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Diffstat (limited to 'lisp/rot13.el')
| -rw-r--r-- | lisp/rot13.el | 29 |
1 files changed, 19 insertions, 10 deletions
diff --git a/lisp/rot13.el b/lisp/rot13.el index dfcf4adc179..4e4e60fea3f 100644 --- a/lisp/rot13.el +++ b/lisp/rot13.el @@ -3,6 +3,7 @@ ;; Copyright (C) 1988, 2001-2021 Free Software Foundation, Inc. ;; Author: Howard Gayle +;; Simon Josefsson ;; Maintainer: emacs-devel@gnu.org ;; This file is part of GNU Emacs. @@ -22,18 +23,26 @@ ;;; Commentary: -;; The entry point, `rot13-other-window', performs a Caesar cipher -;; encrypt/decrypt on the current buffer and displays the result in another -;; window. ROT13 encryption is sometimes used on USENET as a read-at-your- -;; own-risk wrapper for material some might consider offensive, such as -;; ethnic humor. +;; "ROT13 ('rotate by 13 places') is a simple letter substitution +;; cipher that replaces a letter with the 13th letter after it in +;; the alphabet. ROT13 is a special case of the Caesar cipher +;; which was developed in ancient Rome. ;; -;; Written by Howard Gayle. -;; This hack is mainly to show off the char table stuff. +;; Because there are 26 letters (2×13) in the basic Latin +;; alphabet, ROT13 is its own inverse; that is, to undo ROT13, the +;; same algorithm is applied, so the same action can be used for +;; encoding and decoding. The algorithm provides virtually no +;; cryptographic security, and is often cited as a canonical +;; example of weak encryption. ;; -;; New entry points, `rot13', `rot13-string', and `rot13-region' that -;; performs Caesar cipher encrypt/decrypt on buffers and strings, was -;; added by Simon Josefsson. +;; ROT13 is used in online forums as a means of hiding spoilers, +;; punchlines, puzzle solutions, and offensive materials from the +;; casual glance." - Wikipedia article on ROT13 +;; +;; The entry points, `rot13', `rot13-string', and `rot13-region' performs ROT13 +;; encoding/decoding on buffers and strings. The entry point +;; `rot13-other-window' performs a ROT13 encoding/decoding on the current +;; buffer and displays the result in another window. ;;; Code: |