How do I remove a line that does not contain a specific character?

Question

For example, I want do remove all lines in a textile that do not contain the character '@'

I have already tried to use sed like so

sed '/@/!d' data.txt

What am I missing? Shouldn't this work?

I guess you missed the `-i`: `sed -i '' '/@/!d' data.txt` – Wiktor Stribiżew May 07 '20 at 14:38 — Wiktor Stribiżew, May 07 '20 at 14:38
Thanks a bunch! works perfectly. – SenorPantalones May 07 '20 at 14:40 — SenorPantalones, May 07 '20 at 14:40
I don't think the [tag:bash] tag is relevant, or is it? – Ted Lyngmo May 07 '20 at 14:53 — Ted Lyngmo, May 07 '20 at 14:53

score 1 · Answer 1 · answered May 07 '20 at 15:56

1

I prefer using ed over the non-standard sed -i, especially if it needs to be portable:

printf "%s\n" "v/@/d" w | ed -s filename

This deletes every line that doesn't contain a @, and saves the changed file back to disc.

answered May 07 '20 at 15:56

Shawn

score 0 · Answer 2 · answered May 07 '20 at 14:49

0

sed -n '/@/p' [file]

Add -i for in-place editing of the file (if supplied).

answered May 07 '20 at 14:49

Ted Lyngmo

2 Answers2