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

Question

We would like to check if a specified process is currently running via PHP.

We would like to simply supply a PID and see if it is currently executing or not.

Answer 1

Here is how we do it:

if (`ps -p {$pid} -o comm,args=ARGS | grep php`) {

  //process with pid=$pid is running;
}

Answer 2

I would call a bash script using shell_exec

$pid = 23818;
if (shell_exec("ps aux | grep " . $pid . " | wc -l") > 0)
{
    // do something
}

Answer 3

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