original_string: public function doProcess(){
          $command = 'nohup '.$this->command.' > /dev/null 2>&1 & echo $!';
          exec($command ,$pross);
          $this->pid = (int)$pross[0];
      }
code: public function doProcess(){
          $command = 'nohup '.$this->command.' > /dev/null 2>&1 & echo $!';
          exec($command ,$pross);
          $this->pid = (int)$pross[0];
      }
code_tokens: public function doProcess ( ) { $ command = 'nohup ' . $ this -> command . ' > /dev/null 2>&1 & echo $!' ; exec ( $ command , $ pross ) ; $ this -> pid = ( int ) $ pross [ 0 ] ; }
docstring: do the process in background
docstring_tokens: do the process in background