Delete every 3rd and 5th line except 15th line with Stream EDitor

Question

I need to delete every 3rd and 5th line except the 15th line in a text file using sed. Has someone an idea?

Birei · Answer 1 · 2012-02-14 15:25:53Z

up vote 2 down vote

Try next command. You will need the GNU version of sed:

sed '15 b ; 0~3 d ; 0~5 d' infile

First check if line is 15th: print and read next one. Otherwise, delete every 3rd line and every 5th line starting with first one.

answered Feb 14 '12 at 15:25

Birei
43625

kev · Answer 2 · 2012-02-14 16:03:39Z

up vote 2 down vote

It's much easy if you use awk:

$ awk '(NR%3 && NR%5) || NR==15' input.txt

edited Feb 14 '12 at 16:03

answered Feb 14 '12 at 15:26

kev
2,339619

	I think it should be (NR!=15), OQ said except 15th, not except every 15th. – Rich Homolka Feb 14 '12 at 16:01
	@RichHomolka Thanks. Fixed – kev Feb 14 '12 at 16:04

2 Answers