socket_create_listen

(PHP 4 >= 4.1.0, PHP 5, PHP 7, PHP 8)

socket_create_listen — Opens a socket on port to accept connections

说明

socket_create_listen ( int $port , int $backlog = 128 ) : Socket|false

socket_create_listen() creates a new Socket instance of type AF_INET listening on all local interfaces on the given port waiting for new connections.

This function is meant to ease the task of creating a new socket which only listens to accept new connections.

参数

port: The port on which to listen on all interfaces.
backlog: The backlog parameter defines the maximum length the queue of pending connections may grow to. SOMAXCONN may be passed as backlog parameter, see socket_listen() for more information.

返回值

socket_create_listen() returns a new Socket instance on success or false on error. The error code can be retrieved with socket_last_error(). This code may be passed to socket_strerror() to get a textual explanation of the error.

更新日志

版本	说明
8.0.0	On success, this function returns a Socket instance now; previously, a resource was returned.

注释

Note:
If you want to create a socket which only listens on a certain interface you need to use socket_create(), socket_bind() and socket_listen().

参见

socket_create() - 创建一个套接字（通讯节点）
socket_create_pair() - Creates a pair of indistinguishable sockets and stores them in an array
socket_bind() - 给套接字绑定名字
socket_listen() - Listens for a connection on a socket
socket_last_error() - Returns the last error on the socket
socket_strerror() - Return a string describing a socket error

User Contributed Notes

aeolianmeson at ifacfchi dot blitzeclipse dot com 26-Jun-2008 03:34


I believe that on some systems this may not bind to some or all public interfaces.



On my Windows system, I could not connect on the public interface using this, but could when I made the individual calls to create, bind, and listen.



Dustin Oprea

sysspoof at ng-lab dot org 06-Mar-2008 11:03


Please note that port 1 to and with 1024 on linux and bsd system require root privileges. So it is recommended to choose a higher port for your own application.

jdittmer at ppp0 dot net 17-Jul-2004 04:42


If you specify no port number, or 0, a random free port will be chosen.


To use ports for ipc between client/server on the same machine you can use (minus error checking)





server.php:


<?php


$sock = socket_create_listen(0);


socket_getsockname($sock, $addr, $port);


print "Server Listening on $addr:$port\n";


$fp = fopen($port_file, 'w');


fwrite($fp, $port);


fclose($fp);


while($c = socket_accept($sock)) {


   /* do something useful */


   socket_getpeername($c, $raddr, $rport);


   print "Received Connection from $raddr:$rport\n";


}


socket_close($sock);


?>





client.php:


<?php


$fp = fopen($port_file, 'r');


$port = fgets($fp, 1024);


fclose($fp);


$sock = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);


socket_connect($sock, '127.0.0.1', $port);


socket_close($sock);


?>

basim at baassiri dot com 06-Feb-2004 02:50


Remember that ports are only valid from 1 - 65535





[editor's note: typo fixed, thanks abryant at apple dot com]