One to read: “SKIP grep, use AWK” / ”Awk Tutorial, part {1,2,3,4}”

Do you use this pattern in your sh/bash/zsh/etc-sh scripts?

cat somefile | grep 'some string' | awk '{print $2}'

If so, you can replace that as follows:

cat somefile | awk '/some string/ {print $2}'

Or how about this?

grep -v 'something' < somefile | awk '{print $0}'

Try this:

awk '! /something/ {print $0}' < somefile

Ooo OK, how about if you want to get all actions performed by users when the ISO formatted dates (Y-m-d) match the first day of the month, but where you don’t want to also match January (unless you’re talking about the first of January)…

# echo 'BLOGGSF 2001-01-23 SOME_ACTION' | awk '$2 ~ /-01$/ {print $1, $3}'
(EMPTY LINE)
# echo 'BLOGGSF 2002-02-01 SOME_ACTION' | awk '$2 ~ /-01$/ {print $1, $3}'
BLOGGSF SOME_ACTION

This is so cool! Thanks to the tutorials “SKIP grep, use AWK” and the follow-up tutorials starting here…

JonTheNiceGuy

He/Him. Husband and father. Linux advocating geek. Co-Host on the AdminAdmin Podcast, occasional conference speaker.

One thought to “One to read: “SKIP grep, use AWK” / ”Awk Tutorial, part {1,2,3,4}””

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.

To respond on your own website, enter the URL of your response which should contain a link to this post's permalink URL. Your response will then appear (possibly after moderation) on this page. Want to update or remove your response? Update or delete your post and re-enter your post's URL again. (Find out more about Webmentions.)