#!/bin/sh
#
# Copyright (c) 2016 Baptiste Daroussin
# All rights reserved.
#
# 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.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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.
#
# $FreeBSD$
set -e
rc=0
quiet=0
A_flag=0
E_flag=0
e_flag=0
labelcount=0
usage() {
echo "$0: usage $0 [-AEpq] [-L label [ -L label [-L label]]] file1 file2 file3" >&2
}
clean_tmp() {
if [ "${output}" != "/dev/stdout" ]; then
rm -f "${output}"
fi
}
while getopts 'AEeL:pq' opt; do
case "${opt}" in
A) A_flag=1 ;;
E) E_flag=1 ;;
L)
labelcount=$(( labelcount + 1))
if [ ${labelcount} -gt 3 ]; then
echo "$0: too many -L options" >&2
echo "$0 aborted" >&2
exit 2
fi
labels="${labels} -L ${OPTARG}"
;;
p) output=/dev/stdout ;;
q) quiet=1 ;;
*)
usage
exit 2
;;
esac
done
shift $(( ${OPTIND} -1 ))
case "${A_flag}${E_flag}" in
11)
echo "$0: -A and -E are incompatible" >&2
exit 2
;;
10)
diff3_args="-A"
;;
01)
diff3_args="-E"
;;
00)
diff3_args="-E"
;;
esac
if [ $# -ne 3 ]; then
echo "$0: not enough arguments" >&2
usage
exit 2
fi
trap clean_tmp EXIT
if [ -z "${output}" ]; then
output=$(mktemp -t merge)
fi
diff3 ${diff3_args} -m ${labels} "$1" "$2" "$3" >"${output}" || rc=$?
if [ "${output}" != "/dev/stdout" ]; then
if [ -w "$1" ]; then
mv -f "${output}" "$1"
else
echo "$0: $1 permission denied" >&2
fi
fi
if [ ${rc} -eq 1 ]; then
if [ ${quiet} -eq 0 ]; then
echo "$0: warning: conflict during merge" >&2
fi
exit 1
fi
exit 0