luos/features/bootstrap/FeatureContext.php

<?php

use Behat\Behat\Context\ClosuredContextInterface,
Behat\Behat\Context\TranslatedContextInterface,
Behat\Behat\Context\BehatContext,
Behat\Behat\Exception\PendingException;
use Behat\Gherkin\Node\PyStringNode,
Behat\Gherkin\Node\TableNode;

//
// Require 3rd-party libraries here:
//
//   require_once 'PHPUnit/Autoload.php';
//   require_once 'PHPUnit/Framework/Assert/Functions.php';
//
    require_once 'config.php';
/**
 * Features context.
 */
class FeatureContext extends BehatContext
{
    /**
     * Initializes context.
     * Every scenario gets it's own context object.
     *
     * @param array $parameters context parameters (set them up through behat.yml)
     */
    public function __construct(array $parameters)
    {
        // Initialize your context here
        $this->useContext('RestContext', new RestContext($parameters));
    }

    /**
     * @When /^I run "([^"]*)"$/
     */
    public function iRun($command)
    {
        exec($command, $result);
        $this->output = $result;

    }

    /**
     * @Then /^I should see the file "([^"]*)"$/
     */
    public function iShouldSeeTheFile($fileName)
    {
        if (!in_array($fileName, $this->output)) {
            throw new Exception('File named ' . $fileName . ' not found!');
        }

    }


//
// Place your definition and hook methods here:
//
//    /**
//     * @Given /^I have done something with "([^"]*)"$/
//     */
//    public function iHaveDoneSomethingWith($argument)
//    {
//        doSomethingWith($argument);
//    }
//
}