PCNTL Funzioni
PHP Manual

pcntl_signal

(PHP 4 >= 4.1.0, PHP 5)

pcntl_signalInstalls a signal handler

Descrizione

bool pcntl_signal ( int $signo , callable|int $handler [, bool $restart_syscalls = true ] )

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

Elenco dei parametri

signo

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:

void handler ( int $signo )
signo
The signal being handled.

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.

Valori restituiti

Restituisce TRUE in caso di successo, FALSE in caso di fallimento.

Log delle modifiche

Versione Descrizione
4.3.0 As of PHP 4.3.0 PCNTL uses ticks as the signal handle callback mechanism, which is much faster than the previous mechanism. This change follows the same semantics as using "user ticks". You must use the declare() statement to specify the locations in your program where callbacks are allowed to occur for the signal handler to function properly (as used in the example below).

Esempi

Example #1 pcntl_signal() example

<?php
// tick use required as of PHP 4.3.0
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, available as of PHP 4.3.0
// pcntl_signal(SIGUSR1, array($obj, "do_something"));

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

// send SIGUSR1 to current process id
posix_kill(posix_getpid(), SIGUSR1);

echo 
"Done\n";

?>

Note

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

Vedere anche:


PCNTL Funzioni
PHP Manual