</p>
</li>
<li><a name="panic%3a-scan_num%2c-%25s"></a><b>panic: scan_num, %s</b>
<p>(P) scan_num() got called on something that wasn't a number.</p>
</li>
<li><a name="panic%3a-Sequence-(%3f%7b...%7d)%3a-no-code-block-found-in-regex-m%2f%25s%2f"></a><b>panic: Sequence (?{...}): no code block found in regex m/%s/</b>
<p>(P) While compiling a pattern that has embedded (?{}) or (??{}) code
blocks, perl couldn't locate the code block that should have already been
seen and compiled by perl before control passed to the regex compiler.</p>
</li>
<li><a name="panic%3a-strxfrm()-gets-absurd---a-%3d%3e-%25u%2c-ab-%3d%3e-%25u"></a><b>panic: strxfrm() gets absurd - a =&gt; %u, ab =&gt; %u</b>
<p>(P) The interpreter's sanity check of the C function strxfrm() failed.
In your current locale the returned transformation of the string "ab"
is shorter than that of the string "a", which makes no sense.</p>
</li>
<li><a name="panic%3a-sv_chop-%25s"></a><b>panic: sv_chop %s</b>
<p>(P) The sv_chop() routine was passed a position that is not within the
scalar's string buffer.</p>
</li>
<li><a name="panic%3a-sv_insert%2c-midend%3d%25p%2c-bigend%3d%25p"></a><b>panic: sv_insert, midend=%p, bigend=%p</b>
<p>(P) The sv_insert() routine was told to remove more string than there
was string.</p>
</li>
<li><a name="panic%3a-top_env"></a><b>panic: top_env</b>
<p>(P) The compiler attempted to do a goto, or something weird like that.</p>
</li>
<li><a name="panic%3a-unimplemented-op-%25s-(%23%25d)-called"></a><b>panic: unimplemented op %s (#%d) called</b>
<p>(P) The compiler is screwed up and attempted to use an op that isn't
permitted at run time.</p>
</li>
<li><a name="panic%3a-unknown-OA_*%3a-%25x"></a><b>panic: unknown OA_*: %x</b>
<p>(P) The internal routine that handles arguments to <code class="inline"><span class="i">&amp;CORE::foo</span><span class="s">(</span><span class="s">)</span></code>

subroutine calls was unable to determine what type of arguments
were expected.</p>
</li>
<li><a name="panic%3a-utf16_to_utf8%3a-odd-bytelen"></a><b>panic: utf16_to_utf8: odd bytelen</b>
<p>(P) Something tried to call utf16_to_utf8 with an odd (as opposed
to even) byte length.</p>
</li>
<li><a name="panic%3a-utf16_to_utf8_reversed%3a-odd-bytelen"></a><b>panic: utf16_to_utf8_reversed: odd bytelen</b>
<p>(P) Something tried to call utf16_to_utf8_reversed with an odd (as opposed
to even) byte length.</p>
</li>
<li><a name="panic%3a-yylex%2c-%25s"></a><b>panic: yylex, %s</b>
<p>(P) The lexer got into a bad state while processing a case modifier.</p>
</li>
<li><a name="Parentheses-missing-around-%22%25s%22-list"></a><b>Parentheses missing around "%s" list</b>
<p>(W parenthesis) You said something like</p>
<pre class="verbatim"><ol><li>    <a class="l_k" href="functions/my.html">my</a> <span class="i">$foo</span><span class="cm">,</span> <span class="i">$bar</span> = <span class="i">@_</span><span class="sc">;</span></li></ol></pre><p>when you meant</p>
<pre class="verbatim"><ol><li>    <a class="l_k" href="functions/my.html">my</a> <span class="s">(</span><span class="i">$foo</span><span class="cm">,</span> <span class="i">$bar</span><span class="s">)</span> = <span class="i">@_</span><span class="sc">;</span></li></ol></pre><p>Remember that "my", "our", "local" and "state" bind tighter than comma.</p>
</li>
<li><a name="Parsing-code-internal-error-(%25s)"></a><b>Parsing code internal error (%s)</b>
<p>(F) Parsing code supplied by an extension violated the parser's API in
a detectable way.</p>
</li>
<li><a name="Pattern-subroutine-nesting-without-pos-change-exceeded-limit-in-regex"></a><b>Pattern subroutine nesting without pos change exceeded limit in regex</b>
<p>(F) You used a pattern that uses too many nested subpattern calls without
consuming any text.  Restructure the pattern so text is consumed before
the nesting limit is exceeded.</p>
</li>
<li><a name="-p-destination%3a-%25s"></a><b><code class="inline">-p</code>
 destination: %s</b>
<p>(F) An error occurred during the implicit output invoked by the <code class="inline">-p</code>

command-line switch.  (This output goes to STDOUT unless you've
redirected it with select().)</p>
</li>
<li><a name="Perl-API-version-%25s-of-%25s-does-not-match-%25s"></a><b>Perl API version %s of %s does not match %s</b>
<p>(F) The XS module in question was compiled against a different incompatible
version of Perl than the one that has loaded the XS module.</p>
</li>
<li><a name="Perl-folding-rules-are-not-up-to-date-for-0x%25X%3b-please-use-the-perlbug-utility-to-report%3b-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>Perl folding rules are not up-to-date for 0x%X; please use the perlbug
utility to report; in regex; marked by &lt;-- HERE in m/%s/</b>
<p>(S regexp) You used a regular expression with case-insensitive matching,
and there is a bug in Perl in which the built-in regular expression
folding rules are not accurate.  This may lead to incorrect results.
Please report this as a bug using the <a href="perlbug.html">perlbug</a> utility.</p>
</li>
<li><a name="PerlIO-layer-'%3awin32'-is-experimental"></a><b>PerlIO layer ':win32' is experimental</b>
<p>(S experimental::win32_perlio) The <code class="inline"><span class="j">:</span><span class="w">win32</span></code>
 PerlIO layer is
experimental.  If you want to take the risk of using this layer,
simply disable this warning:</p>
<pre class="verbatim"><ol><li>    <a class="l_k" href="functions/no.html">no</a> <span class="w">warnings</span> <span class="q">&quot;experimental::win32_perlio&quot;</span><span class="sc">;</span></li></ol></pre></li>
<li><a name="Perl_my_%25s()-not-available"></a><b>Perl_my_%s() not available</b>
<p>(F) Your platform has very uncommon byte-order and integer size,
so it was not possible to set up some or all fixed-width byte-order
conversion functions.  This is only a problem when you're using the
'&lt;' or '&gt;' modifiers in (un)pack templates.  See <a href="functions/pack.html">pack</a>.</p>
</li>
<li><a name="Perl-%25s-required-(did-you-mean-%25s%3f)--this-is-only-%25s%2c-stopped"></a><b>Perl %s required (did you mean %s?)--this is only %s, stopped</b>
<p>(F) The code you are trying to run has asked for a newer version of
Perl than you are running.  Perhaps <code class="inline"><a class="l_k" href="functions/use.html">use</a> <span class="n">5.10</span></code>
 was written instead
of <code class="inline"><a class="l_k" href="functions/use.html">use</a> <span class="n">5.010</span></code>
 or <code class="inline"><a class="l_k" href="functions/use.html">use</a> <span class="v">v5.10</span></code>
.  Without the leading <code class="inline"><span class="w">v</span></code>
, the number is
interpreted as a decimal, with every three digits after the
decimal point representing a part of the version number.  So 5.10
is equivalent to v5.100.</p>
</li>
<li><a name="Perl-%25s-required--this-is-only-%25s%2c-stopped"></a><b>Perl %s required--this is only %s, stopped</b>
<p>(F) The module in question uses features of a version of Perl more
recent than the currently running version.  How long has it been since
you upgraded, anyway?  See <a href="functions/require.html">require</a>.</p>
</li>
<li><a name="PERL_SH_DIR-too-long"></a><b>PERL_SH_DIR too long</b>
<p>(F) An error peculiar to OS/2.  PERL_SH_DIR is the directory to find the
<code class="inline"><span class="w">sh</span></code>
-shell in.  See "PERL_SH_DIR" in <a href="perlos2.html">perlos2</a>.</p>
</li>
<li><a name="PERL_SIGNALS-illegal%3a-%22%25s%22"></a><b>PERL_SIGNALS illegal: "%s"</b>
<p>(X) See <a href="perlrun.html#PERL_SIGNALS">PERL_SIGNALS in perlrun</a> for legal values.</p>
</li>
<li><a name="Perls-since-%25s-too-modern--this-is-%25s%2c-stopped"></a><b>Perls since %s too modern--this is %s, stopped</b>
<p>(F) The code you are trying to run claims it will not run
on the version of Perl you are using because it is too new.
Maybe the code needs to be updated, or maybe it is simply
wrong and the version check should just be removed.</p>
</li>
<li><a name="perl%3a-warning%3a-Non-hex-character-in-'%24ENV%7bPERL_HASH_SEED%7d'%2c-seed-only-partially-set"></a><b>perl: warning: Non hex character in '$ENV{PERL_HASH_SEED}', seed only partially set</b>
<p>(S) PERL_HASH_SEED should match /^\s*(?:0x)?[0-9a-fA-F]+\s*\z/ but it
contained a non hex character.  This could mean you are not using the
hash seed you think you are.</p>
</li>
<li><a name="perl%3a-warning%3a-Setting-locale-failed."></a><b>perl: warning: Setting locale failed.</b>
<p>(S) The whole warning message will look something like:</p>
<pre class="verbatim"><ol><li>	perl: warning: Setting locale failed.</li><li>	perl: warning: Please check that your locale settings:</li><li>	        LC_ALL = "En_US",</li><li>	        LANG = (unset)</li><li>	    are supported and installed on your system.</li><li>	perl: warning: Falling back to the standard locale ("C").</li></ol></pre><p>Exactly what were the failed locale settings varies.  In the above the
settings were that the LC_ALL was "En_US" and the LANG had no value.
This error means that Perl detected that you and/or your operating
system supplier and/or system administrator have set up the so-called
locale system but Perl could not use those settings.  This was not
dead serious, fortunately: there is a "default locale" called "C" that
Perl can and will use, and the script will be run.  Before you really
fix the problem, however, you will get the same error message each
time you run Perl.  How to really fix the problem can be found in
<a href="perllocale.html">perllocale</a> section <b>LOCALE PROBLEMS</b>.</p>
</li>
<li><a name="perl%3a-warning%3a-strange-setting-in-'%24ENV%7bPERL_PERTURB_KEYS%7d'%3a-'%25s'"></a><b>perl: warning: strange setting in '$ENV{PERL_PERTURB_KEYS}': '%s'</b>
<p>(S) Perl was run with the environment variable PERL_PERTURB_KEYS defined
but containing an unexpected value.  The legal values of this setting
are as follows.</p>
<pre class="verbatim"><ol><li>  <span class="w">Numeric</span> | <span class="w">String</span>        | <span class="w">Result</span></li><li>  --------+---------------+-----------------------------------------</li><li>  <span class="n">0</span>       | <span class="w">NO</span>            | <span class="w">Disables</span> <span class="w">key</span> <span class="w">traversal</span> <span class="w">randomization</span></li><li>  <span class="n">1</span>       | <span class="w">RANDOM</span>        | <span class="w">Enables</span> <span class="w">full</span> <span class="w">key</span> <span class="w">traversal</span> <span class="w">randomization</span></li><li>  <span class="n">2</span>       | <span class="w">DETERMINISTIC</span> | <span class="w">Enables</span> <span class="w">repeatable</span> <span class="w">key</span> <span class="w">traversal</span></li><li>          |               | <span class="w">randomization</span></li></ol></pre><p>Both numeric and string values are accepted, but note that string values are
case sensitive.  The default for this setting is "RANDOM" or 1.</p>
</li>
<li><a name="pid-%25x-not-a-child"></a><b>pid %x not a child</b>
<p>(W exec) A warning peculiar to VMS.  Waitpid() was asked to wait for a
process which isn't a subprocess of the current process.  While this is
fine from VMS' perspective, it's probably not what you intended.</p>
</li>
<li><a name="'P'-must-have-an-explicit-size-in-unpack"></a><b>'P' must have an explicit size in unpack</b>
<p>(F) The unpack format P must have an explicit size, not "*".</p>
</li>
<li><a name="POSIX-class-%5b%3a%25s%3a%5d-unknown-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>POSIX class [:%s:] unknown in regex; marked by &lt;-- HERE in m/%s/</b>
<p>(F) The class in the character class [: :] syntax is unknown.  The &lt;-- HERE
shows whereabouts in the regular expression the problem was discovered.
Note that the POSIX character classes do <b>not</b> have the <code class="inline"><span class="w">is</span></code>
 prefix
the corresponding C interfaces have: in other words, it's <code class="inline">[[:print:]]</code>,
not <code class="inline"><span class="w">isprint</span></code>
.  See <a href="perlre.html">perlre</a>.</p>
</li>
<li><a name="POSIX-getpgrp-can't-take-an-argument"></a><b>POSIX getpgrp can't take an argument</b>
<p>(F) Your system has POSIX getpgrp(), which takes no argument, unlike
the BSD version, which takes a pid.</p>
</li>
<li><a name="POSIX-syntax-%5b%25c-%25c%5d-belongs-inside-character-classes%25s-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>POSIX syntax [%c %c] belongs inside character classes%s in regex; marked by
&lt;-- HERE in m/%s/</b>
<p>(W regexp) Perl thinks that you intended to write a POSIX character
class, but didn't use enough brackets.  These POSIX class constructs [:
:], [= =], and [. .]  go <i>inside</i> character classes, the [] are part of
the construct, for example: <code class="inline"><a class="l_k" href="functions/qr.html">qr/[012[:alpha:]345]/</a></code>.  What the regular
expression pattern compiled to is probably not what you were intending.
For example, <code class="inline"><a class="l_k" href="functions/qr.html">qr/[:alpha:]/</a></code> compiles to a regular bracketed character
class consisting of the four characters <code class="inline"><span class="q">&quot;:&quot;</span></code>
,  <code class="inline"><span class="q">&quot;a&quot;</span></code>
,  <code class="inline"><span class="q">&quot;l&quot;</span></code>
,
<code class="inline"><span class="q">&quot;h&quot;</span></code>
, and <code class="inline"><span class="q">&quot;p&quot;</span></code>
.  To specify the POSIX class, it should have been
written <code class="inline"><a class="l_k" href="functions/qr.html">qr/[[:alpha:]]/</a></code>.</p>
<p>Note that [= =] and [. .] are not currently
implemented; they are simply placeholders for future extensions and
will cause fatal errors.  The &lt;-- HERE shows whereabouts in the regular
expression the problem was discovered.  See <a href="perlre.html">perlre</a>.</p>
<p>If the specification of the class was not completely valid, the message
indicates that.</p>
</li>
<li><a name="POSIX-syntax-%5b.-.%5d-is-reserved-for-future-extensions-in-regex%3b-marked-by--%3c---HERE-in-m%2f%25s%2f"></a><b>POSIX syntax [. .] is reserved for future extensions in regex; marked by 
&lt;-- HERE in m/%s/</b>
<p>(F) Within regular expression character classes ([]) the syntax beginning
with "[." and ending with ".]" is reserved for future extensions.  If you
need to represent those character sequences inside a regular expression
character class, just quote the square brackets with the backslash: "\[."
and ".\]".  The &lt;-- HERE shows whereabouts in the regular expression the
problem was discovered.  See <a href="perlre.html">perlre</a>.</p>
</li>
<li><a name="POSIX-syntax-%5b%3d-%3d%5d-is-reserved-for-future-extensions-in-regex%3b-marked-by--%3c---HERE-in-m%2f%25s%2f"></a><b>POSIX syntax [= =] is reserved for future extensions in regex; marked by 
&lt;-- HERE in m/%s/</b>
<p>(F) Within regular expression character classes ([]) the syntax beginning
with "[=" and ending with "=]" is reserved for future extensions.  If you
need to represent those character sequences inside a regular expression
character class, just quote the square brackets with the backslash: "\[="
and "=\]".  The &lt;-- HERE shows whereabouts in the regular expression the
problem was discovered.  See <a href="perlre.html">perlre</a>.</p>
</li>
<li><a name="Possible-attempt-to-put-comments-in-qw()-list"></a><b>Possible attempt to put comments in qw() list</b>
<p>(W qw) qw() lists contain items separated by whitespace; as with literal
strings, comment characters are not ignored, but are instead treated as
literal data.  (You may have used different delimiters than the
parentheses shown here; braces are also frequently used.)</p>
<p>You probably wrote something like this:</p>
<pre class="verbatim"><ol><li>    <span class="i">@list</span> = <span class="q">qw(</span></li><li>	<span class="q">a # a comment</span></li><li>        <span class="q">b # another comment</span></li><li>    <span class="q">)</span><span class="sc">;</span></li></ol></pre><p>when you should have written this:</p>
<pre class="verbatim"><ol><li>    <span class="i">@list</span> = <span class="q">qw(</span></li><li>	<span class="q">a</span></li><li>        <span class="q">b</span></li><li>    <span class="q">)</span><span class="sc">;</span></li></ol></pre><p>If you really want comments, build your list the
old-fashioned way, with quotes and commas:</p>
<pre class="verbatim"><ol><li>    <span class="i">@list</span> = <span class="s">(</span></li><li>        <span class="q">&#39;a&#39;</span><span class="cm">,</span>    <span class="c"># a comment</span></li><li>        <span class="q">&#39;b&#39;</span><span class="cm">,</span>    <span class="c"># another comment</span></li><li>    <span class="s">)</span><span class="sc">;</span></li></ol></pre></li>
<li><a name="Possible-attempt-to-separate-words-with-commas"></a><b>Possible attempt to separate words with commas</b>
<p>(W qw) qw() lists contain items separated by whitespace; therefore
commas aren't needed to separate the items.  (You may have used
different delimiters than the parentheses shown here; braces are also
frequently used.)</p>
<p>You probably wrote something like this:</p>
<pre class="verbatim"><ol><li>    <span class="q">qw! a, b, c !</span><span class="sc">;</span></li></ol></pre><p>which puts literal commas into some of the list items.  Write it without
commas if you don't want them to appear in your data:</p>
<pre class="verbatim"><ol><li>    <span class="q">qw! a b c !</span><span class="sc">;</span></li></ol></pre></li>
<li><a name="Possible-memory-corruption%3a-%25s-overflowed-3rd-argument"></a><b>Possible memory corruption: %s overflowed 3rd argument</b>
<p>(F) An ioctl() or fcntl() returned more than Perl was bargaining for.
Perl guesses a reasonable buffer size, but puts a sentinel byte at the
end of the buffer just in case.  This sentinel byte got clobbered, and
Perl assumes that memory is now corrupted.  See <a href="functions/ioctl.html">ioctl</a>.</p>
</li>
<li><a name="Possible-precedence-issue-with-control-flow-operator"></a><b>Possible precedence issue with control flow operator</b>
<p>(W syntax) There is a possible problem with the mixing of a control
flow operator (e.g. <code class="inline"><a class="l_k" href="functions/return.html">return</a></code>) and a low-precedence operator like
<code class="inline">or</code>
.  Consider:</p>
<pre class="verbatim"><ol><li>    <a class="l_k" href="functions/sub.html">sub</a> <span class="s">{</span> <a class="l_k" href="functions/return.html">return</a> <span class="i">$a</span> <a class="l_k" href="functions/or.html">or</a> <span class="i">$b</span><span class="sc">;</span> <span class="s">}</span></li></ol></pre><p>This is parsed as:</p>
<pre class="verbatim"><ol><li>    <a class="l_k" href="functions/sub.html">sub</a> <span class="s">{</span> <span class="s">(</span><a class="l_k" href="functions/return.html">return</a> <span class="i">$a</span><span class="s">)</span> <a class="l_k" href="functions/or.html">or</a> <span class="i">$b</span><span class="sc">;</span> <span class="s">}</span></li></ol></pre><p>Which is effectively just:</p>
<pre class="verbatim"><ol><li>    <a class="l_k" href="functions/sub.html">sub</a> <span class="s">{</span> <a class="l_k" href="functions/return.html">return</a> <span class="i">$a</span><span class="sc">;</span> <span class="s">}</span></li></ol></pre><p>Either use parentheses or the high-precedence variant of the operator.</p>
<p>Note this may be also triggered for constructs like:</p>
<pre class="verbatim"><ol><li>    <a class="l_k" href="functions/sub.html">sub</a> <span class="s">{</span> <span class="n">1</span> <a class="l_k" href="functions/if.html">if</a> <a class="l_k" href="functions/die.html">die</a><span class="sc">;</span> <span class="s">}</span></li></ol></pre></li>
<li><a name="Possible-precedence-problem-on-bitwise-%25s-operator"></a><b>Possible precedence problem on bitwise %s operator</b>
<p>(W precedence) Your program uses a bitwise logical operator in conjunction
with a numeric comparison operator, like this :</p>
<pre class="verbatim"><ol><li>    if <span class="s">(</span><span class="i">$x</span> &amp; <span class="i">$y</span> == <span class="n">0</span><span class="s">)</span> <span class="s">{</span> ... <span class="s">}</span></li></ol></pre><p>This expression is actually equivalent to <code class="inline"><span class="i">$x</span> &amp; <span class="s">(</span><span class="i">$y</span> == <span class="n">0</span><span class="s">)</span></code>
, due to the
higher precedence of <code class="inline">==</code>
.  This is probably not what you want.  (If you
really meant to write this, disable the warning, or, better, put the
parentheses explicitly and write <code class="inline"><span class="i">$x</span> &amp; <span class="s">(</span><span class="i">$y</span> == <span class="n">0</span><span class="s">)</span></code>
).</p>
</li>
<li><a name="Possible-unintended-interpolation-of-%24%5c-in-regex"></a><b>Possible unintended interpolation of $\ in regex</b>
<p>(W ambiguous) You said something like <code class="inline"><a class="l_k" href="functions/m.html">m/$\/</a></code> in a regex.
The regex <code class="inline"><a class="l_k" href="functions/m.html">m/foo$\s+bar/m</a></code> translates to: match the word 'foo', the output
record separator (see <a href="perlvar.html#%24%5c">$\ in perlvar</a>) and the letter 's' (one time or more)
followed by the word 'bar'.</p>
<p>If this is what you intended then you can silence the warning by using 
<code class="inline"><a class="l_k" href="functions/m.html">m/${\}/</a></code> (for example: <code class="inline"><a class="l_k" href="functions/m.html">m/foo${\}s+bar/</a></code>).</p>
<p>If instead you intended to match the word 'foo' at the end of the line
followed by whitespace and the word 'bar' on the next line then you can use
<code class="inline"><a class="l_k" href="functions/m.html">m/$(?)\/</a></code> (for example: <code class="inline"><a class="l_k" href="functions/m.html">m/foo$(?)\s+bar/</a></code>).</p>
</li>
<li><a name="Possible-unintended-interpolation-of-%25s-in-string"></a><b>Possible unintended interpolation of %s in string</b>
<p>(W ambiguous) You said something like '@foo' in a double-quoted string
but there was no array <code class="inline"><span class="i">@foo</span></code>
 in scope at the time.  If you wanted a
literal @foo, then write it as \@foo; otherwise find out what happened
to the array you apparently lost track of.</p>
</li>
<li><a name="Precedence-problem%3a-open-%25s-should-be-open(%25s)"></a><b>Precedence problem: open %s should be open(%s)</b>
<p>(S precedence) The old irregular construct</p>
<pre class="verbatim"><ol><li>    <a class="l_k" href="functions/open.html">open</a> <span class="w">FOO</span> || <a class="l_k" href="functions/die.html">die</a><span class="sc">;</span></li></ol></pre><p>is now misinterpreted as</p>
<pre class="verbatim"><ol><li>    <a class="l_k" href="functions/open.html">open</a><span class="s">(</span><span class="w">FOO</span> || <a class="l_k" href="functions/die.html">die</a><span class="s">)</span><span class="sc">;</span></li></ol></pre><p>because of the strict regularization of Perl 5's grammar into unary and
list operators.  (The old open was a little of both.)  You must put
parentheses around the filehandle, or use the new "or" operator instead
of "||".</p>
</li>
<li><a name="Premature-end-of-script-headers"></a><b>Premature end of script headers</b>
<p>See <a href="#500-Server-error">500 Server error</a>.</p>
</li>
<li><a name="printf()-on-closed-filehandle-%25s"></a><b>printf() on closed filehandle %s</b>
<p>(W closed) The filehandle you're writing to got itself closed sometime
before now.  Check your control flow.</p>
</li>
<li><a name="print()-on-closed-filehandle-%25s"></a><b>print() on closed filehandle %s</b>
<p>(W closed) The filehandle you're printing on got itself closed sometime
before now.  Check your control flow.</p>
</li>
<li><a name="Process-terminated-by-SIG%25s"></a><b>Process terminated by SIG%s</b>
<p>(W) This is a standard message issued by OS/2 applications, while *nix
applications die in silence.  It is considered a feature of the OS/2
port.  One can easily disable this by appropriate sighandlers, see
<a href="perlipc.html#Signals">Signals in perlipc</a>.  See also "Process terminated by SIGTERM/SIGINT"
in <a href="perlos2.html">perlos2</a>.</p>
</li>
<li><a name="Prototype-after-'%25c'-for-%25s-%3a-%25s"></a><b>Prototype after '%c' for %s : %s</b>
<p>(W illegalproto) A character follows % or @ in a prototype.  This is
useless, since % and @ gobble the rest of the subroutine arguments.</p>
</li>
<li><a name="Prototype-mismatch%3a-%25s-vs-%25s"></a><b>Prototype mismatch: %s vs %s</b>
<p>(S prototype) The subroutine being declared or defined had previously been
declared or defined with a different function prototype.</p>
</li>
<li><a name="Prototype-not-terminated"></a><b>Prototype not terminated</b>
<p>(F) You've omitted the closing parenthesis in a function prototype
definition.</p>
</li>
<li><a name="Prototype-'%25s'-overridden-by-attribute-'prototype(%25s)'-in-%25s"></a><b>Prototype '%s' overridden by attribute 'prototype(%s)' in %s</b>
<p>(W prototype) A prototype was declared in both the parentheses after
the sub name and via the prototype attribute.  The prototype in
parentheses is useless, since it will be replaced by the prototype
from the attribute before it's ever used.</p>
</li>
<li><a name="Quantifier-follows-nothing-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>Quantifier follows nothing in regex; marked by &lt;-- HERE in m/%s/</b>
<p>(F) You started a regular expression with a quantifier.  Backslash it if
you meant it literally.  The &lt;-- HERE shows whereabouts in the regular
expression the problem was discovered.  See <a href="perlre.html">perlre</a>.</p>
</li>
<li><a name="Quantifier-in-%7b%2c%7d-bigger-than-%25d-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>Quantifier in {,} bigger than %d in regex; marked by &lt;-- HERE in m/%s/</b>
<p>(F) There is currently a limit to the size of the min and max values of
the {min,max} construct.  The &lt;-- HERE shows whereabouts in the regular
expression the problem was discovered.  See <a href="perlre.html">perlre</a>.</p>
</li>
<li><a name="Quantifier-%7bn%2cm%7d-with-n-%3e-m-can't-match-in-regex"></a><b>Quantifier {n,m} with n &gt; m can't match in regex</b>
</li>
<li><a name="Quantifier-%7bn%2cm%7d-with-n-%3e-m-can't-match-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>Quantifier {n,m} with n &gt; m can't match in regex; marked by
&lt;-- HERE in m/%s/</b>
<p>(W regexp) Minima should be less than or equal to maxima.  If you really
want your regexp to match something 0 times, just put {0}.</p>
</li>
<li><a name="Quantifier-unexpected-on-zero-length-expression-in-regex-m%2f%25s%2f"></a><b>Quantifier unexpected on zero-length expression in regex m/%s/</b>
<p>(W regexp) You applied a regular expression quantifier in a place where
it makes no sense, such as on a zero-width assertion.  Try putting the
quantifier inside the assertion instead.  For example, the way to match
"abc" provided that it is followed by three repetitions of "xyz" is
<code class="inline"><span class="q">/abc(?=(?:xyz){3})/</span></code>
, not <code class="inline"><span class="q">/abc(?=xyz){3}/</span></code>
.</p>
</li>
<li><a name="Range-iterator-outside-integer-range"></a><b>Range iterator outside integer range</b>
<p>(F) One (or both) of the numeric arguments to the range operator ".."
are outside the range which can be represented by integers internally.
One possible workaround is to force Perl to use magical string increment
by prepending "0" to your numbers.</p>
</li>
<li><a name="Ranges-of-ASCII-printables-should-be-some-subset-of-%220-9%22%2c-%22A-Z%22%2c-or-%22a-z%22-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>Ranges of ASCII printables should be some subset of "0-9", "A-Z", or
"a-z" in regex; marked by &lt;-- HERE in m/%s/</b>
<p>(W regexp) (only under <code class="inline"><a class="l_k" href="functions/use.html">use</a> <span class="w">re</span> <span class="q">&#39;strict&#39;</span></code>
 or within <code class="inline"><span class="s">(</span><span class="q">?[...])</span></code>
)</p>
<p>Stricter rules help to find typos and other errors.  Perhaps you didn't
even intend a range here, if the <code class="inline"><span class="q">&quot;-&quot;</span></code>
 was meant to be some other
character, or should have been escaped (like <code class="inline"><span class="q">&quot;\-&quot;</span></code>
).  If you did
intend a range, the one that was used is not portable between ASCII and
EBCDIC platforms, and doesn't have an obvious meaning to a casual
reader.</p>
<pre class="verbatim"><ol><li> <span class="s">[</span><span class="n">3</span>-<span class="n">7</span><span class="s">]</span>    <span class="c"># OK; Obvious and portable</span></li><li> <span class="s">[</span><span class="w">d</span>-g<span class="s">]</span>    <span class="c"># OK; Obvious and portable</span></li><li> <span class="s">[</span><span class="w">A</span>-<span class="w">Y</span><span class="s">]</span>    <span class="c"># OK; Obvious and portable</span></li><li> <span class="s">[</span><span class="w">A</span>-z<span class="s">]</span>    <span class="c"># WRONG; Not portable; not clear what is meant</span></li><li> <span class="s">[</span><span class="w">a</span>-<span class="w">Z</span><span class="s">]</span>    <span class="c"># WRONG; Not portable; not clear what is meant</span></li><li> <span class="s">[</span><span class="i">%-</span>.<span class="s">]</span>    <span class="c"># WRONG; Not portable; not clear what is meant</span></li><li> <span class="s">[</span>\<span class="w">x41</span>-<span class="w">Z</span><span class="s">]</span> <span class="c"># WRONG; Not portable; not obvious to non-geek</span></li></ol></pre><p>(You can force portability by specifying a Unicode range, which means that
the endpoints are specified by
<a href="perlrecharclass.html#Character-Ranges">\N{...} </a>, but the meaning may
still not be obvious.)
The stricter rules require that ranges that start or stop with an ASCII
character that is not a control have all their endpoints be the literal
character, and not some escape sequence (like <code class="inline"><span class="q">&quot;\x41&quot;</span></code>
), and the ranges
must be all digits, or all uppercase letters, or all lowercase letters.</p>
</li>
<li><a name="Ranges-of-digits-should-be-from-the-same-group-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>Ranges of digits should be from the same group in regex; marked by
&lt;-- HERE in m/%s/</b>
<p>(W regexp) (only under <code class="inline"><a class="l_k" href="functions/use.html">use</a> <span class="w">re</span> <span class="q">&#39;strict&#39;</span></code>
 or within <code class="inline"><span class="s">(</span><span class="q">?[...])</span></code>
)</p>
<p>Stricter rules help to find typos and other errors.  You included a
range, and at least one of the end points is a decimal digit.  Under the
stricter rules, when this happens, both end points should be digits in
the same group of 10 consecutive digits.</p>
</li>
<li><a name="readdir()-attempted-on-invalid-dirhandle-%25s"></a><b>readdir() attempted on invalid dirhandle %s</b>
<p>(W io) The dirhandle you're reading from is either closed or not really
a dirhandle.  Check your control flow.</p>
</li>
<li><a name="readline()-on-closed-filehandle-%25s"></a><b>readline() on closed filehandle %s</b>
<p>(W closed) The filehandle you're reading from got itself closed sometime
before now.  Check your control flow.</p>
</li>
<li><a name="read()-on-closed-filehandle-%25s"></a><b>read() on closed filehandle %s</b>
<p>(W closed) You tried to read from a closed filehandle.</p>
</li>
<li><a name="read()-on-unopened-filehandle-%25s"></a><b>read() on unopened filehandle %s</b>
<p>(W unopened) You tried to read from a filehandle that was never opened.</p>
</li>
<li><a name="Reallocation-too-large%3a-%25x"></a><b>Reallocation too large: %x</b>
<p>(F) You can't allocate more than 64K on an MS-DOS machine.</p>
</li>
<li><a name="realloc()-of-freed-memory-ignored"></a><b>realloc() of freed memory ignored</b>
<p>(S malloc) An internal routine called realloc() on something that had
already been freed.</p>
</li>
<li><a name="Recompile-perl-with-*-D*DEBUGGING-to-use-*-D*-switch"></a><b>Recompile perl with <b>-D</b>DEBUGGING to use <b>-D</b> switch</b>
<p>(S debugging) You can't use the <b>-D</b> option unless the code to produce
the desired output is compiled into Perl, which entails some overhead,
which is why it's currently left out of your copy.</p>
</li>
<li><a name="Recursive-call-to-Perl_load_module-in-PerlIO_find_layer"></a><b>Recursive call to Perl_load_module in PerlIO_find_layer</b>
<p>(P) It is currently not permitted to load modules when creating
a filehandle inside an %INC hook.  This can happen with <code class="inline"><a class="l_k" href="functions/open.html">open</a> <a class="l_k" href="functions/my.html">my</a>
<span class="i">$fh</span><span class="cm">,</span> <span class="q">&#39;&lt;&#39;</span><span class="cm">,</span> \<span class="i">$scalar</span></code>
, which implicitly loads PerlIO::scalar.  Try
loading PerlIO::scalar explicitly first.</p>
</li>
<li><a name="Recursive-inheritance-detected-in-package-'%25s'"></a><b>Recursive inheritance detected in package '%s'</b>
<p>(F) While calculating the method resolution order (MRO) of a package, Perl
believes it found an infinite loop in the <code class="inline"><span class="i">@ISA</span></code>
 hierarchy.  This is a
crude check that bails out after 100 levels of <code class="inline"><span class="i">@ISA</span></code>
 depth.</p>
</li>
<li><a name="Redundant-argument-in-%25s"></a><b>Redundant argument in %s</b>
<p>(W redundant) You called a function with more arguments than other
arguments you supplied indicated would be needed.  Currently only
emitted when a printf-type format required fewer arguments than were
supplied, but might be used in the future for e.g. <a href="functions/pack.html">pack</a>.</p>
</li>
<li><a name="refcnt_dec%3a-fd-%25d%25s"></a><b>refcnt_dec: fd %d%s</b>
</li>
<li><a name="refcnt%3a-fd-%25d%25s"></a><b>refcnt: fd %d%s</b>
</li>
<li><a name="refcnt_inc%3a-fd-%25d%25s"></a><b>refcnt_inc: fd %d%s</b>
<p>(P) Perl's I/O implementation failed an internal consistency check.  If
you see this message, something is very wrong.</p>
</li>
<li><a name="Reference-found-where-even-sized-list-expected"></a><b>Reference found where even-sized list expected</b>
<p>(W misc) You gave a single reference where Perl was expecting a list
with an even number of elements (for assignment to a hash).  This
usually means that you used the anon hash constructor when you meant
to use parens.  In any case, a hash requires key/value <b>pairs</b>.</p>
<pre class="verbatim"><ol><li>    <span class="i">%hash</span> = <span class="s">{</span> <span class="w">one</span> <span class="cm">=&gt;</span> <span class="n">1</span><span class="cm">,</span> <span class="w">two</span> <span class="cm">=&gt;</span> <span class="n">2</span><span class="cm">,</span> <span class="s">}</span><span class="sc">;</span>	<span class="c"># WRONG</span></li><li>    <span class="i">%hash</span> = <span class="s">[</span> <span class="q">qw/ an anon array /</span> <span class="s">]</span><span class="sc">;</span>	<span class="c"># WRONG</span></li><li>    <span class="i">%hash</span> = <span class="s">(</span> <span class="w">one</span> <span class="cm">=&gt;</span> <span class="n">1</span><span class="cm">,</span> <span class="w">two</span> <span class="cm">=&gt;</span> <span class="n">2</span><span class="cm">,</span> <span class="s">)</span><span class="sc">;</span>	<span class="c"># right</span></li><li>    <span class="i">%hash</span> = <span class="q">qw( one 1 two 2 )</span><span class="sc">;</span>			<span class="c"># also fine</span></li></ol></pre></li>
<li><a name="Reference-is-already-weak"></a><b>Reference is already weak</b>
<p>(W misc) You have attempted to weaken a reference that is already weak.
Doing so has no effect.</p>
</li>
<li><a name="Reference-to-invalid-group-0-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>Reference to invalid group 0 in regex; marked by &lt;-- HERE in m/%s/</b>
<p>(F) You used <code class="inline">\<span class="w">g0</span></code>
 or similar in a regular expression.  You may refer
to capturing parentheses only with strictly positive integers
(normal backreferences) or with strictly negative integers (relative
backreferences).  Using 0 does not make sense.</p>
</li>
<li><a name="Reference-to-nonexistent-group-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>Reference to nonexistent group in regex; marked by &lt;-- HERE in
m/%s/</b>
<p>(F) You used something like <code class="inline">\<span class="n">7</span></code>
 in your regular expression, but there are
not at least seven sets of capturing parentheses in the expression.  If
you wanted to have the character with ordinal 7 inserted into the regular
expression, prepend zeroes to make it three digits long: <code class="inline">\<span class="n">007</span></code>
</p>
<p>The &lt;-- HERE shows whereabouts in the regular expression the problem was
discovered.</p>
</li>
<li><a name="Reference-to-nonexistent-named-group-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>Reference to nonexistent named group in regex; marked by &lt;-- HERE
in m/%s/</b>
<p>(F) You used something like <code class="inline">\k'NAME'</code> or <code class="inline">\<span class="w">k</span><span class="q">&lt;NAME&gt;</span></code>
 in your regular
expression, but there is no corresponding named capturing parentheses
such as <code class="inline">(?'NAME'...)</code> or <code class="inline"><span class="s">(</span><span class="q">?&lt;NAME&gt;...)</span></code>
.  Check if the name has been
spelled correctly both in the backreference and the declaration.</p>
<p>The &lt;-- HERE shows whereabouts in the regular expression the problem was
discovered.</p>
</li>
<li><a name="Reference-to-nonexistent-or-unclosed-group-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>Reference to nonexistent or unclosed group in regex; marked by
&lt;-- HERE in m/%s/</b>
<p>(F) You used something like <code class="inline">\<span class="i">g</span><span class="s">{</span><span class="n">-7</span><span class="s">}</span></code>
 in your regular expression, but there
are not at least seven sets of closed capturing parentheses in the
expression before where the <code class="inline">\<span class="i">g</span><span class="s">{</span><span class="n">-7</span><span class="s">}</span></code>
 was located.</p>
<p>The &lt;-- HERE shows whereabouts in the regular expression the problem was
discovered.</p>
</li>
<li><a name="regexp-memory-corruption"></a><b>regexp memory corruption</b>
<p>(P) The regular expression engine got confused by what the regular
expression compiler gave it.</p>
</li>
<li><a name="Regexp-modifier-%22%2f%25c%22-may-appear-a-maximum-of-twice"></a><b>Regexp modifier "/%c" may appear a maximum of twice</b>
</li>
<li><a name="Regexp-modifier-%22%25c%22-may-appear-a-maximum-of-twice-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>Regexp modifier "%c" may appear a maximum of twice in regex; marked
by &lt;-- HERE in m/%s/</b>
<p>(F) The regular expression pattern had too many occurrences
of the specified modifier.  Remove the extraneous ones.</p>
</li>
<li><a name="Regexp-modifier-%22%25c%22-may-not-appear-after-the-%22-%22-in-regex%3b-marked-by-%3c----HERE-in-m%2f%25s%2f"></a><b>Regexp modifier "%c" may not appear after the "-" in regex; marked by &lt;-- 
HERE in m/%s/</b>
<p>(F) Turning off the given modifier has the side effect of turning on
another one.  Perl currently doesn't allow this.  Reword the regular
expression to use the modifier you want to turn on (and place it before
the minus), instead of the one you want to turn off.</p>
</li>
<li><a name="Regexp-modifier-%22%2f%25c%22-may-not-appear-twice"></a><b>Regexp modifier "/%c" may not appear twice</b>
</li>
<li><a name="Regexp-modifier-%22%25c%22-may-not-appear-twice-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>Regexp modifier "%c" may not appear twice in regex; marked by &lt;--
HERE in m/%s/</b>
<p>(F) The regular expression pattern had too many occurrences
of the specified modifier.  Remove the extraneous ones.</p>
</li>
<li><a name="Regexp-modifiers-%22%2f%25c%22-and-%22%2f%25c%22-are-mutually-exclusive"></a><b>Regexp modifiers "/%c" and "/%c" are mutually exclusive</b>
</li>
<li><a name="Regexp-modifiers-%22%25c%22-and-%22%25c%22-are-mutually-exclusive-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>Regexp modifiers "%c" and "%c" are mutually exclusive in regex;
marked by &lt;-- HERE in m/%s/</b>
<p>(F) The regular expression pattern had more than one of these
mutually exclusive modifiers.  Retain only the modifier that is
supposed to be there.</p>
</li>
<li><a name="Regexp-out-of-space-in-regex-m%2f%25s%2f"></a><b>Regexp out of space in regex m/%s/</b>
<p>(P) A "can't happen" error, because safemalloc() should have caught it
earlier.</p>
</li>
<li><a name="Repeated-format-line-will-never-terminate-(~~-and-%40%23)"></a><b>Repeated format line will never terminate (~~ and @#)</b>
<p>(F) Your format contains the ~~ repeat-until-blank sequence and a
numeric field that will never go blank so that the repetition never
terminates.  You might use ^# instead.  See <a href="perlform.html">perlform</a>.</p>
</li>
<li><a name="Replacement-list-is-longer-than-search-list"></a><b>Replacement list is longer than search list</b>
<p>(W misc) You have used a replacement list that is longer than the
search list.  So the additional elements in the replacement list
are meaningless.</p>
</li>
<li><a name="'%25s'-resolved-to-'%5co%7b%25s%7d%25d'"></a><b>'%s' resolved to '\o{%s}%d'</b>
<p>(W misc, regexp)  You wrote something like <code class="inline">\<span class="n">08</span></code>
, or <code class="inline">\<span class="n">179</span></code>
 in a
double-quotish string.  All but the last digit is treated as a single
character, specified in octal.  The last digit is the next character in
the string.  To tell Perl that this is indeed what you want, you can use
the <code class="inline">\<span class="w">o</span><span class="s">{</span> <span class="s">}</span></code>
 syntax, or use exactly three digits to specify the octal
for the character.</p>
</li>
<li><a name="Reversed-%25s%3d-operator"></a><b>Reversed %s= operator</b>
<p>(W syntax) You wrote your assignment operator backwards.  The = must
always come last, to avoid ambiguity with subsequent unary operators.</p>
</li>
<li><a name="rewinddir()-attempted-on-invalid-dirhandle-%25s"></a><b>rewinddir() attempted on invalid dirhandle %s</b>
<p>(W io) The dirhandle you tried to do a rewinddir() on is either closed
or not really a dirhandle.  Check your control flow.</p>
</li>
<li><a name="Scalars-leaked%3a-%25d"></a><b>Scalars leaked: %d</b>
<p>(S internal) Something went wrong in Perl's internal bookkeeping
of scalars: not all scalar variables were deallocated by the time
Perl exited.  What this usually indicates is a memory leak, which
is of course bad, especially if the Perl program is intended to be
long-running.</p>
</li>
<li><a name="Scalar-value-%40%25s%5b%25s%5d-better-written-as-%24%25s%5b%25s%5d"></a><b>Scalar value @%s[%s] better written as $%s[%s]</b>
<p>(W syntax) You've used an array slice (indicated by @) to select a
single element of an array.  Generally it's better to ask for a scalar
value (indicated by $).  The difference is that <code class="inline"><span class="i">$foo</span>[<span class="i">&amp;bar</span>]</code>
 always
behaves like a scalar, both when assigning to it and when evaluating its
argument, while <code class="inline"><span class="i">@foo</span>[<span class="i">&amp;bar</span>]</code>
 behaves like a list when you assign to it,
and provides a list context to its subscript, which can do weird things
if you're expecting only one subscript.</p>
<p>On the other hand, if you were actually hoping to treat the array
element as a list, you need to look into how references work, because
Perl will not magically convert between scalars and lists for you.  See
<a href="perlref.html">perlref</a>.</p>
</li>
<li><a name="Scalar-value-%40%25s%7b%25s%7d-better-written-as-%24%25s%7b%25s%7d"></a><b>Scalar value @%s{%s} better written as $%s{%s}</b>
<p>(W syntax) You've used a hash slice (indicated by @) to select a single
element of a hash.  Generally it's better to ask for a scalar value
(indicated by $).  The difference is that <code class="inline"><span class="i">$foo</span>{<span class="i">&amp;bar</span>}</code>
 always behaves
like a scalar, both when assigning to it and when evaluating its
argument, while <code class="inline"><span class="i">@foo</span>{<span class="i">&amp;bar</span>}</code>
 behaves like a list when you assign to it,
and provides a list context to its subscript, which can do weird things
if you're expecting only one subscript.</p>
<p>On the other hand, if you were actually hoping to treat the hash element
as a list, you need to look into how references work, because Perl will
not magically convert between scalars and lists for you.  See
<a href="perlref.html">perlref</a>.</p>
</li>
<li><a name="Search-pattern-not-terminated"></a><b>Search pattern not terminated</b>
<p>(F) The lexer couldn't find the final delimiter of a // or m{}
construct.  Remember that bracketing delimiters count nesting level.
Missing the leading <code class="inline"><span class="i">$</span></code>
 from a variable <code class="inline"><span class="i">$m</span></code>
 may cause this error.</p>
<p>Note that since Perl 5.10.0 a // can also be the <i>defined-or</i>
construct, not just the empty search pattern.  Therefore code written
in Perl 5.10.0 or later that uses the // as the <i>defined-or</i> can be
misparsed by pre-5.10.0 Perls as a non-terminated search pattern.</p>
</li>
<li><a name="seekdir()-attempted-on-invalid-dirhandle-%25s"></a><b>seekdir() attempted on invalid dirhandle %s</b>
<p>(W io) The dirhandle you are doing a seekdir() on is either closed or not
really a dirhandle.  Check your control flow.</p>
</li>
<li><a name="%25sseek()-on-unopened-filehandle"></a><b>%sseek() on unopened filehandle</b>
<p>(W unopened) You tried to use the seek() or sysseek() function on a
filehandle that was either never opened or has since been closed.</p>
</li>
<li><a name="select-not-implemented"></a><b>select not implemented</b>
<p>(F) This machine doesn't implement the select() system call.</p>
</li>
<li><a name="Self-ties-of-arrays-and-hashes-are-not-supported"></a><b>Self-ties of arrays and hashes are not supported</b>
<p>(F) Self-ties are of arrays and hashes are not supported in
the current implementation.</p>
</li>
<li><a name="Semicolon-seems-to-be-missing"></a><b>Semicolon seems to be missing</b>
<p>(W semicolon) A nearby syntax error was probably caused by a missing
semicolon, or possibly some other missing operator, such as a comma.</p>
</li>
<li><a name="semi-panic%3a-attempt-to-dup-freed-string"></a><b>semi-panic: attempt to dup freed string</b>
<p>(S internal) The internal newSVsv() routine was called to duplicate a
scalar that had previously been marked as free.</p>
</li>
<li><a name="sem%25s-not-implemented"></a><b>sem%s not implemented</b>
<p>(F) You don't have System V semaphore IPC on your system.</p>
</li>
<li><a name="send()-on-closed-socket-%25s"></a><b>send() on closed socket %s</b>
<p>(W closed) The socket you're sending to got itself closed sometime
before now.  Check your control flow.</p>
</li>
<li><a name="Sequence-%22%5cc%7b%22-invalid"></a><b>Sequence "\c{" invalid</b>
<p>(F) These three characters may not appear in sequence in a
double-quotish context.  This message is raised only on non-ASCII
platforms (a different error message is output on ASCII ones).  If you
were intending to specify a control character with this sequence, you'll
have to use a different way to specify it.</p>
</li>
<li><a name="Sequence-(%3f-incomplete-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>Sequence (? incomplete in regex; marked by &lt;-- HERE in m/%s/</b>
<p>(F) A regular expression ended with an incomplete extension (?.  The
&lt;-- HERE shows whereabouts in the regular expression the problem was
discovered.  See <a href="perlre.html">perlre</a>.</p>
</li>
<li><a name="Sequence-(%3f%25c...)-not-implemented-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>Sequence (?%c...) not implemented in regex; marked by &lt;-- HERE in
m/%s/</b>
<p>(F) A proposed regular expression extension has the character reserved
but has not yet been written.  The &lt;-- HERE shows whereabouts in the
regular expression the problem was discovered.  See <a href="perlre.html">perlre</a>.</p>
</li>
<li><a name="Sequence-(%3f%25s...)-not-recognized-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>Sequence (?%s...) not recognized in regex; marked by &lt;-- HERE in
m/%s/</b>
<p>(F) You used a regular expression extension that doesn't make sense.
The &lt;-- HERE shows whereabouts in the regular expression the problem was
discovered.  This may happen when using the <code class="inline"><span class="s">(</span><span class="q">?^...)</span></code>
 construct to tell
Perl to use the default regular expression modifiers, and you
redundantly specify a default modifier.  For other
causes, see <a href="perlre.html">perlre</a>.</p>
</li>
<li><a name="Sequence-(%3f%23...-not-terminated-in-regex-m%2f%25s%2f"></a><b>Sequence (?#... not terminated in regex m/%s/</b>
<p>(F) A regular expression comment must be terminated by a closing
parenthesis.  Embedded parentheses aren't allowed.  See
<a href="perlre.html">perlre</a>.</p>
</li>
<li><a name="Sequence-(%3f%26...-not-terminated-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>Sequence (?&amp;... not terminated in regex; marked by &lt;-- HERE in
m/%s/</b>
<p>(F) A named reference of the form <code class="inline"><span class="s">(</span><span class="q">?&amp;...)</span></code>
 was missing the final
closing parenthesis after the name.  The &lt;-- HERE shows whereabouts
in the regular expression the problem was discovered.</p>
</li>
<li><a name="Sequence-(%3f%25c...-not-terminated-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>Sequence (?%c... not terminated in regex; marked by &lt;-- HERE
in m/%s/</b>
<p>(F) A named group of the form <code class="inline"><span class="s">(</span><span class="q">?&#39;...&#39;)</span></code>
 or <code class="inline"><span class="s">(</span><span class="q">?&lt;...&gt;)</span></code>
 was missing the final
closing quote or angle bracket.  The &lt;-- HERE shows whereabouts in the
regular expression the problem was discovered.</p>
</li>
<li><a name="Sequence-(%3f(%25c...-not-terminated-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>Sequence (?(%c... not terminated in regex; marked by &lt;-- HERE
in m/%s/</b>
<p>(F) A named reference of the form <code class="inline"><span class="s">(</span><span class="q">?(&#39;...&#39;)...)</span></code>
 or <code class="inline"><span class="s">(</span><span class="q">?(&lt;...&gt;)...)</span></code>
 was
missing the final closing quote or angle bracket after the name.  The
&lt;-- HERE shows whereabouts in the regular expression the problem was
discovered.</p>
</li>
<li><a name="Sequence-(%3f...-not-terminated-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>Sequence (?... not terminated in regex; marked by &lt;-- HERE in
m/%s/</b>
<p>(F) There was no matching closing parenthesis for the '('.  The
&lt;-- HERE shows whereabouts in the regular expression the problem was
discovered.</p>
</li>
<li><a name="Sequence-%5c%25s...-not-terminated-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>Sequence \%s... not terminated in regex; marked by &lt;-- HERE in
m/%s/</b>
<p>(F) The regular expression expects a mandatory argument following the escape
sequence and this has been omitted or incorrectly written.</p>
</li>
<li><a name="Sequence-(%3f%7b...%7d)-not-terminated-with-')'"></a><b>Sequence (?{...}) not terminated with ')'</b>
<p>(F) The end of the perl code contained within the {...} must be
followed immediately by a ')'.</p>
</li>
<li><a name="Sequence-(%3fP%3e...-not-terminated-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>Sequence (?P&gt;... not terminated in regex; marked by &lt;-- HERE in m/%s/</b>
<p>(F) A named reference of the form <code class="inline"><span class="s">(</span><span class="q">?P&gt;...)</span></code>
 was missing the final
closing parenthesis after the name.  The &lt;-- HERE shows whereabouts
in the regular expression the problem was discovered.</p>
</li>
<li><a name="Sequence-(%3fP%3c...-not-terminated-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>Sequence (?P&lt;... not terminated in regex; marked by &lt;-- HERE in m/%s/</b>
<p>(F) A named group of the form <code class="inline"><span class="s">(</span><span class="q">?P&lt;...&gt;&#39;)</span></code>
 was missing the final
closing angle bracket.  The &lt;-- HERE shows whereabouts in the
regular expression the problem was discovered.</p>
</li>
<li><a name="Sequence-%3fP%3d...-not-terminated-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>Sequence ?P=... not terminated in regex; marked by &lt;-- HERE in
m/%s/</b>
<p>(F) A named reference of the form <code class="inline"><span class="s">(</span><span class="q">?P=...)</span></code>
 was missing the final
closing parenthesis after the name.  The &lt;-- HERE shows whereabouts
in the regular expression the problem was discovered.</p>
</li>
<li><a name="Sequence-(%3fR)-not-terminated-in-regex-m%2f%25s%2f"></a><b>Sequence (?R) not terminated in regex m/%s/</b>
<p>(F) An <code class="inline">(?R)</code> or <code class="inline">(?0)</code> sequence in a regular expression was missing the
final parenthesis.</p>
</li>
<li><a name="500-Server-error"></a><b>500 Server error</b>
<p>(A) This is the error message generally seen in a browser window
when trying to run a CGI program (including SSI) over the web.  The
actual error text varies widely from server to server.  The most
frequently-seen variants are "500 Server error", "Method (something)
not permitted", "Document contains no data", "Premature end of script
headers", and "Did not produce a valid header".</p>
<p><b>This is a CGI error, not a Perl error</b>.</p>
<p>You need to make sure your script is executable, is accessible by
the user CGI is running the script under (which is probably not the
user account you tested it under), does not rely on any environment
variables (like PATH) from the user it isn't running under, and isn't
in a location where the CGI server can't find it, basically, more or
less.  Please see the following for more information:</p>
<pre class="verbatim"><ol><li>	http://www.perl.org/CGI_MetaFAQ.html</li><li>	http://www.htmlhelp.org/faq/cgifaq.html</li><li>	http://www.w3.org/Security/Faq/</li></ol></pre><p>You should also look at <a href="perlfaq9.html">perlfaq9</a>.</p>
</li>
<li><a name="setegid()-not-implemented"></a><b>setegid() not implemented</b>
<p>(F) You tried to assign to <code class="inline"><span class="i">$)</span></code>
, and your operating system doesn't
support the setegid() system call (or equivalent), or at least Configure
didn't think so.</p>
</li>
<li><a name="seteuid()-not-implemented"></a><b>seteuid() not implemented</b>
<p>(F) You tried to assign to <code class="inline"><span class="i">$&gt;</span></code>
, and your operating system doesn't
support the seteuid() system call (or equivalent), or at least Configure
didn't think so.</p>
</li>
<li><a name="setpgrp-can't-take-arguments"></a><b>setpgrp can't take arguments</b>
<p>(F) Your system has the setpgrp() from BSD 4.2, which takes no
arguments, unlike POSIX setpgid(), which takes a process ID and process
group ID.</p>
</li>
<li><a name="setrgid()-not-implemented"></a><b>setrgid() not implemented</b>
<p>(F) You tried to assign to <code class="inline"><span class="i">$(</span></code>
, and your operating system doesn't
support the setrgid() system call (or equivalent), or at least Configure
didn't think so.</p>
</li>
<li><a name="setruid()-not-implemented"></a><b>setruid() not implemented</b>
<p>(F) You tried to assign to <code class="inline"><span class="i">$&lt;</span></code>
, and your operating system doesn't
support the setruid() system call (or equivalent), or at least Configure
didn't think so.</p>
</li>
<li><a name="setsockopt()-on-closed-socket-%25s"></a><b>setsockopt() on closed socket %s</b>
<p>(W closed) You tried to set a socket option on a closed socket.  Did you
forget to check the return value of your socket() call?  See
<a href="functions/setsockopt.html">setsockopt</a>.</p>
</li>
<li><a name="Setting-%24%2f-to-a-reference-to-%25s-as-a-form-of-slurp-is-deprecated%2c-treating-as-undef.-This-will-be-fatal-in-Perl-5.28"></a><b>Setting $/ to a reference to %s as a form of slurp is deprecated, treating as undef. This will be fatal in Perl 5.28</b>
<p>(D deprecated) You assigned a reference to a scalar to <code class="inline"><span class="i">$/</span></code>
 where the
referenced item is not a positive integer.  In older perls this <b>appeared</b>
to work the same as setting it to <code class="inline"><a class="l_k" href="functions/undef.html">undef</a></code> but was in fact internally
different, less efficient and with very bad luck could have resulted in
your file being split by a stringified form of the reference.</p>
<p>In Perl 5.20.0 this was changed so that it would be <b>exactly</b> the same as
setting <code class="inline"><span class="i">$/</span></code>
 to undef, with the exception that this warning would be
thrown.</p>
<p>You are recommended to change your code to set <code class="inline"><span class="i">$/</span></code>
 to <code class="inline"><a class="l_k" href="functions/undef.html">undef</a></code> explicitly
if you wish to slurp the file.  In Perl 5.28 assigning <code class="inline"><span class="i">$/</span></code>
 to a 
reference to an integer which isn't positive will throw a fatal error.</p>
</li>
<li><a name="Setting-%24%2f-to-%25s-reference-is-forbidden"></a><b>Setting $/ to %s reference is forbidden</b>
<p>(F) You tried to assign a reference to a non integer to <code class="inline"><span class="i">$/</span></code>
.  In older
Perls this would have behaved similarly to setting it to a reference to
a positive integer, where the integer was the address of the reference.
As of Perl 5.20.0 this is a fatal error, to allow future versions of Perl
to use non-integer refs for more interesting purposes.</p>
</li>
<li><a name="shm%25s-not-implemented"></a><b>shm%s not implemented</b>
<p>(F) You don't have System V shared memory IPC on your system.</p>
</li>
<li><a name="!%3d~-should-be-!~"></a><b>!=~ should be !~</b>
<p>(W syntax) The non-matching operator is !~, not !=~.  !=~ will be
interpreted as the != (numeric not equal) and ~ (1's complement)
operators: probably not what you intended.</p>
</li>
<li><a name="%2f%25s%2f-should-probably-be-written-as-%22%25s%22"></a><b>/%s/ should probably be written as "%s"</b>
<p>(W syntax) You have used a pattern where Perl expected to find a string,
as in the first argument to <code class="inline"><a class="l_k" href="functions/join.html">join</a></code>.  Perl will treat the true or false
result of matching the pattern against $_ as the string, which is
probably not what you had in mind.</p>
</li>
<li><a name="shutdown()-on-closed-socket-%25s"></a><b>shutdown() on closed socket %s</b>
<p>(W closed) You tried to do a shutdown on a closed socket.  Seems a bit
superfluous.</p>
</li>
<li><a name="SIG%25s-handler-%22%25s%22-not-defined"></a><b>SIG%s handler "%s" not defined</b>
<p>(W signal) The signal handler named in %SIG doesn't, in fact, exist.
Perhaps you put it into the wrong package?</p>
</li>
<li><a name="Slab-leaked-from-cv-%25p"></a><b>Slab leaked from cv %p</b>
<p>(S) If you see this message, then something is seriously wrong with the
internal bookkeeping of op trees.  An op tree needed to be freed after
a compilation error, but could not be found, so it was leaked instead.</p>
</li>
<li><a name="sleep(%25u)-too-large"></a><b>sleep(%u) too large</b>
<p>(W overflow) You called <code class="inline"><a class="l_k" href="functions/sleep.html">sleep</a></code> with a number that was larger than
it can reliably handle and <code class="inline"><a class="l_k" href="functions/sleep.html">sleep</a></code> probably slept for less time than
requested.</p>
</li>
<li><a name="Slurpy-parameter-not-last"></a><b>Slurpy parameter not last</b>
<p>(F) In a subroutine signature, you put something after a slurpy (array or
hash) parameter.  The slurpy parameter takes all the available arguments,
so there can't be any left to fill later parameters.</p>
</li>
<li><a name="Smart-matching-a-non-overloaded-object-breaks-encapsulation"></a><b>Smart matching a non-overloaded object breaks encapsulation</b>
<p>(F) You should not use the <code class="inline">~~</code>
 operator on an object that does not
overload it: Perl refuses to use the object's underlying structure
for the smart match.</p>
</li>
<li><a name="Smartmatch-is-experimental"></a><b>Smartmatch is experimental</b>
<p>(S experimental::smartmatch) This warning is emitted if you
use the smartmatch (<code class="inline">~~</code>
) operator.  This is currently an experimental
feature, and its details are subject to change in future releases of
Perl.  Particularly, its current behavior is noticed for being
unnecessarily complex and unintuitive, and is very likely to be
overhauled.</p>
</li>
<li><a name="sort-is-now-a-reserved-word"></a><b>sort is now a reserved word</b>
<p>(F) An ancient error message that almost nobody ever runs into anymore.
But before sort was a keyword, people sometimes used it as a filehandle.</p>
</li>
<li><a name="Source-filters-apply-only-to-byte-streams"></a><b>Source filters apply only to byte streams</b>
<p>(F) You tried to activate a source filter (usually by loading a
source filter module) within a string passed to <code class="inline"><a class="l_k" href="functions/eval.html">eval</a></code>.  This is
not permitted under the <code class="inline"><span class="w">unicode_eval</span></code>
 feature.  Consider using
<code class="inline"><a class="l_k" href="functions/evalbytes.html">evalbytes</a></code> instead.  See <a href="feature.html">feature</a>.</p>
</li>
<li><a name="splice()-offset-past-end-of-array"></a><b>splice() offset past end of array</b>
<p>(W misc) You attempted to specify an offset that was past the end of
the array passed to splice().  Splicing will instead commence at the
end of the array, rather than past it.  If this isn't what you want,
try explicitly pre-extending the array by assigning $#array = $offset.
See <a href="functions/splice.html">splice</a>.</p>
</li>
<li><a name="Split-loop"></a><b>Split loop</b>
<p>(P) The split was looping infinitely.  (Obviously, a split shouldn't
iterate more times than there are characters of input, which is what
happened.)  See <a href="functions/split.html">split</a>.</p>
</li>
<li><a name="Statement-unlikely-to-be-reached"></a><b>Statement unlikely to be reached</b>
<p>(W exec) You did an exec() with some statement after it other than a
die().  This is almost always an error, because exec() never returns
unless there was a failure.  You probably wanted to use system()
instead, which does return.  To suppress this warning, put the exec() in
a block by itself.</p>
</li>
<li><a name="%22state%22-subroutine-%25s-can't-be-in-a-package"></a><b>"state" subroutine %s can't be in a package</b>
<p>(F) Lexically scoped subroutines aren't in a package, so it doesn't make
sense to try to declare one with a package qualifier on the front.</p>
</li>
<li><a name="%22state-%25s%22-used-in-sort-comparison"></a><b>"state %s" used in sort comparison</b>
<p>(W syntax) The package variables $a and $b are used for sort comparisons.
You used $a or $b in as an operand to the <code class="inline">&lt;=&gt;</code>
 or <code class="inline">cmp</code>
 operator inside a
sort comparison block, and the variable had earlier been declared as a
lexical variable.  Either qualify the sort variable with the package
name, or rename the lexical variable.</p>
</li>
<li><a name="%22state%22-variable-%25s-can't-be-in-a-package"></a><b>"state" variable %s can't be in a package</b>
<p>(F) Lexically scoped variables aren't in a package, so it doesn't make
sense to try to declare one with a package qualifier on the front.  Use
local() if you want to localize a package variable.</p>
</li>
<li><a name="stat()-on-unopened-filehandle-%25s"></a><b>stat() on unopened filehandle %s</b>
<p>(W unopened) You tried to use the stat() function on a filehandle that
was either never opened or has since been closed.</p>
</li>
<li><a name="Strings-with-code-points-over-0xFF-may-not-be-mapped-into-in-memory-file-handles"></a><b>Strings with code points over 0xFF may not be mapped into in-memory file handles</b>
<p>(W utf8) You tried to open a reference to a scalar for read or append
where the scalar contained code points over 0xFF.  In-memory files
model on-disk files and can only contain bytes.</p>
</li>
<li><a name="Stub-found-while-resolving-method-%22%25s%22-overloading-%22%25s%22-in-package-%22%25s%22"></a><b>Stub found while resolving method "%s" overloading "%s" in package "%s"</b>
<p>(P) Overloading resolution over @ISA tree may be broken by importation
stubs.  Stubs should never be implicitly created, but explicit calls to
<code class="inline"><span class="w">can</span></code>
 may break this.</p>
</li>
<li><a name="Subroutine-%22%26%25s%22-is-not-available"></a><b>Subroutine "&amp;%s" is not available</b>
<p>(W closure) During compilation, an inner named subroutine or eval is
attempting to capture an outer lexical subroutine that is not currently
available.  This can happen for one of two reasons.  First, the lexical
subroutine may be declared in an outer anonymous subroutine that has
not yet been created.  (Remember that named subs are created at compile
time, while anonymous subs are created at run-time.)  For example,</p>
<pre class="verbatim"><ol><li><a name="a"></a><a name="f"></a>    <a class="l_k" href="functions/sub.html">sub</a> <span class="s">{</span> <a class="l_k" href="functions/my.html">my</a> sub <span class="m">a</span> <span class="s">{</span>...<span class="s">}</span> sub <span class="m">f</span> <span class="s">{</span> \<span class="i">&amp;a</span> <span class="s">}</span> <span class="s">}</span></li></ol></pre><p>At the time that f is created, it can't capture the current "a" sub,
since the anonymous subroutine hasn't been created yet.  Conversely, the
following won't give a warning since the anonymous subroutine has by now
been created and is live:</p>
<pre class="verbatim"><ol><li><a name="a"></a>    <a class="l_k" href="functions/sub.html">sub</a> <span class="s">{</span> <a class="l_k" href="functions/my.html">my</a> sub <span class="m">a</span> <span class="s">{</span>...<span class="s">}</span> <a class="l_k" href="functions/eval.html">eval</a> <span class="q">&#39;sub f { \&amp;a }&#39;</span> <span class="s">}</span>-&gt;<span class="s">(</span><span class="s">)</span><span class="sc">;</span></li></ol></pre><p>The second situation is caused by an eval accessing a lexical subroutine
that has gone out of scope, for example,</p>
<pre class="verbatim"><ol><li><a name="f"></a>    sub <span class="m">f</span> <span class="s">{</span></li><li><a name="a"></a>	<a class="l_k" href="functions/my.html">my</a> sub <span class="m">a</span> <span class="s">{</span>...<span class="s">}</span></li><li>	<a class="l_k" href="functions/sub.html">sub</a> <span class="s">{</span> <a class="l_k" href="functions/eval.html">eval</a> <span class="q">&#39;\&amp;a&#39;</span> <span class="s">}</span></li><li>    <span class="s">}</span></li><li>    <span class="i">f</span><span class="s">(</span><span class="s">)</span>-&gt;<span class="s">(</span><span class="s">)</span><span class="sc">;</span></li></ol></pre><p>Here, when the '\&amp;a' in the eval is being compiled, f() is not currently
being executed, so its &amp;a is not available for capture.</p>
</li>
<li><a name="%22%25s%22-subroutine-%26%25s-masks-earlier-declaration-in-same-%25s"></a><b>"%s" subroutine &amp;%s masks earlier declaration in same %s</b>
<p>(W misc) A "my" or "state" subroutine has been redeclared in the
current scope or statement, effectively eliminating all access to
the previous instance.  This is almost always a typographical error.
Note that the earlier subroutine will still exist until the end of
the scope or until all closure references to it are destroyed.</p>
</li>
<li><a name="Subroutine-%25s-redefined"></a><b>Subroutine %s redefined</b>
<p>(W redefine) You redefined a subroutine.  To suppress this warning, say</p>
<pre class="verbatim"><ol><li>    <span class="s">{</span></li><li>	<a class="l_k" href="functions/no.html">no</a> <span class="w">warnings</span> <span class="q">&#39;redefine&#39;</span><span class="sc">;</span></li><li>	<a class="l_k" href="functions/eval.html">eval</a> <span class="q">&quot;sub name { ... }&quot;</span><span class="sc">;</span></li><li>    <span class="s">}</span></li></ol></pre></li>
<li><a name="Subroutine-%22%25s%22-will-not-stay-shared"></a><b>Subroutine "%s" will not stay shared</b>
<p>(W closure) An inner (nested) <i>named</i> subroutine is referencing a "my"
subroutine defined in an outer named subroutine.</p>
<p>When the inner subroutine is called, it will see the value of the outer
subroutine's lexical subroutine as it was before and during the *first*
call to the outer subroutine; in this case, after the first call to the
outer subroutine is complete, the inner and outer subroutines will no
longer share a common value for the lexical subroutine.  In other words,
it will no longer be shared.  This will especially make a difference
if the lexical subroutines accesses lexical variables declared in its
surrounding scope.</p>
<p>This problem can usually be solved by making the inner subroutine
anonymous, using the <code class="inline"><a class="l_k" href="functions/sub.html">sub</a> <span class="s">{</span><span class="s">}</span></code>
 syntax.  When inner anonymous subs that
reference lexical subroutines in outer subroutines are created, they
are automatically rebound to the current values of such lexical subs.</p>
</li>
<li><a name="Substitution-loop"></a><b>Substitution loop</b>
<p>(P) The substitution was looping infinitely.  (Obviously, a substitution
shouldn't iterate more times than there are characters of input, which
is what happened.)  See the discussion of substitution in
<a href="perlop.html#Regexp-Quote-Like-Operators">Regexp Quote-Like Operators in perlop</a>.</p>
</li>
<li><a name="Substitution-pattern-not-terminated"></a><b>Substitution pattern not terminated</b>
<p>(F) The lexer couldn't find the interior delimiter of an s/// or s{}{}
construct.  Remember that bracketing delimiters count nesting level.
Missing the leading <code class="inline"><span class="i">$</span></code>
 from variable <code class="inline"><span class="i">$s</span></code>
 may cause this error.</p>
</li>
<li><a name="Substitution-replacement-not-terminated"></a><b>Substitution replacement not terminated</b>
<p>(F) The lexer couldn't find the final delimiter of an s/// or s{}{}
construct.  Remember that bracketing delimiters count nesting level.
Missing the leading <code class="inline"><span class="i">$</span></code>
 from variable <code class="inline"><span class="i">$s</span></code>
 may cause this error.</p>
</li>
<li><a name="substr-outside-of-string"></a><b>substr outside of string</b>
<p>(W substr)(F) You tried to reference a substr() that pointed outside of
a string.  That is, the absolute value of the offset was larger than the
length of the string.  See <a href="functions/substr.html">substr</a>.  This warning is fatal if
substr is used in an lvalue context (as the left hand side of an
assignment or as a subroutine argument for example).</p>
</li>
<li><a name="sv_upgrade-from-type-%25d-down-to-type-%25d"></a><b>sv_upgrade from type %d down to type %d</b>
<p>(P) Perl tried to force the upgrade of an SV to a type which was actually
inferior to its current type.</p>
</li>
<li><a name="SWASHNEW-didn't-return-an-HV-ref"></a><b>SWASHNEW didn't return an HV ref</b>
<p>(P) Something went wrong internally when Perl was trying to look up
Unicode characters.</p>
</li>
<li><a name="Switch-(%3f(condition)...-contains-too-many-branches-in-regex%3b-marked-by--%3c---HERE-in-m%2f%25s%2f"></a><b>Switch (?(condition)... contains too many branches in regex; marked by 
&lt;-- HERE in m/%s/</b>
<p>(F) A (?(condition)if-clause|else-clause) construct can have at most
two branches (the if-clause and the else-clause).  If you want one or
both to contain alternation, such as using <code class="inline"><span class="w">this</span>|<span class="w">that</span>|<span class="w">other</span></code>
, enclose
it in clustering parentheses:</p>
<pre class="verbatim"><ol><li>    (?(condition)(?:this|that|other)|else-clause)</li></ol></pre><p>The &lt;-- HERE shows whereabouts in the regular expression the problem
was discovered.  See <a href="perlre.html">perlre</a>.</p>
</li>
<li><a name="Switch-condition-not-recognized-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>Switch condition not recognized in regex; marked by &lt;-- HERE in
m/%s/</b>
<p>(F) The condition part of a (?(condition)if-clause|else-clause) construct
is not known.  The condition must be one of the following:</p>
<pre class="verbatim"><ol><li> <span class="s">(</span><span class="n">1</span><span class="s">)</span> <span class="s">(</span><span class="n">2</span><span class="s">)</span> ...        <span class="w">true</span> <a class="l_k" href="functions/if.html">if</a> <span class="n">1</span><span class="w">st</span><span class="cm">,</span> <span class="n">2</span><span class="w">nd</span><span class="cm">,</span> <span class="w">etc</span>.<span class="cm">,</span> <span class="w">capture</span> <span class="i">matched</span></li><li> <span class="s">(</span><span class="q">&lt;NAME&gt;</span><span class="s">)</span> <span class="s">(</span><span class="q">&#39;NAME&#39;</span><span class="s">)</span>  <span class="w">true</span> <a class="l_k" href="functions/if.html">if</a> <span class="w">named</span> <span class="w">capture</span> <span class="i">matched</span></li><li> <span class="s">(</span><span class="q">?=...) (?</span>&lt;=...<span class="s">)</span>   <span class="w">true</span> <a class="l_k" href="functions/if.html">if</a> <span class="w">subpattern</span> <span class="i">matches</span></li><li> <span class="s">(</span><span class="q">?!...) (?</span>&lt;!...<span class="s">)</span>   <span class="w">true</span> <a class="l_k" href="functions/if.html">if</a> <span class="w">subpattern</span> <span class="w">fails</span> <span class="w">to</span> <span class="i">match</span></li><li> <span class="s">(</span><span class="q">?{ CODE })        true if code returns a true value</span></li><li> <span class="q"> (R)                true if evaluating inside recursion</span></li><li> <span class="q"> (R1) (R2) ...      true if directly inside capture group 1, 2, etc.</span></li><li> <span class="q"> (R&amp;NAME)           true if directly inside named capture</span></li><li> <span class="q"> (DEFINE)           always false; for defining named subpatterns</span></li></ol></pre><p>The &lt;-- HERE shows whereabouts in the regular expression the problem was
discovered.  See <a href="perlre.html">perlre</a>.</p>
</li>
<li><a name="Switch-(%3f(condition)...-not-terminated-in-regex%3b-marked-by-%3c---HERE-in-m%2f%25s%2f"></a><b>Switch (?(condition)... not terminated in regex; marked by
&lt;-- HERE in m/%s/</b>
<p>(F) You omitted to close a (?(condition)...) block somewhere
in the pattern.  Add a closing parenthesis in the appropriate
position.  See <a href="perlre.html">perlre</a>.</p>
</li>
<li><a name="switching-effective-%25s-is-not-implemented"></a><b>switching effective %s is not implemented</b>
<p>(F) While under the <code class="inline"><a class="l_k" href="functions/use.html">use</a> <span class="w">filetest</span></code>
 pragma, we cannot switch the real
and effective uids or gids.</p>
</li>
<li><a name="syntax-error"></a><b>syntax error</b>
<p>(F) Probably means you had a syntax error.  Common reasons include:</p>
<pre class="verbatim"><ol><li>    <span class="w">A</span> <span class="w">keyword</span> <span class="w">is</span> <span class="w">misspelled</span>.</li><li>    <span class="w">A</span> <span class="w">semicolon</span> <span class="w">is</span> <span class="w">missing</span>.</li><li>    <span class="w">A</span> <span class="w">comma</span> <span class="w">is</span> <span class="w">missing</span>.</li><li>    <span class="w">An</span> <span class="w">opening</span> or <span class="w">closing</span> <span class="w">parenthesis</span> <span class="w">is</span> <span class="w">missing</span>.</li><li>    <span class="w">An</span> <span class="w">opening</span> or <span class="w">closing</span> <span class="w">brace</span> <span class="w">is</span> <span class="w">missing</span>.</li><li>    <span class="w">A</span> <span class="w">closing</span> <span class="w">quote</span> <span class="w">is</span> <span class="w">missing</span>.</li></ol></pre><p>Often there will be another error message associated with the syntax
error giving more information.  (Sometimes it helps to turn on <b>-w</b>.)
The error message itself often tells you where it was in the line when
it decided to give up.  Sometimes the actual error is several tokens
before this, because Perl is good at understanding random input.
Occasionally the line number may be misleading, and once in a blue moon
the only way to figure out what's triggering the error is to call
<code class="inline"><span class="w">perl</span> -c</code>
 repeatedly, chopping away half the program each time to see
if the error went away.  Sort of the cybernetic version of 20 questions.</p>
</li>
<li><a name="syntax-error-at-line-%25d%3a-'%25s'-unexpected"></a><b>syntax error at line %d: '%s' unexpected</b>
<p>(A) You've accidentally run your script through the Bourne shell instead
of Perl.  Check the #! line, or manually feed your script into Perl
yourself.</p>
</li>
<li><a name="syntax-error-in-file-%25s-at-line-%25d%2c-next-2-tokens-%22%25s%22"></a><b>syntax error in file %s at line %d, next 2 tokens "%s"</b>
<p>(F) This error is likely to occur if you run a perl5 script through
a perl4 interpreter, especially if the next 2 tokens are "use strict"
or "my $var" or "our $var".</p>
</li>
<li><a name="Syntax-error-in-(%3f%5b...%5d)-in-regex-m%2f%25s%2f"></a><b>Syntax error in (?[...]) in regex m/%s/</b>
<p>(F) Perl could not figure out what you meant inside this construct; this
notifies you that it is giving up trying.</p>
</li>
<li><a name="%25s-syntax-OK"></a><b>%s syntax OK</b>
<p>(F) The final summary message when a <code class="inline"><span class="w">perl</span> -c</code>
 succeeds.</p>
</li>
<li><a name="sysread()-on-closed-filehandle-%25s"></a><b>sysread() on closed filehandle %s</b>
<p>(W closed) You tried to read from a closed filehandle.</p>
</li>
<li><a name="sysread()-on-unopened-filehandle-%25s"></a><b>sysread() on unopened filehandle %s</b>
<p>(W unopened) You tried to read from a filehandle that was never opened.</p>
</li>
<li><a name="System-V-%25s-is-not-implemented-on-this-machine"></a><b>System V %s is not implemented on this machine</b>
<p>(F) You tried to do something with a function beginning with "sem",
"shm", or "msg" but that System V IPC is not implemented in your
machine.  In some machines the functionality can exist but be
unconfigured.  Consult your system support.</p>
</li>
<li><a name="syswrite()-on-closed-filehandle-%25s"></a><b>syswrite() on closed filehandle %s</b>
<p>(W closed) The filehandle you're writing to got itself closed sometime
before now.  Check your control flow.</p>
</li>
<li><a name="-T-and--B-not-implemented-on-filehandles"></a><b><code class="inline">-T</code>
 and <code class="inline">-B</code>
 not implemented on filehandles</b>
<p>(F) Perl can't peek at the stdio buffer of filehandles when it doesn't
know about your kind of stdio.  You'll have to use a filename instead.</p>
</li>
<li><a name="Target-of-goto-is-too-deeply-nested"></a><b>Target of goto is too deeply nested</b>
<p>(F) You tried to use <code class="inline"><a class="l_k" href="functions/goto.html">goto</a></code> to reach a label that was too deeply nested
for Perl to reach.  Perl is doing you a favor by refusing.</p>
</li>
<li><a name="telldir()-attempted-on-invalid-dirhandle-%25s"></a><b>telldir() attempted on invalid dirhandle %s</b>
<p>(W io) The dirhandle you tried to telldir() is either closed or not really
a dirhandle.  Check your control flow.</p>
</li>
<li><a name="tell()-on-unopened-filehandle"></a><b>tell() on unopened filehandle</b>
<p>(W unopened) You tried to use the tell() function on a filehandle that
was either never opened or has since been closed.</p>
</li>
<li><a name="That-use-of-%24%5b-is-unsupported"></a><b>That use of $[ is unsupported</b>
<p>(F) Assignment to <code class="inline"><span class="i">$[</span></code>
 is now strictly circumscribed, and interpreted
as a compiler directive.  You may say only one of</p>
<pre class="verbatim"><ol><li>    <span class="i">$[</span> = <span class="n">0</span><span class="sc">;</span></li><li>    <span class="i">$[</span> = <span class="n">1</span><span class="sc">;</span></li><li>    ...</li><li>    <a class="l_k" href="functions/local.html">local</a> <span class="i">$[</span> = <span class="n">0</span><span class="sc">;</span></li><li>    <a class="l_k" href="functions/local.html">local</a> <span class="i">$[</span> = <span class="n">1</span><span class="sc">;</span></li><li>    ...</li></ol></pre><p>This is to prevent the problem of one module changing the array base out
from under another module inadvertently.  See <a href="perlvar.html#%24%5b">$[ in perlvar</a> and <a href="arybase.html">arybase</a>.</p>
</li>
<li><a name="The-bitwise-feature-is-experimental"></a><b>The bitwise feature is experimental</b>
<p>(S experimental::bitwise) This warning is emitted if you use bitwise
operators (<code class="inline"><span class="i">&amp; |</span> ^ ~ <span class="i">&amp;.</span> |. ^. ~.</code>
) with the "bitwise" feature enabled.
Simply suppress the warning if you want to use the feature, but know
that in doing so you are taking the risk of using an experimental
feature which may change or be removed in a future Perl version:</p>
<pre class="verbatim"><ol><li>    <a class="l_k" href="functions/no.html">no</a> <span class="w">warnings</span> <span class="q">&quot;experimental::bitwise&quot;</span><span class="sc">;</span></li><li>    <a class="l_k" href="functions/use.html">use</a> <span class="w">feature</span> <span class="q">&quot;bitwise&quot;</span><span class="sc">;</span></li><li>    <span class="i">$x</span> |.= <span class="i">$y</span><span class="sc">;</span></li></ol></pre></li>
<li><a name="The-crypt()-function-is-unimplemented-due-to-excessive-paranoia."></a><b>The crypt() function is unimplemented due to excessive paranoia.</b>
<p>(F) Configure couldn't find the crypt() function on your machine,
probably because your vendor didn't supply it, probably because they
think the U.S. Government thinks it's a secret, or at least that they
will continue to pretend that it is.  And if you quote me on that, I
will deny it.</p>
</li>
<li><a name="The-experimental-declared_refs-feature-is-not-enabled"></a><b>The experimental declared_refs feature is not enabled</b>
<p>(F) To declare references to variables, as in <code class="inline"><a class="l_k" href="functions/my.html">my</a> \<span class="i">%x</span></code>
, you must first enable
the feature:</p>
<pre class="verbatim"><ol><li>    <a class="l_k" href="functions/no.html">no</a> <span class="w">warnings</span> <span class="q">&quot;experimental::declared_refs&quot;</span><span class="sc">;</span></li><li>    <a class="l_k" href="functions/use.html">use</a> <span class="w">feature</span> <span class="q">&quot;declared_refs&quot;</span><span class="sc">;</span></li></ol></pre></li>
<li><a name="The-%25s-function-is-unimplemented"></a><b>The %s function is unimplemented</b>
<p>(F) The function indicated isn't implemented on this architecture,
according to the probings of Configure.</p>
</li>
<li><a name="The-regex_sets-feature-is-experimental"></a><b>The regex_sets feature is experimental</b>
<p>(S experimental::regex_sets) This warning is emitted if you
use the syntax <code class="inline"><span class="s">(</span><span class="q">?[   ])</span></code>
 in a regular expression.
The details of this feature are subject to change.
if you want to use it, but know that in doing so you
are taking the risk of using an experimental feature which may
change in a future Perl version, you can do this to silence the
warning:</p>
<pre class="verbatim"><ol><li>    <a class="l_k" href="functions/no.html">no</a> <span class="w">warnings</span> <span class="q">&quot;experimental::regex_sets&quot;</span><span class="sc">;</span></li></ol></pre></li>
<li><a name="The-signatures-feature-is-experimental"></a><b>The signatures feature is experimental</b>
<p>(S experimental::signatures) This warning is emitted if you unwrap a
subroutine's arguments using a signature.  Simply suppress the warning
if you want to use the feature, but know that in doing so you are taking
the risk of using an experimental feature which may change or be removed
in a future Perl version:</p>
<pre class="verbatim"><ol><li>    <a class="l_k" href="functions/no.html">no</a> <span class="w">warnings</span> <span class="q">&quot;experimental::signatures&quot;</span><span class="sc">;</span></li><li>    <a class="l_k" href="functions/use.html">use</a> <span class="w">feature</span> <span class="q">&quot;signatures&quot;</span><span class="sc">;</span></li><li><a name="foo"></a>    sub <span class="m">foo ($left, $right)</span> <span class="s">{</span> ... <span class="s">}</span></li></ol></pre></li>
<li><a name="The-stat-preceding-%25s-wasn't-an-lstat"></a><b>The stat preceding %s wasn't an lstat</b>
<p>(F) It makes no sense to test the current stat buffer for symbolic
linkhood if the last stat that wrote to the stat buffer already went
past the symlink to get to the real file.  Use an actual filename
instead.</p>
</li>
<li><a name="The-'unique'-attribute-may-only-be-applied-to-'our'-variables"></a><b>The 'unique' attribute may only be applied to 'our' variables</b>
<p>(F) This attribute was never supported on <code class="inline"><a class="l_k" href="functions/my.html">my</a></code> or <code class="inline"><a class="l_k" href="functions/sub.html">sub</a></code> declarations.</p>
</li>
<l