A bit of sed and awk magic

The task is to find the total cpu utilization of httpd processes.
Instead of doing all kinds of acrobatics with grep,bc and bash loops , one can simply use awk.

$ps aux | awk '/httpd/{s+=$3}END{print s}'


One a side note , gnu sed can change a file in-place .This is done by using the "i" option.

$sed -i 's/fun/bun/' test.txt