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

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

    s1++; s2++;

  }

  return( *s1 - *s2 );

}

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();

}