lisp/dos-w32.el

   1 ;;; dos-w32.el --- Functions shared among MS-DOS and W32 (NT/95) platforms
   2
   3 ;; Copyright (C) 1996 Free Software Foundation, Inc.
   4
   5 ;; Maintainer: Geoff Voelker (voelker@cs.washington.edu)
   6 ;; Keywords: internal
   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 ;; Parts of this code are duplicated functions taken from dos-fns.el
  28 ;; and winnt.el.
  29
  30 ;;; Code:
  31
  32 ;; Use ";" instead of ":" as a path separator (from files.el).
  33 (setq path-separator ";")
  34
  35 ;; Set the null device (for compile.el).
  36 (setq grep-null-device "NUL")
  37
  38 ;; Set the grep regexp to match entries with drive letters.
  39 (setq grep-regexp-alist
  40   '(("^\\(\\([a-zA-Z]:\\)?[^:( \t\n]+\\)[:( \t]+\\([0-9]+\\)[:) \t]" 1 3)))
  41
  42 ;; For distinguishing file types based upon suffixes.
  43 (defvar file-name-buffer-file-type-alist
  44   '(
  45     ("[:/].*config.sys$" . nil)         ; config.sys text
  46     ("\\.elc$" . t)                     ; emacs stuff
  47     ("\\.\\(obj\\|exe\\|com\\|lib\\|sys\\|chk\\|out\\|bin\\|ico\\|pif\\)$" . t)
  48                                         ; MS-Dos stuff
  49     ("\\.\\(arc\\|zip\\|pak\\|lzh\\|zoo\\)$" . t)
  50                                         ; Packers
  51     ("\\.\\(a\\|o\\|tar\\|z\\|gz\\|taz\\)$" . t)
  52                                         ; Unix stuff
  53     ("\\.tp[ulpw]$" . t)
  54                                         ; Borland Pascal stuff
  55     ("[:/]tags$" . t)
  56                                         ; Emacs TAGS file
  57     )
  58   "*Alist for distinguishing text files from binary files.
  59 Each element has the form (REGEXP . TYPE), where REGEXP is matched
  60 against the file name, and TYPE is nil for text, t for binary.")
  61
  62 ;; Return the pair matching filename on file-name-buffer-file-type-alist,
  63 ;; or nil otherwise.
  64 (defun find-buffer-file-type-match (filename)
  65   (let ((alist file-name-buffer-file-type-alist)
  66         (found nil))
  67     (let ((case-fold-search t))
  68       (setq filename (file-name-sans-versions filename))
  69       (while (and (not found) alist)
  70         (if (string-match (car (car alist)) filename)
  71             (setq found (car alist)))
  72         (setq alist (cdr alist)))
  73       found)))
  74
  75 (defun find-buffer-file-type (filename)
  76   ;; First check if file is on an untranslated filesystem, then on the alist.
  77   (if (untranslated-file-p filename)
  78       t ; for binary
  79     (let ((match (find-buffer-file-type-match filename))
  80           (code))
  81       (if (not match)
  82           default-buffer-file-type
  83         (setq code (cdr match))
  84         (cond ((memq code '(nil t)) code)
  85               ((and (symbolp code) (fboundp code))
  86                (funcall code filename)))))))
  87
  88 (defun find-buffer-file-type-coding-system (command)
  89   "Choose a coding system for a file operation.
  90 If COMMAND is `insert-file-contents', the coding system is chosen based
  91 upon the filename, the contents of `untranslated-filesystem-list' and
  92 `file-name-buffer-file-type-alist', and whether the file exists:
  93
  94   If it matches in `untranslated-filesystem-list':
  95     If the file exists:                                 `no-conversion'
  96     If the file does not exist:                         `undecided'
  97   If it matches in `file-name-buffer-file-type-alist':
  98     If the match is t (for binary):                     `no-conversion'
  99     If the match is nil (for dos-text):                 `undecided-dos'
 100   Otherwise:
 101     If the file exists:                                 `undecided'
 102     If the file does not exist:                         `undecided-dos'
 103
 104 If COMMAND is `write-region', the coding system is chosen based
 105 upon the value of `buffer-file-type': If t, the coding system is
 106 `no-conversion', otherwise it is `undecided-dos'."
 107   (let ((op (nth 0 command))
 108         (target)
 109         (binary nil) (text nil)
 110         (undecided nil))
 111     (cond ((eq op 'insert-file-contents)
 112            (setq target (nth 1 command))
 113            (if (untranslated-file-p target)
 114                (if (file-exists-p target)
 115                    (setq undecided t)
 116                  (setq binary t))
 117              (setq binary (find-buffer-file-type target))
 118              (unless binary
 119                      (if (find-buffer-file-type-match target)
 120                          (setq text t)
 121                        (setq undecided (file-exists-p target))))))
 122           ((eq op 'write-region)
 123            (setq binary buffer-file-type)))
 124     (cond (binary '(no-conversion . no-conversion))
 125           (text '(undecided-dos . undecided-dos))
 126           (undecided '(undecided . undecided))
 127           (t '(undecided-dos . undecided-dos)))))
 128
 129 (modify-coding-system-alist 'file "" 'find-buffer-file-type-coding-system)
 130
 131 (defun find-file-binary (filename)
 132   "Visit file FILENAME and treat it as binary."
 133   (interactive "FFind file binary: ")
 134   (let ((file-name-buffer-file-type-alist '(("" . t))))
 135     (find-file filename)))
 136
 137 (defun find-file-text (filename)
 138   "Visit file FILENAME and treat it as a text file."
 139   (interactive "FFind file text: ")
 140   (let ((file-name-buffer-file-type-alist '(("" . nil))))
 141     (find-file filename)))
 142
 143 (defun find-file-not-found-set-buffer-file-type ()
 144   (save-excursion
 145     (set-buffer (current-buffer))
 146     (setq buffer-file-type (find-buffer-file-type (buffer-file-name))))
 147   nil)
 148
 149 ;;; To set the default file type on new files.
 150 (add-hook 'find-file-not-found-hooks 'find-file-not-found-set-buffer-file-type)
 151
 152
 153 ;;; To accomodate filesystems that do not require CR/LF translation.
 154 (defvar untranslated-filesystem-list nil
 155   "List of filesystems that require no CR/LF translation when reading
 156 and writing files.  Each filesystem in the list is a string naming
 157 the directory prefix corresponding to the filesystem.")
 158
 159 (defun untranslated-canonical-name (filename)
 160   "Return FILENAME in a canonicalized form for use with the functions
 161 dealing with untranslated filesystems."
 162   (if (memq system-type '(ms-dos windows-nt))
 163       ;; The canonical form for DOS/W32 is with A-Z downcased and all
 164       ;; directory separators changed to directory-sep-char.
 165       (let ((name nil))
 166         (setq name (mapconcat
 167                     '(lambda (char)
 168                        (if (and (<= ?A char) (<= char ?Z))
 169                            (char-to-string (+ (- char ?A) ?a))
 170                          (char-to-string char)))
 171                     filename nil))
 172         ;; Use expand-file-name to canonicalize directory separators, except
 173         ;; with bare drive letters (which would have the cwd appended).
 174         (if (string-match "^.:$" name)
 175             name
 176           (expand-file-name name)))
 177     filename))
 178
 179 (defun untranslated-file-p (filename)
 180   "Return t if FILENAME is on a filesystem that does not require
 181 CR/LF translation, and nil otherwise."
 182   (let ((fs (untranslated-canonical-name filename))
 183         (ufs-list untranslated-filesystem-list)
 184         (found nil))
 185     (while (and (not found) ufs-list)
 186       (if (string-match (concat "^" (car ufs-list)) fs)
 187           (setq found t)
 188         (setq ufs-list (cdr ufs-list))))
 189     found))
 190
 191 (defun add-untranslated-filesystem (filesystem)
 192   "Add FILESYSTEM to the list of filesystems that do not require
 193 CR/LF translation.  FILESYSTEM is a string containing the directory
 194 prefix corresponding to the filesystem.  For example, for a Unix
 195 filesystem mounted on drive Z:, FILESYSTEM could be \"Z:\"."
 196   (interactive "fUntranslated file system: ")
 197   (let ((fs (untranslated-canonical-name filesystem)))
 198     (if (member fs untranslated-filesystem-list)
 199         untranslated-filesystem-list
 200       (setq untranslated-filesystem-list
 201             (cons fs untranslated-filesystem-list)))))
 202
 203 (defun remove-untranslated-filesystem (filesystem)
 204   "Remove FILESYSTEM from the list of filesystems that do not require
 205 CR/LF translation.  FILESYSTEM is a string containing the directory
 206 prefix corresponding to the filesystem.  For example, for a Unix
 207 filesystem mounted on drive Z:, FILESYSTEM could be \"Z:\"."
 208   (interactive "fUntranslated file system: ")
 209   (setq untranslated-filesystem-list
 210         (delete (untranslated-canonical-name filesystem)
 211                 untranslated-filesystem-list)))
 212
 213 ;; Process I/O decoding and encoding.
 214
 215 (defun find-binary-process-coding-system (command)
 216   "Choose a coding system for process I/O.
 217 The coding system for decode is 'no-conversion' if 'binary-process-output'
 218 is non-nil, and 'undecided-dos' otherwise.  Similarly, the coding system
 219 for encode is 'no-conversion' if 'binary-process-input' is non-nil,
 220 and 'undecided-dos' otherwise."
 221   (let ((decode 'undecided-dos)
 222         (encode 'undecided-dos))
 223     (if binary-process-output
 224         (setq decode 'no-conversion))
 225     (if binary-process-input
 226         (setq encode 'no-conversion))
 227     (cons decode encode)))
 228
 229 (modify-coding-system-alist 'process "" 'find-binary-process-coding-system)
 230
 231
 232 (provide 'dos-w32)
 233
 234 ;;; dos-w32.el ends here