Question

I’m trying to fork a process by getting PHP to exec PHP whilst piping output to /dev/null and running the cmd in the background

Before I get this running silently – I want to check the cmd runs as expected – however when the command is executed by PHP the process (both master and forked) never terminate and the browser is forver stuck on “Connecting…”

Here is the code:

$script = '/home/username/application/bg_job.php';
$args = 'foo bar';

$cmd = "php -f $script $args";
$return = exec($cmd, $arr_output, $code);

var_dump($return);

I checked the Apache user which runs the script by doing

whoami

and it was “username” – so I’ve logged in as root and run

sudo -u username php -f /home/username/application/bg_job.php foo bar

And it works.

Any ideas what I might be doing wrong?

EDIT – FYI – here is the contents of bg_job.php

<?php
    file_put_contents('/home/username/test.txt', 'Hello !');
?>

Answer 1

I think you are attempting to instigate a background task. On Linux this can be done with the ampersand:

php -f /var/file.php &

There are more details on this blog post.

So your command would become:

$cmd = "php -f $script $args &";