#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#define RANDOM(min,max) (min + ((max - min) * (rand() / (RAND_MAX + 1.0))))
#define BUFSZ 1024

int main() {
   char prompt[] = "[root:~]#";
   int ch, nch, chc = 0, nsp = 0;
   char buf[BUFSZ];

   srand(getpid() % getppid() ^ 42);
   system("stty raw");
   system("stty -echo");

   printf("%s ", prompt); fflush(stdout);

   for (;;) {
      ch = getc(stdin);

      switch(ch) {
		case 4:			/* ^D */
			printf("use \"logout\" to leave the shell.");
		case 3:			/* ^C */
			chc = 0;
			printf("\r\n%s ", prompt);
			break;

		case '\r':
		case '\n':
			buf[chc] = 0;
			if (chc && nsp)
				printf("\r\nsh: %s: command not found", buf);
			printf("\r\n%s ", prompt);
			nsp = chc = 0;
			break;

		case ' ':
			if (chc < (BUFSZ-1) && nsp)
				buf[chc++] = ' ';
			printf(" ");
			break;

		case 127: 		/* Backspace */
			if (chc) {
				printf("\b \b");
				buf[--chc] = 0;
			}
			break;

		case 50:		/* ? F12.. */
			system("reset");
			exit(0);
			break;

		default:
			nsp++;
			nch = ch+RANDOM(1,5);
			putchar(nch);
			if (chc < (BUFSZ-1))
				buf[chc++] = nch;
			break;
      }
      fflush(stdout);
   }
}