Path: utzoo!utgpu!watmath!uunet!wuarchive!uwm.edu!rpi!netserv2!deven
From: deven@rpi.edu (Deven T. Corzine)
Newsgroups: gnu.emacs
Subject: Re: Getting Emacs to not echo characters
Message-ID: <DEVEN.89Nov26160956@netserv2.rpi.edu>
Date: 26 Nov 89 21:09:16 GMT
References: <741@milton.acs.washington.edu>
Organization: Rensselaer Polytechnic Institute, Troy, NY
Lines: 41
In-Reply-To: pete@milton.acs.washington.edu's message of 26 Nov 89 04:07:20 GMT


On 26 Nov 89 04:07:20 GMT,
pete@milton.acs.washington.edu (Pete Pulliam) said:

Pete> I am writing a short emacs lisp program which, at one point,
Pete> requires a password to be typed.  I don't want this password to
Pete> be displayed on the screen, but am having difficulty turning
Pete> echoing off in emacs.  Any info on how to do this would be
Pete> appreciated.

Since this may be of general usefulness, I am posting this as well as
Email to the original poster.  [credit due to tale@rpi.edu for
function, I modified to select minibuffer window when prompting for a
password.]

(defun read-passwd (&optional prompt)
  "Allow user to type a string without it showing.  Returns string.
If optional PROMPT non-nil, use it as the prompt string in the mini-buffer.
Not meant to be called by the user explicitly."
  (let ((passwd "") (echo-keystrokes 0) char (win (selected-window)))
    (if prompt
        (progn
          (select-window (minibuffer-window))
          (message prompt)))
    (while (not (or (= (setq char (read-char)) 13) (= char 10)))
      (if (or (= char 8) (= char 127))
          (if (> (length passwd) 0)
              (setq passwd (substring passwd 0 (1- (length passwd)))))
        (setq passwd (concat passwd (char-to-string char))))
      (if prompt (message (concat prompt (make-string (length passwd) ?*)))))
    (if prompt (progn
                 (select-window win)
                 (message "")))
    passwd))

Deven
-- 
Deven T. Corzine        Internet:  deven@rpi.edu, shadow@pawl.rpi.edu
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