[procedure] read-char [port]

R5RS: Returns the next character available from the input port, updating the port to point to the following character. If no more characters are available, an end of file object is returned. Port may be omitted, in which case it defaults to the value returned by current-input-port.

See also peek-char, eof-object?, current-input-port.

SCM's read-char can take a curses window as a port. See initscr.