pcntl_signal
The pcntl_signal function installs a new signal handler or replaces the current signal handler for the signal indicated by signal.
Parameters
- 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.
Note:
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.
Return Values
Returns true on success or false on failure.
Notes
pcntl_signal doesn't stack the signal handlers, but replaces them.
Changelog
| Version | Description |
| 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. |