this post was submitted on 01 Oct 2024
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Hi,

I would like to display the new lines of /var/log/messages that contain either IN_MyText or OUT_MyText (no matter where in the line)

I've tried

tail -fn 3 /var/log/messages | grep --color --line-buffered -e "(IN|OUT)_MyText"

But the output stay blank, when it should not...

Any ideas ?

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[–] CosmicGiraffe@lemmy.world 4 points 1 month ago

It's marked solved, but since OP didn't post the solution:

-e uses basic regular expressions, where you need to escape the meta-characters ((|)) with a backslash. Alternatively, use extended regex with -E

$ echo a | grep -E "(a|b)"
a
$ echo a | grep -e "\(a\|b\)"
a
$ echo a | grep -e "(a|b)"
$ echo a | grep -E "\(a\|b\)"