Keyboard Shift and Control Keys during get_single_char/1 in linux terminal

[swi]

You may not be reading the pending codes,

see the answer here:

How does one read keyboard input using SWI-prolog without local echo, specifically the arrow keys?

read_key([Code|Codes]) :- get_single_char(Code), read_pending_codes(user,Codes,[]). read_keyatom(KAtom) :- read_key(Codes), codes_keyatom(Codes,KAtom). codes_keyatom([27,91,65],up) :- !. codes_keyatom([27,91,66],down) :- !. codes_keyatom([27,91,67],right) :- !. codes_keyatom([27,91,68],left) :- !. Query 7 ?- read_keyatom(Key). % Press the <up> key here Key = up.