php man page for exit

EXIT(3) 								 1								   EXIT(3)

exit - Output a message and terminate the current script

SYNOPSIS
       void exit ([string  $status])

DESCRIPTION
       void exit (int  $status)

	Terminates execution of the script. Shutdown functions and object destructors will always be executed even if exit is called.

       exit is a language construct and it can be called without parentheses if no $status is passed.

PARAMETERS
	      o $status
		- If $status is a string, this function prints the $status just before exiting.  If $status is an integer, that value will be used
		as the exit status and not printed. Exit statuses should be in the range 0 to 254, the exit status 255	is  reserved  by  PHP  and
		shall not be used. The status 0 is used to terminate the program successfully.

	      Note

		      PHP >= 4.2.0 does NOT print the $status if it is an integer.

RETURN VALUES
	No value is returned.

EXAMPLES
       Example #1

	      exit example

	      <?php

	      $filename = '/path/to/data-file';
	      $file = fopen($filename, 'r')
		  or exit("unable to open file ($filename)");

	      ?>

       Example #2

	      exit status example

	      <?php

	      //exit program normally
	      exit;
	      exit();
	      exit(0);

	      //exit with an error code
	      exit(1);
	      exit(0376); //octal

	      ?>

       Example #3

	      Shutdown functions and destructors run regardless

	      <?php
	      class Foo
	      {
		  public function __destruct()
		  {
		      echo 'Destruct: ' . __METHOD__ . '()' . PHP_EOL;
		  }
	      }

	      function shutdown()
	      {
		  echo 'Shutdown: ' . __FUNCTION__ . '()' . PHP_EOL;
	      }

	      $foo = new Foo();
	      register_shutdown_function('shutdown');

	      exit();
	      echo 'This will not be output.';
	      ?>

	      The above example will output:

	      Shutdown: shutdown()
	       Destruct: Foo::__destruct()

NOTES
       Note

	      Because this is a language construct and not a function, it cannot be called using variable functions.

       Note

	       This language construct is equivalent to die(3).

SEE ALSO
       register_shutdown_function(3).

PHP Documentation Group 														   EXIT(3)