path.html
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<title>ActiveState::Path - Collection of small utility functions</title>
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<h1><a>ActiveState::Path - Collection of small utility functions</a></h1>
<p><a name="__index__"></a></p>
<!-- INDEX BEGIN -->
<ul>
<li><a href="#name">NAME</a></li>
<li><a href="#synopsis">SYNOPSIS</a></li>
<li><a href="#description">DESCRIPTION</a></li>
<li><a href="#bugs">BUGS</a></li>
</ul>
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<p>
</p>
<h1><a name="name">NAME</a></h1>
<p>ActiveState::Path - Collection of small utility functions</p>
<p>
</p>
<hr />
<h1><a name="synopsis">SYNOPSIS</a></h1>
<pre>
<span class="keyword">use</span> <span class="variable">ActiveState::Path</span> <span class="string">qw(find_prog)</span><span class="operator">;</span>
<span class="keyword">my</span> <span class="variable">$ls</span> <span class="operator">=</span> <span class="variable">find_prog</span><span class="operator">(</span><span class="string">"ls"</span><span class="operator">);</span>
</pre>
<p>
</p>
<hr />
<h1><a name="description">DESCRIPTION</a></h1>
<p>This module provides a collection of small utility functions dealing
with file paths.</p>
<p>The following functions are provided:</p>
<dl>
<dt><strong><a name="item_abs_path">abs_path( $path )</a></strong>
<dd>
<p>Returns an absolute pathname denoting the same file as $path. If
$path is already absolute it is returned unchanged. The $path does
not have to reference an existing file or directory.</p>
</dd>
<dd>
<p>This functions differs from <a href="#item_realpath"><code>realpath()</code></a> by only removing "." or ".."
segments at the beginning of $path and by only resolving the
symlinks needed to process the ".." segments correctly. The
<a href="#item_realpath"><code>realpath()</code></a> function also requires the file at $path to exist.</p>
</dd>
</li>
<dt><strong><a name="item_find_prog">find_prog( $name )</a></strong>
<dt><strong>find_prog( $path )</strong>
<dd>
<p>This function returns the full path to the given program if it can be
located on the system. Otherwise <a href="../../lib/Pod/perlfunc.html#item_undef"><code>undef</code></a> is returned.</p>
</dd>
<dd>
<p>The returned path might be relative.</p>
</dd>
</li>
<dt><strong><a name="item_is_abs_path">is_abs_path( $path )</a></strong>
<dd>
<p>Returns TRUE if $path is an absolute file name. This function works
the same as File::Spec method file_name_is_absolute().</p>
</dd>
</li>
<dt><strong><a name="item_join_path">join_path( $base, $path )</a></strong>
<dd>
<p>Returns a path that will reference the same file as $path does when
the current directory is $base. If $path is absolute then it is
returned unchanged.</p>
</dd>
<dd>
<p>The $base should reference an existing directory. The $path does not
have to refence an existing file or directory.</p>
</dd>
<dd>
<p>Any leading "." and ".." segments are removed from the $path before
the paths are joined. In order to process ".." segments <a href="#item_join_path"><code>join_path()</code></a>
will need to resolve symlinks in $base, and the function might croak
if this involves a symlink cycle.</p>
</dd>
</li>
<dt><strong><a name="item_path_list"><code>path_list()</code></a></strong>
<dd>
<p>Returns the list of directories that will be searched to find
programs. The <a href="#item_path_list"><code>path_list()</code></a> is derived from the PATH environment
variable. In scalar context this returns the number of paths to be
searched.</p>
</dd>
<dd>
<p>On Unix when the PATH environment variable is not present then this
function returns an empty list, but most shells still default to a
path list like (<em>/usr/bin</em>, <em>/bin</em>).</p>
</dd>
</li>
<dt><strong><a name="item_realpath">realpath( $path )</a></strong>
<dd>
<p>Returns the canonicalized absolute pathname of the path passed in.
All symbolic links are expanded and references to <em>/./</em>, <em>/../</em> and
extra <em>/</em> characters are resolved. The $path passed in must be an
existing file. The function will croak if not, or if the symbolic
links can't be expanded.</p>
</dd>
<dd>
<p>This differs from the Cwd::realpath() function in that $path does
not have to be a directory.</p>
</dd>
</li>
<dt><strong><a name="item_rel_path">rel_path( $base, $path )</a></strong>
<dd>
<p>Return a relative pathname that denotes the same file as $path when
$base is the current directory.</p>
</dd>
<dd>
<p>The $base should reference an existing directory. The $path does not
have to refence an existing file or directory.</p>
</dd>
<dd>
<p>This function differs from the File::Spec method <code>abs2rel()</code> in that it
make sure that any ".." segments in the returned value is correct when
the corresponding $base segments are symlinks. If the $base path
contains symlink cycles there might not be any relative path that can
be produced, and in that case <a href="#item_rel_path"><code>rel_path()</code></a> falls back to returning
abs_path($path).</p>
</dd>
</li>
<dt><strong><a name="item_unsymlinked">unsymlinked( $path )</a></strong>
<dd>
<p>If $path denotes a symlink expand it, otherwise return $path
unchanged. The $path must reference an existing file. This function
differs from <a href="#item_realpath"><code>realpath()</code></a> by only expanding the symlink at the last
segment of $path.</p>
</dd>
<dd>
<p>On systems that don't implement symlinks this function is a noop,
always returning $path unchanged.</p>
</dd>
<dd>
<p>This function will croak if it's not possible to expand the symlink
because of cycles.</p>
</dd>
</li>
</dl>
<p>
</p>
<hr />
<h1><a name="bugs">BUGS</a></h1>
<p>none.</p>
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