title: How to bring a background program to foreground
body: <p>I am working on CentOS6, and running a django server for my development on a tmux session as：</p>
  
  <p><strong>python manage.py runserver 0.0.0.0:8000</strong></p>
  
  <p>So I can read my debug string print on it.</p>
  
  <p>While there is an unknown reason which made my tmux session lost, and I cannot to bak to my working session using "tmux attach" command.</p>
  
  <p>I still can find my server is running by ps command, but I have no permission to kill this in order to run a new server on the same port.</p>
  
  <p>So, I want to call this backgound server to frontgound again.</p>
  
  <p>As I never use ctrl+z or other ways to take process background, so even I use jobs command, there are no jobs.</p>
  
  <p>But I dont know if I can do this, and how to do this...</p>
  
  <p>Thanks all！！</p>