zenity/help/C/l10n_scripts/progress.sh

#!/bin/sh
(
echo "10" ; sleep 1
echo "# Updating mail logs" ; sleep 1
echo "20" ; sleep 1
echo "# Resetting cron jobs" ; sleep 1
echo "50" ; sleep 1
echo "This line will just be ignored" ; sleep 1
echo "75" ; sleep 1
echo "# Rebooting system" ; sleep 1
echo "100" ; sleep 1
) |
zenity --progress --title="Update System Logs" --text="Scanning mail logs..." --percentage=0

if [ "$?" = -1 ] ; then
        zenity --error --text="Update cancelled."
fi