sudodir.bash

#!/bin/bash

# ----------------------------------------------------------------------

# sudodir
#
# Executes command as owner of current directory.
#
# It also calls xhost to give owner access to X if user allows it.
#
# Usage: sudodir[.bash] command arg ...
#
# This script requires GNU stat and optionally xhost.
#
# Copyright (c) 2022 konsolebox
#
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# “Software”), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
# IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
# CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
# TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
# SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

# ----------------------------------------------------------------------

set -f

function die {
	printf '%s\n' "$1" >&2
	exit "${2-1}"
}

function main {
	local cmd=("$@") owner uid gid uname
	owner=$(stat -c '%u %g %U' .) || die "Failed to get owner."
	set -- ${owner}
	uid=$1 gid=$2 uname=$3

	if [[ ${uid} && uid -ne EUID ]]; then
		if [[ ${DISPLAY} ]] && type -P xhost >/dev/null && \
				[[ $(xhost) != *localuser:${uname}[[:space:]]* ]]; then
			read -p "Allow localuser:${uname} to access X? "
			[[ ${REPLY} == [yY] || ${REPLY} == [yY][eE][sS] ]] && xhost "+SI:localuser:${uname}"
		fi

		exec sudo -EHu "#${uid}" -g "#${gid}" "${cmd[@]}"
	fi
}

main "$@"