processhelper.rst

Process Helper

The Process Helper shows processes as they're running and reports useful information about process status.

To display process details, use the :class:`Symfony\\Component\\Console\\Helper\\ProcessHelper` and run your command with verbosity. For example, running the following code with a very verbose verbosity (e.g. -vv):

use Symfony\Component\Process\Process;

$helper = $this->getHelper('process');
$process = new Process(['figlet', 'Symfony']);

$helper->run($output, $process);

will result in this output:

It will result in more detailed output with debug verbosity (e.g. -vvv):

In case the process fails, debugging is easier:

Note

By default, the process helper uses the error output (stderr) as its default output. This behavior can be changed by passing an instance of :class:`Symfony\\Component\\Console\\Output\\StreamOutput` to the :method:`Symfony\\Component\\Console\\Helper\\ProcessHelper::run` method.

Arguments

There are three ways to use the process helper:

• Using a command line string:

  // ...
  $helper->run($output, 'figlet Symfony');
  

• An array of arguments:

  // ...
  $helper->run($output, ['figlet', 'Symfony']);
  

  Note

  When running the helper against an array of arguments, be aware that these will be automatically escaped.

• Passing a :class:`Symfony\\Component\\Process\\Process` instance:

  use Symfony\Component\Process\Process;
  
  // ...
  $process = new Process(['figlet', 'Symfony']);
  
  $helper->run($output, $process);
  

Customized Display

You can display a customized error message using the third argument of the :method:`Symfony\\Component\\Console\\Helper\\ProcessHelper::run` method:

$helper->run($output, $process, 'The process failed :(');

A custom process callback can be passed as the fourth argument. Refer to the :doc:`Process Component </components/process>` for callback documentation:

use Symfony\Component\Process\Process;

$helper->run($output, $process, 'The process failed :(', function (string $type, string $data): void {
    if (Process::ERR === $type) {
        // ... do something with the stderr output
    } else {
        // ... do something with the stdout
    }
});