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emacs/lisp/dirtrack.el
Chong Yidong 1e86875746 Don't signal error on incorrect dirtrack regexp (Bug#5476)
* dirtrack.el (dirtrack): Warn instead of signalling error if the
regexp is incorrect (Bug#5476).
2010-01-29 14:08:09 -05:00

281 lines
11 KiB
EmacsLisp

;;; dirtrack.el --- Directory Tracking by watching the prompt
;; Copyright (C) 1996, 2001, 2002, 2003, 2004, 2005,
;; 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
;; Author: Peter Breton <pbreton@cs.umb.edu>
;; Created: Sun Nov 17 1996
;; Keywords: processes
;; This file is part of GNU Emacs.
;; GNU Emacs is free software: you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.
;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;; GNU General Public License for more details.
;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
;;; Commentary:
;; Shell directory tracking by watching the prompt.
;;
;; This is yet another attempt at a directory-tracking package for
;; Emacs shell-mode. However, this package makes one strong assumption:
;; that you can customize your shell's prompt to contain the
;; current working directory. Most shells do support this, including
;; almost every type of Bourne and C shell on Unix, the native shells on
;; Windows95 (COMMAND.COM) and Windows NT (CMD.EXE), and most 3rd party
;; Windows shells. If you cannot do this, or do not wish to, this package
;; will be useless to you.
;;
;; Installation:
;;
;; 1) Set your shell's prompt to contain the current working directory.
;; You may need to consult your shell's documentation to find out how to
;; do this.
;;
;; Note that directory tracking is done by matching regular expressions,
;; therefore it is *VERY IMPORTANT* for your prompt to be easily
;; distinguishable from other output. If your prompt regexp is too general,
;; you will see error messages from the dirtrack filter as it attempts to cd
;; to non-existent directories.
;;
;; 2) Set the variable `dirtrack-list' to an appropriate value. This
;; should be a list of two elements: the first is a regular expression
;; which matches your prompt up to and including the pathname part.
;; The second is a number which tells which regular expression group to
;; match to extract only the pathname. If you use a multi-line prompt,
;; add 't' as a third element. Note that some of the functions in
;; 'comint.el' assume a single-line prompt (eg, comint-bol).
;;
;; Determining this information may take some experimentation. Using
;; `dirtrack-debug-mode' may help; it causes the directory-tracking
;; filter to log messages to the buffer `dirtrack-debug-buffer'.
;;
;; 3) Activate `dirtrack-mode'. You may wish to turn ordinary shell
;; tracking off by calling `shell-dirtrack-mode'.
;;
;; Examples:
;;
;; 1) On Windows NT, my prompt is set to emacs$S$P$G.
;; 'dirtrack-list' is set to (list "^emacs \\([a-zA-Z]:.*\\)>" 1)
;;
;; 2) On Solaris running bash, my prompt is set like this:
;; PS1="\w\012emacs@\h(\!) [\t]% "
;; 'dirtrack-list' is set to (list "^\\([/~].*\\)\nemacs@[^%]+% *" 1 t)
;;
;; I'd appreciate other examples from people who use this package.
;;
;; Here's one from Stephen Eglen:
;;
;; Running under tcsh:
;; (setq-default dirtrack-list '("^%E \\([^ ]+\\)" 1))
;;
;; It might be worth mentioning in your file that emacs sources start up
;; files of the form: ~/.emacs_<SHELL> where <SHELL> is the name of the
;; shell. So for example, I have the following in ~/.emacs_tcsh:
;;
;; set prompt = "%%E %~ %h% "
;;
;; This produces a prompt of the form:
;; %E /var/spool 10%
;;
;; This saves me from having to use the %E prefix in other non-emacs
;; shells.
;;
;; A final note:
;;
;; I run LOTS of shell buffers through Emacs, sometimes as different users
;; (eg, when logged in as myself, I'll run a root shell in the same Emacs).
;; If you do this, and the shell prompt contains a ~, Emacs will interpret
;; this relative to the user which owns the Emacs process, not the user
;; who owns the shell buffer. This may cause dirtrack to behave strangely
;; (typically it reports that it is unable to cd to a directory
;; with a ~ in it).
;;
;; The same behavior can occur if you use dirtrack with remote filesystems
;; (using telnet, rlogin, etc) as Emacs will be checking the local
;; filesystem, not the remote one. This problem is not specific to dirtrack,
;; but also affects file completion, etc.
;;; Code:
(eval-when-compile
(require 'comint)
(require 'shell))
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Customization Variables
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(defgroup dirtrack nil
"Directory tracking by watching the prompt."
:prefix "dirtrack-"
:group 'shell)
(defcustom dirtrack-list (list "^emacs \\([a-zA-Z]:.*\\)>" 1)
"List for directory tracking.
First item is a regexp that describes where to find the path in a prompt.
Second is a number, the regexp group to match. Optional third item is
whether the prompt is multi-line. If nil or omitted, prompt is assumed to
be on a single line."
:group 'dirtrack
:type '(sexp (regexp :tag "Prompt Expression")
(integer :tag "Regexp Group")
(boolean :tag "Multiline Prompt")))
(make-variable-buffer-local 'dirtrack-list)
(defcustom dirtrack-debug nil
"If non-nil, the function `dirtrack' will report debugging info."
:group 'dirtrack
:type 'boolean)
(defcustom dirtrack-debug-buffer "*Directory Tracking Log*"
"Buffer in which to write directory tracking debug information."
:group 'dirtrack
:type 'string)
(defcustom dirtrackp t
"If non-nil, directory tracking via `dirtrack' is enabled."
:group 'dirtrack
:type 'boolean)
(make-variable-buffer-local 'dirtrackp)
(defcustom dirtrack-directory-function
(if (memq system-type (list 'ms-dos 'windows-nt 'cygwin))
'dirtrack-windows-directory-function
'file-name-as-directory)
"Function to apply to the prompt directory for comparison purposes."
:group 'dirtrack
:type 'function)
(defcustom dirtrack-canonicalize-function
(if (memq system-type (list 'ms-dos 'windows-nt 'cygwin))
'downcase 'identity)
"Function to apply to the default directory for comparison purposes."
:group 'dirtrack
:type 'function)
(defcustom dirtrack-directory-change-hook nil
"Hook that is called when a directory change is made."
:group 'dirtrack
:type 'hook)
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Functions
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(defun dirtrack-windows-directory-function (dir)
"Return a canonical directory for comparison purposes.
Such a directory is all lowercase, has forward-slashes as delimiters,
and ends with a forward slash."
(file-name-as-directory (downcase (subst-char-in-string ?\\ ?/ dir))))
(defun dirtrack-cygwin-directory-function (dir)
"Return a canonical directory taken from a Cygwin path for comparison purposes."
(if (string-match "/cygdrive/\\([A-Z]\\)\\(.*\\)" dir)
(concat (match-string 1 dir) ":" (match-string 2 dir))
dir))
;;;###autoload
(define-minor-mode dirtrack-mode
"Enable or disable Dirtrack directory tracking in a shell buffer.
This method requires that your shell prompt contain the full
current working directory at all times, and that `dirtrack-list'
is set to match the prompt. This is an alternative to
`shell-dirtrack-mode', which works differently, by tracking `cd'
and similar commands which change the shell working directory."
nil nil nil
(if dirtrack-mode
(add-hook 'comint-preoutput-filter-functions 'dirtrack nil t)
(remove-hook 'comint-preoutput-filter-functions 'dirtrack t)))
(define-obsolete-function-alias 'dirtrack-toggle 'dirtrack-mode "23.1")
(define-obsolete-variable-alias 'dirtrackp 'dirtrack-mode "23.1")
(define-minor-mode dirtrack-debug-mode
"Enable or disable Dirtrack debugging."
nil nil nil
(if dirtrack-debug-mode
(display-buffer (get-buffer-create dirtrack-debug-buffer))))
(define-obsolete-function-alias 'dirtrack-debug-toggle 'dirtrack-debug-mode
"23.1")
(define-obsolete-variable-alias 'dirtrack-debug 'dirtrack-debug-mode "23.1")
(defun dirtrack-debug-message (string)
"Insert string at the end of `dirtrack-debug-buffer'."
(when dirtrack-debug-mode
(with-current-buffer (get-buffer-create dirtrack-debug-buffer)
(goto-char (point-max))
(insert (concat string "\n")))))
;;;###autoload
(defun dirtrack (input)
"Determine the current directory by scanning the process output for a prompt.
The prompt to look for is the first item in `dirtrack-list'.
You can toggle directory tracking by using the function `dirtrack-mode'.
If directory tracking does not seem to be working, you can use the
function `dirtrack-debug-mode' to turn on debugging output."
(unless (or (null dirtrack-mode)
(eq (point) (point-min))) ; no output?
(let (prompt-path
(current-dir default-directory)
(dirtrack-regexp (nth 0 dirtrack-list))
(match-num (nth 1 dirtrack-list))
;; Currently unimplemented, it seems. --Stef
(multi-line (nth 2 dirtrack-list)))
(save-excursion
;; No match
(if (not (string-match dirtrack-regexp input))
(dirtrack-debug-message
(format "Input `%s' failed to match `dirtrack-list'" input))
(setq prompt-path (match-string match-num input))
;; Empty string
(if (not (> (length prompt-path) 0))
(dirtrack-debug-message "Match is empty string")
;; Transform prompts into canonical forms
(setq prompt-path (funcall dirtrack-directory-function
prompt-path)
current-dir (funcall dirtrack-canonicalize-function
current-dir))
(dirtrack-debug-message
(format "Prompt is %s\nCurrent directory is %s"
prompt-path current-dir))
;; Compare them
(if (or (string= current-dir prompt-path)
(string= current-dir (abbreviate-file-name prompt-path)))
(dirtrack-debug-message (format "Not changing directory"))
;; It's possible that Emacs will think the directory
;; won't exist (eg, rlogin buffers)
(if (file-accessible-directory-p prompt-path)
;; Change directory
(and (shell-process-cd prompt-path)
(run-hooks 'dirtrack-directory-change-hook)
(dirtrack-debug-message
(format "Changing directory to %s" prompt-path)))
(warn "Directory %s does not exist" prompt-path)))
)))))
input)
(provide 'dirtrack)
;; arch-tag: 168de071-be88-4937-aff6-2aba9f328d5a
;;; dirtrack.el ends here