Initial revision

lisp/zone-mode.el

+;;; zone-mode.el -- major mode for editing DNS zone files.
+
+;; Copyright (C) 1998 Free Software Foundation, Inc.
+
+;; Author: John Heidemann <johnh@isi.edu>
+;; Keywords: DNS, languages
+
+;; 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 2, 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; see the file COPYING.  If not, write to the
+;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+;; Boston, MA 02111-1307, USA.
+
+;;;
+;;; See the comments in ``define-derived-mode zone-mode''
+;;; (the last function in this file)
+;;; for what this mode is and how to use it automatically.
+;;;
+
+;;;
+;;; Credits:
+;;; Zone-mode was written by John Heidemann <johnh@isi.edu>,
+;;; with bug fixes from Simon Leinen <simon@limmat.switch.ch>.
+;;;
+
+;;; Code:
+
+(defun zone-mode-update-serial ()
+  "Update the serial number in a zone."
+  (interactive)
+  (save-excursion
+    (goto-char (point-min))
+    (while (re-search-forward "\\b\\([0-9]+\\)\\([0-9][0-9]\\)\\([ \t]+;[ \t]+[Ss]erial\\)" (point-max) t)
+      (let* ((old-date (match-string 1))
+	     (old-seq (match-string 2))
+	     (old-seq-num (string-to-number (match-string 2)))
+	     (old-flag (match-string 3))
+	     (cur-date (format-time-string "%Y%m%d"))
+	     (new-seq
+	      (cond
+	       ((not (string= old-date cur-date))
+		"00") ;; reset sequeence number
+	       ((>= old-seq-num 99)
+		(error "Serial number's sequenece cannot increment beyond 99."))
+	       (t
+		(format "%02d" (1+ old-seq-num)))))
+	     (old-serial (concat old-date old-seq))
+	     (new-serial (concat cur-date new-seq)))
+	(if (string-lessp new-serial old-serial)
+	    (error (format "Serial numbers want to move backwards from %s to %s!" old-serial new-serial))
+	  (replace-match (concat cur-date new-seq old-flag) t t))))))
+  
+;;;###autoload
+(defun zone-mode-update-serial-hook ()
+  "Update the serial number in a zone if the file was modified"
+  (interactive)
+  (if (buffer-modified-p (current-buffer))
+      (zone-mode-update-serial))
+  nil ;; so we can run from write-file-hooks
+  )
+
+(defvar zone-mode-syntax-table nil
+  "Zone-mode's syntax table.")
+
+(defun zone-mode-load-time-setup ()
+  "init zone-mode stuff"
+  (setq zone-mode-syntax-table (make-syntax-table))
+  (modify-syntax-entry ?\; "<" zone-mode-syntax-table)
+  (modify-syntax-entry ?\n ">" zone-mode-syntax-table))
+
+;;;###autoload
+(define-derived-mode zone-mode fundamental-mode "zone"
+  "A mode for editing DNS zone files.
+
+Zone-mode does two things:
+
+	- automatically update the serial number for a zone
+		when saving the file
+
+	- fontification"
+
+  (require 'zone-mode)
+  (make-variable-buffer-local 'write-file-hooks)
+  (add-hook 'write-file-hooks 'zone-mode-update-serial-hook)
+
+  (if (null zone-mode-syntax-table)
+      (zone-mode-load-time-setup)) ;; should have been run at load-time
+
+  ;; font-lock support:
+  (set-syntax-table zone-mode-syntax-table)
+  (make-local-variable 'comment-start)
+  (setq comment-start ";")
+  (make-local-variable 'comment-start-skip)
+  ;; Look within the line for a ; following an even number of backslashes
+  ;; after either a non-backslash or the line beginning.
+  (setq comment-start-skip "\\(\\(^\\|[^\\\\\n]\\)\\(\\\\\\\\\\)*\\);+[ \t]*")
+  (make-local-variable 'comment-column)
+  (setq comment-column 40)
+  (make-local-variable 'font-lock-defaults)
+  (setq font-lock-defaults
+	'(nil nil nil nil beginning-of-line)))
+
+(zone-mode-load-time-setup)
+
+(provide 'zone-mode)
+
+;;; zone-mode.el ends here