How to Call Other Commands
==========================

If a command depends on another one being run before it, instead of asking the
user to remember the order of execution, you can call it directly yourself.
This is also useful if you want to create a "meta" command that just runs a
bunch of other commands (for instance, all commands that need to be run when
the project's code has changed on the production servers: clearing the cache,
generating Doctrine2 proxies, dumping web assets, ...).

Calling a command from another one is straightforward::

    use Symfony\Component\Console\Input\ArrayInput;
    use Symfony\Component\Console\Input\InputInterface;
    use Symfony\Component\Console\Output\OutputInterface;
    // ...

    protected function execute(InputInterface $input, OutputInterface $output)
    {
        $command = $this->getApplication()->find('demo:greet');

        $arguments = [
            'command' => 'demo:greet',
            'name'    => 'Fabien',
            '--yell'  => true,
        ];

        $greetInput = new ArrayInput($arguments);
        $returnCode = $command->run($greetInput, $output);

        // ...
    }

First, you :method:`Symfony\\Component\\Console\\Application::find` the
command you want to execute by passing the command name. Then, you need to create
a new :class:`Symfony\\Component\\Console\\Input\\ArrayInput` with the arguments
and options you want to pass to the command.

Eventually, calling the ``run()`` method actually executes the command and
returns the returned code from the command (return value from command's
``execute()`` method).

.. tip::

    If you want to suppress the output of the executed command, pass a
    :class:`Symfony\\Component\\Console\\Output\\NullOutput` as the second
    argument to ``$command->run()``.

.. caution::

    Note that all the commands will run in the same process and some of Symfony's
    built-in commands may not work well this way. For instance, the ``cache:clear``
    and ``cache:warmup`` commands change some class definitions, so running
    something after them is likely to break.

.. note::

    Most of the times, calling a command from code that is not executed on the
    command line is not a good idea. The main reason is that the command's
    output is optimized for the console and not to be passed to other commands.