CODEWITHSUNDEEP
phpexternal-process
Christian Studer
Christian Studer

Reputation: 25637

Invoke external shell script from PHP and get its process ID

How can I invoke an external shell script (Or alternatively an external PHP script) from PHP itself and get its process ID within the same script?

Upvotes: 31

Views: 29256

Answers (4)

TheKarateKid
TheKarateKid

Reputation: 812

What ended up working for me is using pgrep to get the PID of the command (or process name) executed after calling exec() in PHP.

exec($command);
$pid = exec("pgrep $command");

This will work for launching background processes too. However, you must remember to pipe the program's output to /dev/null or else PHP will hang. Also, when calling pgrep you can't include the pipe portion of the command:

$command = "bg_process -o someOption";
exec($command + " > /dev/null &"); //Separate the pipe and '&' from the command
$pid = exec("pgrep $command");

Note that if the system has multiple processes launched with the same exact command, it will return the PIDs of all processes which match the command given to pgrep. If you only pass in a process name, it will return all PIDs with that process name.

Upvotes: 0

Mikhail Vasin
Mikhail Vasin

Reputation: 2580

For a cross-platform solution, check out symfony/process.

use Symfony\Component\Process\Process;
$process = new Process('sleep 100');
$process->start();
var_dump($process->getPid());

After you install symfony/process with composer (composer require symfony/process), you may need to update autoloading info with composer dump-autoload and then require the autoload with require __DIR__ . '/vendor/autoload.php';.

Notice also that you can get PID of a running process only. Refer to the documentation for API details.

Upvotes: 3

Mark Amery
Mark Amery

Reputation: 155206

If you want to do this strictly using tools PHP gives you, rather than Unix-specific wizardry, you can do so with proc_open and proc_get_status, although the need to pass a descriptor spec into proc_open makes it unpleasantly verbose to use:

<?php

$descriptorspec = [
    0 => ['pipe', 'r'],
    1 => ['pipe', 'w'],
    2 => ['pipe', 'w']
];
$proc = proc_open('yourcommand', $descriptorspec, $pipes);
$proc_details = proc_get_status($proc);
$pid = $proc_details['pid'];

echo $pid;

Upvotes: 27

Boris Gu&#233;ry
Boris Gu&#233;ry

Reputation: 47624

$command =  'yourcommand' . ' > /dev/null 2>&1 & echo $!; ';

$pid = exec($command, $output);

var_dump($pid);

Upvotes: 62

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