+(defcustom gnus-button-valid-fqdn-regexp
+ message-valid-fqdn-regexp
+ "Regular expression that matches a valid FQDN."
+ :version "22.1"
+ :group 'gnus-article-buttons
+ :type 'regexp)
+
+;; Regexp suggested by Felix Wiemann in <87oeuomcz9.fsf@news2.ososo.de>
+(defcustom gnus-button-valid-localpart-regexp
+ "[a-z0-9$%(*-=?[_][^<>\")!;:,{}\n\t @]*"
+ "Regular expression that matches a localpart of mail addresses or MIDs."
+ :version "22.1"
+ :group 'gnus-article-buttons
+ :type 'regexp)
+
+(defcustom gnus-button-man-handler 'manual-entry
+ "Function to use for displaying man pages.
+The function must take at least one argument with a string naming the
+man page."
+ :version "22.1"
+ :type '(choice (function-item :tag "Man" manual-entry)
+ (function-item :tag "Woman" woman)
+ (function :tag "Other"))
+ :group 'gnus-article-buttons)
+
+(defcustom gnus-ctan-url "http://tug.ctan.org/tex-archive/"
+ "Top directory of a CTAN \(Comprehensive TeX Archive Network\) archive.
+If the default site is too slow, try to find a CTAN mirror, see
+<URL:http://tug.ctan.org/tex-archive/CTAN.sites?action=/index.html>. See also
+the variable `gnus-button-handle-ctan'."
+ :version "22.1"
+ :group 'gnus-article-buttons
+ :link '(custom-manual "(gnus)Group Parameters")
+ :type '(choice (const "http://www.tex.ac.uk/tex-archive/")
+ (const "http://tug.ctan.org/tex-archive/")
+ (const "http://www.dante.de/CTAN/")
+ (string :tag "Other")))
+
+(defcustom gnus-button-ctan-handler 'browse-url
+ "Function to use for displaying CTAN links.
+The function must take one argument, the string naming the URL."
+ :version "22.1"
+ :type '(choice (function-item :tag "Browse Url" browse-url)
+ (function :tag "Other"))
+ :group 'gnus-article-buttons)
+
+(defcustom gnus-button-handle-ctan-bogus-regexp "^/?tex-archive/\\|^/"
+ "Bogus strings removed from CTAN URLs."
+ :version "22.1"
+ :group 'gnus-article-buttons
+ :type '(choice (const "^/?tex-archive/\\|/")
+ (regexp :tag "Other")))
+
+(defcustom gnus-button-ctan-directory-regexp
+ (regexp-opt
+ (list "archive-tools" "biblio" "bibliography" "digests" "documentation"
+ "dviware" "fonts" "graphics" "help" "indexing" "info" "language"
+ "languages" "macros" "nonfree" "obsolete" "support" "systems"
+ "tds" "tools" "usergrps" "web") t)
+ "Regular expression for ctan directories.
+It should match all directories in the top level of `gnus-ctan-url'."
+ :version "22.1"
+ :group 'gnus-article-buttons
+ :type 'regexp)
+
+(defcustom gnus-button-mid-or-mail-regexp
+ (concat "\\b\\(<?" gnus-button-valid-localpart-regexp "@"
+ gnus-button-valid-fqdn-regexp
+ ">?\\)\\b")
+ "Regular expression that matches a message ID or a mail address."
+ :version "22.1"
+ :group 'gnus-article-buttons
+ :type 'regexp)
+
+(defcustom gnus-button-prefer-mid-or-mail 'gnus-button-mid-or-mail-heuristic
+ "What to do when the button on a string as \"foo123@bar.invalid\" is pushed.
+Strings like this can be either a message ID or a mail address. If it is one
+of the symbols `mid' or `mail', Gnus will always assume that the string is a
+message ID or a mail address, respectively. If this variable is set to the
+symbol `ask', always query the user what do do. If it is a function, this
+function will be called with the string as it's only argument. The function
+must return `mid', `mail', `invalid' or `ask'."
+ :version "22.1"
+ :group 'gnus-article-buttons
+ :type '(choice (function-item :tag "Heuristic function"
+ gnus-button-mid-or-mail-heuristic)
+ (const ask)
+ (const mid)
+ (const mail)))
+
+(defcustom gnus-button-mid-or-mail-heuristic-alist
+ '((-10.0 . ".+\\$.+@")
+ (-10.0 . "#")
+ (-10.0 . "\\*")
+ (-5.0 . "\\+[^+]*\\+.*@") ;; # two plus signs
+ (-5.0 . "@[Nn][Ee][Ww][Ss]") ;; /\@news/i
+ (-5.0 . "@.*[Dd][Ii][Aa][Ll][Uu][Pp]") ;; /\@.*dialup/i;
+ (-1.0 . "^[^a-z]+@")
+ ;;
+ (-5.0 . "\\.[0-9][0-9]+.*@") ;; "\.[0-9]{2,}.*\@"
+ (-5.0 . "[a-z].*[A-Z].*[a-z].*[A-Z].*@") ;; "([a-z].*[A-Z].*){2,}\@"
+ (-3.0 . "[A-Z][A-Z][a-z][a-z].*@")
+ (-5.0 . "\\...?.?@") ;; (-5.0 . "\..{1,3}\@")
+ ;;
+ (-2.0 . "^[0-9]")
+ (-1.0 . "^[0-9][0-9]")
+ ;;
+ ;; -3.0 /^[0-9][0-9a-fA-F]{2,2}/;
+ (-3.0 . "^[0-9][0-9a-fA-F][0-9a-fA-F][^0-9a-fA-F]")
+ ;; -5.0 /^[0-9][0-9a-fA-F]{3,3}/;
+ (-5.0 . "^[0-9][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][^0-9a-fA-F]")
+ ;;
+ (-3.0 . "[0-9][0-9][0-9][0-9][0-9][^0-9].*@") ;; "[0-9]{5,}.*\@"
+ (-3.0 . "[0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][^0-9].*@")
+ ;; "[0-9]{8,}.*\@"
+ (-3.0
+ . "[0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9].*@")
+ ;; "[0-9]{12,}.*\@"
+ ;; compensation for TDMA dated mail addresses:
+ (25.0 . "-dated-[0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9]+.*@")
+ ;;
+ (-20.0 . "\\.fsf@") ;; Gnus
+ (-20.0 . "^slrn")
+ (-20.0 . "^Pine")
+ (-20.0 . "_-_") ;; Subject change in thread
+ ;;
+ (-20.0 . "\\.ln@") ;; leafnode
+ (-30.0 . "@ID-[0-9]+\\.[a-zA-Z]+\\.dfncis\\.de")
+ (-30.0 . "@4[Aa][Xx]\\.com") ;; Forte Agent
+ ;;
+ ;; (5.0 . "") ;; $local_part_len <= 7
+ (10.0 . "^[^0-9]+@")
+ (3.0 . "^[^0-9]+[0-9][0-9]?[0-9]?@")
+ ;; ^[^0-9]+[0-9]{1,3}\@ digits only at end of local part
+ (3.0 . "\@stud")
+ ;;
+ (2.0 . "[a-z][a-z][._-][A-Z][a-z].*@")
+ ;;
+ (0.5 . "^[A-Z][a-z]")
+ (0.5 . "^[A-Z][a-z][a-z]")
+ (1.5 . "^[A-Z][a-z][A-Z][a-z][^a-z]") ;; ^[A-Z][a-z]{3,3}
+ (2.0 . "^[A-Z][a-z][A-Z][a-z][a-z][^a-z]")) ;; ^[A-Z][a-z]{4,4}
+ "An alist of \(RATE . REGEXP\) pairs for `gnus-button-mid-or-mail-heuristic'.
+
+A negative RATE indicates a message IDs, whereas a positive indicates a mail
+address. The REGEXP is processed with `case-fold-search' set to nil."
+ :version "22.1"
+ :group 'gnus-article-buttons
+ :type '(repeat (cons (number :tag "Rate")
+ (regexp :tag "Regexp"))))
+
+(defun gnus-button-mid-or-mail-heuristic (mid-or-mail)
+ "Guess whether MID-OR-MAIL is a message ID or a mail address.
+Returns `mid' if MID-OR-MAIL is a message IDs, `mail' if it's a mail
+address, `ask' if unsure and `invalid' if the string is invalid."
+ (let ((case-fold-search nil)
+ (list gnus-button-mid-or-mail-heuristic-alist)
+ (result 0) rate regexp lpartlen elem)
+ (setq lpartlen
+ (length (gnus-replace-in-string mid-or-mail "^\\(.*\\)@.*$" "\\1")))
+ (gnus-message 8 "`%s', length of local part=`%s'." mid-or-mail lpartlen)
+ ;; Certain special cases...
+ (when (string-match
+ (concat
+ "^0[0-9]+-[0-9][0-9][0-9][0-9]@t-online\\.de$\\|"
+ "^[0-9]+\\.[0-9]+@compuserve\\|"
+ "@public\\.gmane\\.org")
+ mid-or-mail)
+ (gnus-message 8 "`%s' is a known mail address." mid-or-mail)
+ (setq result 'mail))
+ (when (string-match "@.*@\\| " mid-or-mail)
+ (gnus-message 8 "`%s' is invalid." mid-or-mail)
+ (setq result 'invalid))
+ ;; Nothing more to do, if result is not a number here...
+ (when (numberp result)
+ (while list
+ (setq elem (car list)
+ rate (car elem)
+ regexp (cdr elem)
+ list (cdr list))
+ (when (string-match regexp mid-or-mail)
+ (setq result (+ result rate))
+ (gnus-message
+ 9 "`%s' matched `%s', rate `%s', result `%s'."
+ mid-or-mail regexp rate result)))
+ (when (<= lpartlen 7)
+ (setq result (+ result 5.0))
+ (gnus-message 9 "`%s' matched (<= lpartlen 7), result `%s'."
+ mid-or-mail result))
+ (when (>= lpartlen 12)
+ (gnus-message 9 "`%s' matched (>= lpartlen 12)" mid-or-mail)
+ (cond
+ ((string-match "[0-9][^0-9]+[0-9].*@" mid-or-mail)
+ ;; Long local part should contain realname if e-mail address,
+ ;; too many digits: message-id.
+ ;; $score -= 5.0 + 0.1 * $local_part_len;
+ (setq rate (* -1.0 (+ 5.0 (* 0.1 lpartlen))))
+ (setq result (+ result rate))
+ (gnus-message
+ 9 "Many digits in `%s', rate `%s', result `%s'."
+ mid-or-mail rate result))
+ ((string-match "[^aeiouy][^aeiouy][^aeiouy][^aeiouy]+.*\@"
+ mid-or-mail)
+ ;; Too few vowels [^aeiouy]{4,}.*\@
+ (setq result (+ result -5.0))
+ (gnus-message
+ 9 "Few vowels in `%s', rate `%s', result `%s'."
+ mid-or-mail -5.0 result))
+ (t
+ (setq result (+ result 5.0))
+ (gnus-message
+ 9 "`%s', rate `%s', result `%s'." mid-or-mail 5.0 result)))))
+ (gnus-message 8 "`%s': Final rate is `%s'." mid-or-mail result)
+ ;; Maybe we should make this a customizable alist: (condition . 'result)
+ (cond
+ ((symbolp result) result)
+ ;; Now convert number into proper results:
+ ((< result -10.0) 'mid)
+ ((> result 10.0) 'mail)
+ (t 'ask))))
+
+(defun gnus-button-handle-mid-or-mail (mid-or-mail)
+ (let* ((pref gnus-button-prefer-mid-or-mail) guessed
+ (url-mid (concat "news" ":" mid-or-mail))
+ (url-mailto (concat "mailto" ":" mid-or-mail)))
+ (gnus-message 9 "mid-or-mail=%s" mid-or-mail)
+ (when (fboundp pref)
+ (setq guessed
+ ;; get rid of surrounding angles...
+ (funcall pref
+ (gnus-replace-in-string mid-or-mail "^<\\|>$" "")))
+ (if (or (eq 'mid guessed) (eq 'mail guessed))
+ (setq pref guessed)
+ (setq pref 'ask)))
+ (if (eq pref 'ask)
+ (save-window-excursion
+ (if (y-or-n-p (concat "Is <" mid-or-mail "> a mail address? "))
+ (setq pref 'mail)
+ (setq pref 'mid))))
+ (cond ((eq pref 'mid)
+ (gnus-message 8 "calling `gnus-button-handle-news' %s" url-mid)
+ (gnus-button-handle-news url-mid))
+ ((eq pref 'mail)
+ (gnus-message 8 "calling `gnus-url-mailto' %s" url-mailto)
+ (gnus-url-mailto url-mailto))
+ (t (gnus-message 3 "Invalid string.")))))
+
+(defun gnus-button-handle-custom (url)
+ "Follow a Custom URL."
+ (customize-apropos (gnus-url-unhex-string url)))
+
+(defvar gnus-button-handle-describe-prefix "^\\(C-h\\|<?[Ff]1>?\\)")
+
+;; FIXME: Maybe we should merge some of the functions that do quite similar
+;; stuff?
+
+(defun gnus-button-handle-describe-function (url)
+ "Call `describe-function' when pushing the corresponding URL button."
+ (describe-function
+ (intern
+ (gnus-replace-in-string url gnus-button-handle-describe-prefix ""))))
+
+(defun gnus-button-handle-describe-variable (url)
+ "Call `describe-variable' when pushing the corresponding URL button."
+ (describe-variable
+ (intern
+ (gnus-replace-in-string url gnus-button-handle-describe-prefix ""))))
+
+(defun gnus-button-handle-symbol (url)
+"Display help on variable or function.
+Calls `describe-variable' or `describe-function'."
+ (let ((sym (intern url)))
+ (cond
+ ((fboundp sym) (describe-function sym))
+ ((boundp sym) (describe-variable sym))
+ (t (gnus-message 3 "`%s' is not a known function of variable." url)))))
+
+(defun gnus-button-handle-describe-key (url)
+ "Call `describe-key' when pushing the corresponding URL button."
+ (let* ((key-string
+ (gnus-replace-in-string url gnus-button-handle-describe-prefix ""))
+ (keys (ignore-errors (eval `(kbd ,key-string)))))
+ (if keys
+ (describe-key keys)
+ (gnus-message 3 "Invalid key sequence in button: %s" key-string))))
+
+(defun gnus-button-handle-apropos (url)
+ "Call `apropos' when pushing the corresponding URL button."
+ (apropos (gnus-replace-in-string url gnus-button-handle-describe-prefix "")))
+
+(defun gnus-button-handle-apropos-command (url)
+ "Call `apropos' when pushing the corresponding URL button."
+ (apropos-command
+ (gnus-replace-in-string url gnus-button-handle-describe-prefix "")))
+
+(defun gnus-button-handle-apropos-variable (url)
+ "Call `apropos' when pushing the corresponding URL button."
+ (funcall
+ (if (fboundp 'apropos-variable) 'apropos-variable 'apropos)
+ (gnus-replace-in-string url gnus-button-handle-describe-prefix "")))
+
+(defun gnus-button-handle-apropos-documentation (url)
+ "Call `apropos' when pushing the corresponding URL button."
+ (funcall
+ (if (fboundp 'apropos-documentation) 'apropos-documentation 'apropos)
+ (gnus-replace-in-string url gnus-button-handle-describe-prefix "")))
+
+(defun gnus-button-handle-library (url)
+ "Call `locate-library' when pushing the corresponding URL button."
+ (gnus-message 9 "url=`%s'" url)
+ (let* ((lib (locate-library url))
+ (file (gnus-replace-in-string (or lib "") "\.elc" ".el")))
+ (if (not lib)
+ (gnus-message 1 "Cannot locale library `%s'." url)
+ (find-file-read-only file))))
+
+(defun gnus-button-handle-ctan (url)
+ "Call `browse-url' when pushing a CTAN URL button."
+ (funcall
+ gnus-button-ctan-handler
+ (concat
+ gnus-ctan-url
+ (gnus-replace-in-string url gnus-button-handle-ctan-bogus-regexp ""))))
+
+(defcustom gnus-button-tex-level 5
+ "*Integer that says how many TeX-related buttons Gnus will show.
+The higher the number, the more buttons will appear and the more false
+positives are possible. Note that you can set this variable local to
+specific groups. Setting it higher in TeX groups is probably a good idea.
+See Info node `(gnus)Group Parameters' and the variable `gnus-parameters' on
+how to set variables in specific groups."
+ :version "22.1"
+ :group 'gnus-article-buttons
+ :link '(custom-manual "(gnus)Group Parameters")
+ :type 'integer)
+
+(defcustom gnus-button-man-level 5
+ "*Integer that says how many man-related buttons Gnus will show.
+The higher the number, the more buttons will appear and the more false
+positives are possible. Note that you can set this variable local to
+specific groups. Setting it higher in Unix groups is probably a good idea.
+See Info node `(gnus)Group Parameters' and the variable `gnus-parameters' on
+how to set variables in specific groups."
+ :version "22.1"
+ :group 'gnus-article-buttons
+ :link '(custom-manual "(gnus)Group Parameters")
+ :type 'integer)
+
+(defcustom gnus-button-emacs-level 5
+ "*Integer that says how many emacs-related buttons Gnus will show.
+The higher the number, the more buttons will appear and the more false
+positives are possible. Note that you can set this variable local to
+specific groups. Setting it higher in Emacs or Gnus related groups is
+probably a good idea. See Info node `(gnus)Group Parameters' and the variable
+`gnus-parameters' on how to set variables in specific groups."
+ :version "22.1"
+ :group 'gnus-article-buttons
+ :link '(custom-manual "(gnus)Group Parameters")
+ :type 'integer)
+
+(defcustom gnus-button-message-level 5
+ "*Integer that says how many buttons for news or mail messages will appear.
+The higher the number, the more buttons will appear and the more false
+positives are possible."
+ ;; mail addresses, MIDs, URLs for news, ...
+ :version "22.1"
+ :group 'gnus-article-buttons
+ :type 'integer)
+
+(defcustom gnus-button-browse-level 5
+ "*Integer that says how many buttons for browsing will appear.
+The higher the number, the more buttons will appear and the more false
+positives are possible."
+ ;; stuff handled by `browse-url' or `gnus-button-embedded-url'
+ :version "22.1"
+ :group 'gnus-article-buttons
+ :type 'integer)
+