systemd/shell-completion/bash/journalctl

# journalctl(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
}

__get_machines() {
    local a b
    (machinectl list-images --full --no-legend --no-pager; machinectl list --full --no-legend --no-pager; echo ".host") | \
        { while read a b; do echo " $a"; done; } | sort -u;
}

__syslog_priorities=(emerg alert crit err warning notice info debug)

_journalctl() {
    local field_vals= cur=${COMP_WORDS[COMP_CWORD]} prev=${COMP_WORDS[COMP_CWORD-1]}
    local -A OPTS=(
        [STANDALONE]='-a --all --full --system --user
                      --disk-usage -f --follow --header
                      -h --help -l --local -m --merge --no-pager
                      --no-tail -q --quiet --setup-keys --verify
                      --version --list-catalog --update-catalog --list-boots
                      --show-cursor --dmesg -k --pager-end -e -r --reverse
                      --utc -x --catalog --no-full --force --dump-catalog
                      --flush --rotate --sync --no-hostname -N --fields'
        [ARG]='-b --boot -D --directory --file -F --field -t --identifier
                      -M --machine -o --output -u --unit --user-unit -p --priority
                      --root --case-sensitive'
        [ARGUNKNOWN]='-c --cursor --interval -n --lines -S --since -U --until
                      --after-cursor --cursor-file --verify-key -g --grep
                      --vacuum-size --vacuum-time --vacuum-files --output-fields'
    )

    # Use the default completion for shell redirect operators
    if __contains_word "$prev" '>' '>>' '&>'; then
        compopt -o filenames
        COMPREPLY=( $(compgen -f -- "$cur") )
        return 0;
    fi

    if __contains_word "$prev" ${OPTS[ARG]} ${OPTS[ARGUNKNOWN]}; then
        case $prev in
            --boot|-b)
                comps=$(journalctl -F '_BOOT_ID' 2>/dev/null)
                ;;
            --directory|-D|--root)
                comps=$(compgen -d -- "$cur")
                compopt -o filenames
                ;;
            --file)
                comps=$(compgen -f -- "$cur")
                compopt -o filenames
                ;;
            --output|-o)
                comps=$( journalctl --output=help 2>/dev/null )
                ;;
            --field|-F)
                comps=$(journalctl --fields | sort 2>/dev/null)
                ;;
            --machine|-M)
                comps=$( __get_machines )
                ;;
            --priority|-p)
                comps=${__syslog_priorities[*]}
                compopt -o nosort
                ;;
            --unit|-u)
                comps=$(journalctl -F '_SYSTEMD_UNIT' 2>/dev/null)
                # Similarly to systemctl, we need to distinguish between
                # escaped and unescaped names in order to be able to correctly
                # complete them. In this particular case, if the name we're
                # trying to complete is unescaped (i.e. foo\x2dbaz), escape
                # it first, so the compgen below works as expected. For more
                # information about these shenanigans see the systemctl
                # completion file
                if ! [[ $cur =~ '\\' ]]; then
                    cur="$(printf '%q' $cur)"
                fi
                compopt -o filenames
                ;;
            --user-unit)
                comps=$(journalctl -F '_SYSTEMD_USER_UNIT' 2>/dev/null)
                ;;
            --identifier|-t)
                comps=$(journalctl -F 'SYSLOG_IDENTIFIER' 2>/dev/null)
                ;;
            --case-sensitive)
                comps='yes no'
                ;;
            *)
                return 0
                ;;
        esac
        COMPREPLY=( $(compgen -o filenames -W '$comps' -- "$cur") )
        return 0
    fi

    if [[ $cur = -* ]]; then
        COMPREPLY=( $(compgen -W '${OPTS[*]}' -- "$cur") )
        return 0
    elif [[ $cur = *=* ]]; then
        mapfile -t field_vals < <(journalctl -F "${prev%=}" 2>/dev/null)
        COMPREPLY=( $(compgen -W '${field_vals[*]}' -- "${cur#=}") )
    elif [[ $cur = /dev* ]]; then
        compopt -o filenames
        COMPREPLY=( $(compgen -f -- "${cur}") )
    elif [[ $cur = /* ]]; then
        # Append /dev/ to the list of completions, so that
        # after typing /<TAB><TAB> the user sees /dev/ as one
        # of the alternatives. Later on the rule above will
        # take care of showing device files in /dev/.
        mapfile -t field_vals < <(journalctl -F "_EXE" 2>/dev/null; echo '/dev/')
        COMPREPLY=( $(compgen -W '${field_vals[*]}' -- "${cur}") )
        if [[ "${COMPREPLY[@]}" = '/dev/' ]]; then
            compopt -o filenames
            COMPREPLY=( $(compgen -f -- "${cur}") )
        fi
    elif [[ $prev = '=' ]]; then
        mapfile -t field_vals < <(journalctl -F "${COMP_WORDS[COMP_CWORD-2]}" 2>/dev/null)
        COMPREPLY=( $(compgen -W '${field_vals[*]}' -- "$cur") )
    else
        mapfile -t field_vals < <(journalctl --fields 2>/dev/null)
        compopt -o nospace
        COMPREPLY=( $(compgen -W '${field_vals[*]}' -S= -- "$cur") )
    fi
}

complete -F _journalctl journalctl