?
Solved

Linux Registers

Posted on 1997-03-30
1
Medium Priority
?
658 Views
Last Modified: 2013-12-26
I have the following code sample from a DOS program I wrote.  I would like to port the program to Linux, but I don't know how to reach the registers without dos.h  The code also uses int86() which I don't think is usable within Linux.  I am looking for a replacement for the following member function:

// The purpose of the function is to return a key value only if a key
//is hit, otherwise return 0. It does NOT wait for a key to be pressed

int Fractal::GetKey ()
{
  union REGS r;            // Gain access to the registers
  if (!kbhit ())            // Return if no key pressed
       return 0;
  r.h.ah = 0;
  int86 (0x16, &r, &r);      // Get scancode of key
  if (!r.h.al)
    return (r.h.ah | 128);
 return (r.h.al & 255);      // Return the key number
}
0
Comment
Question by:wiggin
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
1 Comment
 
LVL 4

Accepted Solution

by:
jos010697 earned 200 total points
ID: 1292480
It doesn't work that way if you're using a Unix variant. Have
a look at your manual pages for ioctl(). It's purpose is to
set characteristics of an IO device. Something along the
following lines should do the job (check it out, I haven't
tested it)

int GetKey()
{
struct sgttyb tty, tty_org;
char           key;
int            retval;

/* get and save tty settings */
ioctl(fileno(stdin), TIOCGETP, &tty_org);
tty = tty_org;

/* set terminal to raw mode, no echo, no nothing */
tty.sg_flags |= CRMOD;
tty.sg_flags &= ~ECHO;
tty.sg_flags &= ~XTABS;

/* could be: tty.sg_flags |= CBREAK; */
tty.sg_flags |= RAW;
ioctl(0, TIOCSETP, &tty);
fcntl(0, F_SETFL, O_NDELAY);

/* read a keystroke */
if ((retval= read(0, &key, 1)) == 1)
        retval= key;

/* restore terminal settings */
ioctl(fileno(stdin), TIOCSETP, &tty_org);
fcntl(0, F_SETFL, fcntl(0, F_GETFL, 0)&~O_NDELAY);

return retval;
}

kind regards,

Jos
0

Featured Post

New feature and membership benefit!

New feature! Upgrade and increase expert visibility of your issues with Priority Questions.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

In this article, I'll describe -- and show pictures of -- some of the significant additions that have been made available to programmers in the MFC Feature Pack for Visual C++ 2008.  These same feature are in the MFC libraries that come with Visual …
This is to be the first in a series of articles demonstrating the development of a complete windows based application using the MFC classes.  I’ll try to keep each article focused on one (or a couple) of the tasks that one may meet.   Introductio…
This video will show you how to get GIT to work in Eclipse.   It will walk you through how to install the EGit plugin in eclipse and how to checkout an existing repository.
If you’ve ever visited a web page and noticed a cool font that you really liked the look of, but couldn’t figure out which font it was so that you could use it for your own work, then this video is for you! In this Micro Tutorial, you'll learn yo…

765 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question