git - How to extract particular groups in a shell script?

Question

I am trying to extract project name and the version from the git tag information. An example tag looks like this: atlantis/v12. We need to seperate out the first group as project name, ie. atlantis and second as version ie. v12.

Trying to do this git describe --tag | grep -P (.*).*(v[0-9]*)| awk {1} results in zsh: unknown file attribute: v, and with bash syntax error near unexpected token ('`. I need help understanding what could i be doing wrong?

question from:https://stackoverflow.com/questions/65952376/how-to-extract-particular-groups-in-a-shell-script

Answer 1

You forgot to quote the argument of -P in grep, and zsh considers it its duty to attempt filename expansion on them. You have to write it as

grep -P '(.*).*(v[0-9]*)'

Aside from this, your regexp says: Match zero or more characters of anything, followed by zero or more characters of anything, followed by zero or more of those strings which consist of a v with zero or more digits added. Hence your regexp would match any line in the input.