Allows "notify-send" to be run by cron to show up for the user.

cron-prog

#!/bin/sh
# Executes a program as the currently logged in user. e.g. in /etc/crontab:
# */5 22 * * * root cron-prog notify-send "Closing computer now!"

[ "$#" -lt 1 ] && echo "Usage: $0 program options" && exit 1

program="$1"
shift

user=$(whoami)
env_reference_process=$( pgrep -u "$user" xfce4-session || pgrep -u "$user" ciannamon-session || pgrep -u "$user" gnome-session || pgrep -u "$user" gnome-shell || pgrep -u "$user" kdeinit | head -1 )

export DBUS_SESSION_BUS_ADDRESS=$(cat /proc/"$env_reference_process"/environ | grep --null-data ^DBUS_SESSION_BUS_ADDRESS= | sed 's/DBUS_SESSION_BUS_ADDRESS=//')
export DISPLAY=$(cat /proc/"$env_reference_process"/environ | grep --null-data ^DISPLAY= | sed 's/DISPLAY=//')
"$program" "$@"