a dmenu wrapper script for system functions.

sysact

#!/bin/bash
# a dmenu wrapper script for system functions.

actions=(
    '鈴 Sleep'
    '鈴 Hibernate'
    '⏻ Poweroff'
    ' Reboot'
    ' Logout'
)

# the -shb and -shf dmenu color options require dmenu's fuzzyhighlight patch.
colors='-sb #42214d'

main()
{
    set -e

    noconfirm=false
    case $1 in
        -n|--noconfirm) noconfirm=true; shift ;;
    esac

    action=${1,,}
    [[ -z $1 ]] && action=$(
        printf '%s\n' "${actions[@]}" | dmenu -p 'System Action:' $colors
    )

    ctl=$(get_ctl_cmd)

    case $action in
        *' Logout'|logout)
            ask 'Logout?' &&
                kill "$(pstree -ps $$ | grep -Po 'xinit\(\K\d+')"
        ;;
        *' Sleep'|sleep|suspend)
            "$ctl" suspend"$(can_hibernate && echo -then-hibernate)"
        ;;
        *' Poweroff'|poweroff|shutdown)
            ask 'Poweroff?' &&
                "$ctl" poweroff
        ;;
        *' Reboot'|reboot)
            os=$(ask_reboot_os)
            ask 'Reboot?' || return 1
            [[ -n $os ]] && sudo -A grub-reboot "$os"
            "$ctl" reboot
        ;;
        *' Hibernate'|hibernate)
            if can_hibernate; then
                ask 'Hibernate?' && "$ctl" hibernate
            else
                msg='Hibernation is not enabled on this machine.'
                echo "$msg" >&2
                notify-send "$msg"
            fi
        ;;
    esac
}

ask_reboot_os()
{
    command -v grub-reboot  >/dev/null || return 1
    command -v grub-entries >/dev/null || return 1
    entries=$(sudo -A grub-entries -g) || return 1
    readarray -t entries <<< "$entries"
    [[ ${#entries[@]} -le 1 ]] && return 0
    sel=$(printf '%s\n' "${entries[@]}" | dmenu -p 'Reboot to:' $colors) || return 1
    echo "${sel#* }"
}

ask()
{
    [[ $noconfirm = true ]] && return 0
    ans=$(printf 'No\nYes\n' | dmenu -p "$*" \
        -nb darkred -nhb darkred -nf darkgray -nhf darkgray \
        -sb maroon -shb maroon -sf white -shf orange)
    [[ $ans = Yes ]] && return 0 || return 1
}

can_hibernate()
{
    local file=/sys/power/resume
    [[ -f $file ]] && [[ $(<"$file") != 0:0 ]]
}

get_ctl_cmd()
{
    case $(readlink -f /sbin/init) in
        *systemd*) echo systemctl ;;
        *) echo loginctl ;;
    esac
}

main "$@"