/* Noncanonical Mode Example

   Copyright (C) 1991-2018 Free Software Foundation, Inc.

   This program is free software; you can redistribute it and/or

   modify it under the terms of the GNU General Public License

   as published by the Free Software Foundation; either version 2

   of the License, or (at your option) any later version.

   This program is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License

   along with this program; if not, if not, see <http://www.gnu.org/licenses/>.

*/

#include <unistd.h>

#include <stdio.h>

#include <stdlib.h>

#include <termios.h>

/* Use this variable to remember original terminal attributes. */

struct termios saved_attributes;

void

reset_input_mode (void)

{

  tcsetattr (STDIN_FILENO, TCSANOW, &saved_attributes);

}

void

set_input_mode (void)

{

  struct termios tattr;

  char *name;

  /* Make sure stdin is a terminal. */

  if (!isatty (STDIN_FILENO))

    {

      fprintf (stderr, "Not a terminal.\n");

      exit (EXIT_FAILURE);

    }

  /* Save the terminal attributes so we can restore them later. */

  tcgetattr (STDIN_FILENO, &saved_attributes);

  atexit (reset_input_mode);

/*@group*/

  /* Set the funny terminal modes. */

  tcgetattr (STDIN_FILENO, &tattr);

  tattr.c_lflag &= ~(ICANON|ECHO); /* Clear ICANON and ECHO.  */

  tattr.c_cc[VMIN] = 1;

  tattr.c_cc[VTIME] = 0;

  tcsetattr (STDIN_FILENO, TCSAFLUSH, &tattr);

}

/*@end group*/

int

main (void)

{

  char c;

  set_input_mode ();

  while (1)

    {

      read (STDIN_FILENO, &c, 1);

      if (c == '\004')		/* @kbd{C-d} */

	break;

      else

	putchar (c);

    }

  return EXIT_SUCCESS;

}