KDialog can be used to show nice dialog boxes from shell scripts
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README

kdialog allows you to display dialog boxes from shell scripts.
The syntax is very much inspired from the "dialog" command
(which shows text mode dialogs).

However the width and height attributes have been removed for
most dialogs - Qt/KDE have layouts ;)

A tutorial on using kdialog is available at
http://techbase.kde.org/Development/Tutorials/Shell_Scripting_with_KDE_Dialogs
If you change or add any functionality, please contact Brad
Hards <bradh@frogmouth.net> to ensure it is reflected in the
tutorial.

Current maintainer: David Faure <faure@kde.org>