Keyboard input without displaying letters.

This is a discussion on Keyboard input without displaying letters. within the C++ Programming forums, part of the General Programming Boards category; Hi, (Sorry for another question so soon after my last!) Is it possible to allow a user to type an ...

  1. #1
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    Keyboard input without displaying letters.

    Hi, (Sorry for another question so soon after my last!)

    Is it possible to allow a user to type an input without it displaying on the screen as they type the letters.

    This is in a similar way to logging into Linux using a Terminal.

    For Example:

    The user is prompted for a password, the user enters the password followed by a press of the return key. The password is then assigned to a variable. Nothing that they typed is shown on the screen.

    Is it possible to implement such a thing?

    Thanks for any help

  2. #2
    and the hat of wrongness Salem's Avatar
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    It sure is possible (how else would anyone do it otherwise), but there is no standard way.
    You need to say which OS/Compiler you're using in order for us to answer the question.

  3. #3
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    ok, well there is a slight problem with os/compiler.

    im using win200/MS VC++ 6 at college and Win XP/Dev C++ at home

    is there code than can compile for both?

  4. #4
    and the hat of wrongness Salem's Avatar
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    You should be able to write a console mode program which compiles in both.

  5. #5
    Registered User major_small's Avatar
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    did you try using /b and getch()?
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  6. #6
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    Quote Originally Posted by major_small
    did you try using /b and getch()?
    getch() doesnt work in the compilers i use.
    What do you mean by /b ?

  7. #7
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    Quote Originally Posted by explosive
    getch() doesnt work in the compilers i use.
    ?
    My dev-c++ has conio.h and getch(). The following illustrates getch() and works on my Windows box when compiled with Borland C, Microsoft VC++, and as a file in a dev-c++ project:

    Code:
    #include <stdio.h>
    #include <conio.h>
    
    int main(int argc, char *argv[])
    {
      int c;
      printf("Press ctrl-c to quit\n");
      while ((c = getch()) != 3) {
        putchar(c);
        if (c == '\r') {
          putchar('\n');
        }
      }
      return 0;
    }
    (Of course if you don't want to echo the character, you could use, say putchar('*'), to put an asterisk in place of the user input.)

    Regards,

    Dave
    Last edited by Dave Evans; 12-06-2004 at 08:53 AM.

  8. #8
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    Quote Originally Posted by Dave Evans
    My dev-c++ has conio.h and getch(). The following illustrates getch() and works on my Windows box when compiled with Borland C, Microsoft VC++, and as a file in a dev-c++ project:

    Code:
    #include <stdio.h>
    #include <conio.h>
    
    int main(int argc, char *argv[])
    {
      int c;
      printf("Press ctrl-c to quit\n");
      while ((c = getch()) != 3) {
        putchar(c);
        if (c == '\r') {
          putchar('\n');
        }
      }
      return 0;
    }
    (Of course if you don't want to echo the character, you could use, say putchar('*'), to put an asterisk in place of the user input.)

    Regards,

    Dave
    Thanks for that, it works great

  9. #9
    Registered User major_small's Avatar
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    getch() isn't strictly standard, so while it works now, you may want to eventually find another way to do it. also, \b is a backspace character. on any reasonably fast system, outputting a \b (or series thereof) will make it seem like it was never output at all. that doesn't work so well on input though.
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