How can I read a password from the console, echoing splats?

here i have written a code to accept a password entered by the user after he have entered his username,i have written a small code using do while statement to print out the star every time when ever user enter any character,& the loop terminates when the user enters a '!'. but it surprised me w开发者_StackOverflowhen i see the password entered by the user,& the string length of the entered password,THE STRING length always comes out to be 21,in my case,& the output of password is a combination of the password entered by the user & the username......what's going on??????

#include<iostream.h>
#include<conio.h>
#include<string.h>
int main()
{
    char username[15],password[15];
    int i=0;
    cout<<"\nEnter your USERNAME:";
    cin>>username;
    cout<<"\nenter your password:";

    do 
    {
        password[i]=getch();


        if(password[i]=='!')break;
        cout<<"*";
        i++;
    }while(i<15);
    cout<<"\n\nthe password entered was"<<password<<"\nthe length of the password is"           <<strlen(password);
    getch();
    return 0;
} 

---

You have defined:

char password[15];

And as per your loop, it continues until i is equal to 14 (i.e, 15th character). So there is no space for NULL termination. Let it be like this:

char password[16];

Now, just after the loop, add:

password[i] = 0;

i will be at 15 if user didn't enter '!' and if he did, it will be replaced with NULL character. I think this is the easiest fix. If you don't want the '!' to be replaced, place i++; before break;

---

You are not terminating your string with a NULL.

do 
{
    password[i]=getch();
    if(password[i]=='!') break;
    cout<<"*";-
    i++;
}while(i<15);
if (i < 15) password[i] = '\0';

---

A C string must be terminated by the special character '\0', which is not the case with your password/username. You have to set the i+1th character to '\0':

password[i]=getch();
password[i+1] = '\0';

Also you have to consider that your password buffer must also contain this string, so you have just space for 14 characters if you define char password[15]; so your loop can just go to 14.

---

You read 15 characters but you never write a '\0' in the string so it's not terminated.

---

It is

#include <iostream>
#include <string>

please correct that. If your compiler does not know these files, then your compiler is not any good.

Then, why don't you use std::string instead if char-arrays?
That would avoid any of these errors. What you do here, is a mix of c and c++.