Thanks.

> On Mar 28, 2019, at 14:33, Matthew Ryan <matthew@o1labs.org> wrote:
> 
> Hi Helmut,
> 
> The usual way to do this (for any language) is using ANSI escape sequences. Code 8 sets the terminal to conceal characters and code 0 resets the attributes, making them visible again.
> 
> For example, in a unix shell you can test this with echo and read:
> 
> echo -e '\x1b[8m'; read varname; echo -e '\x1b[0m'
> 
> To do the same from OCaml, you can output "\x1b[8m", read the password, and then output "\x1b[0m" afterwards to switch printing back on.
> 
> I believe that this will work on Windows 10, but earlier versions may not have the necessary ANSI support.
> 
> Hope this helps,
> Matthew
> 
> On Thu, 28 Mar 2019, 20:04 Helmut Brandl, <helmut.brandl@gmx.net <mailto:helmut.brandl@gmx.net>> wrote:
> Hello list,
> 
> Is there a portable way in ocaml to turn echoing off on standard input from the terminal to read e.g. passwords? By portable I mean that it works for Windows, Unix and Mac.
> 
> Thanks for any hint.
> 
> Regards
> Helmut