title: How to debug an execution line
body: <p>I want do debug this line:</p>
  
  <pre><code>exec("mysqldump --add-drop-table -h 127.0.0.1 -u$db_user -p$db_pass $db_name &gt; $db_name.sql");
  </code></pre>
  
  <p>... because this is not working. Is it possible?
  I want to create a script that get all content from several databases and this line is not working, it creates a .sql file but does not save any info. there.</p>