PhpBrew\Process::run PHP Method

    public function run($callback = null)
    {
        $this->stdout = '';
        $this->stderr = '';
        $that = $this;
        $out = self::OUT;
        $err = self::ERR;
        $callback = function ($type, $data) use($that, $callback, $out, $err) {
            if ($out == $type) {
                $that->addOutput($data);
            } else {
                $that->addErrorOutput($data);
            }
            if (null !== $callback) {
                call_user_func($callback, $type, $data);
            }
        };
        $descriptors = array(array('pipe', 'r'), array('pipe', 'w'), array('pipe', 'w'));
        $process = proc_open($this->commandline, $descriptors, $pipes, $this->cwd, $this->env, $this->options);
        if (!is_resource($process)) {
            throw new \RuntimeException('Unable to launch a new process.');
        }
        foreach ($pipes as $pipe) {
            stream_set_blocking($pipe, false);
        }
        $stdinLen = 0;
        $stdinOffset = 0;
        if (null === $this->stdin) {
            fclose($pipes[0]);
            $writePipes = null;
        } else {
            $writePipes = array($pipes[0]);
            $stdinLen = strlen($this->stdin);
        }
        unset($pipes[0]);
        while ($pipes || $writePipes) {
            $r = $pipes;
            $w = $writePipes;
            $e = null;
            $n = @stream_select($r, $w, $e, $this->timeout);
            if (false === $n) {
                break;
            } elseif ($n === 0) {
                proc_terminate($process);
                throw new \RuntimeException('The process timed out.');
            }
            if ($w) {
                $written = fwrite($writePipes[0], (string) substr($this->stdin, $stdinOffset), 8192);
                if (false !== $written) {
                    $stdinOffset += $written;
                }
                if ($stdinOffset >= $stdinLen) {
                    fclose($writePipes[0]);
                    $writePipes = null;
                }
            }
            foreach ($r as $pipe) {
                $type = array_search($pipe, $pipes);
                $data = fread($pipe, 8192);
                if (strlen($data) > 0) {
                    call_user_func($callback, $type == 1 ? $out : $err, $data);
                }
                if (false === $data || feof($pipe)) {
                    fclose($pipe);
                    unset($pipes[$type]);
                }
            }
        }
        $this->status = proc_get_status($process);
        $time = 0;
        while (1 == $this->status['running'] && $time < 1000000) {
            $time += 1000;
            usleep(1000);
            $this->status = proc_get_status($process);
        }
        $exitCode = proc_close($process);
        if ($this->status['signaled']) {
            throw new \RuntimeException(sprintf('The process stopped because of a "%s" signal.', $this->status['stopsig']));
        }
        //The exit code returned by the process (which is only meaningful if
        //running is FALSE). Only first call of this function return real
        //value, next calls return -1.
        return $this->exitcode = $this->status['running'] ? $exitCode : $this->status['exitcode'];
    }

 protected function detectProcessorNumberByGrep()
 {
     if (Utils::findBin('grep') && file_exists('/proc/cpuinfo')) {
         $process = new Process('grep -c ^processor /proc/cpuinfo 2>/dev/null');
         $process->run();
         $this->processorNumber = intval($process->getOutput());
         return $this->processorNumber;
     }
     return null;
 }