fork.php

<?php
$pids = array();

for($i=0; $i<10; ++$i) {
  $pid = pcntl_fork();
	if ($pid) {
		$pids[] = $pid;
	} else {
		sleep(2);
		echo "Child " . posix_getpid() . " slept enough.\n";
		exit;
	}
}
foreach( $pids as $pid ) {
	pcntl_waitpid( $pid, $status );
}

/*
→ time php fork.php 
Child 6541 slept enough.
Child 6540 slept enough.
Child 6543 slept enough.
Child 6538 slept enough.
Child 6542 slept enough.
Child 6544 slept enough.
Child 6545 slept enough.
Child 6546 slept enough.
Child 6539 slept enough.
Child 6547 slept enough.
php fork.php  0.12s user 0.05s system 8% cpu 2.087 total
 */