C Interview Questions and Answers

 

How do I read the arrow keys? What about function keys?

Terminfo, some versions of termcap, and some versions of curses have support for
these non-ASCII keys. Typically, a special key sends a multicharacter sequence (usually
beginning with ESC, '33'); parsing these can be tricky. (curses will do
the parsing for you, if you call keypad first.)



Under MS-DOS, if you receive a character with value 0 (not '0'!) while
reading the keyboard, it's a flag indicating that the next character read will
be a code indicating a special key. See any DOS programming guide for lists of keyboard
scan codes. (Very briefly: the up, left, right, and down arrow keys are 72, 75,
77, and 80, and the function keys are 59 through 68.)

Posted by:Richards