📄 function.is-readable.html
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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html> <head> <title>Tells whether the filename is readable</title> <meta http-equiv="content-type" content="text/html; charset=UTF-8"> </head> <body><div style="text-align: center;"> <div class="prev" style="text-align: left; float: left;"><a href="function.is-link.html">is_link</a></div> <div class="next" style="text-align: right; float: right;"><a href="function.is-uploaded-file.html">is_uploaded_file</a></div> <div class="up"><a href="ref.filesystem.html">Filesystem Functions</a></div> <div class="home"><a href="index.html">PHP Manual</a></div></div><hr /><div id="function.is-readable" class="refentry"> <div class="refnamediv"> <h1 class="refname">is_readable</h1> <p class="verinfo">(PHP 4, PHP 5)</p><p class="refpurpose"><span class="refname">is_readable</span> — <span class="dc-title">Tells whether the filename is readable</span></p> </div> <div class="refsect1 description"> <h3 class="title">Description</h3> <div class="methodsynopsis dc-description"> <span class="type">bool</span> <span class="methodname"><b><b>is_readable</b></b></span> ( <span class="methodparam"><span class="type">string</span> <tt class="parameter">$filename</tt></span> )</div> <p class="para rdfs-comment"> Tells whether the filename is readable. </p> </div> <div class="refsect1 parameters"> <h3 class="title">Parameters</h3> <p class="para"> <dl> <dt> <span class="term"><i><tt class="parameter">filename</tt></i></span> <dd> <p class="para"> Path to the file. </p> </dd> </dt> </dl> </p> </div> <div class="refsect1 returnvalues"> <h3 class="title">Return Values</h3> <p class="para"> Returns <b><tt>TRUE</tt></b> if the file or directory specified by <i><tt class="parameter">filename</tt></i> exists and is readable, <b><tt>FALSE</tt></b> otherwise. </p> </div> <div class="refsect1 examples"> <h3 class="title">Examples</h3> <p class="para"> <div class="example"> <p><b>Example #1 <b>is_readable()</b> example</b></p> <div class="example-contents"><div class="phpcode"><code><span style="color: #000000"><span style="color: #0000BB"><?php<br />$filename </span><span style="color: #007700">= </span><span style="color: #DD0000">'test.txt'</span><span style="color: #007700">;<br />if (</span><span style="color: #0000BB">is_readable</span><span style="color: #007700">(</span><span style="color: #0000BB">$filename</span><span style="color: #007700">)) {<br /> echo </span><span style="color: #DD0000">'The file is readable'</span><span style="color: #007700">;<br />} else {<br /> echo </span><span style="color: #DD0000">'The file is not readable'</span><span style="color: #007700">;<br />}<br /></span><span style="color: #0000BB">?></span></span></code></div> </div> </div> </p> </div> <div class="refsect1 notes"> <h3 class="title">Notes</h3> <p class="para"> Keep in mind that PHP may be accessing the file as the user id that the web server runs as (often 'nobody'). Safe mode limitations are not taken into account before PHP 5.1.5. </p> <blockquote><p><b class="note">Note</b>: <span class="simpara">The results of this function are cached. See <a href="function.clearstatcache.html" class="function">clearstatcache()</a> for more details.</span></p></blockquote> <div class="tip"><b class="tip">Tip</b><p class="simpara">As of PHP 5.0.0, this functioncan also be used with <em class="emphasis">some</em> URL wrappers. Refer to <a href="wrappers.html" class="xref">List of Supported Protocols/Wrappers</a> for a listing of which wrappers support <a href="function.stat.html" class="function">stat()</a> family of functionality.</p></div> <blockquote><p><b class="note">Note</b>: The check is done using the real UID/GID instead of the effective one. <br /> </p></blockquote> </div> <div class="refsect1 seealso"> <h3 class="title">See Also</h3> <p class="para"> <ul class="simplelist"> <li class="member"><a href="function.is-writable.html" class="function" rel="rdfs-seeAlso">is_writable()</a></li> <li class="member"><a href="function.file-exists.html" class="function" rel="rdfs-seeAlso">file_exists()</a></li> <li class="member"><a href="function.fgets.html" class="function" rel="rdfs-seeAlso">fgets()</a></li> </ul> </p> </div></div><hr /><div style="text-align: center;"> <div class="prev" style="text-align: left; float: left;"><a href="function.is-link.html">is_link</a></div> <div class="next" style="text-align: right; float: right;"><a href="function.is-uploaded-file.html">is_uploaded_file</a></div> <div class="up"><a href="ref.filesystem.html">Filesystem Functions</a></div> <div class="home"><a href="index.html">PHP Manual</a></div></div></body></html>⌨️ 快捷键说明
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