How to check whether specified PID is currently running without invoking ps from PHP?

If you are on Linux, try this :

if (file_exists( "/proc/$pid" )){
    //process with a pid = $pid is running
}

posix_getpgid($pid); will return false when a process is not running

If you want to have a function for it then:

$running = posix_kill($pid,0);

Send the signal sig to the process with the process identifier pid.

Calling posix_kill with the 0 kill signal will return true if the process is running, false otherwise.

Related