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<html><head><title>XLISP load</title>
<link rel="stylesheet" type="text/css" href="reference.css">
</head>
<body>
<a href="../start.htm">Nyquist / XLISP 2.0</a> -
<a href="../manual/contents.htm">Contents</a> |
<a href="../tutorials/tutorials.htm">Tutorials</a> |
<a href="../examples/examples.htm">Examples</a> |
<a href="reference-index.htm">Reference</a>
<hr>
<h1>load</h1>
<hr>
<p><table cellpadding="0" cellspacing="0" style="margin-left:10px"><tbody>
<tr valign="top">
<td><nobr>Type:</nobr></td>
<td><nobr> - </nobr></td>
<td width="100%"><nobr>function (subr)</nobr></td>
</tr>
<tr valign="top">
<td><nobr>Source:</nobr></td>
<td><nobr> - </nobr></td>
<td width="100%"><nobr>xlsys.c, xlread.c</nobr></td>
</tr>
</tbody></table></p>
<h2>Syntax</h2>
<dl>
<dt>(load <i>file</i> [:verbose <i>v-flag</i>] [:print <i>p-flag</i>]))</dt>
<dd><i>file</i> - a string expression or symbol<br>
<i>v-flag</i> - an optional key-word expression, default is
<a href="t.htm"> T </a><br>
<i>p-flag</i> - an optional key-word expression, default is
<a href="nil.htm">NIL</a><br>
returns - the filename</dd>
</dl>
<h2>Description</h2>
<p>The 'load' function opens the 'file', reads and evaluates all the forms
within the 'file'. 'file' may be a string expression or a symbol. When
'file' is a string, you may specify a complete file location or extensions
like "/usr/local/bin/myfile.lsp" or "A:\LISP\TIM.LSP".
If 'file' is a string and includes a file type or an extension [like
".lsp"], then 'load' accesses the specified file. If there is no
extension on 'file', it will add ".lsp". If the ':verbose' keyword
is present and 'v-flag' is
<nobr>non-<a href="nil.htm">NIL</a> ,</nobr> a load message of
the form:</p>
<pre class="example">
; loading "xxxx.lsp"
</pre>
<p>will be printed to <a href="global-standard-output.htm">*standard-output*</a>.
If the ':print' keyword is present and 'p-flag' is
<nobr>non-<a href="nil.htm">NIL</a> ,</nobr> the resulting value
of each top-level form in 'file' will be printed to
<a href="global-standard-output.htm">*standard-output*</a>. If the file load was
successful, then <a href="t.htm"> T </a> is returned
as the result. If the file load was not successful, a
<a href="nil.htm">NIL</a> is returned.</p>
<p><b>Note:</b> in Nyquist, the XLISP 'load' function first tries to load a
file from the current directory. <nobr>A '.lsp'</nobr> extension is added if
there is not already an alphanumeric extension following a period. <nobr>If
that</nobr> fails, XLISP searches the path, which is obtained from the
XLISPPATH environment variable in Unix and
HKEY_LOCAL_MACHINE\SOFTWARE\CMU\Nyquist\XLISPPATH under Win32.</p>
<h2>Examples</h2>
<pre class="example">
(load 'gloop) <font color="#008844">; prints ; loading "GLOOP.lsp"</font>
<font color="#008844">; returns NIL there is no file</font>
(defun foo (x) (print x)) <font color="#008844">; create a function</font>
(savefun foo) <font color="#008844">; create a file FOO.lsp</font>
(load 'foo) <font color="#008844">; prints ; loading "FOO.lsp"</font>
<font color="#008844">; returns T</font>
(load 'foo :verbose NIL) <font color="#008844">; no printing returns T</font>
(load 'foo :print T) <font color="#008844">; prints FOO returns T</font>
(load 'save :verbose T :print T) <font color="#008844">; prints ; loading "FOO.lsp"</font>
<font color="#008844">; prints FOO returns T</font>
(load "foo") <font color="#008844">; prints ; loading "foo.lsp"</font>
<font color="#008844">; returns NIL - didn't work</font>
<font color="#008844">; because the file is "FOO.lsp"</font>
(load "FOO") <font color="#008844">; prints ; loading "FOO.lsp"</font>
<font color="#008844">; returns T - did work</font>
(load "FOO.lsp") <font color="#008844">; prints ; loading "FOO.lsp"</font>
<font color="#008844">; returns T - did work</font>
</pre>
<p><b>File names:</b> In the PC and DOS world, all file names and extensions
["foo.bat"] are automatically made uppercase. In using XLISP, this
means you don't have to worry about whether the name is "foo.bat",
"FOO.BAT" or even "FoO.bAt", they will all work.
However, in other file systems [UNIX in particular], uppercase and lowercase
do make a difference:</p>
<p>This will create a file named FOO-FILE in UNIX, because XLISP uppercases
its symbols:</p>
<pre class="example">
(open 'foo-file :direction :output)
</pre>
<p>This will create a file named 'foo-file' because UNIX doesn't
uppercase its file names:</p>
<pre class="example">
(open "foo-file" :direction :output)
</pre>
<p>So, if you are having trouble with opening and accessing files, check to
make sure the file name is in the proper case.</p>
<p><b>Common Lisp:</b> Common Lisp has a 'load' function that is similar
to XLISP's 'load'. The only difference is that Common Lisp uses an optional
keyword parameter ':if-does-not-exist' which XLISP does not support.</p>
<p><b>Nyquist:</b> in Nyquist, the XLISP 'load' function first tries to load
a file from the current directory. A '.lsp' extension is added if there is
not already an alphanumeric extension following a period. If that fails,
XLISP searches the path, which is obtained from the XLISPPATH environment
variable in Unix and HKEY_LOCAL_MACHINE\SOFTWARE\CMU\Nyquist\XLISPPATH under
Win32. [The Macintosh version has no search path.]</p>
<p><b>Note:</b> In XLISP, the keyword parameters are order sensitive. If
both ':verbose' and ':print' keywords are used, ':verbose' must come
first.</p>
<p>See the
<a href="../manual/xlisp-man-031.htm#load">load</a>
function in the <nobr>XLISP 2.0</nobr> manual.</p>
<p><nobr> <a href="#top">Back to Top</nobr></a></p>
<hr>
<a href="../start.htm">Nyquist / XLISP 2.0</a> -
<a href="../manual/contents.htm">Contents</a> |
<a href="../tutorials/tutorials.htm">Tutorials</a> |
<a href="../examples/examples.htm">Examples</a> |
<a href="reference-index.htm">Reference</a>
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