### note '{ print }' '{ print $0 }' '1' all are same ###
awk '{ print }' /path/to/file
awk '{}1' /path/to/file
awk '1' /path/to/file
awk '{ print $0 }' /path/to/file
awk '{}1' /etc/passwd
awk '{print $0}' /etc/hosts
awk '{print}' /etc/hosts