<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="content-type" content="text/html; charset=UTF-8"> <title>Portable file locking</title> </head> <body><div class="manualnavbar" style="text-align: center;"> <div class="prev" style="text-align: left; float: left;"><a href="splfileobject.fgetss.html">SplFileObject::fgetss</a></div> <div class="next" style="text-align: right; float: right;"><a href="splfileobject.fpassthru.html">SplFileObject::fpassthru</a></div> <div class="up"><a href="class.splfileobject.html">SplFileObject</a></div> <div class="home"><a href="index.html">PHP Manual</a></div> </div><hr /><div id="splfileobject.flock" class="refentry"> <div class="refnamediv"> <h1 class="refname">SplFileObject::flock</h1> <p class="verinfo">(PHP 5 >= 5.1.0)</p><p class="refpurpose"><span class="refname">SplFileObject::flock</span> — <span class="dc-title">Portable file locking</span></p> </div> <div class="refsect1 description" id="refsect1-splfileobject.flock-description"> <h3 class="title">Description</h3> <div class="methodsynopsis dc-description"> <span class="modifier">public</span> <span class="type">bool</span> <span class="methodname"><strong>SplFileObject::flock</strong></span> ( <span class="methodparam"><span class="type">int</span> <code class="parameter">$operation</code></span> [, <span class="methodparam"><span class="type">int</span> <code class="parameter reference">&$wouldblock</code></span> ] )</div> <p class="para rdfs-comment"> Locks or unlocks the file in the same portable way as <span class="function"><a href="function.flock.html" class="function">flock()</a></span>. </p> </div> <div class="refsect1 parameters" id="refsect1-splfileobject.flock-parameters"> <h3 class="title">Parameters</h3> <p class="para"> <dl> <dt> <span class="term"><em><code class="parameter">operation</code></em></span> <dd> <p class="para"> <em><code class="parameter">operation</code></em> is one of the following: <ul class="itemizedlist"> <li class="listitem"> <span class="simpara"> <strong><code>LOCK_SH</code></strong> to acquire a shared lock (reader). </span> </li> <li class="listitem"> <span class="simpara"> <strong><code>LOCK_EX</code></strong> to acquire an exclusive lock (writer). </span> </li> <li class="listitem"> <span class="simpara"> <strong><code>LOCK_UN</code></strong> to release a lock (shared or exclusive). </span> </li> <li class="listitem"> <span class="simpara"> <strong><code>LOCK_NB</code></strong> to not block while locking (not supported on Windows). </span> </li> </ul> </p> </dd> </dt> <dt> <span class="term"><em><code class="parameter">wouldblock</code></em></span> <dd> <p class="para"> Set to <strong><code>TRUE</code></strong> if the lock would block (EWOULDBLOCK errno condition). </p> </dd> </dt> </dl> </p> </div> <div class="refsect1 returnvalues" id="refsect1-splfileobject.flock-returnvalues"> <h3 class="title">Return Values</h3> <p class="para"> Returns <strong><code>TRUE</code></strong> on success or <strong><code>FALSE</code></strong> on failure. </p> </div> <div class="refsect1 examples" id="refsect1-splfileobject.flock-examples"> <h3 class="title">Examples</h3> <p class="para"> <div class="example" id="example-3955"> <p><strong>Example #1 <span class="methodname"><strong>SplFileObject::flock()</strong></span> example</strong></p> <div class="example-contents"> <div class="phpcode"><code><span style="color: #000000"> <span style="color: #0000BB"><?php<br />$file </span><span style="color: #007700">= new </span><span style="color: #0000BB">SplFileObject</span><span style="color: #007700">(</span><span style="color: #DD0000">"/tmp/lock.txt"</span><span style="color: #007700">, </span><span style="color: #DD0000">"w"</span><span style="color: #007700">);<br />if (</span><span style="color: #0000BB">$file</span><span style="color: #007700">-></span><span style="color: #0000BB">flock</span><span style="color: #007700">(</span><span style="color: #0000BB">LOCK_EX</span><span style="color: #007700">)) { </span><span style="color: #FF8000">// do an exclusive lock<br /> </span><span style="color: #0000BB">$file</span><span style="color: #007700">-></span><span style="color: #0000BB">ftruncate</span><span style="color: #007700">(</span><span style="color: #0000BB">0</span><span style="color: #007700">); </span><span style="color: #FF8000">// truncate file<br /> </span><span style="color: #0000BB">$file</span><span style="color: #007700">-></span><span style="color: #0000BB">fwrite</span><span style="color: #007700">(</span><span style="color: #DD0000">"Write something here\n"</span><span style="color: #007700">);<br /> </span><span style="color: #0000BB">$file</span><span style="color: #007700">-></span><span style="color: #0000BB">flock</span><span style="color: #007700">(</span><span style="color: #0000BB">LOCK_UN</span><span style="color: #007700">); </span><span style="color: #FF8000">// release the lock <br /></span><span style="color: #007700">} else {<br /> echo </span><span style="color: #DD0000">"Couldn't get the lock!"</span><span style="color: #007700">;<br />}<br /></span><span style="color: #0000BB">?></span> </span> </code></div> </div> </div> </p> </div> <div class="refsect1 seealso" id="refsect1-splfileobject.flock-seealso"> <h3 class="title">See Also</h3> <p class="para"> <ul class="simplelist"> <li class="member"> <span class="function"><a href="function.flock.html" class="function" rel="rdfs-seeAlso">flock()</a> - Portable advisory file locking</span></li> </ul> </p> </div> </div><hr /><div class="manualnavbar" style="text-align: center;"> <div class="prev" style="text-align: left; 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