git-commit-vandalism/GIT-VERSION-GEN

#!/bin/sh

GVF=GIT-VERSION-FILE
DEF_VER=v1.1.GIT

# First try git-describe, then see if there is a version file
# (included in release tarballs), then default
VN=$(git-describe --abbrev=4 HEAD 2>/dev/null | sed -e 's/-/./g') ||
VN=$(cat version) ||
VN="$DEF_VER"

VN=$(expr "$VN" : v*'\(.*\)')

dirty=$(sh -c 'git-diff-index --name-only HEAD' 2>/dev/null) || dirty=
case "$dirty" in
'')
	;;
*)
	VN="$VN-dirty" ;;
esac

if test -r $GVF
then
	VC=$(sed -e 's/^GIT_VERSION = //' <$GVF)
else
	VC=unset
fi
test "$VN" = "$VC" || {
	echo >&2 "GIT_VERSION = $VN"
	echo "GIT_VERSION = $VN" >$GVF
}