TUI /Text User Interface/

http://tldp.org/HOWTO/Text-Terminal-HOWTO.html

NCurses

Colors

According to https://dev.yorhel.nl/dump/nccolour:

You can not assume that the default foreground or background colour can be represented by one of the 8 basic colours defined by NCurses. Specifying -1 as colour, to indicate the default foreground or background colour, seems to work fine in any terminal tested so far.

Line drawing characters

export NCURSES_NO_UTF8_ACS=1 

tells ncurses to always use Unicode box drawing characters when a UTF-8 locale is selected.