Variable: read-hide-char
read-hide-char is a variable defined in minibuf.c.
Value
nil
Documentation
Whether to hide input characters in noninteractive mode.
If non-nil, it must be a character, which will be used to mask the input characters. This variable should never be set globally.
This variable also overrides the default character that read-passwd
uses to hide passwords.
Probably introduced at or before Emacs version 25.1.
Source Code
// Defined in /usr/src/emacs/src/minibuf.c
DEFVAR_LISP ("read-hide-char", Vread_hide_char,
doc: /* Whether to hide input characters in noninteractive mode.
If non-nil, it must be a character, which will be used to mask the
input characters. This variable should never be set globally.
This variable also overrides the default character that `read-passwd'
uses to hide passwords. */);