need to change the umask value dynamically

Question

Whatever the umask value I want to change it into umask 077 dynamically.

sed -d 's/umask [0-999]/umask 077/g' /etc/bashrc,

I have tried the above one but it's not working.

`[0-999]` doesn’t do what you think it does; it’s the same as `[0-9]` and only matches a *single* digit. — Biffen, Jul 02 '18 at 12:18
Great Biffen, it's working but plese let me know what is the use of {1,\}/\1 — Manikandan, Jul 03 '18 at 02:41
It looks like it was @WiktorStribiżew's solution that worked for you. — Ryszard Czech, Aug 29 '20 at 19:16
Does this answer your question? [Learning Regular Expressions](https://stackoverflow.com/questions/4736/learning-regular-expressions) — Daniel Widdis, Aug 29 '20 at 21:56

score 0 · Answer 1 · answered Aug 29 '20 at 19:18

You can use

sed -i 's/\(umask \)[0-9]\{1,\}/\1 077/g' /etc/bashrc

It means

-i - the /etc/bashrc will be changed inline
\(umask \)[0-9]\{1,\} - the regex pattern that matches
- \(umask \) - Group 1: umask + space
- [0-9]\{1,\} - 1 or more occurrences of any ASCII digit
\1 077 - the contents of Group 1, space, 077
g' - global` modifier, match and replace all non-overlapping occurrences.

1 Answers1