Kill all Apache processes

# ps -ef - disaply all processes
# grep apache2 - find the rows with apache
# grep -v grep - remove rows with the word grep
# awk '{print $2}' - get the second column of the previous output

# kill -9 $(..) - execute kill -9 on all the values returned from the previous pipes

kill -9 $(ps -ef |grep apache2 |grep -v grep| awk '{print $2}')