#!/bin/sh
# -*- mode: shell-script; coding: utf-8 -*-
#
# addtogroup
#
# Script to add a user to a group if he is not a member yet.
#
# Copyright (C) 2008-2010 Elmar Hoffmann
#
# 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, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
#

set -e

if [ $# -ne 2 ]; then
    echo "Usage: $(basename "$0") USER GROUP"
    exit 2
fi

user="$1"
group="$2"

if ! getent passwd "${user}" > /dev/null; then
    echo "Warning: User '${user}' does not exist!" >&2
    exit 0
fi
if ! getent group "${group}" > /dev/null; then
    echo "Warning: Group '${group}' does not exist!" >&2
    exit 0
fi

if ! getent group "${group}" \
    | sed --expression='s/^\([^:]*:\)\{3\}//;s/,/\n/g' \
    | grep --quiet "^${user}\$"; then
    adduser "${user}" "${group}"
fi
