function.is-writable.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 writable</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-uploaded-file.html">is_uploaded_file</a></div> <div class="next" style="text-align: right; float: right;"><a href="function.is-writeable.html">is_writeable</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-writable" class="refentry"> <div class="refnamediv"> <h1 class="refname">is_writable</h1> <p class="verinfo">(PHP 4, PHP 5)</p><p class="refpurpose"><span class="refname">is_writable</span> — <span class="dc-title">Tells whether the filename is writable</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_writable</b></b></span> ( <span class="methodparam"><span class="type">string</span> <tt class="parameter">$filename</tt></span> )</div> <p class="para rdfs-comment"> Returns <b><tt>TRUE</tt></b> if the <i><tt class="parameter">filename</tt></i> exists and is writable. The filename argument may be a directory name allowing you to check if a directory is writable. </p> <p class="para"> Keep in mind that PHP may be accessing the file as the user id that the web server runs as (often 'nobody'). Safe mode limitations are not taken into account. </p> </div> <div class="refsect1 parameters"> <h3 class="title">Parameters</h3> <p class="para"> <dl> <dt> <span class="term"><i><tt class="parameter">filename</tt></i></span> <dd> <p class="para"> The filename being checked. </p> </dd> </dt> </dl> </p> </div> <div class="refsect1 returnvalues"> <h3 class="title">Return Values</h3> <p class="para"> Returns <b><tt>TRUE</tt></b> if the <i><tt class="parameter">filename</tt></i> exists and is writable. </p> </div> <div class="refsect1 examples"> <h3 class="title">Examples</h3> <p class="para"> <div class="example"> <p><b>Example #1 <b>is_writable()</b> example</b></p> <div class="example-contents"><div class="phpcode"><code><span style="color: #000000"><span style="color: #0000BB"><?php<br />$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_writable</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 writable'</span><span style="color: #007700">;<br />} else {<br /> echo </span><span style="color: #DD0000">'The file is not writable'</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> <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> </div> <div class="refsect1 seealso"> <h3 class="title">See Also</h3> <p class="para"> <ul class="simplelist"> <li class="member"><a href="function.is-readable.html" class="function" rel="rdfs-seeAlso">is_readable()</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.fwrite.html" class="function" rel="rdfs-seeAlso">fwrite()</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-uploaded-file.html">is_uploaded_file</a></div> <div class="next" style="text-align: right; float: right;"><a href="function.is-writeable.html">is_writeable</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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