If you’re writing a bash script which may take a while to finish, such as a backup script, it’s often useful to have a popup notifying of the completion of the script. This can be done with the kdialog tool.
There are a bunch of options for this tool (run
kdialog --help-all for details. For something like a notification popup, do something like the following:
kdialog --caption "Backup Manager" --title "Backup Complete" --msgbox "Backup finished successfully"