is it possible to change what the user types without pressing enter? this is a console program in C.

Question

Is this possible? The idea is typing a password and it being translated to asterisks on the fly- pretty much like a password field on HTML. I've written this code, but it converts the input AFTER the user presses enter, not while he/she is typing.

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

#include <iostream>

int main()
{
    char password[11]; int i, j;
    printf("Enter the password : ");
    gets(password);
    system("cls");
    int str_len = (int)strlen(password);
    printf("Enter the password : ");
    for(i = 0;i<2;i++)
    {
         printf(" ");
         for(j=0;j<str_len/2;j++)
         {
             printf("*");
         }
    }
    system("PAUSE>nul");
}

Answer 1

I don't think it is possible using standard io. You need a library for more advanced text user interface like ncurses.

Answer 2

It is not directly possible using standard C, no. You typically need to convince the terminal to go into "raw" mode, in which the program is able to read each character as it's typed, i.e. not requiring enter to pressed. In the raw mode, you can also often turn off any built-in echo in the terminal, and thus get the display of typed-in characters under program control.

It might be possible to convince a terminal to do these things by outputting various escape codes, but if that is within your scope or not is hard to tell. Also, it depends on the exact terminal (and thus platform) in use.

Answer 3

If you do want to get some extra points from the teacher, you could look into the function int getch() which does what you want. It is located in the header file conio.h.

Googling for getch should provide you with some info - MSDN and cplusplus.com are my favorite pages.