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emacs/lisp/net/zone-mode.el
2001-12-11 06:52:33 +00:00

119 lines
3.8 KiB
EmacsLisp

;;; 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.
;;; Commentary:
;;;
;;; 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 sequence number
((>= old-seq-num 99)
(error "Serial number's sequence 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 ()
"Initialise `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"
(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