sabnzb

#!/bin/bash

/usr/bin/screen -m -d /usr/bin/nice -n 20 /opt/SABnzbd-0.5.2-osx-src/SABnzbd.py -b 0

screen -r 
attaches to the running screen

<CTRL>-a d 
detaches the running screen again.

#!/bin/bash
active=$(/bin/ps aux | grep -v grep | grep SABnzbd.py)
if [ "$active" = "" ]
then
/usr/bin/screen -m -d /usr/bin/nice -n 20 ~/opt/SABnzbd-0.5.0-osx-src/SABnzbd.py -b 0
fi