Question

I have the following code:

#include<iostream>
#include<stdio.h>
using namespace std;
int main(){
    char* username, *password;
    cout<<"Content-type: text/html"<<endl<<endl;
    FILE *in = fopen("useri.txt","r");
    while (fscanf(in,"%s %s",username, password) != EOF) {
        cout<<username<<endl;
    }
    fclose(in);
}

The file looks like:

admin admin

For some reason, all the text in the specific file, is being read into the username var. The code as-is, does print out both the 2 values I have in my file (on separate lines), but that’s wrong, cause it should only print 1.

As soon as I try to print password, the program just exits, with no error (not even segmentation fault). Am I doing something wrong?

Note: I need this to stay C, not C++ (except for the cout part, because I’m lazy).

Answer 1

Memory is not allocated to variables.

char* username, *password;

use malloc() to allocate memory dynamically.

It is not mandatory to use only dynamic memory. you can use static memory also. i.e

//100 is just a sample value. 
//Modify as per your requirement.
#define MAX_STR_LEN 100    

char  username[MAX_STR_LEN], password[MAX_STR_LEN];