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<div class="refnamediv">
<h1 class="refname">pcntl_wait</h1>
<p class="verinfo">(PHP 5)</p><p class="refpurpose"><span class="refname">pcntl_wait</span> — <span class="dc-title">Waits on or returns the status of a forked child</span></p>
</div>
<div class="refsect1 description" id="refsect1-function.pcntl-wait-description">
<h3 class="title">Description</h3>
<div class="methodsynopsis dc-description">
<span class="type">int</span> <span class="methodname"><strong>pcntl_wait</strong></span>
( <span class="methodparam"><span class="type">int</span> <code class="parameter reference">&$status</code></span>
[, <span class="methodparam"><span class="type">int</span> <code class="parameter">$options</code><span class="initializer"> = 0</span></span>
] )</div>
<p class="para rdfs-comment">
The wait function suspends execution of the current process until a
child has exited, or until a signal is delivered whose action is to
terminate the current process or to call a signal handling function. If a
child has already exited by the time of the call (a so-called "zombie"
process), the function returns immediately. Any system resources used by
the child are freed. Please see your system's wait(2) man page for
specific details as to how wait works on your system.
</p>
<blockquote class="note"><p><strong class="note">Note</strong>:
<p class="para">
This function is equivalent to calling <span class="function"><a href="function.pcntl-waitpid.html" class="function">pcntl_waitpid()</a></span>
with a <em>-1</em> <em><code class="parameter">pid</code></em> and no
<em><code class="parameter">options</code></em>.
</p>
</p></blockquote>
</div>
<div class="refsect1 parameters" id="refsect1-function.pcntl-wait-parameters">
<h3 class="title">Parameters</h3>
<p class="para">
<dl>
<dt>
<span class="term"><em><code class="parameter">status</code></em></span>
<dd>
<p class="para">
<span class="function"><strong>pcntl_wait()</strong></span> will store status information
in the <em><code class="parameter">status</code></em> parameter which can be
evaluated using the following functions:
<span class="function"><a href="function.pcntl-wifexited.html" class="function">pcntl_wifexited()</a></span>,
<span class="function"><a href="function.pcntl-wifstopped.html" class="function">pcntl_wifstopped()</a></span>,
<span class="function"><a href="function.pcntl-wifsignaled.html" class="function">pcntl_wifsignaled()</a></span>,
<span class="function"><a href="function.pcntl-wexitstatus.html" class="function">pcntl_wexitstatus()</a></span>,
<span class="function"><a href="function.pcntl-wtermsig.html" class="function">pcntl_wtermsig()</a></span> and
<span class="function"><a href="function.pcntl-wstopsig.html" class="function">pcntl_wstopsig()</a></span>.
</p>
</dd>
</dt>
<dt>
<span class="term"><em><code class="parameter">options</code></em></span>
<dd>
<p class="para">
If wait3 is available on your system (mostly BSD-style systems), you can
provide the optional <em><code class="parameter">options</code></em> parameter. If this
parameter is not provided, wait will be used for the system call. If
wait3 is not available, providing a value for <em><code class="parameter">options
</code></em> will have no effect. The value of <em><code class="parameter">options
</code></em> is the value of zero or more of the following two constants
<em>OR</em>'ed together:
<table class="doctable table">
<caption><strong>Possible values for <em><code class="parameter">options</code></em></strong></caption>
<tbody class="tbody">
<tr>
<td><em>WNOHANG</em></td>
<td>
Return immediately if no child has exited.
</td>
</tr>
<tr>
<td><em>WUNTRACED</em></td>
<td>
Return for children which are stopped, and whose status has
not been reported.
</td>
</tr>
</tbody>
</table>
</p>
</dd>
</dt>
</dl>
</p>
</div>
<div class="refsect1 returnvalues" id="refsect1-function.pcntl-wait-returnvalues">
<h3 class="title">Return Values</h3>
<p class="para">
<span class="function"><strong>pcntl_wait()</strong></span> returns the process ID of the
child which exited, -1 on error or zero if WNOHANG was provided as an
option (on wait3-available systems) and no child was available.
</p>
</div>
<div class="refsect1 seealso" id="refsect1-function.pcntl-wait-seealso">
<h3 class="title">See Also</h3>
<p class="para">
<ul class="simplelist">
<li class="member"> <span class="function"><a href="function.pcntl-fork.html" class="function" rel="rdfs-seeAlso">pcntl_fork()</a> - Forks the currently running process</span></li>
<li class="member"> <span class="function"><a href="function.pcntl-signal.html" class="function" rel="rdfs-seeAlso">pcntl_signal()</a> - Installs a signal handler</span></li>
<li class="member"> <span class="function"><a href="function.pcntl-wifexited.html" class="function" rel="rdfs-seeAlso">pcntl_wifexited()</a> - Checks if status code represents a normal exit</span></li>
<li class="member"> <span class="function"><a href="function.pcntl-wifstopped.html" class="function" rel="rdfs-seeAlso">pcntl_wifstopped()</a> - Checks whether the child process is currently stopped</span></li>
<li class="member"> <span class="function"><a href="function.pcntl-wifsignaled.html" class="function" rel="rdfs-seeAlso">pcntl_wifsignaled()</a> - Checks whether the status code represents a termination due to a signal</span></li>
<li class="member"> <span class="function"><a href="function.pcntl-wexitstatus.html" class="function" rel="rdfs-seeAlso">pcntl_wexitstatus()</a> - Returns the return code of a terminated child</span></li>
<li class="member"> <span class="function"><a href="function.pcntl-wtermsig.html" class="function" rel="rdfs-seeAlso">pcntl_wtermsig()</a> - Returns the signal which caused the child to terminate</span></li>
<li class="member"> <span class="function"><a href="function.pcntl-wstopsig.html" class="function" rel="rdfs-seeAlso">pcntl_wstopsig()</a> - Returns the signal which caused the child to stop</span></li>
<li class="member"> <span class="function"><a href="function.pcntl-waitpid.html" class="function" rel="rdfs-seeAlso">pcntl_waitpid()</a> - Waits on or returns the status of a forked child</span></li>
</ul>
</p>
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