How to write to KDE's OSD or notification from console?
Solution 1:
notify-send 'why hello there'
notify-send is part of the package libnotify-tools.
perl -MDesktop::Notify -e'Desktop::Notify->new->create(body => q{why hello there})->show'
Desktop::Notify is available on CPAN.
Solution 2:
As an alternative:
kdialog --passivepopup 'why hello there' 5
5 is the number of seconds it will last.
Run kdialog --help for other options, like title.