inanzzz | Terminating running commands or processes properly with ctrl+c and kill command

In example below, we are going to use pcntl_signal function to let our command finish its job first and then exit. It is useful for preventing unexpected terminations which originate from ctrl+c action and kill PID command. We'll be using a symfony command as an example.

Command

I will just print a message but you could use it for closing database connection, saving data, closing files, writing to a log file etc.

namespace AppBundle\Command;

use Symfony\Component\Console\Command\Command;
use Symfony\Component\Console\Input\InputInterface;
use Symfony\Component\Console\Output\OutputInterface;

class HelloCommand extends Command
{
    /** @var OutputInterface */
    private $output;

    protected function configure()
    {
        $this->setName('hello');
    }

    protected function execute(InputInterface $input, OutputInterface $output)
    {
        $this->output = $output;

        declare(ticks = 1);

        pcntl_signal(SIGINT, [$this, 'doInterrupt']);
        pcntl_signal(SIGTERM, [$this, 'doTerminate']);

        while (true) {
            $output->writeln('Hello '.date('s'));

            sleep(1);
        }
    }

    /**
     * Ctrl-C
     */
    private function doInterrupt()
    {
        $this->output->writeln('Interruption signal received.');

        exit;
    }

    /**
     * kill PID
     */
    private function doTerminate()
    {
        $this->output->writeln('Termination signal received.');

        exit;
    }
}

kill PID test

$ bin/console hello
Hello 36
Hello 37
Hello 38
Hello 39
Termination signal received.

CTRL+C test

$ bin/console hello
Hello 17
Hello 18
Hello 19
^C
Interruption signal received.