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[emacs.git] / lisp / dirtrack.el
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1 ;;; dirtrack.el --- Directory Tracking by watching the prompt
3 ;; Copyright (C) 1996 Free Software Foundation, Inc.
5 ;; Author: Peter Breton <pbreton@cs.umb.edu>
6 ;; Created: Sun Nov 17 1996
7 ;; Keywords: processes
9 ;; This file is part of GNU Emacs.
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.
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.
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., 59 Temple Place - Suite 330,
24 ;; Boston, MA 02111-1307, USA.
26 ;;; Commentary:
28 ;; Shell directory tracking by watching the prompt.
30 ;; This is yet another attempt at a directory-tracking package for
31 ;; Emacs shell-mode. However, this package makes one strong assumption:
32 ;; that you can customize your shell's prompt to contain the
33 ;; current working directory. Most shells do support this, including
34 ;; almost every type of Bourne and C shell on Unix, the native shells on
35 ;; Windows95 (COMMAND.COM) and Windows NT (CMD.EXE), and most 3rd party
36 ;; Windows shells. If you cannot do this, or do not wish to, this package
37 ;; will be useless to you.
39 ;; Installation:
41 ;; 1) Set your shell's prompt to contain the current working directory.
42 ;; You may need to consult your shell's documentation to find out how to
43 ;; do this.
45 ;; Note that directory tracking is done by matching regular expressions,
46 ;; therefore it is *VERY IMPORTANT* for your prompt to be easily
47 ;; distinguishable from other output. If your prompt regexp is too general,
48 ;; you will see error messages from the dirtrack filter as it attempts to cd
49 ;; to non-existent directories.
51 ;; 2) Set the variable `dirtrack-list' to an appropriate value. This
52 ;; should be a list of two elements: the first is a regular expression
53 ;; which matches your prompt up to and including the pathname part.
54 ;; The second is a number which tells which regular expression group to
55 ;; match to extract only the pathname. If you use a multi-line prompt,
56 ;; add 't' as a third element. Note that some of the functions in
57 ;; 'comint.el' assume a single-line prompt (eg, comint-bol).
59 ;; Determining this information may take some experimentation. Setting
60 ;; the variable `dirtrack-debug' may help; it causes the directory-tracking
61 ;; filter to log messages to the buffer `dirtrack-debug-buffer'. You can easily
62 ;; toggle this setting with the `dirtrack-debug-toggle' function.
64 ;; 3) Add a hook to shell-mode to enable the directory tracking:
66 ;; (add-hook 'shell-mode-hook
67 ;; (function (lambda ()
68 ;; (setq comint-preoutput-filter-functions
69 ;; (append (list 'dirtrack)
70 ;; comint-preoutput-filter-functions)))))
72 ;; You may wish to turn ordinary shell tracking off by calling
73 ;; `shell-dirtrack-toggle' or setting `shell-dirtrackp'.
75 ;; Examples:
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)
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)
84 ;; I'd appreciate other examples from people who use this package.
86 ;; Here's one from Stephen Eglen:
88 ;; Running under tcsh:
89 ;; (setq-default dirtrack-list '("^%E \\([^ ]+\\)" 1))
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:
95 ;; set prompt = "%%E %~ %h% "
97 ;; This produces a prompt of the form:
98 ;; %E /var/spool 10%
100 ;; This saves me from having to use the %E prefix in other non-emacs
101 ;; shells.
103 ;; A final note:
105 ;; I run LOTS of shell buffers through Emacs, sometimes as different users
106 ;; (eg, when logged in as myself, I'll run a root shell in the same Emacs).
107 ;; If you do this, and the shell prompt contains a ~, Emacs will interpret
108 ;; this relative to the user which owns the Emacs process, not the user
109 ;; who owns the shell buffer. This may cause dirtrack to behave strangely
110 ;; (typically it reports that it is unable to cd to a directory
111 ;; with a ~ in it).
113 ;; The same behavior can occur if you use dirtrack with remote filesystems
114 ;; (using telnet, rlogin, etc) as Emacs will be checking the local
115 ;; filesystem, not the remote one. This problem is not specific to dirtrack,
116 ;; but also affects file completion, etc.
118 ;;; Code:
120 (eval-when-compile
121 (require 'comint)
122 (require 'shell))
124 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
125 ;; Customization Variables
126 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
128 (defgroup dirtrack nil
129 "Directory tracking by watching the prompt."
130 :prefix "dirtrack-"
131 :group 'shell)
133 (defcustom dirtrack-list (list "^emacs \\([a-zA-Z]:.*\\)>" 1)
134 "*List for directory tracking.
135 First item is a regexp that describes where to find the path in a prompt.
136 Second is a number, the regexp group to match. Optional third item is
137 whether the prompt is multi-line. If nil or omitted, prompt is assumed to
138 be on a single line."
139 :group 'dirtrack
140 :type '(sexp (regexp :tag "Prompt Expression")
141 (integer :tag "Regexp Group")
142 (boolean :tag "Multiline Prompt")
146 (make-variable-buffer-local 'dirtrack-list)
148 (defcustom dirtrack-debug nil
149 "*If non-nil, the function `dirtrack' will report debugging info."
150 :group 'dirtrack
151 :type 'boolean
154 (defcustom dirtrack-debug-buffer "*Directory Tracking Log*"
155 "Buffer to write directory tracking debug information."
156 :group 'dirtrack
157 :type 'string
160 (defcustom dirtrackp t
161 "*If non-nil, directory tracking via `dirtrack' is enabled."
162 :group 'dirtrack
163 :type 'boolean
166 (make-variable-buffer-local 'dirtrackp)
168 (defcustom dirtrack-directory-function
169 (if (memq system-type (list 'ms-dos 'windows-nt 'cygwin))
170 'dirtrack-windows-directory-function
171 'dirtrack-default-directory-function)
172 "*Function to apply to the prompt directory for comparison purposes."
173 :group 'dirtrack
174 :type 'function
177 (defcustom dirtrack-canonicalize-function
178 (if (memq system-type (list 'ms-dos 'windows-nt 'cygwin))
179 'downcase 'identity)
180 "*Function to apply to the default directory for comparison purposes."
181 :group 'dirtrack
182 :type 'function
185 (defcustom dirtrack-directory-change-hook nil
186 "Hook that is called when a directory change is made."
187 :group 'dirtrack
188 :type 'hook
192 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
193 ;; Functions
194 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
196 (defun dirtrack-default-directory-function (dir)
197 "Return a canonical directory for comparison purposes.
198 Such a directory ends with a forward slash."
199 (let ((directory dir))
200 (if (not (char-equal ?/ (string-to-char (substring directory -1))))
201 (concat directory "/")
202 directory)))
204 (defun dirtrack-windows-directory-function (dir)
205 "Return a canonical directory for comparison purposes.
206 Such a directory is all lowercase, has forward-slashes as delimiters,
207 and ends with a forward slash."
208 (let ((directory dir))
209 (setq directory (downcase (dirtrack-replace-slash directory t)))
210 (if (not (char-equal ?/ (string-to-char (substring directory -1))))
211 (concat directory "/")
212 directory)))
214 (defun dirtrack-cygwin-directory-function (dir)
215 "Return a canonical directory taken from a Cygwin path for comparison purposes."
216 (if (string-match "/cygdrive/\\([A-Z]\\)\\(.*\\)" dir)
217 (concat (match-string 1 dir) ":" (match-string 2 dir))
218 dir))
220 (defconst dirtrack-forward-slash (regexp-quote "/"))
221 (defconst dirtrack-backward-slash (regexp-quote "\\"))
223 (defun dirtrack-replace-slash (string &optional opposite)
224 "Replace forward slashes with backwards ones.
225 If additional argument is non-nil, replace backwards slashes with
226 forward ones."
227 (let ((orig (if opposite
228 dirtrack-backward-slash
229 dirtrack-forward-slash))
230 (replace (if opposite
231 dirtrack-forward-slash
232 dirtrack-backward-slash))
233 (newstring string)
235 (while (string-match orig newstring)
236 (setq newstring (replace-match replace nil t newstring)))
237 newstring))
239 ;; Copied from shell.el
240 (defun dirtrack-toggle ()
241 "Enable or disable Dirtrack directory tracking in a shell buffer."
242 (interactive)
243 (setq dirtrackp (not dirtrackp))
244 (message "Directory tracking %s" (if dirtrackp "ON" "OFF")))
246 (defun dirtrack-debug-toggle ()
247 "Enable or disable Dirtrack debugging."
248 (interactive)
249 (setq dirtrack-debug (not dirtrack-debug))
250 (message "Directory debugging %s" (if dirtrack-debug "ON" "OFF"))
251 (and dirtrack-debug
252 (display-buffer (get-buffer-create dirtrack-debug-buffer))))
254 (defun dirtrack-debug-message (string)
255 (let ((buf (current-buffer))
256 (debug-buf (get-buffer-create dirtrack-debug-buffer))
258 (set-buffer debug-buf)
259 (goto-char (point-max))
260 (insert (concat string "\n"))
261 (set-buffer buf)
264 ;;;###autoload
265 (defun dirtrack (input)
266 "Determine the current directory by scanning the process output for a prompt.
267 The prompt to look for is the first item in `dirtrack-list'.
269 You can toggle directory tracking by using the function `dirtrack-toggle'.
271 If directory tracking does not seem to be working, you can use the
272 function `dirtrack-debug-toggle' to turn on debugging output.
274 You can enable directory tracking by adding this function to
275 `comint-output-filter-functions'.
277 (if (null dirtrackp)
279 (let (prompt-path
280 matched
281 (current-dir default-directory)
282 (dirtrack-regexp (nth 0 dirtrack-list))
283 (match-num (nth 1 dirtrack-list))
284 (multi-line (nth 2 dirtrack-list))
286 ;; No output?
287 (if (eq (point) (point-min))
289 (save-excursion
290 (setq matched (string-match dirtrack-regexp input)))
291 ;; No match
292 (if (null matched)
293 (and dirtrack-debug
294 (dirtrack-debug-message
295 (format
296 "Input `%s' failed to match regexp: %s"
297 input dirtrack-regexp)))
298 (setq prompt-path
299 (substring input
300 (match-beginning match-num) (match-end match-num)))
301 ;; Empty string
302 (if (not (> (length prompt-path) 0))
303 (and dirtrack-debug
304 (dirtrack-debug-message "Match is empty string"))
305 ;; Transform prompts into canonical forms
306 (setq prompt-path (funcall dirtrack-directory-function
307 prompt-path))
308 (setq current-dir (funcall dirtrack-canonicalize-function
309 current-dir))
310 (and dirtrack-debug
311 (dirtrack-debug-message
312 (format
313 "Prompt is %s\nCurrent directory is %s"
314 prompt-path current-dir)))
315 ;; Compare them
316 (if (or (string= current-dir prompt-path)
317 (string= current-dir
318 (abbreviate-file-name prompt-path)))
319 (and dirtrack-debug
320 (dirtrack-debug-message
321 (format "Not changing directory")))
322 ;; It's possible that Emacs will think the directory
323 ;; won't exist (eg, rlogin buffers)
324 (if (file-accessible-directory-p prompt-path)
325 ;; Change directory
326 (and (shell-process-cd prompt-path)
327 (run-hooks 'dirtrack-directory-change-hook)
328 dirtrack-debug
329 (dirtrack-debug-message
330 (format "Changing directory to %s" prompt-path)))
331 (error "Directory %s does not exist" prompt-path)))
332 )))))
333 input)
335 (provide 'dirtrack)
337 ;;; arch-tag: 168de071-be88-4937-aff6-2aba9f328d5a
338 ;;; dirtrack.el ends here