shell: get version automatically

Try something like here:
cd34.com/blog/programming/using-git-to-generate-an-automatic-version-number

#!/bin/sh
revisioncount="$(git log --oneline | wc -l  | tr -d ' ')"
projectversion="$(git describe --tags --long)"
cleanversion=${projectversion%%-*}
echo "obs version $cleanversion.$revisioncount"

Result: obs version 1.1.15.163