systemd/shell-completion/bash/loginctl

# loginctl(1) completion                                  -*- shell-script -*-
#
# This file is part of systemd.
#
# Copyright 2010 Ran Benita
#
# 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_all_sessions () { loginctl --no-legend list-sessions | { while read -r a b; do printf "%s\n" "$a"; done; } ; }
__get_all_users    () { loginctl --no-legend list-users    | { while read -r a b; do printf "%s\n" "$b"; done; } ; }
__get_all_seats    () { loginctl --no-legend list-seats    | { while read -r a b; do printf "%s\n" "$a"; done; } ; }

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

        local -A OPTS=(
               [STANDALONE]='--all -a --help -h --no-pager --privileged -P --version
                             --no-legend --no-ask-password -l --full'
                      [ARG]='--host -H --kill-who --property -p --signal -s --machine'
                      )

        if __contains_word "$prev" ${OPTS[ARG]}; then
                case $prev in
                        --signal|-s)
                                comps=$(compgen -A signal)
                        ;;
                        --kill-who)
                                comps='all leader'
                        ;;
                        --host|-H)
                                comps=$(compgen -A hostname)
                        ;;
                        --property|-p)
                                comps=''
                        ;;
                esac
                COMPREPLY=( $(compgen -W '$comps' -- "$cur") )
                return 0
        fi


        if [[ "$cur" = -* ]]; then
                COMPREPLY=( $(compgen -W '${OPTS[*]}' -- "$cur") )
                return 0
        fi

        local -A VERBS=(
                [SESSIONS]='session-status show-session activate lock-session unlock-session terminate-session kill-session'
                [USERS]='user-status show-user enable-linger disable-linger terminate-user kill-user'
                [SEATS]='seat-status show-seat terminate-seat'
                [STANDALONE]='list-sessions list-users list-seats flush-devices'
                [ATTACH]='attach'
        )

        for ((i=0; i < COMP_CWORD; i++)); do
                if __contains_word "${COMP_WORDS[i]}" ${VERBS[*]} &&
                 ! __contains_word "${COMP_WORDS[i-1]}" ${OPTS[ARG]}; then
                        verb=${COMP_WORDS[i]}
                        break
                fi
        done

        if   [[ -z $verb ]]; then
                comps="${VERBS[*]}"

        elif __contains_word "$verb" ${VERBS[SESSIONS]}; then
                comps=$( __get_all_sessions )

        elif __contains_word "$verb" ${VERBS[USERS]}; then
                comps=$( __get_all_users )

        elif __contains_word "$verb" ${VERBS[SEATS]}; then
                comps=$( __get_all_seats )

        elif __contains_word "$verb" ${VERBS[STANDALONE]}; then
                comps=''

        elif __contains_word "$verb" ${VERBS[ATTACH]}; then
                if [[ $prev = $verb ]]; then
                        comps=$( __get_all_seats )
                else
                        comps=$(compgen -A file -- "$cur" )
                        compopt -o filenames
                fi
        fi

        COMPREPLY=( $(compgen -W '$comps' -- "$cur") )
        return 0
}

complete -F _loginctl loginctl