SOCKET_CREATE_PAIR(3)							 1						     SOCKET_CREATE_PAIR(3)

socket_create_pair - Creates a pair of indistinguishable sockets and stores them in an array

SYNOPSIS

       bool socket_create_pair (int  $domain, int  $type, int  $protocol, array  &$fd)

DESCRIPTION

       socket_create_pair(3)  creates  two  connected and indistinguishable sockets, and stores them in $fd. This function is commonly used in IPC
       (InterProcess Communication).

PARAMETERS

	      o $domain
		- The $domain parameter specifies the protocol family to be used by the socket. See socket_create(3) for the full list.

	      o $type
		- The $type parameter selects the type of communication to be used by the socket. See socket_create(3) for the full list.

	      o $protocol
		- The $protocol parameter sets the specific protocol within the specified $domain to be used when communicating  on  the  returned
		socket.  The  proper  value can be retrieved by name by using getprotobyname(3). If the desired protocol is TCP, or UDP the corre-
		sponding constants SOL_TCP, and SOL_UDP can also be used.  See socket_create(3) for the full list of supported protocols.

	      o $fd
		- Reference to an array in which the two socket resources will be inserted.

RETURN VALUES

	Returns TRUE on success or FALSE on failure.

CHANGELOG

       +--------+---------------------------------------------------+
       |Version |						    |
       |	|						    |
       |	|		     Description		    |
       |	|						    |
       +--------+---------------------------------------------------+
       | 5.3.0	|						    |
       |	|						    |
       |	|  This function is now re-enabled on Windows plat- |
       |	| forms.					    |
       |	|						    |
       | 4.3.0	|						    |
       |	|						    |
       |	|  This  function was due to a bug made unavailable |
       |	| on Windows platforms. 			    |
       |	|						    |
       +--------+---------------------------------------------------+
EXAMPLES

       Example #1

	      socket_create_pair(3) example

	      <?php
	      $sockets = array();

	      /* On Windows we need to use AF_INET */
	      $domain = (strtoupper(substr(PHP_OS, 0, 3)) == 'WIN' ? AF_INET : AF_UNIX);

	      /* Setup socket pair */
	      if (socket_create_pair($domain, SOCK_STREAM, 0, $sockets) === false) {
		  echo "socket_create_pair failed. Reason: ".socket_strerror(socket_last_error());
	      }
	      /* Send and Recieve Data */
	      if (socket_write($sockets[0], "ABCdef123
", strlen("ABCdef123
")) === false) {
		  echo "socket_write() failed. Reason: ".socket_strerror(socket_last_error($sockets[0]));
	      }
	      if (($data = socket_read($sockets[1], strlen("ABCdef123
"), PHP_BINARY_READ)) === false) {
		  echo "socket_read() failed. Reason: ".socket_strerror(socket_last_error($sockets[1]));
	      }
	      var_dump($data);

	      /* Close sockets */
	      socket_close($sockets[0]);
	      socket_close($sockets[1]);
	      ?>

       Example #2

	      socket_create_pair(3) IPC example

	      <?php
	      $ary = array();
	      $strone = 'Message From Parent.';
	      $strtwo = 'Message From Child.';

	      if (socket_create_pair(AF_UNIX, SOCK_STREAM, 0, $ary) === false) {
		  echo "socket_create_pair() failed. Reason: ".socket_strerror(socket_last_error());
	      }
	      $pid = pcntl_fork();
	      if ($pid == -1) {
		  echo 'Could not fork Process.';
	      } elseif ($pid) {
		  /*parent*/
		  socket_close($ary[0]);
		  if (socket_write($ary[1], $strone, strlen($strone)) === false) {
		      echo "socket_write() failed. Reason: ".socket_strerror(socket_last_error($ary[1]));
		  }
		  if (socket_read($ary[1], strlen($strtwo), PHP_BINARY_READ) == $strtwo) {
		      echo "Recieved $strtwo
";
		  }
		  socket_close($ary[1]);
	      } else {
		  /*child*/
		  socket_close($ary[1]);
		  if (socket_write($ary[0], $strtwo, strlen($strtwo)) === false) {
		      echo "socket_write() failed. Reason: ".socket_strerror(socket_last_error($ary[0]));
		  }
		  if (socket_read($ary[0], strlen($strone), PHP_BINARY_READ) == $strone) {
		      echo "Recieved $strone
";
		  }
		  socket_close($ary[0]);
	      }
	      ?>

SEE ALSO

       socket_create(3), socket_create_listen(3), socket_bind(3), socket_listen(3), socket_last_error(3), socket_strerror(3).

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