title: bash script that monitor a disk partition's usage
body: <p>df shows</p>
  
  <pre>
  -bash-4.1# df
  Filesystem           1K-blocks      Used Available Use% Mounted on
  /dev/sda3            1918217320 1783986384  36791092  98% /
  tmpfs                 16417312         0  16417312   0% /dev/shm
  /dev/sda1               482214    148531    308784  33% /boot
  /dev/sdb1            1922858352 1373513440 451669312  76% /disk2
  </pre>
  
  <p>I need to bash script a function that returns 1 if an paritions become 100% full.
  how can this be done?  what commands can I use to parse out the output of df?</p>