php-doc-en/reference/sockets/functions/socket-get-option.xml

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<refentry xmlns="http://docbook.org/ns/docbook" xml:id="function.socket-get-option">
 <refnamediv>
  <refname>socket_get_option</refname>
  <refpurpose>Gets socket options for the socket </refpurpose>
 </refnamediv>
 
 <refsect1 role="description">
  &reftitle.description;
  <methodsynopsis>
   <type>mixed</type><methodname>socket_get_option</methodname>
   <methodparam><type>resource</type><parameter>socket</parameter></methodparam>
   <methodparam><type>int</type><parameter>level</parameter></methodparam>
   <methodparam><type>int</type><parameter>optname</parameter></methodparam>
  </methodsynopsis>
  <para>
   The <function>socket_get_option</function> function retrieves the value for
   the option specified by the <parameter>optname</parameter> parameter for the
   specified <parameter>socket</parameter>.
  </para>
 </refsect1>

 <refsect1 role="parameters">
  &reftitle.parameters;
  <para>
   <variablelist>
    <varlistentry>
     <term><parameter>socket</parameter></term>
     <listitem>
      <para>
       A valid socket resource created with <function>socket_create</function>
       or <function>socket_accept</function>.
      </para>
     </listitem>
    </varlistentry>
    <varlistentry>
     <term><parameter>level</parameter></term>
     <listitem>
      <para>
       The <parameter>level</parameter> parameter specifies the protocol
       level at which the option resides. For example, to retrieve options at
       the socket level, a <parameter>level</parameter> parameter of
       SOL_SOCKET would be used. Other levels, such as TCP, can be used by
       specifying the protocol number of that level. Protocol numbers can be
       found by using the <function>getprotobyname</function> function.
      </para>
     </listitem>
    </varlistentry>
    <varlistentry>
     <term><parameter>optname</parameter></term>
     <listitem>
      <table>
       <title>Available Socket Options</title>
       <tgroup cols="3">
        <thead>
         <row>
          <entry>Option</entry>
          <entry>Description</entry>
          <entry>Type</entry>
         </row>
        </thead>
        <tbody>
         <row>
          <entry>SO_DEBUG</entry>
          <entry>
           Reports whether debugging information is being recorded.
          </entry>
          <entry>
           <type>int</type>
          </entry>
         </row>
         <row>
          <entry>SO_BROADCAST</entry>
          <entry>
           Reports whether transmission of broadcast messages is supported.
          </entry>
          <entry>
           <type>int</type>
          </entry>
         </row>
         <row>
          <entry>SO_REUSEADDR</entry>
          <entry>
           Reports whether local addresses can be reused.
          </entry>
          <entry>
           <type>int</type>
          </entry>
         </row>
         <row>
          <entry>SO_KEEPALIVE</entry>
          <entry>
           Reports whether connections are kept active with periodic transmission
           of messages. If the connected socket fails to respond to these messages,
           the connection is broken and processes writing to that socket are notified
           with a SIGPIPE signal.
          </entry>
          <entry>
           <type>int</type>
          </entry>
         </row>
         <row>
          <entry>SO_LINGER</entry>
          <entry>
           <para>
            Reports whether the <parameter>socket</parameter> lingers on 
            <function>socket_close</function> if data is present. By default, 
            when the socket is closed, it attempts to send all unsent data.
            In the case of a connection-oriented socket, 
            <function>socket_close</function> will wait for its peer to
            acknowledge the data. 
           </para>
           <para>
            If <structfield>l_onoff</structfield> is non-zero and 
            <structfield>l_linger</structfield> is zero, all the 
            unsent data will be discarded and RST (reset) is sent to the 
            peer in the case of a connection-oriented socket. 
           </para>
           <para>
            On the other hand, if <structfield>l_onoff</structfield> is 
            non-zero and <structfield>l_linger</structfield> is non-zero,
            <function>socket_close</function> will block until all the data 
            is sent or the time specified in <structfield>l_linger</structfield>
            elapses. If the socket is non-blocking, 
            <function>socket_close</function> will fail and return an error.
           </para>
          </entry>
          <entry>
           <type>array</type>. The array will contain two keys:
           <structfield>l_onoff</structfield> and 
           <structfield>l_linger</structfield>. 
          </entry>
         </row>
         <row>
          <entry>SO_OOBINLINE</entry>
          <entry>
           Reports whether the <parameter>socket</parameter> leaves out-of-band data inline.
          </entry>
          <entry>
           <type>int</type>
          </entry>
         </row>
         <row>
          <entry>SO_SNDBUF</entry>
          <entry>
           Reports the size of the send buffer.
          </entry>
          <entry>
           <type>int</type>
          </entry>          
         </row>
         <row>
          <entry>SO_RCVBUF</entry>
          <entry>
           Reports the size of the receive buffer.
          </entry>
          <entry>
           <type>int</type>
          </entry>         
         </row>
         <row>
          <entry>SO_ERROR</entry>
          <entry>
           Reports information about error status and clears it.
          </entry>
          <entry>
           <type>int</type> (cannot be set by <function>socket_set_option</function>)
          </entry>
         </row>
         <row>
          <entry>SO_TYPE</entry>
          <entry>
           Reports the <parameter>socket</parameter> type (e.g. 
           <constant>SOCK_STREAM</constant>).
          </entry>
          <entry>
           <type>int</type> (cannot be set by <function>socket_set_option</function>)
          </entry>
         </row>
         <row>
          <entry>SO_DONTROUTE</entry>
          <entry>
           Reports whether outgoing messages bypass the standard routing facilities.
          </entry>
          <entry>
           <type>int</type>
          </entry>
         </row>
         <row>
          <entry>SO_RCVLOWAT</entry>
          <entry>
           Reports the minimum number of bytes to process for <parameter>socket</parameter> 
           input operations.
          </entry>
          <entry>
           <type>int</type>
          </entry>
         </row>
         <row>
          <entry>SO_RCVTIMEO</entry>
          <entry>
           Reports the timeout value for input operations.
          </entry>
          <entry>
           <type>array</type>. The array will contain two keys:
           <structfield>sec</structfield> which is the seconds part on the timeout
           value and <structfield>usec</structfield> which is the microsecond part 
           of the timeout value. 
          </entry>
         </row>
         <row>
          <entry>SO_SNDTIMEO</entry>
          <entry>
           Reports the timeout value specifying the amount of time that an output
           function blocks because flow control prevents data from being sent.
          </entry>
          <entry>
           <type>array</type>. The array will contain two keys:
           <structfield>sec</structfield> which is the seconds part on the timeout
           value and <structfield>usec</structfield> which is the microsecond part 
           of the timeout value. 
          </entry>
         </row>
         <row>
          <entry>SO_SNDLOWAT</entry>
          <entry>
           Reports the minimum number of bytes to process for <parameter>socket</parameter> output operations.
          </entry>
          <entry>
           <type>int</type>
          </entry>
         </row>
        </tbody>
       </tgroup>
      </table>
     </listitem>
    </varlistentry>
   </variablelist>
  </para>
 </refsect1>

 <refsect1 role="returnvalues">
  &reftitle.returnvalues;
  <para>
   Returns the value of the given option, or &false; on errors.
  </para>
 </refsect1>

 <refsect1 role="examples">
  &reftitle.examples;
  <para>
   <example>
    <title><function>socket_set_option</function> example</title>
    <programlisting role="php">
<![CDATA[
<?php
$socket = socket_create_listen(1223);

$linger = array('l_linger' => 1, 'l_onoff' => 1);
socket_set_option($socket, SOL_SOCKET, SO_LINGER, $linger);

var_dump(socket_get_option($socket, SOL_SOCKET, SO_REUSEADDR));
?>
]]>
    </programlisting>
   </example>
  </para>
 </refsect1>

 <refsect1 role="changelog">
  &reftitle.changelog;
  <para>
   <informaltable>
    <tgroup cols="2">
     <thead>
      <row>
       <entry>&Version;</entry>
       <entry>&Description;</entry>
      </row>
     </thead>
     <tbody>
      <row>
       <entry>4.3.0</entry>
       <entry>
        The name of this function was changed. It used to be called
        <literal>socket_getopt()</literal>.
       </entry>
      </row>
     </tbody>
    </tgroup>
   </informaltable>
  </para>
 </refsect1>

</refentry>

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