getversion

#!/bin/sh

# Generate a version string for use when building.
#
# * If RELEASE exists, and is non-empty, use the contents of that file.
#   This is in case we're building from a tarball.
#
# * If we're inside a git tree:
#   - For the "master" branch, use "git describe".
#   - For "detached" branches (mostly for tag checkouts), also use "git describe".
#   - For other branches, use a "$VERSION-$NBCOMMITS-$BRANCH-$DATE-g$COMMIT"
#     sortof version.
#
# * Try to make it up from the directory name (munin-2.0.1 -> 2.0.1)
#
# * If we're still looking for a version, just fallback to "unknown".

current_git_branch() {
    GB="$(git branch | awk '$1 == "*" {print $2}')"
    case $GB in

	# git checkout 402c6d6
	# git branch
	# * (detached from 402c6d6)
	#   devel
	# --> This is new with git 1.8+
	"(detached" ) echo "detached";;

	# git checkout 2.0.9
	# git branch
	# * (no branch)
	#   devel
	"(no" ) echo;;

	*     ) echo $GB;;
    esac
}

generate_version_string() {
    branch="$(current_git_branch)"
    case "${branch}" in
        ""|master|devel|stable-*)
            git describe
            ;;
        *)
            # "foo | read VAR" does *not* work
            # workaround stolen from http://www.etalabs.net/sh_tricks.html
            read VERSION COMMITS HASH <<EOF
$(git describe --long | perl -lne 'print "$1 $2 $3" if m/(.*)-(\d+)-g(\w+)/')
EOF
            # As git describe, we also use the "-g" magic string to denote a git hash
            git log -n 1 --pretty="${VERSION}-${branch}-%ad-c${COMMITS}-g%h" --date=short
            ;;
    esac
}

generate_version_string_from_dir() {
	basename $(pwd) | grep -e '^munin-' | cut -c7-
}

if [ -s "RELEASE" ]; then
    cat RELEASE
elif [ "$(git rev-parse --is-inside-work-tree 2>/dev/null)" = "true" ]; then
    generate_version_string
elif [ ! -z "$(generate_version_string_from_dir)" ]; then
	generate_version_string_from_dir
else
    echo "unknown"
fi