lisp/dos-fns.el

   1 ;;; dos-fns.el --- MS-Dos specific functions.
   2
   3 ;; Copyright (C) 1991, 1993, 1995, 1996 Free Software Foundation, Inc.
   4
   5 ;; Maintainer: Morten Welinder <terra@diku.dk>
   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 ;; Part of this code is taken from (or derived from) demacs.
  28
  29 ;;; Code:
  30
  31 ;; This overrides a trivial definition in files.el.
  32 (defun convert-standard-filename (filename)
  33   "Convert a standard file's name to something suitable for the current OS.
  34 This function's standard definition is trivial; it just returns the argument.
  35 However, on some systems, the function is redefined
  36 with a definition that really does change some file names."
  37   (if (or (msdos-long-file-names)
  38           (not (stringp filename))
  39           (member (file-name-nondirectory filename) '("" "." "..")))
  40       filename
  41     (let* ((dir (file-name-directory filename))
  42            (string (copy-sequence (file-name-nondirectory filename)))
  43            (lastchar (aref string (1- (length string))))
  44            i firstdot)
  45       ;; Change a leading period to a leading underscore.
  46       (if (= (aref string 0) ?.)
  47           (aset string 0 ?_))
  48       ;; Get rid of invalid characters.
  49       (while (setq i (string-match
  50                       "[^-a-zA-Z0-9_.%~^$!#&{}@`'()\200-\376]"
  51                       string))
  52         (aset string i ?_))
  53       ;; If we don't have a period,
  54       ;; and we have a dash or underscore that isn't the first char,
  55       ;; change that to a period.
  56       (if (and (not (string-match "\\." string))
  57                (setq i (string-match "[-_]" string 1)))
  58           (aset string i ?\.))
  59       ;; If we don't have a period in the first 8 chars, insert one.
  60       (if (> (or (string-match "\\." string)
  61                  (length string))
  62              8)
  63           (setq string
  64                 (concat (substring string 0 8)
  65                         "."
  66                         (substring string 8))))
  67       (setq firstdot (or (string-match "\\." string) (1- (length string))))
  68       ;; Truncate to 3 chars after the first period.
  69       (if (> (length string) (+ firstdot 4))
  70           (setq string (substring string 0 (+ firstdot 4))))
  71       ;; Change all periods except the first one into underscores.
  72       (while (string-match "\\." string (1+ firstdot))
  73         (setq i (string-match "\\." string (1+ firstdot)))
  74         (aset string i ?_))
  75       ;; If the last character of the original filename was `~',
  76       ;; make sure the munged name ends with it also.
  77       (if (equal lastchar ?~)
  78           (aset string (1- (length string)) lastchar))
  79       (concat dir string))))
  80
  81 ;; See dos-vars.el for defcustom.
  82 (defvar msdos-shells)
  83
  84 (defvar register-name-alist
  85   '((ax . 0) (bx . 1) (cx . 2) (dx . 3) (si . 4) (di . 5)
  86     (cflag . 6) (flags . 7)
  87     (al . (0 . 0)) (bl . (1 . 0)) (cl . (2 . 0)) (dl . (3 . 0))
  88     (ah . (0 . 1)) (bh . (1 . 1)) (ch . (2 . 1)) (dh . (3 . 1))))
  89
  90 (defun make-register ()
  91   (make-vector 8 0))
  92
  93 (defun register-value (regs name)
  94   (let ((where (cdr (assoc name register-name-alist))))
  95     (cond ((consp where)
  96            (let ((tem (aref regs (car where))))
  97              (if (zerop (cdr where))
  98                  (% tem 256)
  99                (/ tem 256))))
 100           ((numberp where)
 101            (aref regs where))
 102           (t nil))))
 103
 104 (defun set-register-value (regs name value)
 105   (and (numberp value)
 106        (>= value 0)
 107        (let ((where (cdr (assoc name register-name-alist))))
 108          (cond ((consp where)
 109                 (let ((tem (aref regs (car where)))
 110                       (value (logand value 255)))
 111                   (aset regs
 112                         (car where)
 113                         (if (zerop (cdr where))
 114                             (logior (logand tem 65280) value)
 115                           (logior (logand tem 255) (lsh value 8))))))
 116                ((numberp where)
 117                 (aset regs where (logand value 65535))))))
 118   regs)
 119
 120 (defsubst intdos (regs)
 121   (int86 33 regs))
 122
 123 ;; Backward compatibility for obsolescent functions which
 124 ;; set screen size.
 125
 126 (defun mode25 ()
 127   "Changes the number of screen rows to 25."
 128   (interactive)
 129   (set-frame-size (selected-frame) 80 25))
 130
 131 (defun mode4350 ()
 132   "Changes the number of rows to 43 or 50.
 133 Emacs always tries to set the screen height to 50 rows first.
 134 If this fails, it will try to set it to 43 rows, on the assumption
 135 that your video hardware might not support 50-line mode."
 136   (interactive)
 137   (set-frame-size (selected-frame) 80 50)
 138   (if (eq (frame-height (selected-frame)) 50)
 139       nil  ; the original built-in function returned nil
 140     (set-frame-size (selected-frame) 80 43)))
 141
 142 (provide 'dos-fns)
 143
 144 ; dos-fns.el ends here