/*
 * maskread.c
 * Pieter Droogendijk
 */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>

#include <termios.h>

int set_cbreak (struct termios *save_termios)
{
  struct termios buf;
  /* Remove line buffering from stdin */
  if (setvbuf (stdin, NULL, _IONBF, 0) != 0)
    return -1;
  /* Store previous terminal settins of fd 0 (stdin) */
  if (tcgetattr (0, save_termios))
    return -1;
  /* Modify terminal settings. */
  buf = *save_termios;
  buf.c_lflag &= ~(ICANON|ECHO);
  buf.c_cc[VMIN] = 1;
  buf.c_cc[VTIME] = 0;
  /* Set new terminal settings on fd 0. */
  if (tcsetattr (0, TCSAFLUSH, &buf) < 0)
    return -1;
  return 0;
}

int unset_cbreak (struct termios *save_termios)
{
  /* Return line buffering to stdin. */
  if (setvbuf (stdin, NULL, _IOLBF, 0) != 0)
    return -1;
  /* Return original terminal settings to fd 0. */
  if (tcsetattr (0, TCSAFLUSH, save_termios) < 0)
    return -1;
  return 0;
}

int mask_read (char *buf, size_t bufsize)
{
  size_t rv = 0, bufpos = 0;
  struct termios save_termios;
  int inch;
  if (set_cbreak (&save_termios) == -1) {
    rv = -1;
  }
  else {
    while (   rv == 0
           && (inch = getchar()) != EOF
           && inch != '\n'
           && bufpos < bufsize-1 ) {
      if (putchar ('*') == EOF) {
        rv = -1;
      }
      else
      if (fflush (stdout) == EOF) {
        rv = -1;
      }
      else {
        buf[bufpos] = inch;
        bufpos ++;
      }
    }
    buf[bufpos] = '\0';
    if (ferror (stdin) || unset_cbreak (&save_termios) == -1) {
      rv = -1;
    }
  }

  return rv;
}

int main (void)
{
  int rv = EXIT_SUCCESS;
  char hop[32];
  if (mask_read (hop, sizeof hop) == -1) {
    (void)fprintf (stderr, "mask_read() failed: %s.\n", strerror (errno));
    rv = EXIT_FAILURE;
  }
  else {
    (void)printf ("Went and read: '%s'\n", hop);
  }
  return rv;
}