title: Symfony 2 : Log into a specific file
body: <p>I searched a lot before posting my question. I didn't find a clear answer, so here it is.</p>
  
  <p>I want to log messages in a different log file as dev.log or prod.log. I mean a file which won't be poluted by Symfony core messages. I heard about logger and handler in monolog, but it's not very clear.</p>
  
  <p>How can I log messages from my controllers, model to a specific log file ?</p>