socket_accept

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

    socket_accept — Soket üzerinden bağlantı kabul eder

    Açıklama

    socket_accept(Socket $soket): Socket|false

    soket soketi socket_create() ile oluşturulup, socket_bind() kullanarak bir isimle ilişkilendirildikten sonra socket_listen() ile gelen bağlantılar dinlenmeye başlanır. Bu işlev böyle bir soket üzerinden gelen bağlantıları kabul etmek için kullanılır. Başarılı bir bağlantı, iletişim için kullanılacak yeni bir Socket nesnesinin dönmesini sağlar. Soket kuyruğunda bekleyen çok sayıda bağlantı varsa socket_accept() bunlardan birinde veri hazır olana dek bekler. Soket socket_set_blocking() veya socket_set_nonblock() ile engellenmeyen kipe sokulmuşsa bu işlev false döndürür.

    socket_accept() tarafından döndürülen Socket nesnesi yeni bağlantılar kabul etmek için kullanılamaz. Bununla birlikte, soket ile belirtilen dinleme soketi açık olarak kalır ve defalarca kullanılabilir.

    Bağımsız Değişkenler

    soket

    socket_create() ile oluşturulmuş geçerli bir Socket nesnesi.

    Dönen Değerler

    Bir hata durumunda false yoksa yeni bir Socket nesnesi döner. Hata kodu socket_last_error() işlevi ile alınabilir. Bu hata kodunu socket_strerror() işlevine aktararak hatayı açıklayan dizgeyi alabilirsiniz.

    Sürüm Bilgisi

    Sürüm: Açıklama
    8.0.0 Başarı durumunda artık bir Socket nesnesi dönüyor; evvelce resource türünde bir değer dönerdi.

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    User Contributed Notes 7 notes

    up
    24
    lars at opdenkamp dot eu
    16 years ago
    If you want to make a daemon process that forks on each client connection, you'll find out that there's a bug in PHP. The child processes send SIGCHLD to their parent when they exit but the parent can't handle signals while it's waiting for socket_accept (blocking).

    Here is a piece of code that makes a non-blocking forking server.

    #!/usr/bin/php -q
    <?php
    /**
    * Listens for requests and forks on each connection
    */

    $__server_listening = true;

    error_reporting(E_ALL);
    set_time_limit(0);
    ob_implicit_flush();
    declare(    ticks = 1);

    become_daemon();

    /* nobody/nogroup, change to your host's uid/gid of the non-priv user */
    change_identity(65534, 65534);

    /* handle signals */
    pcntl_signal(SIGTERM, 'sig_handler');
    pcntl_signal(SIGINT, 'sig_handler');
    pcntl_signal(SIGCHLD, 'sig_handler');

    /* change this to your own host / port */
    server_loop("127.0.0.1", 1234);

    /**
    * Change the identity to a non-priv user
    */
    function change_identity( $uid, $gid )
    {
    if( !    posix_setgid( $gid ) )
    {
    print     "Unable to setgid to " . $gid . "!\n";
    exit;
    }

    if( !    posix_setuid( $uid ) )
    {
    print     "Unable to setuid to " . $uid . "!\n";
    exit;
    }
    }

    /**
    * Creates a server socket and listens for incoming client connections
    * @param string $address The address to listen on
    * @param int $port The port to listen on
    */
    function server_loop($address, $port)
    {
    GLOBAL     $__server_listening;

    if((    $sock = socket_create(AF_INET, SOCK_STREAM, 0)) < 0)
    {
    echo     "failed to create socket: ".socket_strerror($sock)."\n";
    exit();
    }

    if((    $ret = socket_bind($sock, $address, $port)) < 0)
    {
    echo     "failed to bind socket: ".socket_strerror($ret)."\n";
    exit();
    }

    if( (     $ret = socket_listen( $sock, 0 ) ) < 0 )
    {
    echo     "failed to listen to socket: ".socket_strerror($ret)."\n";
    exit();
    }

    socket_set_nonblock($sock);

    echo     "waiting for clients to connect\n";

    while (    $__server_listening)
    {
    $connection = @socket_accept($sock);
    if (    $connection === false)
    {
    usleep(100);
    }elseif (    $connection > 0)
    {
    handle_client($sock, $connection);
    }else
    {
    echo     "error: ".socket_strerror($connection);
    die;
    }
    }
    }

    /**
    * Signal handler
    */
    function sig_handler($sig)
    {
    switch(    $sig)
    {
    case     SIGTERM:
    case     SIGINT:
    exit();
    break;

    case     SIGCHLD:
    pcntl_waitpid(-1, $status);
    break;
    }
    }

    /**
    * Handle a new client connection
    */
    function handle_client($ssock, $csock)
    {
    GLOBAL     $__server_listening;

    $pid = pcntl_fork();

    if (    $pid == -1)
    {
    /* fork failed */
    echo "fork failure!\n";
    die;
    }elseif (    $pid == 0)
    {
    /* child process */
    $__server_listening = false;
    socket_close($ssock);
    interact($csock);
    socket_close($csock);
    }else
    {
    socket_close($csock);
    }
    }

    function     interact($socket)
    {
    /* TALK TO YOUR CLIENT */
    }

    /**
    * Become a daemon by forking and closing the parent
    */
    function become_daemon()
    {
    $pid = pcntl_fork();

    if (    $pid == -1)
    {
    /* fork failed */
    echo "fork failure!\n";
    exit();
    }elseif (    $pid)
    {
    /* close the parent */
    exit();
    }else
    {
    /* child becomes our daemon */
    posix_setsid();
    chdir('/');
    umask(0);
    return     posix_getpid();

    }
    }

    ?>
    up
    18
    Boylett
    16 years ago
    If you want to have multiple clients on a server you will have to use non blocking.

    <?php

    $clients     = array();
    $socket = socket_create(AF_INET,SOCK_STREAM,SOL_TCP);
    socket_bind($socket,'127.0.0.1',$port);
    socket_listen($socket);
    socket_set_nonblock($socket);

    while(    true)
    {
    if((    $newc = socket_accept($socket)) !== false)
    {
    echo     "Client $newc has connected\n";
    $clients[] = $newc;
    }
    }

    ?>
    up
    4
    Greg MacLellan
    20 years ago
    The socket returned by this resource will be non-blocking, regardless of what the listening socket is set to. This is actually true for all FCNTL modifiers.
    up
    2
    renmengyang567 at gmail dot com
    5 years ago
    <explain>
    This case is a very simple interaction between the TCP client side and the TCP server side

    <?php
    // create for simple-tcp-server
    $sock = socket_create(AF_INET, SOCK_STREAM, getprotobyname('tcp'));
    socket_bind($sock, '127.0.0.1',5000);
    socket_listen($sock,1);
    $clnt_sock = socket_accept($sock); //阻塞
    $st = "hello world ^_^";
    socket_write($clnt_sock, $st,strlen($st));
    socket_close($clnt_sock);
    socket_close($sock);
    ?>

    <?php
    //create for simple-tcp-client
    $clnt_sock = socket_create(AF_INET, SOCK_STREAM, getprotobyname('tcp'));
    socket_connect($clnt_sock, '127.0.0.1', 5000);
    $ret= socket_read($clnt_sock, 1024);
    print     "from simple-tcp-server:".$ret.PHP_EOL;
    socket_close($clnt_sock);
    ?>

    <fruit>
    from simple-tcp-server:hello world ^_^
    up
    -1
    gmkarl at gmail dot com
    16 years ago
    Be aware signal handler functions set with pcntl_signal are not called while a socket is blocking waiting for a connection; the signal is absorbed silently and the handler called when a connection is made.
    up
    -7
    simon at 180solutions dot com
    18 years ago
    >Accepting a connection using php-sockets:
    >
    >$fd = socket_create(AF_INET, SOCK_STREAM, 6 /* OR >getprotobyname("TCP")*/);
    >
    >$PORT = 5000;
    >
    >socket_bind($fd, "0.0.0.0", $PORT);
    >
    >while(true)
    >{
    >$remote_fd = socket_accept($fd);
    >
    >remote_socket_client_handle($remote_fd);
    >
    >}
    >
    >It is simple!

    This example doesn't work. You have to call socket_listen($fd) after your bind in order to accept incoming connections.

    Simon
    up
    -8
    mightyplow at gmail dot com
    9 years ago
    In order to make many clients connectable to the server, you have to set the accepted socket also to non-blocking. Otherwise the accepted connection will block further incoming connections.

    while (true) {
    $newSock = @socket_accept($sock);

    if ($newSock) {
    echo 'client connected';

    socket_set_nonblock($newSock);
    }
    }
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