sed: Repeat pattern in replace section

Question

I want to replace a normal PATERN1 by a repeating pattern (PATERN2), in my case repeating 'N' 500 times.

Is it possible to do it simply with sed?

sed 's/PATERN1/N{500times}/g'

Cheers,

Ricardo

Possible duplicate of https://stackoverflow.com/questions/15072875/insert-with-sed-n-repeated-characters — Corentin Limier, Dec 06 '18 at 14:27
Thank you, I hadn't found that before! I don't understand if it's possible with sed, but there is a similar solution there with perl: perl -pe 's/PATERN1/"N"x500 . ""/e' — Ricardo Guerreiro, Dec 06 '18 at 14:53

score 2 · Accepted Answer · answered Dec 06 '18 at 14:58

2

Using sed you can do this:

s="foo abc PATTERN foo bar PATTERN"

sed "s/PATT[^[:blank:]]*/$(printf '%.0bN' {1..10})/g" <<< "$s"

foo abc NNNNNNNNNN foo bar NNNNNNNNNN

Here printf '%.0bN' {1..10} will return a string of N repeated 10 times.

answered Dec 06 '18 at 14:58

anubhava

This is just a copy/paste of one of the solution provided by @GillesQuenot on the "original" question. – Corentin Limier Dec 06 '18 at 15:43
1

Just for reference I learnt `printf` trick from [this 7+ years old answer](https://stackoverflow.com/a/5349842/548225) – anubhava Dec 06 '18 at 15:46

1 Answers1