I am developing a webservice in PHP/Linux where I need to kill a process. I tried using exec("kill ".$pid); and exec("kill -KILL ".$pid); but the return value was always 1 and the process still remained. I wrote up a small shell script and have exec run that script. The script worked fine if invoked through command line but through php it didn't do anything. I have a hunch that this is because killing a process might need root privilages so I updated the script to: sudo -p my_passsword -u root kill $pid yet it didn't work. I still think the problem is access rights. question is how to solve it. Any help will be greatly appreciated. Sincerely Fahad