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<h1>sprintf</h1>
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<ul>
<li><a name="sprintf-FORMAT%2c-LIST"></a><b>sprintf FORMAT, LIST</b>
<p></p>
<p>Returns a string formatted by the usual <code class="inline"><a class="l_k" href="../functions/printf.html">printf</a></code> conventions of the C
library function <code class="inline"><a class="l_k" href="../functions/sprintf.html">sprintf</a></code>. See below for more details
and see <code class="inline"><a class="l_k" href="../functions/sprintf.html">sprintf(3)</a></code> or <code class="inline"><a class="l_k" href="../functions/printf.html">printf(3)</a></code> on your system for an explanation of
the general principles.</p>
<p>For example:</p>
<pre class="verbatim"><ol><li> <span class="c"># Format number with up to 8 leading zeroes</span></li><li> <span class="i">$result</span> = <a class="l_k" href="../functions/sprintf.html">sprintf</a><span class="s">(</span><span class="q">"%08d"</span><span class="cm">,</span> <span class="i">$number</span><span class="s">)</span><span class="sc">;</span></li><li></li><li> <span class="c"># Round number to 3 digits after decimal point</span></li><li> <span class="i">$rounded</span> = <a class="l_k" href="../functions/sprintf.html">sprintf</a><span class="s">(</span><span class="q">"%.3f"</span><span class="cm">,</span> <span class="i">$number</span><span class="s">)</span><span class="sc">;</span></li></ol></pre><p>Perl does its own <code class="inline"><a class="l_k" href="../functions/sprintf.html">sprintf</a></code> formatting--it emulates the C
function <code class="inline"><a class="l_k" href="../functions/sprintf.html">sprintf</a></code>, but it doesn't use it (except for floating-point
numbers, and even then only the standard modifiers are allowed). As a
result, any non-standard extensions in your local <code class="inline"><a class="l_k" href="../functions/sprintf.html">sprintf</a></code> are not
available from Perl.</p>
<p>Unlike <code class="inline"><a class="l_k" href="../functions/printf.html">printf</a></code>, <code class="inline"><a class="l_k" href="../functions/sprintf.html">sprintf</a></code> does not do what you probably mean when you
pass it an array as your first argument. The array is given scalar context,
and instead of using the 0th element of the array as the format, Perl will
use the count of elements in the array as the format, which is almost never
useful.</p>
<p>Perl's <code class="inline"><a class="l_k" href="../functions/sprintf.html">sprintf</a></code> permits the following universally-known conversions:</p>
<pre class="verbatim"><ol><li> %% a percent sign</li><li> %c a character with the given number</li><li> %s a string</li><li> %d a signed integer, in decimal</li><li> %u an unsigned integer, in decimal</li><li> %o an unsigned integer, in octal</li><li> %x an unsigned integer, in hexadecimal</li><li> %e a floating-point number, in scientific notation</li><li> %f a floating-point number, in fixed decimal notation</li><li> %g a floating-point number, in %e or %f notation</li></ol></pre><p>In addition, Perl permits the following widely-supported conversions:</p>
<pre class="verbatim"><ol><li> %X like %x, but using upper-case letters</li><li> %E like %e, but using an upper-case "E"</li><li> %G like %g, but with an upper-case "E" (if applicable)</li><li> %b an unsigned integer, in binary</li><li> %B like %b, but using an upper-case "B" with the # flag</li><li> %p a pointer (outputs the Perl value's address in hexadecimal)</li><li> %n special: *stores* the number of characters output so far</li><li> into the next variable in the parameter list</li></ol></pre><p>Finally, for backward (and we do mean "backward") compatibility, Perl
permits these unnecessary but widely-supported conversions:</p>
<pre class="verbatim"><ol><li> %i a synonym for %d</li><li> %D a synonym for %ld</li><li> %U a synonym for %lu</li><li> %O a synonym for %lo</li><li> %F a synonym for %f</li></ol></pre><p>Note that the number of exponent digits in the scientific notation produced
by <code class="inline"><span class="i">%e</span></code>
, <code class="inline"><span class="i">%E</span></code>
, <code class="inline"><span class="i">%g</span></code>
and <code class="inline"><span class="i">%G</span></code>
for numbers with the modulus of the
exponent less than 100 is system-dependent: it may be three or less
(zero-padded as necessary). In other words, 1.23 times ten to the
99th may be either "1.23e99" or "1.23e099".</p>
<p>Between the <code class="inline"><span class="i">%</span></code>
and the format letter, you may specify a number of
additional attributes controlling the interpretation of the format.
In order, these are:</p>
<ul>
<li><a name="format-parameter-index"></a><b>format parameter index</b>
<p>An explicit format parameter index, such as <code class="inline">2$</code>. By default sprintf
will format the next unused argument in the list, but this allows you
to take the arguments out of order, e.g.:</p>
<pre class="verbatim"><ol><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'%2$d %1$d'</span><span class="cm">,</span> <span class="n">12</span><span class="cm">,</span> <span class="n">34</span><span class="sc">;</span> <span class="c"># prints "34 12"</span></li><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'%3$d %d %1$d'</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"># prints "3 1 1"</span></li></ol></pre></li>
<li><a name="flags"></a><b>flags</b>
<p>one or more of:</p>
<pre class="verbatim"><ol><li> space prefix non-negative number with a space</li><li> + prefix non-negative number with a plus sign</li><li> - left-justify within the field</li><li> 0 use zeros, not spaces, to right-justify</li><li> # ensure the leading "0" for any octal,</li><li> prefix non-zero hexadecimal with "0x" or "0X",</li><li> prefix non-zero binary with "0b" or "0B"</li></ol></pre><p>For example:</p>
<pre class="verbatim"><ol><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<% d>'</span><span class="cm">,</span> <span class="n">12</span><span class="sc">;</span> <span class="c"># prints "< 12>"</span></li><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%+d>'</span><span class="cm">,</span> <span class="n">12</span><span class="sc">;</span> <span class="c"># prints "<+12>"</span></li><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%6s>'</span><span class="cm">,</span> <span class="n">12</span><span class="sc">;</span> <span class="c"># prints "< 12>"</span></li><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%-6s>'</span><span class="cm">,</span> <span class="n">12</span><span class="sc">;</span> <span class="c"># prints "<12 >"</span></li><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%06s>'</span><span class="cm">,</span> <span class="n">12</span><span class="sc">;</span> <span class="c"># prints "<000012>"</span></li><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%#o>'</span><span class="cm">,</span> <span class="n">12</span><span class="sc">;</span> <span class="c"># prints "<014>"</span></li><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%#x>'</span><span class="cm">,</span> <span class="n">12</span><span class="sc">;</span> <span class="c"># prints "<0xc>"</span></li><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%#X>'</span><span class="cm">,</span> <span class="n">12</span><span class="sc">;</span> <span class="c"># prints "<0XC>"</span></li><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%#b>'</span><span class="cm">,</span> <span class="n">12</span><span class="sc">;</span> <span class="c"># prints "<0b1100>"</span></li><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%#B>'</span><span class="cm">,</span> <span class="n">12</span><span class="sc">;</span> <span class="c"># prints "<0B1100>"</span></li></ol></pre><p>When a space and a plus sign are given as the flags at once,
a plus sign is used to prefix a positive number.</p>
<pre class="verbatim"><ol><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%+ d>'</span><span class="cm">,</span> <span class="n">12</span><span class="sc">;</span> <span class="c"># prints "<+12>"</span></li><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<% +d>'</span><span class="cm">,</span> <span class="n">12</span><span class="sc">;</span> <span class="c"># prints "<+12>"</span></li></ol></pre><p>When the # flag and a precision are given in the %o conversion,
the precision is incremented if it's necessary for the leading "0".</p>
<pre class="verbatim"><ol><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%#.5o>'</span><span class="cm">,</span> <span class="n">012</span><span class="sc">;</span> <span class="c"># prints "<00012>"</span></li><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%#.5o>'</span><span class="cm">,</span> <span class="n">012345</span><span class="sc">;</span> <span class="c"># prints "<012345>"</span></li><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%#.0o>'</span><span class="cm">,</span> <span class="n">0</span><span class="sc">;</span> <span class="c"># prints "<0>"</span></li></ol></pre></li>
<li><a name="vector-flag"></a><b>vector flag</b>
<p>This flag tells perl to interpret the supplied string as a vector of
integers, one for each character in the string. Perl applies the format to
each integer in turn, then joins the resulting strings with a separator (a
dot <code class="inline">.</code> by default). This can be useful for displaying ordinal values of
characters in arbitrary strings:</p>
<pre class="verbatim"><ol><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">"%vd"</span><span class="cm">,</span> <span class="q">"AB\x{100}"</span><span class="sc">;</span> <span class="c"># prints "65.66.256"</span></li><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">"version is v%vd\n"</span><span class="cm">,</span> <span class="i">$^V</span><span class="sc">;</span> <span class="c"># Perl's version</span></li></ol></pre><p>Put an asterisk <code class="inline"><span class="i">*</span></code>
before the <code class="inline"><span class="w">v</span></code>
to override the string to
use to separate the numbers:</p>
<pre class="verbatim"><ol><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">"address is %*vX\n"</span><span class="cm">,</span> <span class="q">":"</span><span class="cm">,</span> <span class="i">$addr</span><span class="sc">;</span> <span class="c"># IPv6 address</span></li><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">"bits are %0*v8b\n"</span><span class="cm">,</span> <span class="q">" "</span><span class="cm">,</span> <span class="i">$bits</span><span class="sc">;</span> <span class="c"># random bitstring</span></li></ol></pre><p>You can also explicitly specify the argument number to use for
the join string using e.g. <code class="inline">*2$v</code>:</p>
<pre class="verbatim"><ol><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'%*4$vX %*4$vX %*4$vX'</span><span class="cm">,</span> <span class="i">@addr</span>[<span class="n">1</span>..<span class="n">3</span>]<span class="cm">,</span> <span class="q">":"</span><span class="sc">;</span> <span class="c"># 3 IPv6 addresses</span></li></ol></pre></li>
<li><a name="(minimum)-width"></a><b>(minimum) width</b>
<p>Arguments are usually formatted to be only as wide as required to
display the given value. You can override the width by putting
a number here, or get the width from the next argument (with <code class="inline"><span class="i">*</span></code>
)
or from a specified argument (with e.g. <code class="inline">*2$</code>):</p>
<pre class="verbatim"><ol><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%s>'</span><span class="cm">,</span> <span class="q">"a"</span><span class="sc">;</span> <span class="c"># prints "<a>"</span></li><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%6s>'</span><span class="cm">,</span> <span class="q">"a"</span><span class="sc">;</span> <span class="c"># prints "< a>"</span></li><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%*s>'</span><span class="cm">,</span> <span class="n">6</span><span class="cm">,</span> <span class="q">"a"</span><span class="sc">;</span> <span class="c"># prints "< a>"</span></li><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%*2$s>'</span><span class="cm">,</span> <span class="q">"a"</span><span class="cm">,</span> <span class="n">6</span><span class="sc">;</span> <span class="c"># prints "< a>"</span></li><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%2s>'</span><span class="cm">,</span> <span class="q">"long"</span><span class="sc">;</span> <span class="c"># prints "<long>" (does not truncate)</span></li></ol></pre><p>If a field width obtained through <code class="inline"><span class="i">*</span></code>
is negative, it has the same
effect as the <code class="inline">-</code>
flag: left-justification.</p>
</li>
<li><a name="precision%2c-or-maximum-width"></a><b>precision, or maximum width
</b>
<p>You can specify a precision (for numeric conversions) or a maximum
width (for string conversions) by specifying a <code class="inline">.</code> followed by a number.
For floating point formats, with the exception of 'g' and 'G', this specifies
the number of decimal places to show (the default being 6), e.g.:</p>
<pre class="verbatim"><ol><li> <span class="c"># these examples are subject to system-specific variation</span></li><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%f>'</span><span class="cm">,</span> <span class="n">1</span><span class="sc">;</span> <span class="c"># prints "<1.000000>"</span></li><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%.1f>'</span><span class="cm">,</span> <span class="n">1</span><span class="sc">;</span> <span class="c"># prints "<1.0>"</span></li><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%.0f>'</span><span class="cm">,</span> <span class="n">1</span><span class="sc">;</span> <span class="c"># prints "<1>"</span></li><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%e>'</span><span class="cm">,</span> <span class="n">10</span><span class="sc">;</span> <span class="c"># prints "<1.000000e+01>"</span></li><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%.1e>'</span><span class="cm">,</span> <span class="n">10</span><span class="sc">;</span> <span class="c"># prints "<1.0e+01>"</span></li></ol></pre><p>For 'g' and 'G', this specifies the maximum number of digits to show,
including prior to the decimal point as well as after it, e.g.:</p>
<pre class="verbatim"><ol><li> <span class="c"># these examples are subject to system-specific variation</span></li><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%g>'</span><span class="cm">,</span> <span class="n">1</span><span class="sc">;</span> <span class="c"># prints "<1>"</span></li><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%.10g>'</span><span class="cm">,</span> <span class="n">1</span><span class="sc">;</span> <span class="c"># prints "<1>"</span></li><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%g>'</span><span class="cm">,</span> <span class="n">100</span><span class="sc">;</span> <span class="c"># prints "<100>"</span></li><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%.1g>'</span><span class="cm">,</span> <span class="n">100</span><span class="sc">;</span> <span class="c"># prints "<1e+02>"</span></li><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%.2g>'</span><span class="cm">,</span> <span class="n">100.01</span><span class="sc">;</span> <span class="c"># prints "<1e+02>"</span></li><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%.5g>'</span><span class="cm">,</span> <span class="n">100.01</span><span class="sc">;</span> <span class="c"># prints "<100.01>"</span></li><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%.4g>'</span><span class="cm">,</span> <span class="n">100.01</span><span class="sc">;</span> <span class="c"># prints "<100>"</span></li></ol></pre><p>For integer conversions, specifying a precision implies that the
output of the number itself should be zero-padded to this width,
where the 0 flag is ignored:</p>
<pre class="verbatim"><ol><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%.6d>'</span><span class="cm">,</span> <span class="n">1</span><span class="sc">;</span> <span class="c"># prints "<000001>"</span></li><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%+.6d>'</span><span class="cm">,</span> <span class="n">1</span><span class="sc">;</span> <span class="c"># prints "<+000001>"</span></li><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%-10.6d>'</span><span class="cm">,</span> <span class="n">1</span><span class="sc">;</span> <span class="c"># prints "<000001 >"</span></li><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%10.6d>'</span><span class="cm">,</span> <span class="n">1</span><span class="sc">;</span> <span class="c"># prints "< 000001>"</span></li><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%010.6d>'</span><span class="cm">,</span> <span class="n">1</span><span class="sc">;</span> <span class="c"># prints "< 000001>"</span></li><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%+10.6d>'</span><span class="cm">,</span> <span class="n">1</span><span class="sc">;</span> <span class="c"># prints "< +000001>"</span></li><li></li><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%.6x>'</span><span class="cm">,</span> <span class="n">1</span><span class="sc">;</span> <span class="c"># prints "<000001>"</span></li><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%#.6x>'</span><span class="cm">,</span> <span class="n">1</span><span class="sc">;</span> <span class="c"># prints "<0x000001>"</span></li><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%-10.6x>'</span><span class="cm">,</span> <span class="n">1</span><span class="sc">;</span> <span class="c"># prints "<000001 >"</span></li><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%10.6x>'</span><span class="cm">,</span> <span class="n">1</span><span class="sc">;</span> <span class="c"># prints "< 000001>"</span></li><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%010.6x>'</span><span class="cm">,</span> <span class="n">1</span><span class="sc">;</span> <span class="c"># prints "< 000001>"</span></li><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%#10.6x>'</span><span class="cm">,</span> <span class="n">1</span><span class="sc">;</span> <span class="c"># prints "< 0x000001>"</span></li></ol></pre><p>For string conversions, specifying a precision truncates the string
to fit in the specified width:</p>
<pre class="verbatim"><ol><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%.5s>'</span><span class="cm">,</span> <span class="q">"truncated"</span><span class="sc">;</span> <span class="c"># prints "<trunc>"</span></li><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%10.5s>'</span><span class="cm">,</span> <span class="q">"truncated"</span><span class="sc">;</span> <span class="c"># prints "< trunc>"</span></li></ol></pre><p>You can also get the precision from the next argument using <code class="inline">.*</code>:</p>
<pre class="verbatim"><ol><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%.6x>'</span><span class="cm">,</span> <span class="n">1</span><span class="sc">;</span> <span class="c"># prints "<000001>"</span></li><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%.*x>'</span><span class="cm">,</span> <span class="n">6</span><span class="cm">,</span> <span class="n">1</span><span class="sc">;</span> <span class="c"># prints "<000001>"</span></li></ol></pre><p>If a precision obtained through <code class="inline"><span class="i">*</span></code>
is negative, it has the same
effect as no precision.</p>
<pre class="verbatim"><ol><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%.*s>'</span><span class="cm">,</span> <span class="n">7</span><span class="cm">,</span> <span class="q">"string"</span><span class="sc">;</span> <span class="c"># prints "<string>"</span></li><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%.*s>'</span><span class="cm">,</span> <span class="n">3</span><span class="cm">,</span> <span class="q">"string"</span><span class="sc">;</span> <span class="c"># prints "<str>"</span></li><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%.*s>'</span><span class="cm">,</span> <span class="n">0</span><span class="cm">,</span> <span class="q">"string"</span><span class="sc">;</span> <span class="c"># prints "<>"</span></li><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%.*s>'</span><span class="cm">,</span> <span class="n">-1</span><span class="cm">,</span> <span class="q">"string"</span><span class="sc">;</span> <span class="c"># prints "<string>"</span></li><li></li><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%.*d>'</span><span class="cm">,</span> <span class="n">1</span><span class="cm">,</span> <span class="n">0</span><span class="sc">;</span> <span class="c"># prints "<0>"</span></li><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%.*d>'</span><span class="cm">,</span> <span class="n">0</span><span class="cm">,</span> <span class="n">0</span><span class="sc">;</span> <span class="c"># prints "<>"</span></li><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%.*d>'</span><span class="cm">,</span> <span class="n">-1</span><span class="cm">,</span> <span class="n">0</span><span class="sc">;</span> <span class="c"># prints "<0>"</span></li></ol></pre><p>You cannot currently get the precision from a specified number,
but it is intended that this will be possible in the future using
e.g. <code class="inline">.*2$</code>:</p>
<pre class="verbatim"><ol><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%.*2$x>'</span><span class="cm">,</span> <span class="n">1</span><span class="cm">,</span> <span class="n">6</span><span class="sc">;</span> <span class="c"># INVALID, but in future will print "<000001>"</span></li></ol></pre></li>
<li><a name="size"></a><b>size</b>
<p>For numeric conversions, you can specify the size to interpret the
number as using <code class="inline"><span class="w">l</span></code>
, <code class="inline"><span class="w">h</span></code>
, <code class="inline"><span class="w">V</span></code>
, <code class="inline"><a class="l_k" href="../functions/q.html">q</a></code>, <code class="inline"><span class="w">L</span></code>
, or <code class="inline"><span class="w">ll</span></code>
. For integer
conversions (<code class="inline"><span class="w">d</span> <span class="w">u</span> <span class="w">o</span> <span class="w">x</span> <span class="w">X</span> <span class="w">b</span> <span class="w">i</span> <span class="w">D</span> <span class="w">U</span> <span class="w">O</span></code>
), numbers are usually assumed to be
whatever the default integer size is on your platform (usually 32 or 64
bits), but you can override this to use instead one of the standard C types,
as supported by the compiler used to build Perl:</p>
<pre class="verbatim"><ol><li> l interpret integer as C type "long" or "unsigned long"</li><li> h interpret integer as C type "short" or "unsigned short"</li><li> q, L or ll interpret integer as C type "long long", "unsigned long long".</li><li> or "quads" (typically 64-bit integers)</li></ol></pre><p>The last will produce errors if Perl does not understand "quads" in your
installation. (This requires that either the platform natively supports quads
or Perl was specifically compiled to support quads.) You can find out
whether your Perl supports quads via <a href="../Config.html">Config</a>:</p>
<pre class="verbatim"><ol><li> <a class="l_k" href="../functions/use.html">use</a> <span class="w">Config</span><span class="sc">;</span></li><li> <span class="s">(</span><span class="i">$Config</span>{<span class="w">use64bitint</span>} eq <span class="q">'define'</span> || <span class="i">$Config</span>{<span class="w">longsize</span>} >= <span class="n">8</span><span class="s">)</span> &&</li><li> <a class="l_k" href="../functions/print.html">print</a> <span class="q">"quads\n"</span><span class="sc">;</span></li></ol></pre><p>For floating point conversions (<code class="inline"><span class="w">e</span> <span class="w">f</span> <span class="w">g</span> <span class="w">E</span> <span class="w">F</span> <span class="w">G</span></code>
), numbers are usually assumed
to be the default floating point size on your platform (double or long double),
but you can force 'long double' with <code class="inline"><a class="l_k" href="../functions/q.html">q</a></code>, <code class="inline"><span class="w">L</span></code>
, or <code class="inline"><span class="w">ll</span></code>
if your
platform supports them. You can find out whether your Perl supports long
doubles via <a href="../Config.html">Config</a>:</p>
<pre class="verbatim"><ol><li> <a class="l_k" href="../functions/use.html">use</a> <span class="w">Config</span><span class="sc">;</span></li><li> <span class="i">$Config</span>{<span class="w">d_longdbl</span>} eq <span class="q">'define'</span> && <a class="l_k" href="../functions/print.html">print</a> <span class="q">"long doubles\n"</span><span class="sc">;</span></li></ol></pre><p>You can find out whether Perl considers 'long double' to be the default
floating point size to use on your platform via <a href="../Config.html">Config</a>:</p>
<pre class="verbatim"><ol><li> <a class="l_k" href="../functions/use.html">use</a> <span class="w">Config</span><span class="sc">;</span></li><li> <span class="s">(</span><span class="i">$Config</span>{<span class="w">uselongdouble</span>} eq <span class="q">'define'</span><span class="s">)</span> &&</li><li> <a class="l_k" href="../functions/print.html">print</a> <span class="q">"long doubles by default\n"</span><span class="sc">;</span></li></ol></pre><p>It can also be the case that long doubles and doubles are the same thing:</p>
<pre class="verbatim"><ol><li> <a class="l_k" href="../functions/use.html">use</a> <span class="w">Config</span><span class="sc">;</span></li><li> <span class="s">(</span><span class="i">$Config</span>{<span class="w">doublesize</span>} == <span class="i">$Config</span>{<span class="w">longdblsize</span>}<span class="s">)</span> &&</li><li> <a class="l_k" href="../functions/print.html">print</a> <span class="q">"doubles are long doubles\n"</span><span class="sc">;</span></li></ol></pre><p>The size specifier <code class="inline"><span class="w">V</span></code>
has no effect for Perl code, but it is supported
for compatibility with XS code; it means 'use the standard size for
a Perl integer (or floating-point number)', which is already the
default for Perl code.</p>
</li>
<li><a name="order-of-arguments"></a><b>order of arguments</b>
<p>Normally, sprintf takes the next unused argument as the value to
format for each format specification. If the format specification
uses <code class="inline"><span class="i">*</span></code>
to require additional arguments, these are consumed from
the argument list in the order in which they appear in the format
specification <i>before</i> the value to format. Where an argument is
specified using an explicit index, this does not affect the normal
order for the arguments (even when the explicitly specified index
would have been the next argument in any case).</p>
<p>So:</p>
<pre class="verbatim"><ol><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%*.*s>'</span><span class="cm">,</span> <span class="i">$a</span><span class="cm">,</span> <span class="i">$b</span><span class="cm">,</span> <span class="i">$c</span><span class="sc">;</span></li></ol></pre><p>would use <code class="inline"><span class="i">$a</span></code>
for the width, <code class="inline"><span class="i">$b</span></code>
for the precision and <code class="inline"><span class="i">$c</span></code>
as the value to format, while:</p>
<pre class="verbatim"><ol><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">'<%*1$.*s>'</span><span class="cm">,</span> <span class="i">$a</span><span class="cm">,</span> <span class="i">$b</span><span class="sc">;</span></li></ol></pre><p>would use <code class="inline"><span class="i">$a</span></code>
for the width and the precision, and <code class="inline"><span class="i">$b</span></code>
as the
value to format.</p>
<p>Here are some more examples - beware that when using an explicit
index, the <code class="inline"><span class="i">$</span></code>
may need to be escaped:</p>
<pre class="verbatim"><ol><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">"%2\$d %d\n"</span><span class="cm">,</span> <span class="n">12</span><span class="cm">,</span> <span class="n">34</span><span class="sc">;</span> <span class="c"># will print "34 12\n"</span></li><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">"%2\$d %d %d\n"</span><span class="cm">,</span> <span class="n">12</span><span class="cm">,</span> <span class="n">34</span><span class="sc">;</span> <span class="c"># will print "34 12 34\n"</span></li><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">"%3\$d %d %d\n"</span><span class="cm">,</span> <span class="n">12</span><span class="cm">,</span> <span class="n">34</span><span class="cm">,</span> <span class="n">56</span><span class="sc">;</span> <span class="c"># will print "56 12 34\n"</span></li><li> <a class="l_k" href="../functions/printf.html">printf</a> <span class="q">"%2\$*3\$d %d\n"</span><span class="cm">,</span> <span class="n">12</span><span class="cm">,</span> <span class="n">34</span><span class="cm">,</span> <span class="n">3</span><span class="sc">;</span> <span class="c"># will print " 34 12\n"</span></li></ol></pre></li>
</ul>
<p>If <code class="inline"><a class="l_k" href="../functions/use.html">use</a> <span class="w">locale</span></code>
is in effect, and POSIX::setlocale() has been called,
the character used for the decimal separator in formatted floating
point numbers is affected by the LC_NUMERIC locale. See <a href="../perllocale.html">perllocale</a>
and <a href="../POSIX.html">POSIX</a>.</p>
</li>
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