systemd/shell-completion/bash/localectl

# localectl(1) completion                                 -*- shell-script -*-
# SPDX-License-Identifier: LGPL-2.1-or-later
#
# 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
}

__locale_fields=( LANG LANGUAGE LC_CTYPE LC_NUMERIC LC_TIME
                  LC_COLLATE LC_MONETARY LC_MESSAGES LC_PAPER
                  LC_NAME LC_ADDRESS LC_TELEPHONE
                  LC_MEASUREMENT LC_IDENTIFICATION )
# LC_ALL is omitted on purpose

_localectl() {
    local i verb comps locale_vals
    local cur=${COMP_WORDS[COMP_CWORD]} prev=${COMP_WORDS[COMP_CWORD-1]}
    local OPTS='-h --help --version --no-convert --no-pager --no-ask-password
                    -H --host -M --machine'

    if __contains_word "$prev" $OPTS; then
        case $prev in
            --host|-H)
                comps=''
                ;;
        esac
        COMPREPLY=( $(compgen -W '$comps' -- "$cur") )
        return 0
    fi

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

    local -A VERBS=(
        [STANDALONE]='status list-locales list-keymaps list-x11-keymap-models list-x11-keymap-layouts list-x11-keymap-options'
        [VARIANTS]='list-x11-keymap-variants'
        [LOCALES]='set-locale'
        [KEYMAPS]='set-keymap'
        [X11]='set-x11-keymap'
    )

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

    if [[ -z $verb ]]; then
        comps=${VERBS[*]}
    elif __contains_word "$verb" ${VERBS[VARIANTS]}; then
        comps=$(command localectl list-x11-keymap-layouts)
    elif __contains_word "$verb" ${VERBS[LOCALES]}; then
        if [[ $cur = *=* ]]; then
            mapfile -t locale_vals < <(command localectl list-locales 2>/dev/null)
            COMPREPLY=( $(compgen -W '${locale_vals[*]}' -- "${cur#=}") )
        elif [[ $prev = "=" ]]; then
            mapfile -t locale_vals < <(command localectl list-locales 2>/dev/null)
            COMPREPLY=( $(compgen -W '${locale_vals[*]}' -- "$cur") )
        else
            compopt -o nospace
            COMPREPLY=( $(compgen -W '${__locale_fields[*]}' -S= -- "$cur") )
        fi
        return 0
    elif __contains_word "$verb" ${VERBS[KEYMAPS]}; then
        comps=$(command localectl list-keymaps)
    elif __contains_word "$verb" ${VERBS[STANDALONE]} ${VERBS[X11]}; then
        comps=''
    fi

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

complete -F _localectl localectl