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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, 2001-2011 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 3 of the License, or
14 ;; (at your option) 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. If not, see <http://www.gnu.org/licenses/>.
24 ;;; Commentary:
26 ;; Shell directory tracking by watching the prompt.
28 ;; This is yet another attempt at a directory-tracking package for
29 ;; Emacs shell-mode. However, this package makes one strong assumption:
30 ;; that you can customize your shell's prompt to contain the
31 ;; current working directory. Most shells do support this, including
32 ;; almost every type of Bourne and C shell on Unix, the native shells on
33 ;; Windows95 (COMMAND.COM) and Windows NT (CMD.EXE), and most 3rd party
34 ;; Windows shells. If you cannot do this, or do not wish to, this package
35 ;; will be useless to you.
37 ;; Installation:
39 ;; 1) Set your shell's prompt to contain the current working directory.
40 ;; You may need to consult your shell's documentation to find out how to
41 ;; do this.
43 ;; Note that directory tracking is done by matching regular expressions,
44 ;; therefore it is *VERY IMPORTANT* for your prompt to be easily
45 ;; distinguishable from other output. If your prompt regexp is too general,
46 ;; you will see error messages from the dirtrack filter as it attempts to cd
47 ;; to non-existent directories.
49 ;; 2) Set the variable `dirtrack-list' to an appropriate value. This
50 ;; should be a list of two elements: the first is a regular expression
51 ;; which matches your prompt up to and including the pathname part.
52 ;; The second is a number which tells which regular expression group to
53 ;; match to extract only the pathname. If you use a multi-line prompt,
54 ;; add 't' as a third element. Note that some of the functions in
55 ;; 'comint.el' assume a single-line prompt (eg, comint-bol).
57 ;; Determining this information may take some experimentation. Using
58 ;; `dirtrack-debug-mode' may help; it causes the directory-tracking
59 ;; filter to log messages to the buffer `dirtrack-debug-buffer'.
61 ;; 3) Activate `dirtrack-mode'. You may wish to turn ordinary shell
62 ;; tracking off by calling `shell-dirtrack-mode'.
64 ;; Examples:
66 ;; 1) On Windows NT, my prompt is set to emacs$S$P$G.
67 ;; 'dirtrack-list' is set to (list "^emacs \\([a-zA-Z]:.*\\)>" 1)
69 ;; 2) On Solaris running bash, my prompt is set like this:
70 ;; PS1="\w\012emacs@\h(\!) [\t]% "
71 ;; 'dirtrack-list' is set to (list "^\\([/~].*\\)\nemacs@[^%]+% *" 1 t)
73 ;; I'd appreciate other examples from people who use this package.
75 ;; Here's one from Stephen Eglen:
77 ;; Running under tcsh:
78 ;; (setq-default dirtrack-list '("^%E \\([^ ]+\\)" 1))
80 ;; It might be worth mentioning in your file that emacs sources start up
81 ;; files of the form: ~/.emacs_<SHELL> where <SHELL> is the name of the
82 ;; shell. So for example, I have the following in ~/.emacs_tcsh:
84 ;; set prompt = "%%E %~ %h% "
86 ;; This produces a prompt of the form:
87 ;; %E /var/spool 10%
89 ;; This saves me from having to use the %E prefix in other non-emacs
90 ;; shells.
92 ;; A final note:
94 ;; I run LOTS of shell buffers through Emacs, sometimes as different users
95 ;; (eg, when logged in as myself, I'll run a root shell in the same Emacs).
96 ;; If you do this, and the shell prompt contains a ~, Emacs will interpret
97 ;; this relative to the user which owns the Emacs process, not the user
98 ;; who owns the shell buffer. This may cause dirtrack to behave strangely
99 ;; (typically it reports that it is unable to cd to a directory
100 ;; with a ~ in it).
102 ;; The same behavior can occur if you use dirtrack with remote filesystems
103 ;; (using telnet, rlogin, etc) as Emacs will be checking the local
104 ;; filesystem, not the remote one. This problem is not specific to dirtrack,
105 ;; but also affects file completion, etc.
107 ;;; Code:
109 (eval-when-compile
110 (require 'comint)
111 (require 'shell))
113 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
114 ;; Customization Variables
115 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
117 (defgroup dirtrack nil
118 "Directory tracking by watching the prompt."
119 :prefix "dirtrack-"
120 :group 'shell)
122 (defcustom dirtrack-list (list "^emacs \\([a-zA-Z]:.*\\)>" 1)
123 "List for directory tracking.
124 First item is a regexp that describes where to find the path in a prompt.
125 Second is a number, the regexp group to match. Optional third item is
126 whether the prompt is multi-line. If nil or omitted, prompt is assumed to
127 be on a single line."
128 :group 'dirtrack
129 :type '(sexp (regexp :tag "Prompt Expression")
130 (integer :tag "Regexp Group")
131 (boolean :tag "Multiline Prompt")))
133 (make-variable-buffer-local 'dirtrack-list)
135 (defcustom dirtrack-debug nil
136 "If non-nil, the function `dirtrack' will report debugging info."
137 :group 'dirtrack
138 :type 'boolean)
140 (defcustom dirtrack-debug-buffer "*Directory Tracking Log*"
141 "Buffer in which to write directory tracking debug information."
142 :group 'dirtrack
143 :type 'string)
145 (defcustom dirtrack-directory-function
146 (if (memq system-type '(ms-dos windows-nt cygwin))
147 'dirtrack-windows-directory-function
148 'file-name-as-directory)
149 "Function to apply to the prompt directory for comparison purposes."
150 :group 'dirtrack
151 :type 'function)
153 (defcustom dirtrack-canonicalize-function
154 (if (memq system-type '(ms-dos windows-nt cygwin))
155 'downcase 'identity)
156 "Function to apply to the default directory for comparison purposes."
157 :group 'dirtrack
158 :type 'function)
160 (defcustom dirtrack-directory-change-hook nil
161 "Hook that is called when a directory change is made."
162 :group 'dirtrack
163 :type 'hook)
166 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
167 ;; Functions
168 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
171 (defun dirtrack-windows-directory-function (dir)
172 "Return a canonical directory for comparison purposes.
173 Such a directory is all lowercase, has forward-slashes as delimiters,
174 and ends with a forward slash."
175 (file-name-as-directory (downcase (subst-char-in-string ?\\ ?/ dir))))
177 (defun dirtrack-cygwin-directory-function (dir)
178 "Return a canonical directory taken from a Cygwin path for comparison purposes."
179 (if (string-match "/cygdrive/\\([A-Z]\\)\\(.*\\)" dir)
180 (concat (match-string 1 dir) ":" (match-string 2 dir))
181 dir))
184 ;;;###autoload
185 (define-minor-mode dirtrack-mode
186 "Enable or disable Dirtrack directory tracking in a shell buffer.
187 This method requires that your shell prompt contain the full
188 current working directory at all times, and that `dirtrack-list'
189 is set to match the prompt. This is an alternative to
190 `shell-dirtrack-mode', which works differently, by tracking `cd'
191 and similar commands which change the shell working directory."
192 nil nil nil
193 (if dirtrack-mode
194 (add-hook 'comint-preoutput-filter-functions 'dirtrack nil t)
195 (remove-hook 'comint-preoutput-filter-functions 'dirtrack t)))
197 (define-obsolete-function-alias 'dirtrack-toggle 'dirtrack-mode "23.1")
198 (define-obsolete-variable-alias 'dirtrackp 'dirtrack-mode "23.1")
201 (define-minor-mode dirtrack-debug-mode
202 "Enable or disable Dirtrack debugging."
203 nil nil nil
204 (if dirtrack-debug-mode
205 (display-buffer (get-buffer-create dirtrack-debug-buffer))))
207 (define-obsolete-function-alias 'dirtrack-debug-toggle 'dirtrack-debug-mode
208 "23.1")
209 (define-obsolete-variable-alias 'dirtrack-debug 'dirtrack-debug-mode "23.1")
212 (defun dirtrack-debug-message (string)
213 "Insert string at the end of `dirtrack-debug-buffer'."
214 (when dirtrack-debug-mode
215 (with-current-buffer (get-buffer-create dirtrack-debug-buffer)
216 (goto-char (point-max))
217 (insert (concat string "\n")))))
219 ;;;###autoload
220 (defun dirtrack (input)
221 "Determine the current directory by scanning the process output for a prompt.
222 The prompt to look for is the first item in `dirtrack-list'.
224 You can toggle directory tracking by using the function `dirtrack-mode'.
226 If directory tracking does not seem to be working, you can use the
227 function `dirtrack-debug-mode' to turn on debugging output."
228 (unless (or (null dirtrack-mode)
229 (eq (point) (point-min))) ; no output?
230 (let (prompt-path
231 (current-dir default-directory)
232 (dirtrack-regexp (nth 0 dirtrack-list))
233 (match-num (nth 1 dirtrack-list)))
234 ;; Currently unimplemented, it seems. --Stef
235 ;; (multi-line (nth 2 dirtrack-list)))
236 (save-excursion
237 ;; No match
238 (if (not (string-match dirtrack-regexp input))
239 (dirtrack-debug-message
240 (format "Input `%s' failed to match `dirtrack-list'" input))
241 (setq prompt-path (match-string match-num input))
242 ;; Empty string
243 (if (not (> (length prompt-path) 0))
244 (dirtrack-debug-message "Match is empty string")
245 ;; Transform prompts into canonical forms
246 (setq prompt-path (funcall dirtrack-directory-function
247 prompt-path)
248 current-dir (funcall dirtrack-canonicalize-function
249 current-dir))
250 (dirtrack-debug-message
251 (format "Prompt is %s\nCurrent directory is %s"
252 prompt-path current-dir))
253 ;; Compare them
254 (if (or (string= current-dir prompt-path)
255 (string= current-dir (abbreviate-file-name prompt-path)))
256 (dirtrack-debug-message (format "Not changing directory"))
257 ;; It's possible that Emacs will think the directory
258 ;; won't exist (eg, rlogin buffers)
259 (if (file-accessible-directory-p prompt-path)
260 ;; Change directory
261 (and (shell-process-cd prompt-path)
262 (run-hooks 'dirtrack-directory-change-hook)
263 (dirtrack-debug-message
264 (format "Changing directory to %s" prompt-path)))
265 (warn "Directory %s does not exist" prompt-path)))
266 )))))
267 input)
269 (provide 'dirtrack)
271 ;;; dirtrack.el ends here