How to kill a running bash file with php

Question

I have two buttons "Start Acquisition" and "Stop Acquisition",

The start button executes a bash file and it works fine:

<form action="Control.php" method="post">
<input value="Continous Acquisition " name="Continuous" type="submit">
</form>

<?php
if (isset($_POST['Continous'])) {
shell_exec('sh /Desktop/run_test.sh');
}
?>

I have no idea how to stop the execution when the Stop button is pressed

<form action="Control.php" method="post">

<input value="Stop Acquisition " name="Stop" type="submit">

 </form>

Any help would be appreciated. Thank you.

Answer 1

To run a program in the background, the command should take this form:

nohup sh /Desktop/run_test.sh &

To stop the program, first find the process id (PID), assuming here that there is only one instance, otherwise you'll need to differentiate the instances:

$exec_output = array();
$actual_pid = 0;
exec("pgrep -fl /Desktop/run_test.sh", $exec_output);
if ($exec_output and preg_match('/^(\d+) .*$/', $exec_output[0], $match)) {
    $actual_pid = $match[1];
}

Then issue a kill command

if ($actual_pid != 0) exec("kill -9 $actual_pid");