// Write a encryption program which encrypts the string by adding 1 to its ASCII value.
#include <stdio.h>
#include <string.h>

void encrypt(char *str)
{
    char *ptr = str;
    while (*ptr != '\0')
    {
        *ptr = *ptr   1; // This will add integer 1 to the value of character stored in ptr i.e. its ASCII value.
        *ptr  ;
    }
}

void decrypt(char *str){
    char *ptr = str;
    while (*ptr != '\0')
    {
        *ptr = *ptr -1; // This will subtract 1 from the ASCII value and restore the original string.
        *ptr  ;
    }
    
}
int main()
{
    char message[] = "We are what we choose to be!"; 
    encrypt(message);
    printf("The encrypted message is %s\n\n", message);

    char pwd[20] = "omkaushik";
    char input[20];
    printf("Enter password to decrypt the message\n");
    gets(input);

    int result = strcmp(pwd, input);
   while (result != 0)
   {
     printf("The password entered is wrong\n");
     printf("Enter the password again\n");
     gets(input);
     int result = strcmp(pwd, input);
   }
   decrypt(message);
        printf("The password entered is accepted....\n");
        printf("%s",message);

    return 0;
}

In this program when I enter the correct password at the start, it decrypts the message successfully but when I enter a wrong password and later try to enter the correct password, it doesn't exit the loop.

CodePudding user response：

First gets is deprecated and unsafe and should never be used. Second, and this is your question, inside your loop you declare a local variable instead of updating the one in the outer scope

 int result = strcmp(pwd, input);

replace it with

 result = strcmp(pwd, input);

Will update the test inside the loop