Ytdyklly

#!/bin/bash

export DISPLAY=:0

state=$(upower -i $(upower -e | grep BAT) | grep --color=never -E "state" )

stat=${state:25:32}

batperct=$(upower -i $(upower -e | grep '/battery') | grep  -E "percentage:")

bat=${batperct:24:26}

intbat=$(echo $bat | cut -d'%' -f1)

if [ "$intbat" -lt "15" -a "$stat" == "discharging" ]; then

    notify-send 'battery low..! please plugin charger..... charge is only' "$intbat"    

fi  

The script runs fine when run as a normal user (bash script.sh). The desktop notification is displayed.

If I run it as root with sudo bash script.sh, the desktop notification is not displayed.

How can I use notify-send to notify users as root?

I am using Arch Linux.

The command notify-send needs the environment variable DBUS_SESSION_BUS_ADDRESS set and must be called with the owner of this session bus as user.

In the following script the function notify_users searches for all dbus-daemons that control a session bus. The command line of such a daemon looks like this:

dbus-daemon --fork --session --address=unix:abstract=/tmp/dbus-ceVHx19Kiy

For this processes the owner and the dbus address is determined. Then we are able to use notify-send. This script should inform all user logged in with a GDM session. But I never tested that.

Note: If you call this as non-root, you might get queried for a password due to the use of sudo.

#!/bin/bash



# Inform all logged on users

# Usage: notify_users TITLE MESSAGE [urgency [icon]]

notify_users()

{

    typeset title="$1"

    typeset message="$2"

    typeset urgency="${3:-critical}"

    typeset icon="${4:-}"



    case "$urgency" in

        "low") : ;;

        "normal") : ;;

        "critical") : ;;

        *)

            urgency="normal"

            ;;

    esac



    typeset ls user bus_addr



    typeset IFS=$'n'



    # for all dbus-daemon processes that create a session bus

    for ln in "$(ps -eo user,args | grep "dbus-daemon.*--session.*--address=" | grep -v grep)"; do

        # get the user name

        user="$(echo "$ln" | cut -d' ' -f 1)"

        # get dbus address

        bus_addr="$(echo "$ln" | sed 's/^.*--address=//;s/ .*$//')"

        # run notify-send with the correct user

        DBUS_SESSION_BUS_ADDRESS="$bus_addr" sudo -u $user -E /usr/bin/notify-send -u "$urgency" -i "$icon" "$title" "$message"

    done

}



state="$(upower -i $(upower -e | grep BAT))"



# if the state contains the word "discharging"

if [[ "$state" = *discharging* ]]; then



    perc=$(echo "$state" | grep "percentage" | awk '{print $2}' | tr -d '%')



    icon="$(echo "$state" | grep "icon-name:" | awk '{print $2}' | tr -d "'"" )"



    if [ "$perc" -lt 15 ]; then

        notify_users "Battery Low!"  "Please plugin charger ... charge is only $perc%" "critical" "$icon"

    fi

fi