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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>Returns the current position of the file read/write pointer</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.fstat.html">fstat</a></div> <div class="next" style="text-align: right; float: right;"><a href="function.ftruncate.html">ftruncate</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.ftell" class="refentry"> <div class="refnamediv"> <h1 class="refname">ftell</h1> <p class="verinfo">(PHP 4, PHP 5)</p><p class="refpurpose"><span class="refname">ftell</span> — <span class="dc-title">Returns the current position of the file read/write pointer</span></p> </div> <div class="refsect1 description"> <h3 class="title">Description</h3> <div class="methodsynopsis dc-description"> <span class="type">int</span> <span class="methodname"><b><b>ftell</b></b></span> ( <span class="methodparam"><span class="type">resource</span> <tt class="parameter">$handle</tt></span> )</div> <p class="para rdfs-comment"> Returns the position of the file pointer referenced by <i><tt class="parameter">handle</tt></i>. </p> </div> <div class="refsect1 parameters"> <h3 class="title">Parameters</h3> <p class="para"> <dl> <dt> <span class="term"><i><tt class="parameter">handle</tt></i></span> <dd> <p class="para"> The file pointer must be valid, and must point to a file successfully opened by <a href="function.fopen.html" class="function">fopen()</a> or <a href="function.popen.html" class="function">popen()</a>. <b>ftell()</b> gives undefined results for append-only streams (opened with "a" flag). </p> </dd> </dt> </dl> </p> </div> <div class="refsect1 returnvalues"> <h3 class="title">Return Values</h3> <p class="para"> Returns the position of the file pointer referenced by <i><tt class="parameter">handle</tt></i> as an integer; i.e., its offset into the file stream. </p> <p class="para"> If an error occurs, returns <b><tt>FALSE</tt></b>. </p> </div> <div class="refsect1 examples"> <h3 class="title">Examples</h3> <p class="para"> <div class="example"> <p><b>Example #1 <b>ftell()</b> example</b></p> <div class="example-contents"><div class="phpcode"><code><span style="color: #000000"><span style="color: #0000BB"><?php<br /><br /></span><span style="color: #FF8000">// opens a file and read some data<br /></span><span style="color: #0000BB">$fp </span><span style="color: #007700">= </span><span style="color: #0000BB">fopen</span><span style="color: #007700">(</span><span style="color: #DD0000">"/etc/passwd"</span><span style="color: #007700">, </span><span style="color: #DD0000">"r"</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">$data </span><span style="color: #007700">= </span><span style="color: #0000BB">fgets</span><span style="color: #007700">(</span><span style="color: #0000BB">$fp</span><span style="color: #007700">, </span><span style="color: #0000BB">12</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">// where are we ?<br /></span><span style="color: #007700">echo </span><span style="color: #0000BB">ftell</span><span style="color: #007700">(</span><span style="color: #0000BB">$fp</span><span style="color: #007700">); </span><span style="color: #FF8000">// 11<br /><br /></span><span style="color: #0000BB">fclose</span><span style="color: #007700">(</span><span style="color: #0000BB">$fp</span><span style="color: #007700">);<br /><br /></span><span style="color: #0000BB">?></span></span></code></div> </div> </div> </p> </div> <div class="refsect1 seealso"> <h3 class="title">See Also</h3> <p class="para"> <ul class="simplelist"> <li class="member"><a href="function.fopen.html" class="function" rel="rdfs-seeAlso">fopen()</a></li> <li class="member"><a href="function.popen.html" class="function" rel="rdfs-seeAlso">popen()</a></li> <li class="member"><a href="function.fseek.html" class="function" rel="rdfs-seeAlso">fseek()</a></li> <li class="member"><a href="function.rewind.html" class="function" rel="rdfs-seeAlso">rewind()</a></li> </ul> </p> </div></div><hr /><div style="text-align: center;"> <div class="prev" style="text-align: left; float: left;"><a href="function.fstat.html">fstat</a></div> <div class="next" style="text-align: right; float: right;"><a href="function.ftruncate.html">ftruncate</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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