kill_process.sh

#!/bin/bash
# kill-process.sh

NOPROCESS=2

process=xxxyyyzzz  # Use nonexistent process.
# For demo purposes only...
# ... don't want to actually kill any actual process with this script.
#
# If, for example, you wanted to use this script to logoff the Internet,
#     process=pppd

t=`pidof $process`       # Find pid (process id) of $process.
# The pid is needed by 'kill' (can't 'kill' by program name).

if [ -z "$t" ]           # If process not present, 'pidof' returns null.
then
  echo "Process $process was not running."
  echo "Nothing killed."
  exit $NOPROCESS
fi  

kill $t                  # May need 'kill -9' for stubborn process.

# Need a check here to see if process allowed itself to be killed.
# Perhaps another " t=`pidof $process` " or ...


# This entire script could be replaced by
#        kill $(pidof -x process_name)
# or
#        killall process_name
# but it would not be as instructive.

exit 0