Linux Registers

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
}