#include <stdio.h>

#include <stdlib.h>

#include <string.h>

// for installation notes see C0.c

// this program can be called with

//

//  ./args2-good | ./C2

//

// or

//

// ./args2-bad | ./C2

int match(char *s1, char *s2) {

  while( *s1 != '\0' && *s2 != 0 && *s1 == *s2 ){

    s1++; s2++;

  }

  return( *s1 - *s2 );

}

// since gets() is insecure and produces lots of warnings, 

// I use my own input function instead ;o)

char ch;

int i;

void get_line(char *dst) {

  char buffer[8];

  i = 0;

  while ((ch = getchar()) != '\n') {

    buffer[i++] = ch; 

  }

  buffer[i] = '\0';

  strcpy(dst, buffer);

}

void welcome() { printf("Welcome to the Machine!\n"); exit(0); }

void goodbye() { printf("Invalid identity, exiting!\n"); exit(1); }

main(){

  char name[8];

  char pw[8]; 

  printf("login: "); 

  get_line(name);

  printf("password: "); 

  get_line(pw);

  if(match(name, pw) == 0)

    welcome();

  else

    goodbye();

}