Availability:built-in
get_single_char(-Code)Get a single character from input stream‘user’(regardless of
the current input stream). Unlike get_code/1,
this predicate does not wait for a return. The character is not echoed
to the user's terminal. This predicate is meant for keyboard menu
selection, etc. If SWI-Prolog was started with the --no-tty
option this predicate reads an entire line of input and returns the
first non-blank character on this line, or the character code of the
newline (10) if the entire line consisted of blank characters. See also with_tty_raw/1.