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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, 2001, 2002, 2003, 2004, 2005,
4 ;; 2006, 2007, 2008 Free Software Foundation, Inc.
6 ;; Author: Peter Breton <pbreton@cs.umb.edu>
7 ;; Created: Sun Nov 17 1996
8 ;; Keywords: processes
10 ;; This file is part of GNU Emacs.
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 3, or (at your option)
15 ;; any later version.
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.
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., 51 Franklin Street, Fifth Floor,
25 ;; Boston, MA 02110-1301, USA.
27 ;;; Commentary:
29 ;; Shell directory tracking by watching the prompt.
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.
40 ;; Installation:
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.
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.
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).
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'. You can easily
63 ;; toggle this setting with the `dirtrack-debug-toggle' function.
65 ;; 3) Add a hook to shell-mode to enable the directory tracking:
67 ;; (add-hook 'shell-mode-hook
68 ;; (lambda () (add-hook 'comint-preoutput-filter-functions 'dirtrack nil t)))
70 ;; You may wish to turn ordinary shell tracking off by calling
71 ;; `shell-dirtrack-toggle' or setting `shell-dirtrackp'.
73 ;; Examples:
75 ;; 1) On Windows NT, my prompt is set to emacs$S$P$G.
76 ;; 'dirtrack-list' is set to (list "^emacs \\([a-zA-Z]:.*\\)>" 1)
78 ;; 2) On Solaris running bash, my prompt is set like this:
79 ;; PS1="\w\012emacs@\h(\!) [\t]% "
80 ;; 'dirtrack-list' is set to (list "^\\([/~].*\\)\nemacs@[^%]+% *" 1 t)
82 ;; I'd appreciate other examples from people who use this package.
84 ;; Here's one from Stephen Eglen:
86 ;; Running under tcsh:
87 ;; (setq-default dirtrack-list '("^%E \\([^ ]+\\)" 1))
89 ;; It might be worth mentioning in your file that emacs sources start up
90 ;; files of the form: ~/.emacs_<SHELL> where <SHELL> is the name of the
91 ;; shell. So for example, I have the following in ~/.emacs_tcsh:
93 ;; set prompt = "%%E %~ %h% "
95 ;; This produces a prompt of the form:
96 ;; %E /var/spool 10%
98 ;; This saves me from having to use the %E prefix in other non-emacs
99 ;; shells.
101 ;; A final note:
103 ;; I run LOTS of shell buffers through Emacs, sometimes as different users
104 ;; (eg, when logged in as myself, I'll run a root shell in the same Emacs).
105 ;; If you do this, and the shell prompt contains a ~, Emacs will interpret
106 ;; this relative to the user which owns the Emacs process, not the user
107 ;; who owns the shell buffer. This may cause dirtrack to behave strangely
108 ;; (typically it reports that it is unable to cd to a directory
109 ;; with a ~ in it).
111 ;; The same behavior can occur if you use dirtrack with remote filesystems
112 ;; (using telnet, rlogin, etc) as Emacs will be checking the local
113 ;; filesystem, not the remote one. This problem is not specific to dirtrack,
114 ;; but also affects file completion, etc.
116 ;;; Code:
118 (eval-when-compile
119 (require 'comint)
120 (require 'shell))
122 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
123 ;; Customization Variables
124 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
126 (defgroup dirtrack nil
127 "Directory tracking by watching the prompt."
128 :prefix "dirtrack-"
129 :group 'shell)
131 (defcustom dirtrack-list (list "^emacs \\([a-zA-Z]:.*\\)>" 1)
132 "List for directory tracking.
133 First item is a regexp that describes where to find the path in a prompt.
134 Second is a number, the regexp group to match. Optional third item is
135 whether the prompt is multi-line. If nil or omitted, prompt is assumed to
136 be on a single line."
137 :group 'dirtrack
138 :type '(sexp (regexp :tag "Prompt Expression")
139 (integer :tag "Regexp Group")
140 (boolean :tag "Multiline Prompt")))
142 (make-variable-buffer-local 'dirtrack-list)
144 (defcustom dirtrack-debug nil
145 "If non-nil, the function `dirtrack' will report debugging info."
146 :group 'dirtrack
147 :type 'boolean)
149 (defcustom dirtrack-debug-buffer "*Directory Tracking Log*"
150 "Buffer to write directory tracking debug information."
151 :group 'dirtrack
152 :type 'string)
154 (defcustom dirtrackp t
155 "If non-nil, directory tracking via `dirtrack' is enabled."
156 :group 'dirtrack
157 :type 'boolean)
159 (make-variable-buffer-local 'dirtrackp)
161 (defcustom dirtrack-directory-function
162 (if (memq system-type (list 'ms-dos 'windows-nt 'cygwin))
163 'dirtrack-windows-directory-function
164 'file-name-as-directory)
165 "Function to apply to the prompt directory for comparison purposes."
166 :group 'dirtrack
167 :type 'function)
169 (defcustom dirtrack-canonicalize-function
170 (if (memq system-type (list 'ms-dos 'windows-nt 'cygwin))
171 'downcase 'identity)
172 "Function to apply to the default directory for comparison purposes."
173 :group 'dirtrack
174 :type 'function)
176 (defcustom dirtrack-directory-change-hook nil
177 "Hook that is called when a directory change is made."
178 :group 'dirtrack
179 :type 'hook)
182 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
183 ;; Functions
184 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
187 (defun dirtrack-windows-directory-function (dir)
188 "Return a canonical directory for comparison purposes.
189 Such a directory is all lowercase, has forward-slashes as delimiters,
190 and ends with a forward slash."
191 (file-name-as-directory (downcase (subst-char-in-string ?\\ ?/ dir))))
193 (defun dirtrack-cygwin-directory-function (dir)
194 "Return a canonical directory taken from a Cygwin path for comparison purposes."
195 (if (string-match "/cygdrive/\\([A-Z]\\)\\(.*\\)" dir)
196 (concat (match-string 1 dir) ":" (match-string 2 dir))
197 dir))
199 ;; Copied from shell.el
200 (defun dirtrack-toggle ()
201 "Enable or disable Dirtrack directory tracking in a shell buffer."
202 (interactive)
203 (if (setq dirtrackp (not dirtrackp))
204 (add-hook 'comint-preoutput-filter-functions 'dirtrack nil t)
205 (remove-hook 'comint-preoutput-filter-functions 'dirtrack t))
206 (message "Directory tracking %s" (if dirtrackp "ON" "OFF")))
208 (defun dirtrack-debug-toggle ()
209 "Enable or disable Dirtrack debugging."
210 (interactive)
211 (setq dirtrack-debug (not dirtrack-debug))
212 (message "Directory debugging %s" (if dirtrack-debug "ON" "OFF"))
213 (and dirtrack-debug
214 (display-buffer (get-buffer-create dirtrack-debug-buffer))))
216 (defun dirtrack-debug-message (string)
217 (let ((buf (current-buffer))
218 (debug-buf (get-buffer-create dirtrack-debug-buffer))
220 (set-buffer debug-buf)
221 (goto-char (point-max))
222 (insert (concat string "\n"))
223 (set-buffer buf)
226 ;;;###autoload
227 (defun dirtrack (input)
228 "Determine the current directory by scanning the process output for a prompt.
229 The prompt to look for is the first item in `dirtrack-list'.
231 You can toggle directory tracking by using the function `dirtrack-toggle'.
233 If directory tracking does not seem to be working, you can use the
234 function `dirtrack-debug-toggle' to turn on debugging output.
236 You can enable directory tracking by adding this function to
237 `comint-output-filter-functions'."
238 (if (or (null dirtrackp)
239 ;; No output?
240 (eq (point) (point-min)))
242 (let (prompt-path
243 (current-dir default-directory)
244 (dirtrack-regexp (nth 0 dirtrack-list))
245 (match-num (nth 1 dirtrack-list))
246 ;; Currently unimplemented, it seems. --Stef
247 (multi-line (nth 2 dirtrack-list)))
248 (save-excursion
249 ;; No match
250 (if (null (string-match dirtrack-regexp input))
251 (and dirtrack-debug
252 (dirtrack-debug-message
253 (format
254 "Input `%s' failed to match `dirtrack-regexp'" input)))
255 (setq prompt-path (match-string match-num input))
256 ;; Empty string
257 (if (not (> (length prompt-path) 0))
258 (and dirtrack-debug
259 (dirtrack-debug-message "Match is empty string"))
260 ;; Transform prompts into canonical forms
261 (setq prompt-path (funcall dirtrack-directory-function
262 prompt-path))
263 (setq current-dir (funcall dirtrack-canonicalize-function
264 current-dir))
265 (and dirtrack-debug
266 (dirtrack-debug-message
267 (format
268 "Prompt is %s\nCurrent directory is %s"
269 prompt-path current-dir)))
270 ;; Compare them
271 (if (or (string= current-dir prompt-path)
272 (string= current-dir
273 (abbreviate-file-name prompt-path)))
274 (and dirtrack-debug
275 (dirtrack-debug-message
276 (format "Not changing directory")))
277 ;; It's possible that Emacs will think the directory
278 ;; won't exist (eg, rlogin buffers)
279 (if (file-accessible-directory-p prompt-path)
280 ;; Change directory
281 (and (shell-process-cd prompt-path)
282 (run-hooks 'dirtrack-directory-change-hook)
283 dirtrack-debug
284 (dirtrack-debug-message
285 (format "Changing directory to %s" prompt-path)))
286 (error "Directory %s does not exist" prompt-path)))
287 )))))
288 input)
290 (provide 'dirtrack)
292 ;; arch-tag: 168de071-be88-4937-aff6-2aba9f328d5a
293 ;;; dirtrack.el ends here