Getting instance name with grep and regex

Question

I have this output in my shell by typing the command foobar:

NAME                                               ZONE            STATUS   ACTION  LAST_ERROR
foobar--docker-worker-yyb55u-4ivg  europe-west1-c  RUNNING  NONE

I want to grep the complete name. Which I try doing like this:

$ foobar | grep -q -P "(foobar--[^\s]+)" but this returns me: foobar--docker-worker-yyb55u-4ivg europe-west1-c RUNNING NONE

Which I don't understand because I tested the regex here: https://regex101.com/r/sX471v/1

Any advice is welcome, thanks!

You seem to neet the `-o` option to only get the match value. Try replacing `-P` with `-oP` — Wiktor Stribiżew, Nov 15 '16 at 13:09

score 1 · Accepted Answer · answered Nov 15 '16 at 13:10

1

grep display the full line where a match occurs by default. Use its -o option to prevent this behaviour and display the match only. You also need to remove the -q "quiet" option which removes all output :

foobar | grep -Po "(foobar--[^\s]+)"

answered Nov 15 '16 at 13:10

Aaron

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Getting instance name with grep and regex

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