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<title>Receives data from a connected socket</title>
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<h1 class="refname">socket_recv</h1>
<p class="verinfo">(PHP 4 >= 4.1.0, PHP 5)</p><p class="refpurpose"><span class="refname">socket_recv</span> — <span class="dc-title">Receives data from a connected socket </span></p>
</div>
<div class="refsect1 description" id="refsect1-function.socket-recv-description">
<h3 class="title">Description</h3>
<div class="methodsynopsis dc-description">
<span class="type">int</span> <span class="methodname"><strong>socket_recv</strong></span>
( <span class="methodparam"><span class="type">resource</span> <code class="parameter">$socket</code></span>
, <span class="methodparam"><span class="type">string</span> <code class="parameter reference">&$buf</code></span>
, <span class="methodparam"><span class="type">int</span> <code class="parameter">$len</code></span>
, <span class="methodparam"><span class="type">int</span> <code class="parameter">$flags</code></span>
)</div>
<p class="para rdfs-comment">
The <span class="function"><strong>socket_recv()</strong></span> function receives
<em><code class="parameter">len</code></em> bytes of data in <em><code class="parameter">buf</code></em> from
<em><code class="parameter">socket</code></em>. <span class="function"><strong>socket_recv()</strong></span> can
be used to gather data from connected sockets. Additionally, one or
more flags can be specified to modify the behaviour of the
function.
</p>
<p class="para">
<em><code class="parameter">buf</code></em> is passed by reference, so it must be
specified as a variable in the argument list. Data read from
<em><code class="parameter">socket</code></em> by <span class="function"><strong>socket_recv()</strong></span>
will be returned in <em><code class="parameter">buf</code></em>.
</p>
</div>
<div class="refsect1 parameters" id="refsect1-function.socket-recv-parameters">
<h3 class="title">Parameters</h3>
<p class="para">
<dl>
<dt>
<span class="term"><em><code class="parameter">socket</code></em></span>
<dd>
<p class="para">
The <em><code class="parameter">socket</code></em> must be a socket resource previously
created by socket_create().
</p>
</dd>
</dt>
<dt>
<span class="term"><em><code class="parameter">buf</code></em></span>
<dd>
<p class="para">
The data received will be fetched to the variable specified with
<em><code class="parameter">buf</code></em>. If an error occurs, if the
connection is reset, or if no data is
available, <em><code class="parameter">buf</code></em> will be set to <strong><code>NULL</code></strong>.
</p>
</dd>
</dt>
<dt>
<span class="term"><em><code class="parameter">len</code></em></span>
<dd>
<p class="para">
Up to <em><code class="parameter">len</code></em> bytes will be fetched from remote host.
</p>
</dd>
</dt>
<dt>
<span class="term"><em><code class="parameter">flags</code></em></span>
<dd>
<p class="para">
The value of <em><code class="parameter">flags</code></em> can be any combination of
the following flags, joined with the binary OR (<em>|</em>)
operator.
</p>
<table class="doctable table">
<caption><strong>Possible values for <em><code class="parameter">flags</code></em></strong></caption>
<thead>
<tr>
<th>Flag</th>
<th>Description</th>
</tr>
</thead>
<tbody class="tbody">
<tr>
<td><strong><code>MSG_OOB</code></strong></td>
<td>
Process out-of-band data.
</td>
</tr>
<tr>
<td><strong><code>MSG_PEEK</code></strong></td>
<td>
Receive data from the beginning of the receive queue without
removing it from the queue.
</td>
</tr>
<tr>
<td><strong><code>MSG_WAITALL</code></strong></td>
<td>
Block until at least <em><code class="parameter">len</code></em> are received.
However, if a signal is caught or the remote host disconnects, the
function may return less data.
</td>
</tr>
<tr>
<td><strong><code>MSG_DONTWAIT</code></strong></td>
<td>
With this flag set, the function returns even if it would normally
have blocked.
</td>
</tr>
</tbody>
</table>
</dd>
</dt>
</dl>
</p>
</div>
<div class="refsect1 returnvalues" id="refsect1-function.socket-recv-returnvalues">
<h3 class="title">Return Values</h3>
<p class="para">
<span class="function"><strong>socket_recv()</strong></span> returns the number of bytes received,
or <strong><code>FALSE</code></strong> if there was an error. The actual error code can be retrieved by
calling <span class="function"><a href="function.socket-last-error.html" class="function">socket_last_error()</a></span>. This error code may be
passed to <span class="function"><a href="function.socket-strerror.html" class="function">socket_strerror()</a></span> to get a textual explanation
of the error.
</p>
</div>
<div class="refsect1 examples" id="refsect1-function.socket-recv-examples">
<h3 class="title">Examples</h3>
<p class="para">
<div class="example" id="example-4595">
<p><strong>Example #1 <span class="function"><strong>socket_recv()</strong></span> example</strong></p>
<div class="example-contents"><p>
This example is a simple rewrite of the first example from
<a href="sockets.examples.html" class="xref">Examples</a> to
use <span class="function"><strong>socket_recv()</strong></span>.
</p></div>
<div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br />error_reporting</span><span style="color: #007700">(</span><span style="color: #0000BB">E_ALL</span><span style="color: #007700">);<br /><br />echo </span><span style="color: #DD0000">"<h2>TCP/IP Connection</h2>\n"</span><span style="color: #007700">;<br /><br /></span><span style="color: #FF8000">/* Get the port for the WWW service. */<br /></span><span style="color: #0000BB">$service_port </span><span style="color: #007700">= </span><span style="color: #0000BB">getservbyname</span><span style="color: #007700">(</span><span style="color: #DD0000">'www'</span><span style="color: #007700">, </span><span style="color: #DD0000">'tcp'</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">/* Get the IP address for the target host. */<br /></span><span style="color: #0000BB">$address </span><span style="color: #007700">= </span><span style="color: #0000BB">gethostbyname</span><span style="color: #007700">(</span><span style="color: #DD0000">'www.example.com'</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">/* Create a TCP/IP socket. */<br /></span><span style="color: #0000BB">$socket </span><span style="color: #007700">= </span><span style="color: #0000BB">socket_create</span><span style="color: #007700">(</span><span style="color: #0000BB">AF_INET</span><span style="color: #007700">, </span><span style="color: #0000BB">SOCK_STREAM</span><span style="color: #007700">, </span><span style="color: #0000BB">SOL_TCP</span><span style="color: #007700">);<br />if (</span><span style="color: #0000BB">$socket </span><span style="color: #007700">=== </span><span style="color: #0000BB">false</span><span style="color: #007700">) {<br /> echo </span><span style="color: #DD0000">"socket_create() failed: reason: " </span><span style="color: #007700">. </span><span style="color: #0000BB">socket_strerror</span><span style="color: #007700">(</span><span style="color: #0000BB">socket_last_error</span><span style="color: #007700">()) . </span><span style="color: #DD0000">"\n"</span><span style="color: #007700">;<br />} else {<br /> echo </span><span style="color: #DD0000">"OK.\n"</span><span style="color: #007700">;<br />}<br /><br />echo </span><span style="color: #DD0000">"Attempting to connect to '</span><span style="color: #0000BB">$address</span><span style="color: #DD0000">' on port '</span><span style="color: #0000BB">$service_port</span><span style="color: #DD0000">'..."</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$result </span><span style="color: #007700">= </span><span style="color: #0000BB">socket_connect</span><span style="color: #007700">(</span><span style="color: #0000BB">$socket</span><span style="color: #007700">, </span><span style="color: #0000BB">$address</span><span style="color: #007700">, </span><span style="color: #0000BB">$service_port</span><span style="color: #007700">);<br />if (</span><span style="color: #0000BB">$result </span><span style="color: #007700">=== </span><span style="color: #0000BB">false</span><span style="color: #007700">) {<br /> echo </span><span style="color: #DD0000">"socket_connect() failed.\nReason: (</span><span style="color: #0000BB">$result</span><span style="color: #DD0000">) " </span><span style="color: #007700">. </span><span style="color: #0000BB">socket_strerror</span><span style="color: #007700">(</span><span style="color: #0000BB">socket_last_error</span><span style="color: #007700">(</span><span style="color: #0000BB">$socket</span><span style="color: #007700">)) . </span><span style="color: #DD0000">"\n"</span><span style="color: #007700">;<br />} else {<br /> echo </span><span style="color: #DD0000">"OK.\n"</span><span style="color: #007700">;<br />}<br /><br /></span><span style="color: #0000BB">$in </span><span style="color: #007700">= </span><span style="color: #DD0000">"HEAD / HTTP/1.1\r\n"</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$in </span><span style="color: #007700">.= </span><span style="color: #DD0000">"Host: www.example.com\r\n"</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$in </span><span style="color: #007700">.= </span><span style="color: #DD0000">"Connection: Close\r\n\r\n"</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$out </span><span style="color: #007700">= </span><span style="color: #DD0000">''</span><span style="color: #007700">;<br /><br />echo </span><span style="color: #DD0000">"Sending HTTP HEAD request..."</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">socket_write</span><span style="color: #007700">(</span><span style="color: #0000BB">$socket</span><span style="color: #007700">, </span><span style="color: #0000BB">$in</span><span style="color: #007700">, </span><span style="color: #0000BB">strlen</span><span style="color: #007700">(</span><span style="color: #0000BB">$in</span><span style="color: #007700">));<br />echo </span><span style="color: #DD0000">"OK.\n"</span><span style="color: #007700">;<br /><br />echo </span><span style="color: #DD0000">"Reading response:\n\n"</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$buf </span><span style="color: #007700">= </span><span style="color: #DD0000">'This is my buffer.'</span><span style="color: #007700">;<br />if (</span><span style="color: #0000BB">false </span><span style="color: #007700">!== (</span><span style="color: #0000BB">$bytes </span><span style="color: #007700">= </span><span style="color: #0000BB">socket_recv</span><span style="color: #007700">(</span><span style="color: #0000BB">$socket</span><span style="color: #007700">, </span><span style="color: #0000BB">$buf</span><span style="color: #007700">, </span><span style="color: #0000BB">2048</span><span style="color: #007700">, </span><span style="color: #0000BB">MSG_WAITALL</span><span style="color: #007700">))) {<br /> echo </span><span style="color: #DD0000">"Read </span><span style="color: #0000BB">$bytes</span><span style="color: #DD0000"> bytes from socket_recv(). Closing socket..."</span><span style="color: #007700">;<br />} else {<br /> echo </span><span style="color: #DD0000">"socket_recv() failed; reason: " </span><span style="color: #007700">. </span><span style="color: #0000BB">socket_strerror</span><span style="color: #007700">(</span><span style="color: #0000BB">socket_last_error</span><span style="color: #007700">(</span><span style="color: #0000BB">$socket</span><span style="color: #007700">)) . </span><span style="color: #DD0000">"\n"</span><span style="color: #007700">;<br />}<br /></span><span style="color: #0000BB">socket_close</span><span style="color: #007700">(</span><span style="color: #0000BB">$socket</span><span style="color: #007700">);<br /><br />echo </span><span style="color: #0000BB">$buf </span><span style="color: #007700">. </span><span style="color: #DD0000">"\n"</span><span style="color: #007700">;<br />echo </span><span style="color: #DD0000">"OK.\n\n"</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">?></span>
</span>
</code></div>
</div>
<div class="example-contents"><p>
The above example will produce something like:
</p></div>
<div class="example-contents screen">
<div class="cdata"><pre>
<h2>TCP/IP Connection</h2>
OK.
Attempting to connect to '208.77.188.166' on port '80'...OK.
Sending HTTP HEAD request...OK.
Reading response:
Read 123 bytes from socket_recv(). Closing socket...HTTP/1.1 200 OK
Date: Mon, 14 Sep 2009 08:56:36 GMT
Server: Apache/2.2.3 (Red Hat)
Last-Modified: Tue, 15 Nov 2005 13:24:10 GMT
ETag: "b80f4-1b6-80bfd280"
Accept-Ranges: bytes
Content-Length: 438
Connection: close
Content-Type: text/html; charset=UTF-8
OK.
</pre></div>
</div>
</div>
</p>
</div>
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