正则表达式Linux / etc / group

Question

I have a problem with a regex: I want to find every group that has the user "usager" in it. Normally in linux, the usernames are situated after the last ":" so here is the regex that I made "[^:]+$". .

What should I do? What could I add to my regex to find "usager"?

Answer 1

This should probably do it. There's probably a better way to do it but at least it introduces you to positive lookahead

^\w*(?=:.*usager)

I used this site to test the regular expression: http://gskinner.com/RegExr/?34598

Answer 2

Maybe:

^([^:]*):.*\busager\b

The parentheses capture the group name; the \\b marks word boundaries, so that :usager, , :usager$ , ,usager, and ,usager$ are all matched (where $ marks the end of the entry). If your regex sub-species doesn't support \\b , then you can use:

^([^:]*):.*[:,]usager(,|$)

instead, or with non-capturing parentheses:

^([^:]*):.*[:,]usager(?:,|$)

Or appropriate variations on these themes for the sub-species of regex that you are using.