yabdialog (previously called hdialog) is a CLI utility that displays a variety of dialogs, alerts and panels with more control over color and placement than you get with the alert and filepanel commands included with Haiku. It also contains additional widgets and lets you control your clipboard.
The yabdialog command should be callable from any scripting language that can issue a SYSTEM call and receive string data back from standard input.
All parameters must be supplied...