non-line-buffered key input in C

I'm learning C from a book that uses the getche() function from the
<conio.h> library. However, the preprocessor/compiler (gcc 3.3 on
Panther) doesn't recognize the function nor the library. The getchar()
function only works line-buffered.

How do I get a program to accept character input from the keyboard
without waiting for the user to press Return?

Any help would be much-appreciated.

Eric

In article <uhzke.134983$AE6.11272@tornado.texas.rr.com>,
Eric Pellegrin <epellegrin2.no.spam.please.DeleteThis@sw.rr.com> wrote:

 > I'm learning C from a book that uses the getche() function from the
 > <conio.h> library. However, the preprocessor/compiler (gcc 3.3 on
 > Panther) doesn't recognize the function nor the library. The getchar()
 > function only works line-buffered.
 >
 > How do I get a program to accept character input from the keyboard
 > without waiting for the user to press Return?

You can use Unix calls to put the standard input into an unbuffered
state, or you can use Carbon calls to poll for events with WaitNextEvent
or use Carbon's GetKeys() to read the state of the keyboard, or you can
use CarbonEvent calls to register a callback that will be called on each
keyDown, or you can use Cocoa, and override the -(void)keyDown: handler,
which by default calls the -interpretKeyEvent: handler, or you can use
OpenGL's Glut to have keyDowns delivered to your callback, you can do an
optional install of X11 and use X11 callbacks to get at the keyboard, or
you can reference the keyboard directly using IOKit.

That's 8 ways to do it. If you are just learning C, you should just type
the carriage return, and modify your code to ignore the extra character,
until you know more.

--
David Phillip Oster<!-- ~MESSAGE_AFTER~ -->