/* Save this as 'secret.c' and type 'cc secret.c -o secret' to compile. */

#include <stdio.h>
#include <sys/ioctl.h>
#include <signal.h>
#include <pwd.h>

main(argc, argv)
int argc;
char **argv;
{
  struct sgttyb basic;
  short flags;
  char str[32];
  int i;

/* Ignore all interrupts that may try to mess up this program like ^C, ^Z */
  for (i = 1; i < 33; signal(i++, SIG_IGN));

/* Shut off echo and receive key strokes as they are hit from the terminal */

  ioctl(fileno(stdin), TIOCGETP, &basic);
  flags = basic.sg_flags;
  basic.sg_flags |= CBREAK;
  basic.sg_flags &= ~ECHO;
  ioctl(fileno(stdin), TIOCSETP, &basic);

  do {
    /* Prompt for the input */
    fprintf(stdout, "Enter Secret Word> "), fflush(stdout);

    /* Get the input until a return or a lot of keys are hit */
    for (i = 0; (i < 31) && ((str[i] = getchar()) != '\n'); i++);
    /* Terminate the string */
    str[i] = '\0';

    /* Acknowledge that you have accepted the return by echoing it */

    fprintf(stdout, "\n");

     /* Repeat until the word has been entered */
  }
  while (strcmp(crypt(str, "hi"), "higSfxQjrCp7Y"));

/* Restore the terminal back to the original settings */
  basic.sg_flags = flags;
  ioctl(fileno(stdin), TIOCSETP, &basic);

/* Do something with the secret string here, I just print it out...
   You could have fun with it */
  fprintf(stdout, "->%s\n", str);
  fflush(stdout);
}