1 ;;; cookie1.el --- retrieve random phrases from fortune cookie files
3 ;; Copyright (C) 1993, 2001-2012 Free Software Foundation, Inc.
5 ;; Author: Eric S. Raymond <esr@snark.thyrsus.com>
7 ;; Keywords: games, extensions
8 ;; Created: Mon Mar 22 17:06:26 1993
10 ;; This file is part of GNU Emacs.
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 3 of the License, or
15 ;; (at your option) any later version.
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.
22 ;; You should have received a copy of the GNU General Public License
23 ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
27 ;; Support for random cookie fetches from phrase files, used for such
28 ;; critical applications as emulating Zippy the Pinhead and confounding
29 ;; the NSA Trunk Trawler.
31 ;; The two entry points are `cookie' and `cookie-insert'. The helper
32 ;; function `shuffle-vector' may be of interest to programmers.
34 ;; The code expects phrase files to be in one of two formats:
36 ;; * ITS-style LINS format (strings terminated by ASCII 0 characters,
37 ;; leading whitespace ignored).
39 ;; * UNIX fortune file format (quotes terminated by %% on a line by itself).
41 ;; Everything up to the first delimiter is treated as a comment. Other
42 ;; formats could be supported by adding alternates to the regexp
43 ;; `cookie-delimiter'.
45 ;; strfile(1) is the program used to compile the files for fortune(6).
46 ;; In order to achieve total compatibility with strfile(1), cookie files
47 ;; should start with two consecutive delimiters (and no comment).
49 ;; This code derives from Steve Strassmann's 1987 spook.el package, but
50 ;; has been generalized so that it supports multiple simultaneous
51 ;; cookie databases and fortune files. It is intended to be called
52 ;; from other packages such as yow.el and spook.el.
56 (defconst cookie-delimiter
"\n%%\n\\|\n%\n\\|\0"
57 "Delimiter used to separate cookie file entries.")
59 (defvar cookie-cache
(make-vector 511 0)
60 "Cache of cookie files that have already been snarfed.")
63 (defun cookie (phrase-file startmsg endmsg
)
64 "Return a random phrase from PHRASE-FILE.
65 When the phrase file is read in, display STARTMSG at the beginning
66 of load, ENDMSG at the end."
67 (let ((cookie-vector (cookie-snarf phrase-file startmsg endmsg
)))
68 (shuffle-vector cookie-vector
)
69 (aref cookie-vector
0)))
72 (defun cookie-insert (phrase-file &optional count startmsg endmsg
)
73 "Insert random phrases from PHRASE-FILE; COUNT of them.
74 When the phrase file is read in, display STARTMSG at the beginning
75 of load, ENDMSG at the end."
76 (let ((cookie-vector (cookie-snarf phrase-file startmsg endmsg
)))
77 (shuffle-vector cookie-vector
)
78 (let ((start (point)))
80 (cookie1 (min (- (length cookie-vector
) 1) (or count
1)) cookie-vector
)
82 (fill-region-as-paragraph start
(point) nil
))))
84 (defun cookie1 (arg cookie-vec
)
85 "Inserts a cookie phrase ARG times."
87 (t (insert (aref cookie-vec arg
))
89 (cookie1 (1- arg
) cookie-vec
))))
92 (defun cookie-snarf (phrase-file startmsg endmsg
)
93 "Reads in the PHRASE-FILE, returns it as a vector of strings.
94 Emit STARTMSG and ENDMSG before and after. Caches the result; second
95 and subsequent calls on the same file won't go to disk."
96 (or (file-readable-p phrase-file
)
97 (error "Cannot read file `%s'" phrase-file
))
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? "))
106 (setq sym
(intern phrase-file cookie-cache
))
107 (message "%s" startmsg
)
109 (let ((buf (generate-new-buffer "*cookie*"))
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)))
117 (re-search-forward cookie-delimiter
)
118 (setq result
(cons (buffer-substring beg
(match-beginning 0))
121 (message "%s" endmsg
)
122 (set sym
(apply 'vector result
)))))))
124 (defun read-cookie (prompt phrase-file startmsg endmsg
&optional require-match
)
125 "Prompt with PROMPT and read with completion among cookies in PHRASE-FILE.
126 STARTMSG and ENDMSG are passed along to `cookie-snarf'.
127 Optional fifth arg REQUIRE-MATCH non-nil forces a matching cookie."
128 ;; Make sure the cookies are in the cache.
129 (or (intern-soft phrase-file cookie-cache
)
130 (cookie-snarf phrase-file startmsg endmsg
))
131 (completing-read prompt
132 (let ((sym (intern phrase-file cookie-cache
)))
133 ;; We cache the alist form of the cookie in a property.
134 (or (get sym
'completion-alist
)
136 (vec (cookie-snarf phrase-file
139 (while (>= (setq i
(1- i
)) 0)
140 (setq alist
(cons (list (aref vec i
)) alist
)))
141 (put sym
'completion-alist alist
))))
142 nil require-match nil nil
))
144 ; Thanks to Ian G Batten <BattenIG@CS.BHAM.AC.UK>
145 ; [of the University of Birmingham Computer Science Department]
146 ; for the iterative version of this shuffle.
149 (defun shuffle-vector (vector)
150 "Randomly permute the elements of VECTOR (all permutations equally likely)."
154 (len (length vector
)))
156 (setq j
(+ i
(random (- len i
))))
157 (setq temp
(aref vector i
))
158 (aset vector i
(aref vector j
))
165 ;;; cookie1.el ends here