dpkg/get-version

#!/bin/sh
#
# get-version
#
# Copyright © 2009, 2013-2014 Guillem Jover <guillem@debian.org>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <https://www.gnu.org/licenses/>.
#

if [ -f .dist-version ]; then
  # Get the version from the file distributed in the tarball.
  version=$(cat .dist-version)
elif [ -d .git ]; then
  # Get the version from the git repository. Since tags cannot contain colons
  # or tildes, we use percent and underscore instead. Reverse that switch here.
  version=$(git describe --abbrev=4 HEAD 2>/dev/null | tr %_ :~)

  # 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 [ -z $version ]; then
    version="1.18.23"
  fi
  if [ -n "$dirty" ]; then
    version="$version-dirty"
  fi
else
  echo "error: cannot get project version." 1>&2
  exit 1
fi
# Use printf to avoid the trailing new line that m4_esyscmd would not handle.
printf "$version"