On Wed, May 07, 2008 at 05:39:00PM +0200, [EMAIL PROTECTED] wrote: > i need to test (NOWAIT), the presence of keypressed/depressed on a terminal > and then read the scan code, like for a piano pc keyboard. > > my questions are as follows: > > 1. is it a general C function which may scan a terminal without waiting? > > 2. how to get the scancodes?
It depends on if you're wanting the actual hard-wired keyboard (on the console), or if you're taking input from a tty/pty. You won't get a true scancode from a tty/pty, but you will get a character (0x00 to 0xFF). Regarding I/O without waiting: there is not a general libc function for this. Garrett mentioned getc(), which blocks (waits). You might want to consider seeing if the kqueue/kevent stuff on the BSDs will work with pty/tty input. You can use that to set up an event in the kernel which tells the kernel "run function XYZ when I/O is seen on this fh/fd". It's like select() in that respect, but is faster. > of course i can poll tje (0x64) keyboard port on a i386 architecture, > but this is not a general method, and it is suited for a distant terminal > for instance. I agree. This method is also very old, and I'd be surprised if it would work with USB keyboards. I would assume it would also interfere with any existing keyboard I/O handler the OS has, but I'm not sure. -- | Jeremy Chadwick jdc at parodius.com | | Parodius Networking http://www.parodius.com/ | | UNIX Systems Administrator Mountain View, CA, USA | | Making life hard for others since 1977. PGP: 4BD6C0CB | _______________________________________________ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"
