systemd/shell-completion/bash/systemd-cgls

# systemd-cgls(1) completion                  -*- shell-script -*-
# SPDX-License-Identifier: LGPL-2.1+
#
# This file is part of systemd.
#
# systemd is free software; you can redistribute it and/or modify it
# under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation; either version 2.1 of the License, or
# (at your option) any later version.
#
# systemd 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 Lesser General Public License
# along with systemd; If not, see <http://www.gnu.org/licenses/>.

__contains_word() {
    local w word=$1; shift
    for w in "$@"; do
        [[ $w = "$word" ]] && return
    done
}

__get_machines() {
    local a b
    machinectl list --no-legend --no-pager | { while read a b; do echo " $a"; done; };
}

__get_units_have_cgroup() {
    systemctl $1 list-units | {
        while read -r a b c d; do
            [[ $c == "active" && ${a##*.} =~ (service|socket|mount|swap|slice|scope) ]] && echo " $a"
        done
    };
}

_systemd_cgls() {
    local cur=${COMP_WORDS[COMP_CWORD]} prev=${COMP_WORDS[COMP_CWORD-1]}
    local i verb comps

    local -A OPTS=(
        [STANDALONE]='-h --help --version --all -l --full -k --no-pager'
        [ARG]='-M --machine -u --unit --user-unit'
    )

    _init_completion || return

    if __contains_word "$prev" ${OPTS[ARG]}; then
        case $prev in
            --machine|-M)
                comps=$( __get_machines )
                ;;
            --unit|-u)
                comps=$( __get_units_have_cgroup --system )
                ;;
            --user-unit)
                comps=$( __get_units_have_cgroup --user )
                ;;
        esac
        COMPREPLY=( $(compgen -W '$comps' -- "$cur") )
        return 0
    fi

    COMPREPLY=( $(compgen -W '${OPTS[*]}' -- "$cur") )
}

complete -F _systemd_cgls systemd-cgls