;;; cookie1.el --- retrieve random phrases from fortune cookie files -*- lexical-binding: t -*-
;; Copyright (C) 1993, 2001-2024 Free Software Foundation, Inc.
;; Author: Eric S. Raymond <esr@snark.thyrsus.com>
;; Maintainer: emacs-devel@gnu.org
;; Keywords: games, extensions
;; Created: Mon Mar 22 17:06:26 1993
;; This file is part of GNU Emacs.
;; GNU Emacs is free software: you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.
;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;; GNU General Public License for more details.
;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs. If not, see <https://www.gnu.org/licenses/>.
;;; Commentary:
;; Support for random cookie fetches from phrase files, used for such
;; critical applications as confounding the NSA Trunk Trawler.
;;
;; The two entry points are `cookie' and `cookie-insert'. The helper
;; function `cookie-shuffle-vector' may be of interest to programmers.
;;
;; The code expects phrase files to be in one of two formats:
;;
;; * ITS-style LINS format (strings terminated by ASCII 0 characters,
;; leading whitespace ignored).
;;
;; * UNIX fortune file format (quotes terminated by %% on a line by itself).
;;
;; Everything up to the first delimiter is treated as a comment. Other
;; formats could be supported by adding alternates to the regexp
;; `cookie-delimiter'.
;;
;; strfile(1) is the program used to compile the files for fortune(6).
;; In order to achieve total compatibility with strfile(1), cookie files
;; should start with two consecutive delimiters (and no comment).
;;
;; This code derives from Steve Strassmann's 1987 spook.el package, but
;; has been generalized so that it supports multiple simultaneous
;; cookie databases and fortune files. It is intended to be called
;; from other packages such as spook.el.
;;; Code:
(defgroup cookie nil
"Random cookies from phrase files."
:prefix "cookie-"
:group 'games)
(defcustom cookie-file nil
"Default phrase file for cookie functions."
:type '(choice (const nil) file)
:version "24.4")
(defconst cookie-delimiter "\n%%\n\\|\n%\n\\|\0"
"Delimiter used to separate cookie file entries.")
(defvar cookie-cache (make-vector 511 0)
"Cache of cookie files that have already been snarfed.")
(defun cookie-check-file (file)
"Return either FILE or `cookie-file'.
Signal an error if the result is nil or not readable."
(or (setq file (or file cookie-file)) (user-error "No phrase file specified"))
(or (file-readable-p file) (user-error "Cannot read file `%s'" file))
file)
;;;###autoload
(defun cookie (phrase-file &optional startmsg endmsg)
"Return a random phrase from PHRASE-FILE.
When the phrase file is read in, display STARTMSG at the beginning
of load, ENDMSG at the end.
Interactively, PHRASE-FILE defaults to `cookie-file', unless that
is nil or a prefix argument is used."
(interactive (list (if (or current-prefix-arg (not cookie-file))
(read-file-name "Cookie file: " nil
cookie-file t cookie-file)
cookie-file) nil nil))
(setq phrase-file (cookie-check-file phrase-file))
(let ((cookie-vector (cookie-snarf phrase-file startmsg endmsg))
res)
(cookie-shuffle-vector cookie-vector)
(setq res (aref cookie-vector 0))
(if (called-interactively-p 'interactive)
(message "%s" res)
res)))
;;;###autoload
(defun cookie-insert (phrase-file &optional count startmsg endmsg)
"Insert random phrases from PHRASE-FILE; COUNT of them.
When the phrase file is read in, display STARTMSG at the beginning
of load, ENDMSG at the end."
(setq phrase-file (cookie-check-file phrase-file))
(let ((cookie-vector (cookie-snarf phrase-file startmsg endmsg)))
(cookie-shuffle-vector cookie-vector)
(let ((start (point)))
(insert ?\n)
(cookie1 (min (- (length cookie-vector) 1) (or count 1)) cookie-vector)
(insert ?\n)
(fill-region-as-paragraph start (point) nil))))
(defun cookie1 (arg cookie-vec)
"Insert a cookie phrase ARG times."
(cond ((zerop arg) t)
(t (insert (aref cookie-vec arg))
(insert " ")
(cookie1 (1- arg) cookie-vec))))
;;;###autoload
(defun cookie-snarf (phrase-file &optional startmsg endmsg)
"Read the PHRASE-FILE, return it as a vector of strings.
Emit STARTMSG and ENDMSG before and after. Cache the result; second
and subsequent calls on the same file won't go to disk."
(setq phrase-file (cookie-check-file phrase-file))
(let ((sym (intern-soft phrase-file cookie-cache)))
(and sym (not (time-equal-p
(symbol-function sym)
(file-attribute-modification-time
(file-attributes phrase-file))))
(yes-or-no-p (concat phrase-file
" has changed. Read new contents? "))
(setq sym nil))
(if sym
(symbol-value sym)
(setq sym (intern phrase-file cookie-cache))
(if startmsg (message "%s" startmsg))
(fset sym (file-attribute-modification-time
(file-attributes phrase-file)))
(let (result)
(with-temp-buffer
(insert-file-contents (expand-file-name phrase-file))
(re-search-forward cookie-delimiter)
(while (progn (skip-chars-forward " \t\n\r\f") (not (eobp)))
(let ((beg (point)))
(re-search-forward cookie-delimiter)
(setq result (cons (buffer-substring beg (match-beginning 0))
result)))))
(if endmsg (message "%s" endmsg))
(set sym (apply 'vector result))))))
(defun cookie-read (prompt phrase-file &optional startmsg endmsg require-match)
"Prompt with PROMPT and read with completion among cookies in PHRASE-FILE.
STARTMSG and ENDMSG are passed along to `cookie-snarf'.
Argument REQUIRE-MATCH non-nil forces a matching cookie."
(setq phrase-file (cookie-check-file phrase-file))
;; Make sure the cookies are in the cache.
(or (intern-soft phrase-file cookie-cache)
(cookie-snarf phrase-file startmsg endmsg))
(completing-read prompt
(let ((sym (intern phrase-file cookie-cache)))
;; We cache the alist form of the cookie in a property.
(or (get sym 'completion-alist)
(let* ((alist nil)
(vec (cookie-snarf phrase-file
startmsg endmsg))
(i (length vec)))
(while (>= (setq i (1- i)) 0)
(setq alist (cons (list (aref vec i)) alist)))
(put sym 'completion-alist alist))))
nil require-match nil nil))
(define-obsolete-function-alias 'read-cookie 'cookie-read "24.4")
;; Thanks to Ian G Batten <BattenIG@CS.BHAM.AC.UK>
;; [of the University of Birmingham Computer Science Department]
;; for the iterative version of this shuffle.
(defun cookie-shuffle-vector (vector)
"Randomly permute the elements of VECTOR (all permutations equally likely)."
(let ((len (length vector))
j temp)
(dotimes (i len)
(setq j (+ i (random (- len i)))
temp (aref vector i))
(aset vector i (aref vector j))
(aset vector j temp))
vector))
(define-obsolete-function-alias 'shuffle-vector 'cookie-shuffle-vector "24.4")
(defun cookie-apropos (regexp phrase-file &optional display)
"Return a list of all entries matching REGEXP from PHRASE-FILE.
Interactively, uses `read-regexp' to read REGEXP.
Interactively, PHRASE-FILE defaults to `cookie-file', unless that
is nil or a prefix argument is used.
If called interactively, or if DISPLAY is non-nil, display a list of matches."
(interactive (list (read-regexp "Apropos phrase (regexp): ")
(if (or current-prefix-arg (not cookie-file))
(read-file-name "Cookie file: " nil
cookie-file t cookie-file)
cookie-file) t))
(setq phrase-file (cookie-check-file phrase-file))
;; Make sure phrases are loaded.
(cookie phrase-file)
(let* ((case-fold-search t)
(cookie-table-symbol (intern phrase-file cookie-cache))
(string-table (symbol-value cookie-table-symbol))
(matches nil))
(dotimes (i (length string-table))
(and (string-match-p regexp (aref string-table i))
(setq matches (cons (aref string-table i) matches))))
(and matches
(setq matches (sort matches 'string-lessp)))
(and display
(if matches
(let ((l matches))
(with-output-to-temp-buffer "*Cookie Apropos*"
(while l
(princ (car l))
(setq l (cdr l))
(and l (princ "\n\n")))
(help-print-return-message)))
(message "No matches found.")))
matches))
(declare-function doctor-ret-or-read "doctor" (arg))
(defun cookie-doctor (phrase-file)
"Feed cookie phrases from PHRASE-FILE to the doctor.
Interactively, PHRASE-FILE defaults to `cookie-file', unless that
is nil or a prefix argument is used."
(interactive (list (if (or current-prefix-arg (not cookie-file))
(read-file-name "Cookie file: " nil
cookie-file t cookie-file)
cookie-file)))
(setq phrase-file (cookie-check-file phrase-file))
(doctor) ; start the psychotherapy
(message "")
(switch-to-buffer "*doctor*")
(sit-for 0)
(while (not (input-pending-p))
(insert (cookie phrase-file))
(sit-for 0)
(doctor-ret-or-read 1)
(doctor-ret-or-read 1)))
(provide 'cookie1)
;;; cookie1.el ends here