lisp/net/zone-mode.el

   1 ;;; zone-mode.el -- major mode for editing DNS zone files.
   2
   3 ;; Copyright (C) 1998 Free Software Foundation, Inc.
   4
   5 ;; Author: John Heidemann <johnh@isi.edu>
   6 ;; Keywords: DNS, languages
   7
   8 ;; This file is part of GNU Emacs.
   9
  10 ;; GNU Emacs is free software; you can redistribute it and/or modify
  11 ;; it under the terms of the GNU General Public License as published by
  12 ;; the Free Software Foundation; either version 2, or (at your option)
  13 ;; any later version.
  14
  15 ;; GNU Emacs is distributed in the hope that it will be useful,
  16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 ;; GNU General Public License for more details.
  19
  20 ;; You should have received a copy of the GNU General Public License
  21 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  22 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  23 ;; Boston, MA 02111-1307, USA.
  24
  25 ;;;
  26 ;;; See the comments in ``define-derived-mode zone-mode''
  27 ;;; (the last function in this file)
  28 ;;; for what this mode is and how to use it automatically.
  29 ;;;
  30
  31 ;;;
  32 ;;; Credits:
  33 ;;; Zone-mode was written by John Heidemann <johnh@isi.edu>,
  34 ;;; with bug fixes from Simon Leinen <simon@limmat.switch.ch>.
  35 ;;;
  36
  37 ;;; Code:
  38
  39 (defun zone-mode-update-serial ()
  40   "Update the serial number in a zone."
  41   (interactive)
  42   (save-excursion
  43     (goto-char (point-min))
  44     (while (re-search-forward "\\b\\([0-9]+\\)\\([0-9][0-9]\\)\\([ \t]+;[ \t]+[Ss]erial\\)" (point-max) t)
  45       (let* ((old-date (match-string 1))
  46              (old-seq (match-string 2))
  47              (old-seq-num (string-to-number (match-string 2)))
  48              (old-flag (match-string 3))
  49              (cur-date (format-time-string "%Y%m%d"))
  50              (new-seq
  51               (cond
  52                ((not (string= old-date cur-date))
  53                 "00") ;; reset sequeence number
  54                ((>= old-seq-num 99)
  55                 (error "Serial number's sequenece cannot increment beyond 99."))
  56                (t
  57                 (format "%02d" (1+ old-seq-num)))))
  58              (old-serial (concat old-date old-seq))
  59              (new-serial (concat cur-date new-seq)))
  60         (if (string-lessp new-serial old-serial)
  61             (error (format "Serial numbers want to move backwards from %s to %s!" old-serial new-serial))
  62           (replace-match (concat cur-date new-seq old-flag) t t))))))
  63
  64 ;;;###autoload
  65 (defun zone-mode-update-serial-hook ()
  66   "Update the serial number in a zone if the file was modified"
  67   (interactive)
  68   (if (buffer-modified-p (current-buffer))
  69       (zone-mode-update-serial))
  70   nil ;; so we can run from write-file-hooks
  71   )
  72
  73 (defvar zone-mode-syntax-table nil
  74   "Zone-mode's syntax table.")
  75
  76 (defun zone-mode-load-time-setup ()
  77   "init zone-mode stuff"
  78   (setq zone-mode-syntax-table (make-syntax-table))
  79   (modify-syntax-entry ?\; "<" zone-mode-syntax-table)
  80   (modify-syntax-entry ?\n ">" zone-mode-syntax-table))
  81
  82 ;;;###autoload
  83 (define-derived-mode zone-mode fundamental-mode "zone"
  84   "A mode for editing DNS zone files.
  85
  86 Zone-mode does two things:
  87
  88         - automatically update the serial number for a zone
  89                 when saving the file
  90
  91         - fontification"
  92
  93   (make-local-hook 'write-file-hooks)
  94   (add-hook 'write-file-hooks 'zone-mode-update-serial-hook)
  95
  96   (if (null zone-mode-syntax-table)
  97       (zone-mode-load-time-setup)) ;; should have been run at load-time
  98
  99   ;; font-lock support:
 100   (set-syntax-table zone-mode-syntax-table)
 101   (make-local-variable 'comment-start)
 102   (setq comment-start ";")
 103   (make-local-variable 'comment-start-skip)
 104   ;; Look within the line for a ; following an even number of backslashes
 105   ;; after either a non-backslash or the line beginning.
 106   (setq comment-start-skip "\\(\\(^\\|[^\\\\\n]\\)\\(\\\\\\\\\\)*\\);+[ \t]*")
 107   (make-local-variable 'comment-column)
 108   (setq comment-column 40)
 109   (make-local-variable 'font-lock-defaults)
 110   (setq font-lock-defaults
 111         '(nil nil nil nil beginning-of-line)))
 112
 113 (zone-mode-load-time-setup)
 114
 115 (provide 'zone-mode)
 116
 117 ;;; zone-mode.el ends here