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8eb74eec | 1 | ;;; cookie1.el --- retrieve random phrases from fortune cookie files |
d5edbd11 ER |
2 | |
3 | ;; Copyright (C) 1993 Free Software Foundation, Inc. | |
4 | ||
5 | ;; Author: Eric S. Raymond <esr@snark.thyrsus.com> | |
6 | ;; Maintainer: FSF | |
7 | ;; Keywords: games | |
8 | ;; Created: Mon Mar 22 17:06:26 1993 | |
9 | ||
10 | ;; This file is part of GNU Emacs. | |
11 | ||
12 | ;; GNU Emacs is free software; you can redistribute it and/or modify | |
13 | ;; it under the terms of the GNU General Public License as published by | |
14 | ;; the Free Software Foundation; either version 2, or (at your option) | |
15 | ;; any later version. | |
16 | ||
17 | ;; GNU Emacs is distributed in the hope that it will be useful, | |
18 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of | |
19 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
20 | ;; GNU General Public License for more details. | |
21 | ||
22 | ;; You should have received a copy of the GNU General Public License | |
23 | ;; along with GNU Emacs; see the file COPYING. If not, write to | |
24 | ;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. | |
25 | ||
26 | ;;; Commentary: | |
27 | ||
28 | ;; Support for random cookie fetches from phrase files, used for such | |
29 | ;; critical applications as emulating Zippy the Pinhead and confounding | |
30 | ;; the NSA Trunk Trawler. | |
31 | ;; | |
32 | ;; The two entry points are `cookie' and `cookie-insert'. The helper | |
33 | ;; functions `pick-random' and `shuffle-vector' may be of interest to | |
34 | ;; programmers. | |
35 | ;; | |
45b44a5a ER |
36 | ;; The code expects phrase files to be in one of two formats: |
37 | ;; | |
38 | ;; * ITS-style LINS format (strings terminated by ASCII 0 characters, | |
39 | ;; leading whitespace ignored). | |
40 | ;; | |
41 | ;; * UNIX fortune file format (quotes terminated by %% on a line by itself). | |
42 | ;; | |
43 | ;; Everything up to the first delimiter is treated as a comment. Other | |
44 | ;; formats could be supported by adding alternates to the regexp | |
45 | ;; `cookie-delimiter'. | |
d5edbd11 ER |
46 | ;; |
47 | ;; This code derives from Steve Strassman's 1987 spook.el package, but | |
45b44a5a ER |
48 | ;; has been generalized so that it supports multiple simultaneous |
49 | ;; cookie databases and fortune files. It is intended to be called | |
50 | ;; from other packages such as yow.el and spook.el. | |
cf597dc8 ER |
51 | ;; |
52 | ;; TO DO: teach cookie-snarf to auto-detect ITS PINS or UNIX fortune(6) | |
53 | ;; format and do the right thing. | |
d5edbd11 ER |
54 | |
55 | ;;; Code: | |
56 | ||
57 | ; Randomize the seed in the random number generator. | |
58 | (random t) | |
59 | ||
45b44a5a | 60 | (defconst cookie-delimiter "\n%%\n\\|\0" |
d5edbd11 ER |
61 | "Delimiter used to separate cookie file entries.") |
62 | ||
4054367c RM |
63 | (defvar cookie-cache (make-vector 511 0) |
64 | "Cache of cookie files that have already been snarfed.") | |
65 | ||
f58c6f70 | 66 | ;;;###autoload |
d5edbd11 ER |
67 | (defun cookie (phrase-file startmsg endmsg) |
68 | "Return a random phrase from PHRASE-FILE. When the phrase file | |
69 | is read in, display STARTMSG at beginning of load, ENDMSG at end." | |
70 | (let ((cookie-vector (cookie-snarf phrase-file startmsg endmsg))) | |
71 | (shuffle-vector cookie-vector) | |
72 | (aref cookie-vector 1))) | |
73 | ||
f58c6f70 | 74 | ;;;###autoload |
d5edbd11 ER |
75 | (defun cookie-insert (phrase-file &optional count startmsg endmsg) |
76 | "Insert random phrases from PHRASE-FILE; COUNT of them. When the phrase file | |
77 | is read in, display STARTMSG at beginning of load, ENDMSG at end." | |
78 | (let ((cookie-vector (cookie-snarf phrase-file startmsg endmsg))) | |
79 | (shuffle-vector cookie-vector) | |
80 | (let ((start (point))) | |
81 | (insert ?\n) | |
82 | (cookie1 (min (- (length cookie-vector) 1) (or count 1)) cookie-vector) | |
83 | (insert ?\n) | |
84 | (fill-region-as-paragraph start (point) nil)))) | |
85 | ||
86 | (defun cookie1 (arg cookie-vec) | |
87 | "Inserts a cookie phrase ARG times." | |
88 | (cond ((zerop arg) t) | |
89 | (t (insert (aref cookie-vec arg)) | |
90 | (insert " ") | |
91 | (cookie1 (1- arg) cookie-vec)))) | |
92 | ||
f58c6f70 | 93 | ;;;###autoload |
d5edbd11 ER |
94 | (defun cookie-snarf (phrase-file startmsg endmsg) |
95 | "Reads in the PHRASE-FILE, returns it as a vector of strings. Emit | |
96 | STARTMSG and ENDMSG before and after. Caches the result; second and | |
97 | subsequent calls on the same file won't go to disk." | |
4054367c RM |
98 | (let ((sym (intern-soft phrase-file cookie-cache))) |
99 | (and sym (not (equal (symbol-function sym) | |
100 | (nth 5 (file-attributes phrase-file)))) | |
101 | (yes-or-no-p (concat phrase-file | |
102 | " has changed. Read new contents? ")) | |
103 | (setq sym nil)) | |
104 | (if sym | |
105 | (symbol-value sym) | |
106 | (setq sym (intern phrase-file cookie-cache)) | |
107 | (message startmsg) | |
108 | (save-excursion | |
109 | (let ((buf (generate-new-buffer "*cookie*")) | |
110 | (result nil)) | |
111 | (set-buffer buf) | |
112 | (fset sym (nth 5 (file-attributes phrase-file))) | |
113 | (insert-file-contents (expand-file-name phrase-file)) | |
114 | (re-search-forward cookie-delimiter) | |
115 | (while (progn (skip-chars-forward " \t\n\r\f") (not (eobp))) | |
116 | (let ((beg (point))) | |
117 | (re-search-forward cookie-delimiter) | |
118 | (setq result (cons (buffer-substring beg (1- (point))) | |
119 | result)))) | |
120 | (kill-buffer buf) | |
121 | (message endmsg) | |
122 | (set sym (apply 'vector result))))))) | |
d5edbd11 ER |
123 | |
124 | (defun pick-random (n) | |
125 | "Returns a random number from 0 to N-1 inclusive." | |
126 | (% (logand 0777777 (random)) n)) | |
127 | ||
128 | ; Thanks to Ian G Batten <BattenIG@CS.BHAM.AC.UK> | |
129 | ; [of the University of Birmingham Computer Science Department] | |
130 | ; for the iterative version of this shuffle. | |
131 | ; | |
f58c6f70 | 132 | ;;;###autoload |
d5edbd11 ER |
133 | (defun shuffle-vector (vector) |
134 | "Randomly permute the elements of VECTOR (all permutations equally likely)" | |
135 | (let ((i 0) | |
136 | j | |
137 | temp | |
138 | (len (length vector))) | |
139 | (while (< i len) | |
140 | (setq j (+ i (pick-random (- len i)))) | |
141 | (setq temp (aref vector i)) | |
142 | (aset vector i (aref vector j)) | |
143 | (aset vector j temp) | |
144 | (setq i (1+ i)))) | |
145 | vector) | |
146 | ||
3aa7cce7 | 147 | (provide 'cookie1) |
d5edbd11 | 148 | |
20a82895 | 149 | ;;; cookie1.el ends here |