pcntl_signal

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

    pcntl_signal — Installs a signal handler

    Descripción

    pcntl_signal(int$signal, callable|int$handler, bool$restart_syscalls = true): bool

    The pcntl_signal() function installs a new signal handler or replaces the current signal handler for the signal indicated by signal.

    Parámetros

    signal

    The signal number.

    handler

    The signal handler. This may be either a callable, which will be invoked to handle the signal, or either of the two global constants SIG_IGN or SIG_DFL, which will ignore the signal or restore the default signal handler respectively.

    If a callable is given, it must implement the following signature:

    handler(int$signo, mixed$siginfo): void
    signal
    The signal being handled.
    siginfo
    If operating systems supports siginfo_t structures, this will be an array of signal information dependent on the signal.

    Nota:

    Note that when you set a handler to an object method, that object's reference count is increased which makes it persist until you either change the handler to something else, or your script ends.

    restart_syscalls

    Specifies whether system call restarting should be used when this signal arrives.

    Valores devueltos

    Devuelve true en caso de éxito o false en caso de error.

    Historial de cambios

    VersiónDescripción
    7.1.0 As of PHP 7.1.0 the handler callback is given a second argument containing the siginfo of the specific signal. This data is only supplied if the operating system has the siginfo_t structure. If the OS does not implement siginfo_t NULL is supplied.

    Ejemplos

    Ejemplo #1 pcntl_signal() example

    <?php
    // tick use required
    declare(ticks = 1);

    // signal handler function
    function sig_handler($signo)
    {

    switch (    $signo) {
    case     SIGTERM:
    // handle shutdown tasks
    exit;
    break;
    case     SIGHUP:
    // handle restart tasks
    break;
    case     SIGUSR1:
    echo     "Caught SIGUSR1...\n";
    break;
    default:
    // handle all other signals
    }

    }

    echo     "Installing signal handler...\n";

    // setup signal handlers
    pcntl_signal(SIGTERM, "sig_handler");
    pcntl_signal(SIGHUP, "sig_handler");
    pcntl_signal(SIGUSR1, "sig_handler");

    // or use an object
    // pcntl_signal(SIGUSR1, array($obj, "do_something"));

    echo"Generating signal SIGUSR1 to self...\n";

    // send SIGUSR1 to current process id
    // posix_* functions require the posix extension
    posix_kill(posix_getpid(), SIGUSR1);

    echo     "Done\n";

    ?>

    Notas

    pcntl_signal() doesn't stack the signal handlers, but replaces them.

    Ver también

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