true unbuffered input.

[David Burhans]

In article <1990Jan15.222652.21085 at hellgate.utah.edu> efinley%ug.utah.edu at cs.utah.edu (Elliott Finley) writes:
>
>I can't seem to get true unbuffered input.   ...stuff deleted...

 To do this you meed to change the your mode from cooked to CBREAK or RAW.
 Use ioctl(2) to accomplish this change.

 Man pages of interest: ioctl(2), tty(4).
 Include files of interest: sgtty.h, sys/ioctl.h.
 An example program follows:
---------------------------<Cut Here>-------------------------------------
#include <stdio.h>
#include <sgtty.h>
main() {
  int c;
  struct sgttyb oldargs, newargs;

  printf("stdin:%d\n",fileno(stdin));
  ioctl(fileno(stdin), TIOCGETP, &oldargs);

  newargs = oldargs;
  newargs.sg_flags |= CBREAK;
  newargs.sg_flags &= ~(ECHO | CRMOD);
  ioctl(fileno(stdin), TIOCSETP, &newargs);

  while(c = getchar(), c != '\004') {  /* while c != ^D */
    switch (c) {
      case '\033': fputs("<Esc>", stdout); break;
      case '\n':   fputs("\\n\n\r", stdout); break;
      case '\r':   fputs("\\r\n\r", stdout); break;
      case '\t':   fputs("\\t", stdout); break;
      default:     fprintf(stdout,"%c",c); break;
    }
  }
  ioctl(fileno(stdin), TIOCSETP, &oldargs);
}
-- 
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David Burhans/6565 Frantz Rd./Columbus, Oh 43017
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