In this particular case why is cat /tmp/com.txt | awk '{ print substr($1, 1, length($1) -5) }' | uniq > domains.txt preferable to: awk '{ print subst

In this particular case why is cat /tmp/com.txt | awk '{ print substr($1, 1, length($1) -5) }' | uniq > domains.txt preferable to: awk '{ print substr($1, 1, length($1) -5) }' /tmp/com.txt | uniq > domains.txt