Script for the root to send desktop notifications to all active sessions

notify-send-all

#!/bin/bash
#
# notify-send-all - Script to send desktop notifications to all active sessions
#
# https://gist.github.com/aplatanado/e8810dbceece820b4ae5aa0ee5ca200a
#

### Utility functions
# A few utility functions to show errors, handle programa exit and more

PROGRAM_NAME="$(basename "$0")"

function error_exit() {
  echo "${2:-"Unknown error"}" 1>&2
  exit "${1:-1}"
}

### Loginctl commands
# Functions to make it easy to invoke some loginctl commands

function list-sessions() {
  loginctl list-sessions --no-pager --no-legend | awk '{print $1}'
}

function show-session() {
  local session_id=$1; shift
  local property loginctl_params
  
  for property in $@; do
    loginctl_params="$loginctl_params -p $property"
  done
  
  loginctl show-session --no-pager --no-legend $loginctl_params $session_id
}

### Main function

function notify-send-all() {
  local session_id
  local Active Display Name
  
  test "$UID" -eq 0 ||
    error_exit 1 "You must be root to use this tool."
  type -P notify-send &> /dev/null ||
    error_exit 2 "The command notify-send was not found."
  
  for session_id in $(list-sessions); do
    eval $(show-session $session_id Active Display Name)
    if [[ "$Active" == "yes" ]]; then
      su "$Name" -c "DISPLAY=$Display notify-send "'"$@"' -- "$@"
    fi
  done
  
  exit 0
}

notify-send-all "$@"