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From: Helmut Brandl <helmut.brandl@gmx.net>
To: Matthew Ryan <matthew@o1labs.org>
Cc: caml users <caml-list@inria.fr>
Subject: Re: [Caml-list] Turn echoing off on standard input to read e.g. passwords
Date: Thu, 28 Mar 2019 14:40:57 -0600	[thread overview]
Message-ID: <AD44EE98-7BEC-4515-9A07-9D84C756157D@gmx.net> (raw)
In-Reply-To: <CAHsMTAENQt=0aQS5hUnm=sgbK0NZgUUOCpfQihWTCbw0-jC4xQ@mail.gmail.com>

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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


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  reply	other threads:[~2019-03-28 21:26 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-03-28 20:03 Helmut Brandl
2019-03-28 20:33 ` Matthew Ryan
2019-03-28 20:40   ` Helmut Brandl [this message]
2019-03-28 21:12   ` Daniel Bünzli
2019-03-29  3:05   ` Chet Murthy
2019-03-29 23:13     ` Chet Murthy
2019-04-01  9:05 ` Jeremie Dimino

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