set_exception_handler(3) [php man page]

SET_EXCEPTION_HANDLER(3)						 1						  SET_EXCEPTION_HANDLER(3)

set_exception_handler - Sets a user-defined exception handler function

SYNOPSIS

       callable set_exception_handler (callable  $exception_handler)

DESCRIPTION

	Sets  the  default exception handler if an exception is not caught within a try/catch block. Execution will stop after the $exception_han-
       dler is called.

PARAMETERS

	      o $exception_handler
		- Name of the function to be called when an uncaught exception occurs. This handler function needs to accept one parameter,  which
		will be the exception object that was thrown. This is the handler signature:
		void handler (Exception  $ex) NULL may be passed instead, to reset this handler to its default state.

	      Caution

		      Note  that  providing  an  explicit  Exception  type  hint for the $ex parameter in your callback will cause issues with the
		     changed exception hierarchy in PHP 7.

RETURN VALUES

	Returns the name of the previously defined exception handler, or NULL on error. If no previous handler was defined, NULL is also returned.

CHANGELOG

       +--------+---------------------------------------------------+
       |Version |						    |
       |	|						    |
       |	|		     Description		    |
       |	|						    |
       +--------+---------------------------------------------------+
       | 5.5.0	|						    |
       |	|						    |
       |	|  Previously, if NULL was passed then	this  func- |
       |	| tion	returned TRUE. It returns the previous han- |
       |	| dler since PHP 5.5.0. 			    |
       |	|						    |
       +--------+---------------------------------------------------+
EXAMPLES

       Example #1

	      set_exception_handler(3) example

	      <?php
	      function exception_handler($exception) {
		echo "Uncaught exception: " , $exception->getMessage(), "
";
	      }

	      set_exception_handler('exception_handler');

	      throw new Exception('Uncaught Exception');
	      echo "Not Executed
";
	      ?>

SEE ALSO

       restore_exception_handler(3), restore_error_handler(3), error_reporting(3), information about the callback type, PHP 5 Exceptions.

PHP Documentation Group 												  SET_EXCEPTION_HANDLER(3)

PCNTL_SIGNAL(3) 							 1							   PCNTL_SIGNAL(3)

pcntl_signal - Installs a signal handler

SYNOPSIS

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

DESCRIPTION

	The pcntl_signal(3) function installs a new signal handler or replaces the current signal handler for the signal indicated by $signo.

PARAMETERS

	      o $signo
		- The signal number.

	      o $handler
		-  The signal handler. This may be either a callable, which will be invoked to handle the signal, or either of the two global con-
		stants 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)

		     o $signo
		       - The signal being handled.

	      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.

	      o $restart_syscalls
		- Specifies whether system call restarting should be used when this signal arrives.

RETURN VALUES

	Returns TRUE on success or FALSE on failure.

CHANGELOG

       +--------+---------------------------------------------------+
       |Version |						    |
       |	|						    |
       |	|		     Description		    |
       |	|						    |
       +--------+---------------------------------------------------+
       | 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  func- |
       |	| tion properly (as used in the example below).     |
       |	|						    |
       +--------+---------------------------------------------------+
EXAMPLES

       Example #1

	      pcntl_signal(3) 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...
";
			   break;
		       default:
			   // handle all other signals
		   }

	      }

	      echo "Installing signal handler...
";

	      // 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...
";

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

	      echo "Done
";

	      ?>

NOTES

       pcntl_signal(3) doesn't stack the signal handlers, but replaces them.

SEE ALSO

       pcntl_fork(3), pcntl_waitpid(3).

PHP Documentation Group 													   PCNTL_SIGNAL(3)