Send signal to a process with PHP https://youtu.be/H2lp_jcfmu0

command.php

#!/usr/bin/env php
<?php

define('PID_PATH', '/tmp/myapp.pid');

define ('PID', (int) file_get_contents(PID_PATH));

if (empty($argv[1])) {
    echo <<<INFO

Usage:
    ${$argv[0]} [status|restart|stop]

INFO;
exit;
}

$command = $argv[1];

if ($command === 'status') {
    posix_kill(PID, SIGUSR1);
}

if ($command === 'restart') {
    posix_kill(PID, SIGCONT);
}

if ($command === 'stop') {
    posix_kill(PID, SIGTERM);
}

daemon.php

#!/usr/bin/env php
<?php

declare(ticks = 1);

define('PID_PATH', '/tmp/myapp.pid');

register_shutdown_function(function () {
    // Will run when shutdown.
    echo 'Deleting temporary file...' . PHP_EOL;
    unlink(PID_PATH);
    echo 'Done.' . PHP_EOL;
});

pcntl_signal(SIGUSR1, function () {
    // Do something when catch "info" signal.
    echo 'Show information about this process.' . PHP_EOL;
});

pcntl_signal(SIGCONT, function () {
    // Do something when catch "continue/restart" signal.
    echo 'Restart...'. PHP_EOL;
});

pcntl_signal(SIGTERM, function () {
    // Do something when catch "terminate" signal.
    die('Catch terminate signal. Exiting process...' . PHP_EOL);
});

echo 'Run with PID ' . posix_getpid() . PHP_EOL;

$fp = fopen(PID_PATH, 'w');
fwrite($fp, posix_getpid());
fclose($fp);

while (true) {
    // Do something inside event-loop
    sleep(1);
}