PhpBrew\Command\UseCommand::execute PHP Method

    public function execute($buildName)
    {
        if (!$buildName) {
            // This exception is used for tracing tests
            throw new Exception('build name is required.');
        }
        // this block is important for tests only
        $root = Config::getRoot();
        $home = Config::getHome();
        if (!file_exists("{$root}/php/{$buildName}")) {
            throw new Exception("build {$buildName} doesn't exist.");
        }
        putenv("PHPBREW_ROOT={$root}");
        putenv("PHPBREW_HOME={$home}");
        putenv("PHPBREW_PHP={$buildName}") or die('putenv failed');
        putenv("PHPBREW_PATH={$root}/php/{$buildName}/bin");
        putenv("PHPBREW_BIN={$home}/bin");
        if (!getenv('TRAVIS')) {
            $this->logger->warning("You should not see this, if you see this, it means you didn't load the ~/.phpbrew/bashrc script, please check if bashrc is sourced in your shell.");
        }
    }