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<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"/><meta name="viewport" content="width=device-width, initial-scale=0.8"/><title>15.1.3 Unix and Mac OS Paths</title><link rel="stylesheet" type="text/css" href="../scribble.css" title="default"/><link rel="stylesheet" type="text/css" href="extras.css" title="default"/><link rel="stylesheet" type="text/css" href="../racket.css" title="default"/><link rel="stylesheet" type="text/css" href="../manual-style.css" title="default"/><link rel="stylesheet" type="text/css" href="../manual-racket.css" title="default"/><link rel="stylesheet" type="text/css" href="../manual-racket.css" title="default"/><link rel="stylesheet" type="text/css" href="../doc-site.css" title="default"/><script type="text/javascript" src="../scribble-common.js"></script><script type="text/javascript" src="../manual-racket.js"></script><script type="text/javascript" src="../manual-racket.js"></script><script type="text/javascript" src="../doc-site.js"></script><script type="text/javascript" src="../local-redirect/local-redirect.js"></script><script type="text/javascript" src="../local-redirect/local-user-redirect.js"></script><!--[if IE 6]><style type="text/css">.SIEHidden { overflow: hidden; }</style><![endif]--></head><body id="doc-racket-lang-org"><div class="tocset"><div class="tocview"><div class="tocviewlist tocviewlisttopspace"><div class="tocviewtitle"><table cellspacing="0" cellpadding="0"><tr><td style="width: 1em;"><a href="javascript:void(0);" title="Expand/Collapse" class="tocviewtoggle" onclick="TocviewToggle(this,"tocview_0");">►</a></td><td></td><td><a href="index.html" class="tocviewlink" data-pltdoc="x">The Racket Reference</a></td></tr></table></div><div class="tocviewsublisttop" style="display: none;" id="tocview_0"><table cellspacing="0" cellpadding="0"><tr><td align="right">1 </td><td><a href="model.html" class="tocviewlink" data-pltdoc="x">Language Model</a></td></tr><tr><td align="right">2 </td><td><a href="notation.html" class="tocviewlink" data-pltdoc="x">Notation for Documentation</a></td></tr><tr><td align="right">3 </td><td><a href="syntax.html" class="tocviewlink" data-pltdoc="x">Syntactic Forms</a></td></tr><tr><td align="right">4 </td><td><a href="data.html" class="tocviewlink" data-pltdoc="x">Datatypes</a></td></tr><tr><td align="right">5 </td><td><a href="structures.html" class="tocviewlink" data-pltdoc="x">Structures</a></td></tr><tr><td align="right">6 </td><td><a href="mzlib_class.html" class="tocviewlink" data-pltdoc="x">Classes and Objects</a></td></tr><tr><td align="right">7 </td><td><a href="mzlib_unit.html" class="tocviewlink" data-pltdoc="x">Units</a></td></tr><tr><td align="right">8 </td><td><a href="contracts.html" class="tocviewlink" data-pltdoc="x">Contracts</a></td></tr><tr><td align="right">9 </td><td><a href="match.html" class="tocviewlink" data-pltdoc="x">Pattern Matching</a></td></tr><tr><td align="right">10 </td><td><a href="control.html" class="tocviewlink" data-pltdoc="x">Control Flow</a></td></tr><tr><td align="right">11 </td><td><a href="concurrency.html" class="tocviewlink" data-pltdoc="x">Concurrency and Parallelism</a></td></tr><tr><td align="right">12 </td><td><a href="Macros.html" class="tocviewlink" data-pltdoc="x">Macros</a></td></tr><tr><td align="right">13 </td><td><a href="input-and-output.html" class="tocviewlink" data-pltdoc="x">Input and Output</a></td></tr><tr><td align="right">14 </td><td><a href="security.html" class="tocviewlink" data-pltdoc="x">Reflection and Security</a></td></tr><tr><td align="right">15 </td><td><a href="os.html" class="tocviewselflink" data-pltdoc="x">Operating System</a></td></tr><tr><td align="right">16 </td><td><a href="memory.html" class="tocviewlink" data-pltdoc="x">Memory Management</a></td></tr><tr><td align="right">17 </td><td><a href="unsafe.html" class="tocviewlink" data-pltdoc="x">Unsafe Operations</a></td></tr><tr><td align="right">18 </td><td><a href="running.html"
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<span class="RktInBG"><span class="hspace"></span><span class="RktIn">.</span><span class="hspace"></span></span> as a path element always means the directory indicated by
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preceding path, and <span class="RktInBG"><span class="hspace"></span><span class="RktIn">..</span><span class="hspace"></span></span> as a path element always means the
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parent of the directory indicated by the preceding path. A leading
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<span class="RktInBG"><span class="hspace"></span><span class="RktIn">~</span><span class="hspace"></span></span> in a path is not treated specially, but
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<span class="RktSym"><a href="Manipulating_Paths.html#%28def._%28%28quote._~23~25kernel%29._expand-user-path%29%29" class="RktValLink" data-pltdoc="x">expand-user-path</a></span> can be used to convert a leading <span class="RktInBG"><span class="hspace"></span><span class="RktIn">~</span><span class="hspace"></span></span>
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element to a user-specific directory. No other character or byte has a
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special meaning within a path. Multiple adjacent <span class="RktInBG"><span class="hspace"></span><span class="RktIn">/</span><span class="hspace"></span></span> are
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equivalent to a single <span class="RktInBG"><span class="hspace"></span><span class="RktIn">/</span><span class="hspace"></span></span> (i.e., they act as a single path
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separator).</p><p>A path root is always <span class="RktInBG"><span class="hspace"></span><span class="RktIn">/</span><span class="hspace"></span></span>. A path starting with <span class="RktInBG"><span class="hspace"></span><span class="RktIn">/</span><span class="hspace"></span></span> is
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an absolute, complete path, and a path starting with any other
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character is a relative path.</p><p>Any pathname that ends with a <span class="RktInBG"><span class="hspace"></span><span class="RktIn">/</span><span class="hspace"></span></span> syntactically refers to a
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directory, as does any path whose last element is <span class="RktInBG"><span class="hspace"></span><span class="RktIn">.</span><span class="hspace"></span></span> or
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<span class="RktInBG"><span class="hspace"></span><span class="RktIn">..</span><span class="hspace"></span></span>.</p><p>A Unix and Mac OS path is <a href="pathutils.html#%28tech._cleanse%29" data-pltdoc="x">cleanse</a>d by replacing multiple adjacent
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<span class="RktInBG"><span class="hspace"></span><span class="RktIn">/</span><span class="hspace"></span></span>s with a single <span class="RktInBG"><span class="hspace"></span><span class="RktIn">/</span><span class="hspace"></span></span>.</p><p>For <span class="RktPn">(</span><span class="RktSym"><a href="Manipulating_Paths.html#%28def._%28%28quote._~23~25kernel%29._bytes-~3epath-element%29%29" class="RktValLink" data-pltdoc="x">bytes->path-element</a></span><span class="stt"> </span><span class="RktVar">bstr</span><span class="RktPn">)</span>, <span class="RktSym">bstr</span> must not
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contain any <span class="RktInBG"><span class="hspace"></span><span class="RktIn">/</span><span class="hspace"></span></span>, otherwise the <span class="RktSym"><a href="exns.html#%28def._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._exn~3afail~3acontract%29%29" class="RktValLink" data-pltdoc="x">exn:fail:contract</a></span> exception is raised.
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The result of <span class="RktPn">(</span><span class="RktSym"><a href="Manipulating_Paths.html#%28def._%28%28quote._~23~25kernel%29._path-element-~3ebytes%29%29" class="RktValLink" data-pltdoc="x">path-element->bytes</a></span><span class="stt"> </span><span class="RktVar">path</span><span class="RktPn">)</span> or
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<span class="RktPn">(</span><span class="RktSym"><a href="Manipulating_Paths.html#%28def._%28%28quote._~23~25kernel%29._path-element-~3estring%29%29" class="RktValLink" data-pltdoc="x">path-element->string</a></span><span class="stt"> </span><span class="RktVar">path</span><span class="RktPn">)</span> is always the same as the result
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of <span class="RktPn">(</span><span class="RktSym"><a href="Manipulating_Paths.html#%28def._%28%28quote._~23~25kernel%29._path-~3ebytes%29%29" class="RktValLink" data-pltdoc="x">path->bytes</a></span><span class="stt"> </span><span class="RktVar">path</span><span class="RktPn">)</span> and <span class="RktPn">(</span><span class="RktSym"><a href="Manipulating_Paths.html#%28def._%28%28quote._~23~25kernel%29._path-~3estring%29%29" class="RktValLink" data-pltdoc="x">path->string</a></span><span class="stt"> </span><span class="RktVar">path</span><span class="RktPn">)</span>. Since that is not the case for other platforms, however,
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<span class="RktSym"><a href="Manipulating_Paths.html#%28def._%28%28quote._~23~25kernel%29._path-element-~3ebytes%29%29" class="RktValLink" data-pltdoc="x">path-element->bytes</a></span> and <span class="RktSym"><a href="Manipulating_Paths.html#%28def._%28%28quote._~23~25kernel%29._path-element-~3estring%29%29" class="RktValLink" data-pltdoc="x">path-element->string</a></span> should
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be used when converting individual path elements.</p><p>On Mac OS, Finder aliases are zero-length files.</p><h5 x-source-module="(lib "scribblings/reference/reference.scrbl")" x-source-pkg="racket-doc" x-part-tag=""unixpathrep"">15.1.3.1<tt> </tt><a name="(part._unixpathrep)"></a>Unix Path Representation</h5><p>A path on Unix and Mac OS is natively a byte string. For presentation to
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users and for other string-based operations, a path is converted
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to/from a string using the current locale’s encoding with <span class="RktInBG"><span class="hspace"></span><span class="RktIn">?</span><span class="hspace"></span></span>
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(encoding) or <span class="RktVal">#\uFFFD</span><span class="RktMeta"></span> (decoding) in place of errors. Beware
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that the encoding may not accommodate all possible paths as
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distinct strings.</p><div class="navsetbottom"><span class="navleft"><form class="searchform"><input class="searchbox" id="searchbox" type="text" tabindex="1" placeholder="...search manuals..." title="Enter a search string to search the manuals" onkeypress="return DoSearchKey(event, this, "8.6", "../");"/></form> <a href="https://docs.racket-lang.org/index.html" title="up to the documentation top" data-pltdoc="x" onclick="return GotoPLTRoot("8.6");">top</a><span class="tocsettoggle"> <a href="javascript:void(0);" title="show/hide table of contents" onclick="TocsetToggle();">contents</a></span></span><span class="navright"> <a href="More_Path_Utilities.html" title="backward to "15.1.2 More Path Utilities"" data-pltdoc="x">← prev</a> <a href="pathutils.html" title="up to "15.1 Paths"" data-pltdoc="x">up</a> <a href="windowspaths.html" title="forward to "15.1.4 Windows Paths"" data-pltdoc="x">next →</a></span> </div></div></div><div id="contextindicator"> </div></body></html>
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