lisp/play/spook.el

   1 ;;; spook.el --- spook phrase utility for overloading the NSA line eater
   2
   3 ;; Maintainer: FSF
   4 ;; Last-Modified: 05 Dec 1991
   5 ;; Keywords: games
   6
   7 ;; Copyright (C) 1988 Free Software Foundation, Inc.
   8
   9 ;; This file is part of GNU Emacs.
  10
  11 ;; GNU Emacs is free software; you can redistribute it and/or modify
  12 ;; it under the terms of the GNU General Public License as published by
  13 ;; the Free Software Foundation; either version 2, or (at your option)
  14 ;; any later version.
  15
  16 ;; GNU Emacs is distributed in the hope that it will be useful,
  17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 ;; GNU General Public License for more details.
  20
  21 ;; You should have received a copy of the GNU General Public License
  22 ;; along with GNU Emacs; see the file COPYING.  If not, write to
  23 ;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
  24
  25 ;;; Commentary:
  26
  27 ; Steve Strassmann (straz@media-lab.media.mit.edu) didn't write
  28 ; this, and even if he did, he really didn't mean for you to use it
  29 ; in an anarchistic way.
  30 ; May 1987
  31
  32 ; To use this:
  33 ;  Make sure you have the variable SPOOK-PHRASES-FILE pointing to
  34 ;  a valid phrase file. Phrase files are in the same format as
  35 ;  zippy's yow.lines (ITS-style LINS format).
  36 ;  Strings are terminated by ascii 0 characters. Leading whitespace ignored.
  37 ;  Everything up to the first \000 is a comment.
  38 ;
  39 ;  Just before sending mail, do M-x spook.
  40 ;  A number of phrases will be inserted into your buffer, to help
  41 ;  give your message that extra bit of attractiveness for automated
  42 ;  keyword scanners.
  43
  44 ;;; Code:
  45
  46 ; Variables
  47 (defvar spook-phrases-file (concat data-directory "spook.lines")
  48    "Keep your favorite phrases here.")
  49
  50 (defvar spook-phrase-default-count 15
  51    "Default number of phrases to insert")
  52
  53 (defvar spook-vector nil
  54   "Important phrases for NSA mail-watchers")
  55
  56 ; Randomize the seed in the random number generator.
  57 (random t)
  58
  59 ; Call this with M-x spook.
  60 (defun spook ()
  61   "Adds that special touch of class to your outgoing mail."
  62   (interactive)
  63   (if (null spook-vector)
  64       (setq spook-vector (snarf-spooks)))
  65   (shuffle-vector spook-vector)
  66   (let ((start (point)))
  67     (insert ?\n)
  68     (spook1 (min (- (length spook-vector) 1) spook-phrase-default-count))
  69     (insert ?\n)
  70     (fill-region-as-paragraph start (point) nil)))
  71
  72 (defun spook1 (arg)
  73   "Inserts a spook phrase ARG times."
  74   (cond ((zerop arg) t)
  75         (t (insert (aref spook-vector arg))
  76            (insert " ")
  77            (spook1 (1- arg)))))
  78
  79 (defun snarf-spooks ()
  80   "Reads in the phrase file"
  81   (message "Checking authorization...")
  82   (save-excursion
  83     (let ((buf (generate-new-buffer "*spook*"))
  84           (result '()))
  85       (set-buffer buf)
  86       (insert-file-contents (expand-file-name spook-phrases-file))
  87       (search-forward "\0")
  88       (while (progn (skip-chars-forward " \t\n\r\f") (not (eobp)))
  89         (let ((beg (point)))
  90           (search-forward "\0")
  91           (setq result (cons (buffer-substring beg (1- (point)))
  92                              result))))
  93       (kill-buffer buf)
  94       (message "Checking authorization... Approved.")
  95       (setq spook-vector (apply 'vector result)))))
  96
  97 (defun pick-random (n)
  98   "Returns a random number from 0 to N-1 inclusive."
  99   (% (logand 0777777 (random)) n))
 100
 101 ; Thanks to Ian G Batten <BattenIG@CS.BHAM.AC.UK>
 102 ; [of the University of Birmingham Computer Science Department]
 103 ; for the iterative version of this shuffle.
 104 ;
 105 (defun shuffle-vector (vector)
 106   "Randomly permute the elements of VECTOR (all permutations equally likely)"
 107   (let ((i 0)
 108         j
 109         temp
 110         (len (length vector)))
 111     (while (< i len)
 112       (setq j (+ i (pick-random (- len i))))
 113       (setq temp (aref vector i))
 114       (aset vector i (aref vector j))
 115       (aset vector j temp)
 116       (setq i (1+ i))))
 117   vector)
 118
 119 ;;; spook.el ends here