code.delx.au - gnu-emacs/blob - lisp/net/zone-mode.el

   1 ;;; zone-mode.el --- major mode for editing DNS zone files
   2
   3 ;; Copyright (C) 1998, 2002, 2003, 2004, 2005,
   4 ;;   2006 Free Software Foundation, Inc.
   5
   6 ;; Author: John Heidemann <johnh@isi.edu>
   7 ;; Keywords: DNS, languages
   8
   9 ;; This file is part of GNU Emacs.
  10
  11 ;; GNU Emacs is free software; you can redistribute it and/or modify
  12 ;; it under the terms of the GNU General Public License as published by
  13 ;; the Free Software Foundation; either version 2, or (at your option)
  14 ;; any later version.
  15
  16 ;; GNU Emacs is distributed in the hope that it will be useful,
  17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 ;; GNU General Public License for more details.
  20
  21 ;; You should have received a copy of the GNU General Public License
  22 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  23 ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  24 ;; Boston, MA 02110-1301, USA.
  25
  26 ;;; Commentary:
  27
  28 ;;;
  29 ;;; See the comments in ``define-derived-mode zone-mode''
  30 ;;; (the last function in this file)
  31 ;;; for what this mode is and how to use it automatically.
  32 ;;;
  33
  34 ;;;
  35 ;;; Credits:
  36 ;;; Zone-mode was written by John Heidemann <johnh@isi.edu>,
  37 ;;; with bug fixes from Simon Leinen <simon@limmat.switch.ch>.
  38 ;;;
  39
  40 ;;; Code:
  41
  42 (defun zone-mode-update-serial ()
  43   "Update the serial number in a zone."
  44   (interactive)
  45   (save-excursion
  46     (goto-char (point-min))
  47     (while (re-search-forward "\\b\\([0-9]+\\)\\([0-9][0-9]\\)\\([ \t]+;[ \t]+[Ss]erial\\)" (point-max) t)
  48       (let* ((old-date (match-string 1))
  49              (old-seq (match-string 2))
  50              (old-seq-num (string-to-number (match-string 2)))
  51              (old-flag (match-string 3))
  52              (cur-date (format-time-string "%Y%m%d"))
  53              (new-seq
  54               (cond
  55                ((not (string= old-date cur-date))
  56                 "00") ;; reset sequence number
  57                ((>= old-seq-num 99)
  58                 (error "Serial number's sequence cannot increment beyond 99"))
  59                (t
  60                 (format "%02d" (1+ old-seq-num)))))
  61              (old-serial (concat old-date old-seq))
  62              (new-serial (concat cur-date new-seq)))
  63         (if (string-lessp new-serial old-serial)
  64             (error "Serial numbers want to move backwards from %s to %s" old-serial new-serial)
  65           (replace-match (concat cur-date new-seq old-flag) t t))))))
  66
  67 ;;;###autoload
  68 (defun zone-mode-update-serial-hook ()
  69   "Update the serial number in a zone if the file was modified."
  70   (interactive)
  71   (if (buffer-modified-p (current-buffer))
  72       (zone-mode-update-serial))
  73   nil ;; so we can run from write-file-hooks
  74   )
  75
  76 (defvar zone-mode-syntax-table nil
  77   "Zone-mode's syntax table.")
  78
  79 (defun zone-mode-load-time-setup ()
  80   "Initialize `zone-mode' stuff."
  81   (setq zone-mode-syntax-table (make-syntax-table))
  82   (modify-syntax-entry ?\; "<" zone-mode-syntax-table)
  83   (modify-syntax-entry ?\n ">" zone-mode-syntax-table))
  84
  85 ;;;###autoload
  86 (define-derived-mode zone-mode fundamental-mode "zone"
  87   "A mode for editing DNS zone files.
  88
  89 Zone-mode does two things:
  90
  91         - automatically update the serial number for a zone
  92                 when saving the file
  93
  94         - fontification"
  95
  96   (add-hook 'write-file-functions 'zone-mode-update-serial-hook nil t)
  97
  98   (if (null zone-mode-syntax-table)
  99       (zone-mode-load-time-setup)) ;; should have been run at load-time
 100
 101   ;; font-lock support:
 102   (set-syntax-table zone-mode-syntax-table)
 103   (make-local-variable 'comment-start)
 104   (setq comment-start ";")
 105   (make-local-variable 'comment-start-skip)
 106   ;; Look within the line for a ; following an even number of backslashes
 107   ;; after either a non-backslash or the line beginning.
 108   (setq comment-start-skip "\\(\\(^\\|[^\\\\\n]\\)\\(\\\\\\\\\\)*\\);+[ \t]*")
 109   (make-local-variable 'comment-column)
 110   (setq comment-column 40)
 111   (make-local-variable 'font-lock-defaults)
 112   (setq font-lock-defaults
 113         '(nil nil nil nil beginning-of-line)))
 114
 115 (zone-mode-load-time-setup)
 116
 117 (provide 'zone-mode)
 118
 119 ;;; arch-tag: 6a2940ef-fd4f-4de7-b979-b027b09821fe
 120 ;;; zone-mode.el ends here