code.delx.au - gnu-emacs/blob - lisp/dirtrack.el

   1 ;;; dirtrack.el --- Directory Tracking by watching the prompt
   2
   3 ;; Copyright (C) 1996 Free Software Foundation, Inc.
   4
   5 ;; Author: Peter Breton <pbreton@cs.umb.edu>
   6 ;; Created: Sun Nov 17 1996
   7 ;; Keywords: processes
   8 ;; Time-stamp: <1998-03-14 09:24:38 pbreton>
   9
  10 ;; This file is part of GNU Emacs.
  11
  12 ;; GNU Emacs is free software; you can redistribute it and/or modify
  13 ;; it under the terms of the GNU General Public License as published by
  14 ;; the Free Software Foundation; either version 2, or (at your option)
  15 ;; any later version.
  16
  17 ;; GNU Emacs is distributed in the hope that it will be useful,
  18 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20 ;; GNU General Public License for more details.
  21
  22 ;; You should have received a copy of the GNU General Public License
  23 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  24 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  25 ;; Boston, MA 02111-1307, USA.
  26
  27 ;;; Commentary:
  28
  29 ;; Shell directory tracking by watching the prompt.
  30 ;;
  31 ;; This is yet another attempt at a directory-tracking package for
  32 ;; Emacs shell-mode. However, this package makes one strong assumption:
  33 ;; that you can customize your shell's prompt to contain the
  34 ;; current working directory. Most shells do support this, including
  35 ;; almost every type of Bourne and C shell on Unix, the native shells on
  36 ;; Windows95 (COMMAND.COM) and Windows NT (CMD.EXE), and most 3rd party
  37 ;; Windows shells. If you cannot do this, or do not wish to, this package
  38 ;; will be useless to you.
  39 ;;
  40 ;; Installation:
  41 ;;
  42 ;; 1) Set your shell's prompt to contain the current working directory.
  43 ;; You may need to consult your shell's documentation to find out how to
  44 ;; do this.
  45 ;;
  46 ;; Note that directory tracking is done by matching regular expressions,
  47 ;; therefore it is *VERY IMPORTANT* for your prompt to be easily
  48 ;; distinguishable from other output. If your prompt regexp is too general,
  49 ;; you will see error messages from the dirtrack filter as it attempts to cd
  50 ;; to non-existent directories.
  51 ;;
  52 ;; 2) Set the variable `dirtrack-list' to an appropriate value. This
  53 ;; should be a list of two elements: the first is a regular expression
  54 ;; which matches your prompt up to and including the pathname part.
  55 ;; The second is a number which tells which regular expression group to
  56 ;; match to extract only the pathname. If you use a multi-line prompt,
  57 ;; add 't' as a third element. Note that some of the functions in
  58 ;; 'comint.el' assume a single-line prompt (eg, comint-bol).
  59 ;;
  60 ;; Determining this information may take some experimentation. Setting
  61 ;; the variable `dirtrack-debug' may help; it causes the directory-tracking
  62 ;; filter to log messages to the buffer `dirtrack-debug-buffer'.
  63 ;;
  64 ;; 3) Add a hook to shell-mode to enable the directory tracking:
  65 ;;
  66 ;; (add-hook 'shell-mode-hook
  67 ;;   (function (lambda ()
  68 ;;            (setq comint-output-filter-functions
  69 ;;                  (append (list 'dirtrack)
  70 ;;                          comint-output-filter-functions)))))
  71 ;;
  72 ;; You may wish to turn ordinary shell tracking off by calling
  73 ;; `shell-dirtrack-toggle' or setting `shell-dirtrackp'.
  74 ;;
  75 ;; Examples:
  76 ;;
  77 ;; 1) On Windows NT, my prompt is set to emacs$S$P$G.
  78 ;; 'dirtrack-list' is set to (list "^emacs \\([a-zA-Z]:.*\\)>" 1)
  79 ;;
  80 ;; 2) On Solaris running bash, my prompt is set like this:
  81 ;;    PS1="\w\012emacs@\h(\!) [\t]% "
  82 ;;    'dirtrack-list' is set to (list "^\\([/~].*\\)\nemacs@[^%]+% *" 1 t)
  83 ;;
  84 ;; I'd appreciate other examples from people who use this package.
  85 ;;
  86 ;; Here's one from Stephen Eglen:
  87 ;;
  88 ;;   Running under tcsh:
  89 ;;   (setq-default dirtrack-list '("^%E \\([^ ]+\\)" 1))
  90 ;;
  91 ;;   It might be worth mentioning in your file that emacs sources start up
  92 ;;   files of the form: ~/.emacs_<SHELL> where <SHELL> is the name of the
  93 ;;   shell.  So for example, I have the following in ~/.emacs_tcsh:
  94 ;;
  95 ;;   set prompt = "%%E %~ %h% "
  96 ;;
  97 ;;   This produces a prompt of the form:
  98 ;;   %E /var/spool 10%
  99 ;;
 100 ;;   This saves me from having to use the %E prefix in other non-emacs
 101 ;;   shells.
 102
 103 ;;; Code:
 104
 105 (eval-when-compile
 106   (require 'comint)
 107   (require 'shell))
 108
 109 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 110 ;; Customization Variables
 111 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 112
 113 (defgroup dirtrack nil
 114   "Directory tracking by watching the prompt."
 115   :prefix "dirtrack-"
 116   :group 'shell)
 117
 118 (defcustom dirtrack-list (list "^emacs \\([a-zA-Z]:.*\\)>" 1)
 119   "*List for directory tracking.
 120 First item is a regexp that describes where to find the path in a prompt.
 121 Second is a number, the regexp group to match. Optional third item is
 122 whether the prompt is multi-line. If nil or omitted, prompt is assumed to
 123 be on a single line."
 124   :group 'dirtrack
 125   :type  '(sexp (regexp  :tag "Prompt Expression")
 126                 (integer :tag "Regexp Group")
 127                 (boolean :tag "Multiline Prompt")
 128                 )
 129   )
 130
 131 (make-variable-buffer-local 'dirtrack-list)
 132
 133 (defcustom dirtrack-debug nil
 134   "*If non-nil, the function `dirtrack' will report debugging info."
 135   :group 'dirtrack
 136   :type  'boolean
 137   )
 138
 139 (defcustom dirtrack-debug-buffer "*Directory Tracking Log*"
 140   "Buffer to write directory tracking debug information."
 141   :group 'dirtrack
 142   :type  'string
 143   )
 144
 145 (defcustom dirtrackp t
 146   "*If non-nil, directory tracking via `dirtrack' is enabled."
 147   :group 'dirtrack
 148   :type  'boolean
 149   )
 150
 151 (make-variable-buffer-local 'dirtrackp)
 152
 153 (defcustom dirtrack-directory-function
 154   (if (memq system-type (list 'ms-dos 'windows-nt))
 155       'dirtrack-windows-directory-function
 156     'dirtrack-default-directory-function)
 157   "*Function to apply to the prompt directory for comparison purposes."
 158   :group 'dirtrack
 159   :type  'function
 160   )
 161
 162 (defcustom dirtrack-canonicalize-function
 163   (if (memq system-type (list 'ms-dos 'windows-nt))
 164       'downcase 'identity)
 165   "*Function to apply to the default directory for comparison purposes."
 166   :group 'dirtrack
 167   :type  'function
 168   )
 169
 170 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 171 ;; Functions
 172 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 173
 174 (defun dirtrack-default-directory-function (dir)
 175   "Return a canonical directory for comparison purposes.
 176 Such a directory ends with a forward slash."
 177   (let ((directory dir))
 178     (if (not (char-equal ?/ (string-to-char (substring directory -1))))
 179         (concat directory "/")
 180       directory)))
 181
 182 (defun dirtrack-windows-directory-function (dir)
 183   "Return a canonical directory for comparison purposes.
 184 Such a directory is all lowercase, has forward-slashes as delimiters,
 185 and ends with a forward slash."
 186   (let ((directory dir))
 187     (setq directory (downcase (dirtrack-replace-slash directory t)))
 188     (if (not (char-equal ?/ (string-to-char (substring directory -1))))
 189         (concat directory "/")
 190       directory)))
 191
 192 (defconst dirtrack-forward-slash  (regexp-quote "/"))
 193 (defconst dirtrack-backward-slash (regexp-quote "\\"))
 194
 195 (defun dirtrack-replace-slash (string &optional opposite)
 196   "Replace forward slashes with backwards ones.
 197 If additional argument is non-nil, replace backwards slashes with
 198 forward ones."
 199   (let ((orig     (if opposite
 200                       dirtrack-backward-slash
 201                     dirtrack-forward-slash))
 202         (replace  (if opposite
 203                       dirtrack-forward-slash
 204                     dirtrack-backward-slash))
 205         (newstring string)
 206         )
 207     (while (string-match orig newstring)
 208       (setq newstring (replace-match replace nil t newstring)))
 209   newstring))
 210
 211 ;; Copied from shell.el
 212 (defun dirtrack-toggle ()
 213   "Enable or disable Dirtrack directory tracking in a shell buffer."
 214   (interactive)
 215   (setq dirtrackp (not dirtrackp))
 216   (message "Directory tracking %s" (if dirtrackp "ON" "OFF")))
 217
 218 (defun dirtrack-debug-message (string)
 219   (let ((buf (current-buffer))
 220         (debug-buf (get-buffer-create dirtrack-debug-buffer))
 221         )
 222     (set-buffer debug-buf)
 223     (goto-char (point-max))
 224     (insert (concat string "\n"))
 225     (set-buffer buf)
 226   ))
 227
 228 ;;;###autoload
 229 (defun dirtrack (input)
 230   (if (null dirtrackp)
 231       nil
 232     (let ((prompt-path)
 233           (current-dir default-directory)
 234           (matched)
 235           (dirtrack-regexp    (nth 0 dirtrack-list))
 236           (match-num          (nth 1 dirtrack-list))
 237           (multi-line         (nth 2 dirtrack-list))
 238           )
 239       ;; No output?
 240       (if (eq (point) (point-min))
 241           nil
 242         (save-excursion
 243           (goto-char (point-max))
 244           ;; Look for the prompt
 245           (if multi-line
 246               (setq matched
 247                     (re-search-backward
 248                      dirtrack-regexp
 249                      comint-last-output-start
 250                      t))
 251             (beginning-of-line)
 252             (setq matched (looking-at dirtrack-regexp)))
 253           ;; No match
 254           (if (null matched)
 255               (and dirtrack-debug
 256                    (dirtrack-debug-message
 257                     (format
 258                      "Failed to match regexp: %s"
 259                     dirtrack-regexp)))
 260             (setq prompt-path
 261                   (buffer-substring-no-properties
 262                    (match-beginning match-num) (match-end match-num)))
 263             ;; Empty string
 264             (if (not (> (length prompt-path) 0))
 265                 (and dirtrack-debug
 266                      (dirtrack-debug-message "Match is empty string"))
 267               ;; Transform prompts into canonical forms
 268               (setq prompt-path (funcall dirtrack-directory-function
 269                                          prompt-path))
 270               (setq current-dir (funcall dirtrack-canonicalize-function
 271                                          current-dir))
 272               (and dirtrack-debug
 273                    (dirtrack-debug-message
 274                     (format
 275                      "Prompt is %s\nCurrent directory is %s"
 276                      prompt-path current-dir)))
 277               ;; Compare them
 278               (if (or (string= current-dir prompt-path)
 279                       (string= current-dir
 280                                (abbreviate-file-name prompt-path)))
 281                   (and dirtrack-debug
 282                        (dirtrack-debug-message
 283                         (format "Not changing directory")))
 284                 ;; It's possible that Emacs will think the directory
 285                 ;; won't exist (eg, rlogin buffers)
 286                 (if (file-accessible-directory-p prompt-path)
 287                     ;; Change directory
 288                     (and (shell-process-cd prompt-path)
 289                          dirtrack-debug
 290                          (dirtrack-debug-message
 291                           (format "Changing directory to %s" prompt-path)))
 292                   (error "Directory %s does not exist" prompt-path)))
 293               )))))))
 294
 295 (provide 'dirtrack)
 296
 297 ;;; dirtrack.el ends here