Ctrl+D doesn't stop application from executing in command window

Question

I\'ve written a program to encrypt a given message by XOR. It works, but It doesn\'t end. Here is the code.(I have created 3 files):

encrypt.h :

void         


        

Answer 1

isprint() can help:

#include 
#include 

void encrypt(char *message)
{
    while (*message) {
        *message = *message ^ 31;
        message++;
    }
}

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

    while (fgets(msg, 80, stdin) != NULL) {
        if (!isprint((unsigned char)*msg)) break;
        encrypt(msg);
        printf("%s", msg);
    }
    return 0;
}