systemd/shell-completion/bash/systemd-id128

# networkctl(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
    return 1
}

_systemd_id128() {
    local i verb comps
    local cur=${COMP_WORDS[COMP_CWORD]} prev=${COMP_WORDS[COMP_CWORD-1]}
    local -A OPTS=(
        [STANDALONE]='-h --help --version -p --pretty'
        [ARG]='-a --app-specific'
    )

    local -A VERBS=(
        [STANDALONE]='new machine-id boot-id invocation-id help'
    )

    _init_completion || return

    if __contains_word "$prev" ${OPTS[ARG]}; then
        case $prev in
            --app-specific|-a)
                comps=""
                ;;
        esac
        COMPREPLY=( $(compgen -W '$comps' -- "$cur") )
        return 0
    fi

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

    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[STANDALONE]}; then
        comps=''
    fi

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

complete -F _systemd_id128 systemd-id128