//Declaration:  int strcmp(const char *str1, const char *str2); 
//Return:       returns an integer based on the outcome: 
                < 0  :  str1 is less than str2 
                0    :  str1 is equal to str2 
                >0   :  str1 is greater than str2   
  

#include<stdio.h>
#include<string.h>

int main(void){
    char s[80];

    printf("Enter password: ");
    gets(s);
    if(strcmp(s, "pass")) {
      printf("Invalid Password\n");
      return 0;
    }
    return 1;
}

/*
Enter password: 34
Invalid Password
*/