get-version

#!/bin/sh
#
# get-version
#
# Copyright © 2009 Guillem Jover <guillem@hadrons.org>
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
# 3. The name of the author may not be used to endorse or promote products
#    derived from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
# INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
# AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
# THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
# EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
# PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
# OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
# WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
# OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
# ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

if [ -f .dist-version ]; then
  # Get the version from the file distributed in the tarball.
  version=$(cat .dist-version)
elif [ -d .git ]; then
  # Ger the version from the git repository.
  version=$(git describe --abbrev=4 HEAD 2>/dev/null)
  if [ -z "$version" ]; then
    version="initial"
  fi

  # Check if we are on a dirty checkout.
  git update-index --refresh -q >/dev/null
  dirty=$(git diff-index --name-only HEAD 2>/dev/null)
  if [ -n "$dirty" ]; then
    version="$version-dirty"
  fi
else
  echo "error: cannot get project version." 1>&2
  exit 1
fi

printf "$version"