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digitalmars.D - Hide input string from stdin

reply Michael Chen <michael example.com> writes:
I tried to write a small program that receive string as password. 
  However, I didn't find available library for hide input string, 
even in core library.  Any suggestion?
May 22 2016
next sibling parent Jonathan M Davis via Digitalmars-d <digitalmars-d puremagic.com> writes:
On Sunday, May 22, 2016 22:38:46 Michael Chen via Digitalmars-d wrote:

 I tried to write a small program that receive string as password.
   However, I didn't find available library for hide input string,
 even in core library.  Any suggestion?


If you're using *nix, then you can use ncurses.

http://code.dlang.org/packages/ncurses

e.g. I have this function in one of my programs:

string getPassword()
{
    import deimos.ncurses.curses;
    import std.conv;

    enum bs = 127;
    enum enter = 10;

    initscr();
    raw();
    noecho();
    timeout(-1);
    scope(exit) endwin();

    printw("password: ");
    refresh();

    dchar[] password;
    while(1)
    {
        immutable c = getch();

        if(c == enter)
            break;
        if(c == bs)
        {
            if(!password.empty)
            {
                password = password[0 .. $ - 1];
                password.assumeSafeAppend();
            }
        }
        else
            password ~= c;
    }
    return to!string(password);
}

- Jonathan M Davis
May 22 2016
prev sibling next sibling parent reply Era Scarecrow <rtcvb32 yahoo.com> writes:
On Sunday, 22 May 2016 at 22:38:46 UTC, Michael Chen wrote:

 I tried to write a small program that receive string as 
 password.
  However, I didn't find available library for hide input 
 string, even in core library.  Any suggestion?


  Hmmm if you don't mind flooding the console (with either a 
pattern or spaces or newlines), you could spawn a separate thread 
to spam the console until it gets the flag to quit... Certainly 
not the best idea, but it would work... (Probably).
May 22 2016
parent Steven Schveighoffer <schveiguy yahoo.com> writes:
On 5/22/16 10:12 PM, Era Scarecrow wrote:

 On Sunday, 22 May 2016 at 22:38:46 UTC, Michael Chen wrote:

 I tried to write a small program that receive string as password.
  However, I didn't find available library for hide input string, even
 in core library.  Any suggestion?


   Hmmm if you don't mind flooding the console (with either a pattern or
 spaces or newlines), you could spawn a separate thread to spam the
 console until it gets the flag to quit... Certainly not the best idea,
 but it would work... (Probably).


I admire your willingness to look at all approaches for this problem :)

-Steve
May 23 2016
prev sibling parent reply Wyatt <wyatt.epp gmail.com> writes:
On Sunday, 22 May 2016 at 22:38:46 UTC, Michael Chen wrote:

 I tried to write a small program that receive string as 
 password.
  However, I didn't find available library for hide input 
 string, even in core library.  Any suggestion?


For Linux, I think you could just use getpass() from 
core.sys.posix.unistd.  Not sure what the Windows equivalent is.  
An agnostic, user-facing version isn't a terrible idea.  Or 
arguably better, a good way to disable echo on stdin; maybe file 
a bug about this against std.stdio?

-Wyatt
May 23 2016
parent Nemanja Boric <4burgos gmail.com> writes:
On Monday, 23 May 2016 at 15:56:14 UTC, Wyatt wrote:

 On Sunday, 22 May 2016 at 22:38:46 UTC, Michael Chen wrote:

 I tried to write a small program that receive string as 
 password.
  However, I didn't find available library for hide input 
 string, even in core library.  Any suggestion?


 For Linux, I think you could just use getpass() from 
 core.sys.posix.unistd.  Not sure what the Windows equivalent 
 is.  An agnostic, user-facing version isn't a terrible idea.  
 Or arguably better, a good way to disable echo on stdin; maybe 
 file a bug about this against std.stdio?

 -Wyatt


Here's example `getpass` (in C++, but can be translated 
trivially) for Windows, using `SetConsoleMode` with turning off 
`ENABLE_ECHO_OUTPUT`.

http://www.cplusplus.com/articles/E6vU7k9E/#WIN-e1
May 23 2016