[SOLVED] Combining multiple regexs in a sed statement

Issue

I would like to discover the version number of docker-compose. The format differs per version.

Ex: Running docker-compose --version

docker-compose version 1.29.2, build someId
Docker Compose version v2.12.2

I have separate sed statements that grab the version number, but if possible I'd like to combine them.

echo `docker-compose --version` | sed -nr 's|^docker-compose version (.*)(,.*)|\1|p'
echo `docker-compose --version` | sed -nr 's|^Docker compose version v(.*)|\1|p'

If I or the two regexes together using a pipe, the reference needs to change to either \1 or \3 depending where it's caught.

Is there a better way using sed?

Solution

You may use this single sed to grab version number from for both lines shown in question:

sed -E 's/^[dD]ocker[- ][cC]ompose version +v?([^,]+).*/\1/'

1.29.2
2.12.2

Breakdown:

• ^: Start
• [dD]ocker[- ][cC]ompose version: Match starting string with mixed cases letters and hyphen/space separator
• +v?: Match 1+ spaces followed by an optional v
• ([^,]+): Match 1+ of any char that is not comma and capture in group #1
• .*: Match everything till end
• \1: Back-reference to capture group #1

Answered By - anubhava

Answer Checked By - Katrina (WPSolving Volunteer)