#!/usr/bin/perl
#When a program forks the fork returns the pid of the 
#child so the parent can use this to kill it at will.

my $pid = fork();
print "pid $pid created\n";

if ( $pid == 0 ) {
   # child process so do stuff here
   # usually have an exit to ensure child
   # does not escape this if clause
 exit;
}
else {
   # parent process, waits a while
   sleep 3;
   # kills child
   if( kill 9, $pid ){ print "pid $pid killed\n"};
}
# parent continues on here (as will child if not killed or exited)