(read-password): New function.

1 files changed, 22 insertions, 0 deletions

diff --git a/lisp/subr.el b/lisp/subr.el
index 7e21ef9a46b..cadb2fd313f 100644
--- a/lisp/subr.el
+++ b/lisp/subr.el
@@ -752,6 +752,28 @@ any other non-digit terminates the character code and is then used as input."))
       (setq first nil))
     code))
 
+(defun read-password (prompt &optional default)
+  "Read a password, echoing `.' for each character typed.
+End with RET, LFD, or ESC.  DEL or C-h rubs out.  C-u kills line.
+Optional DEFAULT is password to start with."
+  (let ((pass nil)
+        (c 0)
+        (echo-keystrokes 0)
+        (cursor-in-echo-area t))
+    (while (progn (message "%s%s"
+                           prompt
+                           (make-string (length pass) ?.))
+                  (setq c (read-char))
+                  (and (/= c ?\r) (/= c ?\n) (/= c ?\e)))
+      (if (= c ?\C-u)
+          (setq pass "")
+        (if (and (/= c ?\b) (/= c ?\177))
+            (setq pass (concat pass (char-to-string c)))
+          (if (> (length pass) 0)
+              (setq pass (substring pass 0 -1))))))
+    (message nil)
+    (or pass default "")))
+
 (defun force-mode-line-update (&optional all)
   "Force the mode-line of the current buffer to be redisplayed.
 With optional non-nil ALL, force redisplay of all mode-lines."