gen-version

#!/bin/sh
#vfile="VERSION"

#The first argument of the script is the file we store the version
vfile="${1}"

#Check if we have git and we are actually in a git repository
if git describe > /dev/null 2>&1; then
	# Find the branch name. If it isn't "master" use it in the version
	branch="$(git rev-parse --abbrev-ref HEAD)"
	if [ "${branch}" != "master" ]; then
		# If branch is not named release*
		if [ "${branch#release}" = "${branch}" ]; then
			# Remove 'user/' prefix and replace '/' with '_' if applicable
			version="$(echo ${branch#user/} | tr "/" "_")-"
		fi
	fi
	
	#Call git describe to generate a version string
	#The string consists of:
	# -The "closest" annotated tag
	# -The number of commits since the tag (if there are any)
	# -The abbreviated SHA hash of the last commit (if there have been commits since the tag)
	version="${version}$(git describe --dirty=~)"

	#Check if the version has changed. We don't want to touch the file otherwise
	#If the file doesn't exist or the version it contains is different than the
	#one we just computed overwrite it
	if [ ! -f "${vfile}" ] || [ "$(cat ${vfile})" != "${version}" ]; then
		echo "${version}" > "${vfile}"
	fi
#If we can't use "git describe" to get a version, and the version file does not
#exist echo a warning and write "Unknown" as version
elif [ ! -f "${vfile}" ]; then
	echo "Warning: No git or ${vfile} file found." 1>&2
	echo "Unknown" > "${vfile}"
fi
#In case we can't use "git describe" but the version file exists there is
#nothing to do

#Return the version
#cat $vfile