Hello,
I am looking for some Linux library/programming language that can be used on a variety of Linux platforms and can operate in both textual and GUI mode interfaces. For example YCP (the Yast programming language) will display in GUI if in Gnome/KDE environment and run in text/ncurses mode when display is not available. The problem is that YCP is SUSE specific. Any ideas will be appreciated!
Although it may be different from what you need, the CCC project is nice environment that works under windows and linux as well. It is a Clipper to C++ compiler to let the old Clipper programs survive. They can work in terminal mode and with e. g. GTK as well. Unfortunately the documentations are mostly in Hungarian.
Here, they have screenshots side-by-side: http://www.fship.com/vfs.html
BTW, I use FlagShip, but for web programming.
Your assumption is not correct, the part of YaST that allows to have text(ncurses)/graphical(qt, gtk) user interfaces is not tied to YaST itself.
Actually libyui only requires the standard C++ library and phtreads (IIRC). The UI plugins require of course the respective libraries (Qt, ncurses). YaST uses libyui via a set of YCP bindings that export a YCP like API on top of libyui.
The library is a bit lowlevel (one layer below an event loop), my colleage Klaus Kämpf wrote about using it some time ago in his blog, including binding to scripting languages it using swig.
The only part that is SUSE specific is the packaging, so you would need to package it yourself. Stackoverflow did not allow me to link more than once. The code of the library is linked from Klaus blog. Replace libyui for "qt" and "ncurses" for the plugin's code.