I can be wrong, but When I make a fork() ($pid=pcntl_fork())the only difference for the child and parent process is the $pid value. Both process have the same memory image, credentials, open files, signal handlers and by the way the same variables. It's not thrue with PCNTL I dont know for other langages, for exemple try the following test program => The parent has two variables $a and $b. If I make a change in the child, this change has no impact on the parent.

Tell me where I'm wrong. Thanks for your help

Marcel

The example for test :

<?php

	function sig_handler($signo) {
	   switch($signo){
	         case SIGINT:
	             $msg=  "STOP THE WAR\n";
	             exit();
	             break;
	         case SIGHUP:
	             // handle restart tasks
	             break;
	         case SIGCHLD:
	             while( pcntl_waitpid(-1,$status,WNOHANG)>0 ) {}
	             break;
	         default:
	             // handle all other signals
	     }
	}
	
	pcntl_signal(SIGCHLD, "sig_handler");
	pcntl_signal(SIGHUP, "sig_handler");
	pcntl_signal(SIGINT, "sig_handler");
	
	
	$a=10;
	$b=10;
	while(1){
	    $c=$a+$b;
		echo "\SEPARATOR";
		echo "\n I'am the parent C1=> $c ";
	    sleep(4);
	
	    $pid=pcntl_fork();
	    if($pid==-1){
	        print "failure\n";}
	    if(!$pid){
	        $a=0;
		    $b=0;
			$c=$a+$b;
			print "\nI AM THE CHILD C in child => $c";
			sleep(4);
		    exit();
	    }
	    print "\n I'm the parent  C2=> ".$c;
     }
?>