Awk
From Hackepedia
Jump to navigationJump to searchIt's usually a better idea to use one command instead of using a pipe to another command, where possible. A common mistake I used to make:
# grep root /etc/passwd | awk -F: '{print $7}' /bin/bash
which I was taught can be easily done all in awk:
# awk -F: '/root/ {print $7}' /etc/passwd /bin/bash
I wanted to find out how much resident memory xfce4 was using on my system, and it appears most xfce applications start with "xf":
$ ps auwx | awk '/xf/{print $5}' 15924 14668 11948 11764 12944 16264 1860
I wanted to use awk to add the results together instead of doing it manually:
$ ps auwx | awk '/xf/{ tot += $5 } END { print tot }' 69108
N.B. This can be misleading in the case of programs that use large amounts of shared memory (like java).