Thread: To enter password without displaying it

  1. #1
    Registered User
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    Jan 2009
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    12

    To enter password without displaying it

    In a password checking program,when the password is enterd it should not be displayed.Which function should be used for that? If scanf() and gets() are used the text entered will be displayed.

  2. #2
    ... kermit's Avatar
    Join Date
    Jan 2003
    Posts
    1,534
    I don't believe there is a way in standard C to do that. You can use a nonstandard function such as getch to do what you want.
    Last edited by kermit; 01-07-2009 at 10:09 AM.

  3. #3
    Registered User Codeplug's Avatar
    Join Date
    Mar 2003
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    4,981
    In Windows, you can turn off echo for any standard input function with SetConsoleMode().
    Code:
    #include <stdio.h>
    #include <windows.h>
    
    int main()
    {
        HANDLE hStdin = GetStdHandle(STD_INPUT_HANDLE); 
        DWORD mode = 0;
        char buff[25];
    
        GetConsoleMode(hStdin, &mode);
        SetConsoleMode(hStdin, mode & (~ENABLE_ECHO_INPUT));
    
        fgets(buff, sizeof(buff), stdin);
    
        SetConsoleMode(hStdin, mode);
    
        printf("You entered: %s", buff);
    
        return 0;
    }
    In *nix you can use the "termios" interface to disable echo.
    Code:
    #include <stdio.h>
    #include <termios.h>
    #include <unistd.h>
    
    int main()
    {
        termios oldt;
        tcgetattr(STDIN_FILENO, &oldt);
        termios newt = oldt;
        newt.c_lflag &= ~ECHO;
        tcsetattr(STDIN_FILENO, TCSANOW, &newt);
    
        fgets(buff, sizeof(buff), stdin);
    
        tcsetattr(STDIN_FILENO, TCSANOW, &oldt);
    
        printf("You entered: %s", buff);
    
        return 0;
    }
    gg

  4. #4
    Registered User C_ntua's Avatar
    Join Date
    Jun 2008
    Posts
    1,853
    This is a "classic" question. Search the forum and/or FAQ

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