phlib/console-process

Console signal implementation using PHPs Process control functions.

There are 2 implementations.

1. Background command. Allows a process to be interrupted using the signal handler.
2. Daemon command. Builds on the Background command to allow forking (detaching) the process.

Install

Via Composer

$ composer require phlib/console-process

Background Command

Basic Usage

The Background Command works in the same way as you're used to with the normal Symfony Command.

<?php

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

class MyProcessCommand extends BackgroundCommand
{
    protected function configure()
    {
        $this->setName('my:process')
            ->setDescription('My background process.');
    }

    protected function execute(InputInterface $input, OutputInterface $output)
    {
        $output->writeln('Doing important work!');
    }
}

Lifecycle Methods

The background command has one additional method, to the standard Symfony command methods, which gets called when the process finishes. The method is onShutdown which takes a InputInterface and an OutputInterface. This can be used for any final cleanup for example.

class MyProcessCommand extends BackgroundCommand
{
    // ...
    
    protected function onShutdown(InputInterface $input, OutputInterface $output)
    {
        $output->writeln('onShutdown method called.');
    }
}

Daemon Command

Basic Usage

Apart from extending a different class, the Daemon Command looks and works in a similar way to the Background Command. The PID file argument is optional. If it is not specified the process generates it's own PID file based on the command name.

<?php

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

class MyProcessCommand extends DaemonCommand
{
    protected function configure()
    {
        $this->setName('my:process')
            ->setDescription('My background process.');
    }

    protected function execute(InputInterface $input, OutputInterface $output)
    {
        $output->writeln('Doing important work!');
    }
}

Output

Once a daemon process is detached, the original output is also lost. The daemon command class provides a protected method to specify a new output. If this method isn't overriden, then by default, the output is a NullOutput Symfony object. The following example demonstrates overriding the method.

use Symfony\Component\Console\Output\StreamOutput;

class MyProcessCommand extends DaemonCommand
{
    // ... 
    
    protected function createChildOutput()
    {
        return new StreamOutput(fopen(getcwd() . '/my-daemon.log', 'a'));
    }
}

Lifecycle Methods

The daemon command has additional methods, to the standard Symfony command methods and the background command, which gets called during the process lifecycle. The following example demonstrates overriding the methods.

class MyProcessCommand extends DaemonCommand
{
    // ...

    protected function onBeforeDaemonize(InputInterface $input, OutputInterface $output)
    {
        $output->writeln('onBeforeDaemonize method called.');
    }

    protected function onAfterDaemonizeChild(InputInterface $input, OutputInterface $output)
    {
        $output->writeln('onAfterDaemonizeChild method called.');
    }

    protected function onAfterDaemonizeParent(InputInterface $input, OutputInterface $output)
    {
        $output->writeln('onAfterDaemonizeParent method called.');
    }
}

Command Line

# path/to/my/process start -d

# path/to/my/process status

# path/to/my/process stop

Options

Name	Short	Type	Required	Default	Description
action		Argument	yes		start, stop, status
daemonize	d	Option	no	no	Detaches the process
pid-file	p	Option	no	auto	Name of the PID file to use. Not used if daemonize is not set.

License

This package is free software: you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with this program. If not, see http://www.gnu.org/licenses/.