title: How to run a system command in Qt?
body: <p>I have to run a system command in Qt. 
  but I have to give an argument for that command.</p>
  
  <p>for example opening gedit with a text file.
  like "gedit /home/oDx/Documents/a.txt"</p>
  
  <p>but the path "/home/oDx/Documents/a.txt" will be in a variable like "docPath".
  so how can i do it!?</p>