Ending a shell_exec process PHP

Question

been trying to figure this one out for a couple of hours now. No luck.

I am trying to build a system that can run reports (running scripts in the background) using shell_exec.

The following code starts the script that runs the report: shell_exec("php /var/www/html/lab-40/test/invoice_reminder.php");

Now how would I go about ending that script execution using PHP?

I've tried things like PIDS but I have no clue how I would go about this. Thanks for the help in advance!

EDIT: I am not trying to end the process if the e.g tab is closed.

So from a web-based control panel, lets say the user wants to cancel running the report — user3724476, Feb 04 '19 at 11:32
Check out this [comment](http://php.net/manual/en/function.shell-exec.php#59898) on `shell_exec` help page. — Furgas, Feb 04 '19 at 11:37
Possible duplicate of [PHP shell\_exec - how to terminate the process if the connection is closed?](https://stackoverflow.com/a/16103650/10967889) — weegee, Feb 04 '19 at 11:41
@daksh I don't want the script to be killed upon the tab being closed. — user3724476, Feb 04 '19 at 11:43
@user3724476 `shell_exec('kill -KILL ProcessID');` this might help — weegee, Feb 04 '19 at 11:44
@Furgas Thanks for that. With actually getting the PID I assume it's this part of the shell_exec that gets it "& echo $!". — user3724476, Feb 04 '19 at 11:44
For better control of child processes, take a look át [PCNTL Functions](http://php.net/manual/en/ref.pcntl.php) and [POSIX Functions](http://php.net/manual/en/ref.posix.php). — Wiimm, Feb 04 '19 at 12:07

score 2 · Accepted Answer · answered Feb 04 '19 at 11:55

Based on this comment on shell_exec help page (& will bring the process to the background, and echo $! will print the process PID):

<?php

function shell_exec_background(string $command): int {
    return (int)shell_exec(
        sprintf(
            'nohup %s 1> /dev/null 2> /dev/null & echo $!',
            $command
        )
    );
}

function is_pid_running(int $pid): bool {
    exec(
        sprintf(
            'kill -0 %d 1> /dev/null 2> /dev/null',
            $pid
        ),
        $output,
        $exit_code
    );

    return $exit_code === 0;
}

function kill_pid(int $pid): bool {
    exec(
        sprintf(
            'kill -KILL %d 1> /dev/null 2> /dev/null',
            $pid
        ),
        $output,
        $exit_code
    );

    return $exit_code === 0;
}

$pid = shell_exec_background('php /var/www/html/lab-40/test/invoice_reminder.php');
var_dump($pid);
var_dump(is_pid_running($pid));
var_dump(kill_pid($pid));

Ending a shell_exec process PHP

1 Answers1