<html><head><meta http-equiv="Content-Type" content="text/html; charset=ANSI_X3.4-1968"><title>Chapter 11. Pathnames</title><link rel="stylesheet" href="ecl.css" type="text/css"><meta name="generator" content="DocBook XSL Stylesheets V1.75.2"><link rel="home" href="index.html" title="The ECL manual"><link rel="up" href="pt01.html" title="Part I. Standards"><link rel="prev" href="ch10.html" title="Chapter 10. Hash tables"><link rel="next" href="ch11s02.html" title="11.2. Wild pathnames and matching"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Chapter 11. Pathnames</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="ch10.html">Prev</a> </td><th width="60%" align="center">Part I. Standards</th><td width="20%" align="right"> <a accesskey="n" href="ch11s02.html">Next</a></td></tr></table><hr></div><div class="chapter" title="Chapter 11. Pathnames"><div class="titlepage"><div><div><h2 class="title"><a name="sec.ansi.pathnames"></a>Chapter 11. Pathnames</h2></div></div></div><div class="toc"><dl><dt><span class="section"><a href="ch11.html#sec.ansi.pathnames.syntax">11.1. Syntax</a></span></dt><dt><span class="section"><a href="ch11s02.html">11.2. Wild pathnames and matching</a></span></dt></dl></div><div class="section" title="11.1. Syntax"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="sec.ansi.pathnames.syntax"></a>11.1. Syntax</h2></div></div></div><p>A pathname in the file system of Common-Lisp consists of six elements: host, device, directory, name, type and version. Pathnames are read and printed using the <code class="literal">#P</code> reader macro followed by the namestring. A namestring is a string which represents a pathname. The syntax of namestrings for logical pathnames is well explained in the <a class="xref" href="bi01.html#bib.ANSI">ANSI</a> and it can be roughly summarized as follows: </p><pre class="synopsis"><code class="literal">[<span class="optional"><em class="replaceable"><code>hostname</code></em>:</span>][<span class="optional">;</span>][<span class="optional"><em class="replaceable"><code>directory-item</code></em>;</span>]<sup>0 or more</sup>[<span class="optional"><em class="replaceable"><code>name</code></em></span>][<span class="optional">.<em class="replaceable"><code>type</code></em>[<span class="optional">.<em class="replaceable"><code>version</code></em></span>]</span>]</code> <em class="replaceable"><code>hostname</code></em> = <em class="replaceable"><code>word</code></em> <em class="replaceable"><code>directory-item</code></em> = <em class="replaceable"><code>wildcard-word</code></em> <em class="replaceable"><code>type</code></em>, <em class="replaceable"><code>name</code></em> = <em class="replaceable"><code>wildcard-word</code></em> without dots</pre><p> Here, <em class="replaceable"><code>wildcard-word</code></em> is a sequence of any character excluding <code class="literal">#\Null</code> and dots. <em class="replaceable"><code>word</code></em> is like a <em class="replaceable"><code>wildcard-word</code></em> but asterisks are excluded.</p><p>The way <span class="application">ECL</span> parses a namestring is by first looking for the <em class="replaceable"><code>hostname</code></em> component in the previous template. If it is found and it corresponds to a previously defined logical hostname, it assumes that the namestring corresponds to a logical pathname. If <em class="replaceable"><code>hostname</code></em> is not found or it is not a logical hostname, then <span class="application">ECL</span> tries the physical pathname syntax </p><pre class="synopsis"><code class="literal">[<span class="optional"><em class="replaceable"><code>device</code></em>:</span>][<span class="optional">[<span class="optional">//<em class="replaceable"><code>hostname</code></em></span>]/</span>][<span class="optional"><em class="replaceable"><code>directory-item</code></em>/</span>]<sup>0 or more</sup>[<span class="optional"><em class="replaceable"><code>name</code></em></span>][<span class="optional">.<em class="replaceable"><code>type</code></em></span>]</code> <em class="replaceable"><code>device</code></em>, <em class="replaceable"><code>hostname</code></em> = <em class="replaceable"><code>word</code></em> <em class="replaceable"><code>directory-item</code></em> = <em class="replaceable"><code>wildcard-word</code></em> <em class="replaceable"><code>type</code></em> = <em class="replaceable"><code>wildcard-word</code></em> without dots <em class="replaceable"><code>name</code></em> = [<span class="optional">.</span>]<em class="replaceable"><code>wildcard-word</code></em></pre><p> If this syntax also fails, then the namestring is not a valid pathname string and a <span class="type">parse-error</span> will be signalled.</p><p>It is important to remark that in <span class="application">ECL</span>, all physical namestrings result into pathnames with a version equal to <code class="literal">:NEWEST</code>. Pathnames which are not logical and have any other version (i. e. <code class="literal">NIL</code> or a number), cannot be printed readably, but can produce a valid namestring which results of ignoring the version.</p><p>Finally, an important rule applies to physical namestrings: if a namestring contains one or more periods `.', the last period separates the namestring into the file name and the filetype. However, a namestring with a single leading period results in a name with a period in it. This is for compatibility with Unix filenames such as <code class="filename">.bashrc</code>, where the leading period indicates that the file is hidden.</p><p>The previous rule has in important consequence, because it means that if you want to create a pathname without a name, you have to do it explicitely. In other words, <code class="literal">".*"</code> is equivalent to <code class="code">(MAKE-PATHNAME :NAME ".*" :TYPE NIL)</code>, while <code class="code">(MAKE-PATHNAME :NAME NIL :TYPE :WILD)</code> creates a pathname whose type is a wildcard.</p><p>The following table illustrates how the physical pathnames work with practical examples.</p><div class="table"><a name="id645347"></a><p class="title"><b>Table 11.1. Examples of physical namestrings</b></p><div class="table-contents"><table summary="Examples of physical namestrings" border="1"><colgroup><col><col><col></colgroup><thead><tr><th>Namestring</th><th>Name</th><th>Type</th><th>Directory</th><th>Device</th></tr></thead><tbody><tr><td>"foo.lsp"</td><td>"foo"</td><td>"lsp"</td><td>NIL</td><td>NIL</td></tr><tr><td>".bashrc"</td><td>".bashrc"</td><td>NIL</td><td>NIL</td><td>NIL</td></tr><tr><td>".ecl.lsp"</td><td>".ecl"</td><td>"lsp"</td><td>NIL</td><td>NIL</td></tr><tr><td>"foo.*"</td><td>"foo"</td><td>:WILD</td><td>NIL</td><td>NIL</td></tr><tr><td>"*.*"</td><td>:WILD</td><td>:WILD</td><td>NIL</td><td>NIL</td></tr><tr><td>"ecl/build/bare.lsp"</td><td>"bare"</td><td>"lsp"</td><td>(:relative "ecl" "build")</td><td>NIL</td></tr><tr><td>"ecl/build/"</td><td>NIL</td><td>NIL</td><td>(:relative "ecl" "build")</td><td>NIL</td></tr><tr><td>"../../ecl/build/"</td><td>NIL</td><td>NIL</td><td>(:relative :up :up "ecl" "build")</td><td>NIL</td></tr><tr><td>"/etc/"</td><td>NIL</td><td>NIL</td><td>(:absolute "etc")</td><td>NIL</td></tr><tr><td>"C:/etc/"</td><td>NIL</td><td>NIL</td><td>(:absolute "etc")</td><td>"C"</td></tr><tr><td>".*"</td><td>".*"</td><td>NIL</td><td>NIL</td><td>NIL</td></tr><tr><td>#.(MAKE-PATHNAME :TYPE "*")</td><td>NIL</td><td>:WILD</td><td>NIL</td><td>NIL</td></tr></tbody></table></div></div><br class="table-break"></div></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="ch10.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="pt01.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="ch11s02.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">Chapter 10. Hash tables </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> 11.2. Wild pathnames and matching</td></tr></table></div></body></html>
