lisp/obsolete/uncompress.el

   1 ;;; uncompress.el --- auto-decompression hook for visiting .Z files
   2
   3 ;; Copyright (C) 1992, 1994, 2001 Free Software Foundation, Inc.
   4
   5 ;; Maintainer: FSF
   6 ;; Keywords: files
   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 ;;; Commentary:
  26
  27 ;; This package can be used to arrange for automatic uncompress of
  28 ;; compressed files when they are visited.
  29 ;; All that's necessary is to load it.  This can conveniently be done from
  30 ;; your .emacs file.
  31
  32 ;; M-x auto-compression-mode is a more modern replacement for this package.
  33
  34 ;;; Code:
  35
  36 ;; When we are about to make a backup file,
  37 ;; uncompress the file we visited
  38 ;; so that making the backup can work properly.
  39 ;; This is used as a write-file-hook.
  40
  41 (defvar uncompress-program "gunzip"
  42   "Program to use for uncompression.")
  43
  44 (defun uncompress-backup-file ()
  45   (and buffer-file-name make-backup-files (not buffer-backed-up)
  46        (not (file-exists-p buffer-file-name))
  47        (call-process uncompress-program nil nil nil buffer-file-name))
  48   nil)
  49
  50 (or (assoc "\\.Z$" auto-mode-alist)
  51     (setq auto-mode-alist
  52           (cons '("\\.Z$" . uncompress-while-visiting) auto-mode-alist)))
  53 (or (assoc "\\.gz$" auto-mode-alist)
  54     (setq auto-mode-alist
  55           (cons '("\\.gz$" . uncompress-while-visiting) auto-mode-alist)))
  56 (or (assoc "\\.tgz$" auto-mode-alist)
  57     (setq auto-mode-alist
  58           (cons '("\\.tgz$" . uncompress-while-visiting) auto-mode-alist)))
  59
  60 (defun uncompress-while-visiting ()
  61   "Temporary \"major mode\" used for .Z and .gz files, to uncompress them.
  62 It then selects a major mode from the uncompressed file name and contents."
  63   (if (and (not (null buffer-file-name))
  64            (string-match "\\.Z$" buffer-file-name))
  65       (set-visited-file-name
  66        (substring buffer-file-name 0 (match-beginning 0)))
  67     (if (and (not (null buffer-file-name))
  68              (string-match "\\.gz$" buffer-file-name))
  69         (set-visited-file-name
  70          (substring buffer-file-name 0 (match-beginning 0)))
  71       (if (and (not (null buffer-file-name))
  72                (string-match "\\.tgz$" buffer-file-name))
  73           (set-visited-file-name
  74            (concat (substring buffer-file-name 0 (match-beginning 0)) ".tar")))))
  75   (message "Uncompressing...")
  76   (let ((buffer-read-only nil)
  77         (coding-system-for-write 'no-conversion)
  78         (coding-system-for-read
  79          (car (find-operation-coding-system
  80                'insert-file-contents
  81                buffer-file-name t))))
  82     (shell-command-on-region (point-min) (point-max) uncompress-program t))
  83   (goto-char (point-min))
  84   (message "Uncompressing...done")
  85   (set-buffer-modified-p nil)
  86   (make-local-variable 'write-file-hooks)
  87   (or (memq 'uncompress-backup-file write-file-hooks)
  88       (setq write-file-hooks (cons 'uncompress-backup-file write-file-hooks)))
  89   (normal-mode))
  90
  91 (or (memq 'find-compressed-version find-file-not-found-hooks)
  92     (setq find-file-not-found-hooks
  93           (cons 'find-compressed-version find-file-not-found-hooks)))
  94
  95 (defun find-compressed-version ()
  96   "Hook to read and uncompress the compressed version of a file."
  97   ;; Just pretend we had visited the compressed file,
  98   ;; and uncompress-while-visiting will do the rest.
  99   (let (name)
 100     (if (file-exists-p (setq name (concat buffer-file-name ".Z")))
 101         (setq buffer-file-name name)
 102       (if (file-exists-p (setq name (concat buffer-file-name ".gz")))
 103           (setq buffer-file-name name)))
 104     (if (eq name buffer-file-name)
 105         (progn
 106           (insert-file-contents buffer-file-name t)
 107           (goto-char (point-min))
 108           ;; No need for this, because error won't be set to t
 109           ;; if this function returns t.
 110           ;; (setq error nil)
 111           t))))
 112
 113 (provide 'uncompress)
 114
 115 ;;; uncompress.el ends here