catsit/catsit.sh

#!/bin/sh
set -eu

die() {
	echo "${0}:" "$@" >&2
	exit 1
}

: ${CATSITD_PIPE:=/var/run/catsitd.pipe}

while getopts 'c:' opt; do
	case "${opt}" in
		(c) CATSITD_PIPE=$OPTARG;;
		(?) exit 1;;
	esac
done
shift $((OPTIND - 1))

if ! [ -p "${CATSITD_PIPE}" ]; then
	die "${CATSITD_PIPE} is not a named pipe"
fi
if ! [ -w "${CATSITD_PIPE}" ]; then
	die "${CATSITD_PIPE} is not writable"
fi

[ $# -lt 1 ] && die 'action required'
[ $# -lt 2 ] && die 'service name required'

action=$(echo "${1}" | tr 'A-Z' 'a-z')
for valid in start stop restart status $(kill -l | tr 'A-Z' 'a-z'); do
	[ "${action}" = "${valid}" ] && break
done
if [ "${action}" != "${valid}" ]; then
	die "${action} is not a valid action or signal"
fi

echo "$@" > "${CATSITD_PIPE}"