#!/bin/bash
# I, Ian Kelling, follow the GNU license recommendations at
# https://www.gnu.org/licenses/license-recommendations.en.html. They
# recommend that small programs, < 300 lines, be licensed under the
# Apache License 2.0. This file contains or is part of one or more small
# programs. If a small program grows beyond 300 lines, I plan to switch
# its license to GPL.

# Copyright 2024 Ian Kelling

# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at

#     http://www.apache.org/licenses/LICENSE-2.0

# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.


case $1 in
  -h|--help)
    cat <<'EOF'
usage: failmail CMD [ARGS...]

Send mail in case of failure of CMD

Emails to $MAILTO or if unset, $USER@localhost
EOF
    exit 0
    ;;
esac

mailto=$USER@localhost
if [[ $MAILTO ]]; then
  mailto=$MAILTO
fi

t=$(mktemp)
code=0
"$@" &>"$t" || code=$?
if (( code )); then
  mail -s "$HOSTNAME: code: $code cmd: $*" $mailto <"$t"
  rm "$t"
fi
exit 0