pcntl_signal - Installs a signal handler
Вернуться к: PCNTL Функции
pcntl_signal
(PHP 4 >= 4.1.0, PHP 5, PHP 7)
pcntl_signal — Installs a signal handler
Описание
$signo
, callable|int $handler
[, bool $restart_syscalls = true
] )
The pcntl_signal() function installs a new
signal handler or replaces the current signal handler for the signal indicated by signo.
Список параметров
-
signo -
The signal number.
-
handler -
The signal handler. This may be either a callable, which will be invoked to handle the signal, or either of the two global constants
SIG_IGNorSIG_DFL, which will ignore the signal or restore the default signal handler respectively.If a callable is given, it must implement the following signature:
void handler ( int$signo)-
signo - The signal being handled.
Замечание:
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.
Возвращаемые значения
Возвращает TRUE в случае успешного завершения или FALSE в случае возникновения ошибки.
Список изменений
| Версия | Описание |
|---|---|
| 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). |
Примеры
Пример #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 SIGUSR1 to self...\n";
// send SIGUSR1 to current process id
// posix_* functions require the posix extension
posix_kill(posix_getpid(), SIGUSR1);
echo "Done\n";
?>
Примечания
pcntl_signal() doesn't stack the signal handlers, but replaces them.
Смотрите также
- pcntl_fork() - Forks the currently running process
- pcntl_waitpid() - Waits on or returns the status of a forked child
Вернуться к: PCNTL Функции