(thing-at-point-uri-schemes): New variable.

[bpt/emacs.git] / lisp / net / tramp.el

;;; tramp.el --- Transparent Remote Access, Multiple Protocol -*- coding: iso-8859-1; -*-

;; Copyright (C) 1998, 1999, 2000 Free Software Foundation, Inc.

;; Author: Kai.Grossjohann@CS.Uni-Dortmund.DE 
;; Keywords: comm, 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 2, 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; see the file COPYING.  If not, write to the
;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
;; Boston, MA 02111-1307, USA.

;;; Commentary:

;; This package provides remote file editing, similar to ange-ftp.
;; The difference is that ange-ftp uses FTP to transfer files between
;; the local and the remote host, whereas tramp.el uses a combination
;; of rsh and rcp or other work-alike programs, such as ssh/scp.
;;
;; For more detailed instructions, please see the info file, which is
;; included in the file `tramp.tar.gz' mentioned below.
;;
;; Notes:
;; -----
;; 
;; This package only works for Emacs 20 and higher, and for XEmacs 21
;; and higher.  (XEmacs 20 is missing the `with-timeout' macro.  Emacs
;; 19 is reported to have other problems.  For XEmacs 21, you need the
;; package `fsf-compat' for the `with-timeout' macro.)
;;
;; This version might not work with pre-Emacs 21 VC unless VC is
;; loaded before tramp.el.  Could you please test this and tell me about
;; the result?  Thanks.
;;
;; Also see the todo list at the bottom of this file.
;;
;; The current version of tramp.el can be retrieved from the following
;; URL:  ftp://ls6-ftp.cs.uni-dortmund.de/pub/src/emacs/tramp.tar.gz
;; For your convenience, the *.el file is available separately from
;; the same directory.
;;
;; There's a mailing list for this, as well.  Its name is:
;;                tramp-devel@mail.freesoftware.fsf.org
;; Send a mail with `help' in the subject (!) to the administration
;; address for instructions on joining the list.  The administration
;; address is:
;;            tramp-devel-request@mail.freesoftware.fsf.org
;; You can also use the Web to subscribe, under the following URL:
;;            http://mail.freesoftware.fsf.org/mailman/listinfo/tramp-devel
;;
;; For the adventurous, the current development sources are available
;; via CVS.  You can find instructions about this at the following URL:
;;            http://savannah.gnu.org/projects/tramp/
;; Click on "CVS" in the navigation bar near the top.
;;
;; Don't forget to put on your asbestos longjohns, first!

;;; Code:

;; In the Tramp CVS repository, the version numer is auto-frobbed from
;; the Makefile, so you should edit the top-level Makefile to change
;; the version number.
(defconst tramp-version "2.0.24"
  "This version of tramp.")

(defconst tramp-bug-report-address "tramp-devel@mail.freesoftware.fsf.org"
  "Email address to send bug reports to.")

(require 'timer)
(require 'format-spec)                  ;from Gnus 5.8, also in tar ball
;; The explicit check is not necessary in Emacs, which provides the
;; feature even if implemented in C, but it appears to be necessary
;; in XEmacs.
(unless (and (fboundp 'base64-encode-region)
	     (fboundp 'base64-decode-region))
  (require 'base64))                       ;for the mimencode methods
(require 'shell)
(require 'advice)

(autoload 'tramp-uuencode-region "tramp-uu"
  "Implementation of `uuencode' in Lisp.")

(unless (fboundp 'uudecode-decode-region)
  (autoload 'uudecode-decode-region "uudecode"))

;; ;; It does not work to load EFS after loading TRAMP.  
;; (when (fboundp 'efs-file-handler-function)
;;   (require 'efs))

(eval-when-compile
  (require 'cl)
  (require 'custom)
  ;; Emacs 19.34 compatibility hack -- is this needed?
  (or (>= emacs-major-version 20)
      (load "cl-seq")))

(unless (boundp 'custom-print-functions)
  (defvar custom-print-functions nil))	; not autoloaded before Emacs 20.4

;; XEmacs is distributed with few Lisp packages.  Further packages are
;; installed using EFS.  If we use a unified filename format, then
;; Tramp is required in addition to EFS.  (But why can't Tramp just
;; disable EFS when Tramp is loaded?  Then XEmacs can ship with EFS
;; just like before.)  Another reason for using a separate filename
;; syntax on XEmacs is that EFS hooks into XEmacs in many places, but
;; Tramp only knows how to deal with `file-name-handler-alist', not
;; the other places.
;;;###autoload
(defvar tramp-unified-filenames (not (featurep 'xemacs))
  "Non-nil means to use unified Ange-FTP/Tramp filename syntax.
Nil means to use a separate filename syntax for Tramp.")

;;; User Customizable Internal Variables:

(defgroup tramp nil
  "Edit remote files with a combination of rsh and rcp or similar programs."
  :group 'files)

(defcustom tramp-verbose 9
  "*Verbosity level for tramp.el.  0 means be silent, 10 is most verbose."
  :group 'tramp
  :type 'integer)

(defcustom tramp-debug-buffer nil
  "*Whether to send all commands and responses to a debug buffer."
  :group 'tramp
  :type 'boolean)

(defcustom tramp-auto-save-directory nil
  "*Put auto-save files in this directory, if set.
The idea is to use a local directory so that auto-saving is faster."
  :group 'tramp
  :type '(choice (const nil)
                 string))

(defcustom tramp-encoding-shell
  (if (memq system-type '(windows-nt))
      (getenv "COMSPEC")
    "/bin/sh")
  "*Use this program for encoding and decoding commands on the local host.
This shell is used to execute the encoding and decoding command on the
local host, so if you want to use `~' in those commands, you should
choose a shell here which groks tilde expansion.  `/bin/sh' normally
does not understand tilde expansion.

For encoding and deocding, commands like the following are executed:

    /bin/sh -c COMMAND < INPUT > OUTPUT

This variable can be used to change the \"/bin/sh\" part.  See the
variable `tramp-encoding-command-switch' for the \"-c\" part.  Also, see the
variable `tramp-encoding-reads-stdin' to specify whether the commands read
standard input or a file.

Note that this variable is not used for remote commands.  There are
mechanisms in tramp.el which automatically determine the right shell to
use for the remote host."
  :group 'tramp
  :type '(file :must-match t))

(defcustom tramp-encoding-command-switch
  (if (string-match "cmd\\.exe" tramp-encoding-shell)
      "/c"
    "-c")
  "*Use this switch together with `tramp-encoding-shell' for local commands.
See the variable `tramp-encoding-shell' for more information."
  :group 'tramp
  :type 'string)

(defcustom tramp-encoding-reads-stdin t
  "*If non-nil, encoding commands read from standard input.
If nil, the filename is the last argument.

Note that the commands always must write to standard output."
  :group 'tramp
  :type 'boolean)

(defcustom tramp-multi-sh-program
  tramp-encoding-shell
  "*Use this program for bootstrapping multi-hop connections.
This variable is similar to `tramp-encoding-shell', but it is only used
when initializing a multi-hop connection.  Therefore, the set of
commands sent to this shell is quite restricted, and if you are
careful it works to use CMD.EXE under Windows (instead of a Bourne-ish
shell which does not normally exist on Windows anyway).

To use multi-hop methods from Windows, you also need suitable entries
in `tramp-multi-connection-function-alist' for the first hop.

This variable defaults to the value of `tramp-encoding-shell'."
  :group 'tramp
  :type '(file :must-match t))

;; CCC I have changed all occurrences of comint-quote-filename with
;; tramp-shell-quote-argument, except in tramp-handle-expand-many-files.
;; There, comint-quote-filename was removed altogether.  If it turns
;; out to be necessary there, something will need to be done.
;;-(defcustom tramp-file-name-quote-list
;;-  '(?] ?[ ?\| ?& ?< ?> ?\( ?\) ?\; ?\  ?\* ?\? ?\! ?\" ?\' ?\` ?# ?\@ ?\+ )
;;-  "*Protect these characters from the remote shell.
;;-Any character in this list is quoted (preceded with a backslash)
;;-because it means something special to the shell.  This takes effect
;;-when sending file and directory names to the remote shell.
;;-
;;-See `comint-file-name-quote-list' for details."
;;-  :group 'tramp
;;-  :type '(repeat character))

(defcustom tramp-methods
  '( ("rcp"   (tramp-connection-function  tramp-open-connection-rsh)
              (tramp-rsh-program          "rsh")
              (tramp-rcp-program          "rcp")
              (tramp-remote-sh            "/bin/sh")
              (tramp-rsh-args             nil)
              (tramp-rcp-args             nil)
              (tramp-rcp-keep-date-arg    "-p")
              (tramp-su-program           nil)
              (tramp-su-args              nil)
              (tramp-telnet-program       nil)
              (tramp-telnet-args          nil))
     ("scp"   (tramp-connection-function  tramp-open-connection-rsh)
              (tramp-rsh-program          "ssh")
              (tramp-rcp-program          "scp")
              (tramp-remote-sh            "/bin/sh")
              (tramp-rsh-args             ("-e" "none"))
              (tramp-rcp-args             nil)
              (tramp-rcp-keep-date-arg    "-p")
              (tramp-su-program           nil)
              (tramp-su-args              nil)
              (tramp-telnet-program       nil)
              (tramp-telnet-args          nil))
     ("scp1"  (tramp-connection-function  tramp-open-connection-rsh)
              (tramp-rsh-program          "ssh")
              (tramp-rcp-program          "scp")
              (tramp-remote-sh            "/bin/sh")
              (tramp-rsh-args             ("-1" "-e" "none"))
              (tramp-rcp-args             ("-1"))
              (tramp-rcp-keep-date-arg    "-p")
              (tramp-su-program           nil)
              (tramp-su-args              nil)
              (tramp-telnet-program       nil)
              (tramp-telnet-args          nil))
     ("scp2"  (tramp-connection-function  tramp-open-connection-rsh)
              (tramp-rsh-program          "ssh")
              (tramp-rcp-program          "scp")
              (tramp-remote-sh            "/bin/sh")
              (tramp-rsh-args             ("-2" "-e" "none"))
              (tramp-rcp-args             ("-2"))
              (tramp-rcp-keep-date-arg    "-p")
              (tramp-su-program           nil)
              (tramp-su-args              nil)
              (tramp-telnet-program       nil)
              (tramp-telnet-args          nil))
     ("scp1_old"
              (tramp-connection-function  tramp-open-connection-rsh)
              (tramp-rsh-program          "ssh1")
              (tramp-rcp-program          "scp1")
              (tramp-remote-sh            "/bin/sh")
              (tramp-rsh-args             ("-e" "none"))
              (tramp-rcp-args             nil)
              (tramp-rcp-keep-date-arg    "-p")
              (tramp-su-program           nil)
              (tramp-su-args              nil)
              (tramp-telnet-program       nil)
              (tramp-telnet-args          nil))
     ("scp2_old"
              (tramp-connection-function  tramp-open-connection-rsh)
              (tramp-rsh-program          "ssh2")
              (tramp-rcp-program          "scp2")
              (tramp-remote-sh            "/bin/sh")
              (tramp-rsh-args             ("-e" "none"))
              (tramp-rcp-args             nil)
              (tramp-rcp-keep-date-arg    "-p")
              (tramp-su-program           nil)
              (tramp-su-args              nil)
              (tramp-telnet-program       nil)
              (tramp-telnet-args          nil))
     ("rsync" (tramp-connection-function  tramp-open-connection-rsh)
              (tramp-rsh-program          "ssh")
              (tramp-rcp-program          "rsync")
              (tramp-remote-sh            "/bin/sh")
              (tramp-rsh-args             ("-e" "none"))
              (tramp-rcp-args             ("-e" "ssh"))
              (tramp-rcp-keep-date-arg    "-t")
              (tramp-su-program           nil)
              (tramp-su-args              nil)
              (tramp-telnet-program       nil)
              (tramp-telnet-args          nil))
     ("rsh"   (tramp-connection-function  tramp-open-connection-rsh)
              (tramp-rsh-program          "rsh")
              (tramp-rcp-program          nil)
              (tramp-remote-sh            "/bin/sh")
              (tramp-rsh-args             nil)
              (tramp-rcp-args             nil)
              (tramp-rcp-keep-date-arg    nil)
              (tramp-su-program           nil)
              (tramp-su-args              nil)
              (tramp-telnet-program       nil)
              (tramp-telnet-args          nil))
     ("ssh"   (tramp-connection-function  tramp-open-connection-rsh)
              (tramp-rsh-program          "ssh")
              (tramp-rcp-program          nil)
              (tramp-remote-sh            "/bin/sh")
              (tramp-rsh-args             ("-e" "none"))
              (tramp-rcp-args             nil)
              (tramp-rcp-keep-date-arg    nil)
              (tramp-su-program           nil)
              (tramp-su-args              nil)
              (tramp-telnet-program       nil)
              (tramp-telnet-args          nil))
     ("ssh1"  (tramp-connection-function  tramp-open-connection-rsh)
              (tramp-rsh-program          "ssh")
              (tramp-rcp-program          nil)
              (tramp-remote-sh            "/bin/sh")
              (tramp-rsh-args             ("-1" "-e" "none"))
              (tramp-rcp-args             ("-1"))
              (tramp-rcp-keep-date-arg    nil)
              (tramp-su-program           nil)
              (tramp-su-args              nil)
              (tramp-telnet-program       nil)
              (tramp-telnet-args          nil))
     ("ssh2"  (tramp-connection-function  tramp-open-connection-rsh)
              (tramp-rsh-program          "ssh")
              (tramp-rcp-program          nil)
              (tramp-remote-sh            "/bin/sh")
              (tramp-rsh-args             ("-2" "-e" "none"))
              (tramp-rcp-args             ("-2"))
              (tramp-rcp-keep-date-arg    nil)
              (tramp-su-program           nil)
              (tramp-su-args              nil)
              (tramp-telnet-program       nil)
              (tramp-telnet-args          nil))
     ("ssh1_old"
              (tramp-connection-function  tramp-open-connection-rsh)
              (tramp-rsh-program          "ssh1")
              (tramp-rcp-program          nil)
              (tramp-remote-sh            "/bin/sh")
              (tramp-rsh-args             ("-e" "none"))
              (tramp-rcp-args             nil)
              (tramp-rcp-keep-date-arg    nil)
              (tramp-su-program           nil)
              (tramp-su-args              nil)
              (tramp-telnet-program       nil)
              (tramp-telnet-args          nil))
     ("ssh2_old"
              (tramp-connection-function  tramp-open-connection-rsh)
              (tramp-rsh-program          "ssh2")
              (tramp-rcp-program          nil)
              (tramp-remote-sh            "/bin/sh")
              (tramp-rsh-args             ("-e" "none"))
              (tramp-rcp-args             nil)
              (tramp-rcp-keep-date-arg    nil)
              (tramp-su-program           nil)
              (tramp-su-args              nil)
              (tramp-telnet-program       nil)
              (tramp-telnet-args          nil))
     ("telnet"
              (tramp-connection-function  tramp-open-connection-telnet)
              (tramp-rsh-program          nil)
              (tramp-rcp-program          nil)
              (tramp-remote-sh            "/bin/sh")
              (tramp-rsh-args             nil)
              (tramp-rcp-args             nil)
              (tramp-rcp-keep-date-arg    nil)
              (tramp-su-program           nil)
              (tramp-su-args              nil)
              (tramp-telnet-program       "telnet")
              (tramp-telnet-args          nil))
     ("su"    (tramp-connection-function  tramp-open-connection-su)
              (tramp-rsh-program          nil)
              (tramp-rcp-program          nil)
              (tramp-remote-sh            "/bin/sh")
              (tramp-rsh-args             nil)
              (tramp-rcp-args             nil)
              (tramp-rcp-keep-date-arg    nil)
              (tramp-su-program           "su")
              (tramp-su-args              ("-" "%u"))
              (tramp-telnet-program       nil)
              (tramp-telnet-args          nil))
     ("sudo"  (tramp-connection-function  tramp-open-connection-su)
              (tramp-rsh-program          nil)
              (tramp-rcp-program          nil)
              (tramp-remote-sh            "/bin/sh")
              (tramp-rsh-args             nil)
              (tramp-rcp-args             nil)
              (tramp-rcp-keep-date-arg    nil)
              (tramp-su-program           "sudo")
              (tramp-su-args              ("-u" "%u" "-s"))
              (tramp-telnet-program       nil)
              (tramp-telnet-args          nil))
     ("multi" (tramp-connection-function  tramp-open-connection-multi)
              (tramp-rsh-program          nil)
              (tramp-rcp-program          nil)
              (tramp-remote-sh            "/bin/sh")
              (tramp-rsh-args             nil)
              (tramp-rcp-args             nil)
              (tramp-rcp-keep-date-arg    nil)
              (tramp-su-program           nil)
              (tramp-su-args              nil)
              (tramp-telnet-program       nil)
              (tramp-telnet-args          nil))
     ("scpx"  (tramp-connection-function  tramp-open-connection-rsh)
              (tramp-rsh-program          "ssh")
              (tramp-rcp-program          "scp")
              (tramp-remote-sh            "/bin/sh")
              (tramp-rsh-args             ("-e" "none" "-t" "-t" "/bin/sh"))
              (tramp-rcp-args             nil)
              (tramp-rcp-keep-date-arg    "-p")
              (tramp-telnet-program       nil)
              (tramp-telnet-args          nil))
     ("sshx"  (tramp-connection-function  tramp-open-connection-rsh)
              (tramp-rsh-program          "ssh")
              (tramp-rcp-program          nil)
              (tramp-remote-sh            "/bin/sh")
              (tramp-rsh-args             ("-e" "none" "-t" "-t" "/bin/sh"))
              (tramp-rcp-args             nil)
              (tramp-rcp-keep-date-arg    nil)
              (tramp-su-program           nil)
              (tramp-su-args              nil)
              (tramp-telnet-program       nil)
              (tramp-telnet-args          nil))
     ("krlogin"
              (tramp-connection-function  tramp-open-connection-rsh)
	      (tramp-rsh-program          "krlogin")
	      (tramp-rcp-program          nil)
	      (tramp-remote-sh            "/bin/sh")
	      (tramp-rsh-args             ("-x"))
	      (tramp-rcp-args             nil)
	      (tramp-rcp-keep-date-arg    nil)
	      (tramp-su-program           nil)
	      (tramp-su-args              nil)
	      (tramp-telnet-program       nil)
              (tramp-telnet-args          nil))
     ("plink"
              (tramp-connection-function  tramp-open-connection-rsh)
	      (tramp-rsh-program          "plink")
	      (tramp-rcp-program          nil)
	      (tramp-remote-sh            "/bin/sh")
	      (tramp-rsh-args             ("-ssh")) ;optionally add "-v"
	      (tramp-rcp-args             nil)
	      (tramp-rcp-keep-date-arg    nil)
	      (tramp-su-program           nil)
	      (tramp-su-args              nil)
	      (tramp-telnet-program       nil)
              (tramp-telnet-args          nil))
     ("pscp"
              (tramp-connection-function  tramp-open-connection-rsh)
	      (tramp-rsh-program          "plink")
	      (tramp-rcp-program          "pscp")
	      (tramp-remote-sh            "/bin/sh")
	      (tramp-rsh-args             ("-ssh"))
	      (tramp-rcp-args             nil)
	      (tramp-rcp-keep-date-arg    "-p")
	      (tramp-su-program           nil)
	      (tramp-su-args              nil)
	      (tramp-telnet-program       nil)
              (tramp-telnet-args          nil))
     ("fcp"   
	      (tramp-connection-function  tramp-open-connection-rsh)
              (tramp-rsh-program          "fsh")
              (tramp-rcp-program          "fcp")
              (tramp-remote-sh            "/bin/sh -i")
              (tramp-rsh-args             ("sh" "-i"))
              (tramp-rcp-args             nil)
              (tramp-rcp-keep-date-arg    "-p")
              (tramp-su-program           nil)
              (tramp-su-args              nil)
              (tramp-telnet-program       nil)
              (tramp-telnet-args          nil))
     )
  "*Alist of methods for remote files.
This is a list of entries of the form (NAME PARAM1 PARAM2 ...).
Each NAME stands for a remote access method.  Each PARAM is a
pair of the form (KEY VALUE).  The following KEYs are defined:
 * `tramp-connection-function'
    This specifies the function to use to connect to the remote host.
    Currently, `tramp-open-connection-rsh', `tramp-open-connection-telnet'
    and `tramp-open-connection-su' are defined.  See the documentation
    of these functions for more details.
  * `tramp-remote-sh'
    This specifies the Bourne shell to use on the remote host.  This
    MUST be a Bourne-like shell.  It is normally not necessary to set
    this to any value other than \"/bin/sh\": tramp wants to use a shell
    which groks tilde expansion, but it can search for it.  Also note
    that \"/bin/sh\" exists on all Unixen, this might not be true for
    the value that you decide to use.  You Have Been Warned.
  * `tramp-rsh-program'
    This specifies the name of the program to use for rsh; this might be
    the full path to rsh or the name of a workalike program.
  * `tramp-rsh-args'
    This specifies the list of arguments to pass to the above
    mentioned program.  Please note that this is a list of arguments,
    that is, normally you don't want to put \"-a -b\" or \"-f foo\"
    here.  Instead, you want two list elements, one for \"-a\" and one
    for \"-b\", or one for \"-f\" and one for \"foo\".
  * `tramp-rcp-program'
    This specifies the name of the program to use for rcp; this might be
    the full path to rcp or the name of a workalike program.
  * `tramp-rcp-args'
    This specifies the list of parameters to pass to the above mentioned
    program, the hints for `tramp-rsh-args' also apply here.
  * `tramp-rcp-keep-date-arg'
    This specifies the parameter to use for `rcp' when the timestamp
    of the original file should be kept.  For `rcp', use `-p', for
    `rsync', use `-t'.
  * `tramp-su-program'
    This specifies the name of the program to use for `su'.
  * `tramp-su-args'
    This specifies the list of arguments to pass to `su'.
    \"%u\" is replaced by the user name, use \"%%\" for a literal
    percent character.
  * `tramp-telnet-program'
    Specifies the telnet program to use when using
    `tramp-open-connection-telnet' to log in.
  * `tramp-telnet-args'
    Specifies list of arguments to pass to `telnet'.  The hints for
    `tramp-rsh-args' also apply here.

What does all this mean?  Well, you should specify `tramp-rsh-program',
`tramp-telnet-program' or `tramp-su-program' for all methods; this program
is used to log in to the remote site.  Then, there are two ways to
actually transfer the files between the local and the remote side.
One way is using an additional rcp-like program.  If you want to do
this, set `tramp-rcp-program' in the method.

Another possibility for file transfer is inline transfer, i.e. the
file is passed through the same buffer used by `tramp-rsh-program'.  In
this case, the file contents need to be protected since the
`tramp-rsh-program' might use escape codes or the connection might not
be eight-bit clean.  Therefore, file contents are encoded for transit.
See the variable `tramp-coding-commands' for details.

So, to summarize: if the method is an out-of-band method, then you
must specify `tramp-rcp-program' and `tramp-rcp-args'.  If it is an
inline method, then these two parameters should be nil.  Every method,
inline or out of band, must specify `tramp-connection-function' plus
the associated arguments (for example, the telnet program if you chose
`tramp-open-connection-telnet').

Notes:

When using `tramp-open-connection-su' the phrase `open connection to a
remote host' sounds strange, but it is used nevertheless, for
consistency.  No connection is opened to a remote host, but `su' is
started on the local host.  You are not allowed to specify a remote
host other than `localhost' or the name of the local host."
  :group 'tramp
  :type '(repeat
          (cons string
                (set (list (const tramp-connection-function) function)
                     (list (const tramp-rsh-program)
			   (choice (const nil) string))
                     (list (const tramp-rcp-program)
			   (choice (const nil) string))
                     (list (const tramp-remote-sh)
			   (choice (const nil) string))
                     (list (const tramp-rsh-args) (repeat string))
                     (list (const tramp-rcp-args) (repeat string))
                     (list (const tramp-rcp-keep-date-arg)
			   (choice (const nil) string))
                     (list (const tramp-su-program)
			   (choice (const nil) string))
                     (list (const tramp-su-args) (repeat string))
                     (list (const tramp-encoding-command)
			   (choice (const nil) string))
                     (list (const tramp-decoding-command)
			   (choice (const nil) string))
                     (list (const tramp-encoding-function)
			   (choice (const nil) function))
                     (list (const tramp-decoding-function)
			   (choice (const nil) function))
                     (list (const tramp-telnet-program)
			   (choice (const nil) string))
                     (list (const tramp-telnet-args) (repeat string))))))

(defcustom tramp-multi-methods '("multi" "multiu")
  "*List of multi-hop methods.
Each entry in this list should be a method name as mentioned in the
variable `tramp-methods'."
  :group 'tramp
  :type '(repeat string))

(defcustom tramp-multi-connection-function-alist
  '(("telnet" tramp-multi-connect-telnet "telnet %h%n")
    ("rsh"    tramp-multi-connect-rlogin "rsh %h -l %u%n")
    ("ssh"    tramp-multi-connect-rlogin "ssh %h -l %u%n")
    ("su"     tramp-multi-connect-su     "su - %u%n")
    ("sudo"   tramp-multi-connect-su     "sudo -u %u -s%n"))
  "*List of connection functions for multi-hop methods.
Each list item is a list of three items (METHOD FUNCTION COMMAND),
where METHOD is the name as used in the file name, FUNCTION is the
function to be executed, and COMMAND is the shell command used for
connecting.

COMMAND may contain percent escapes.  `%u' will be replaced with the
user name, `%h' will be replaced with the host name, and `%n' will be
replaced with an end-of-line character, as specified in the variable
`tramp-rsh-end-of-line'.  Use `%%' for a literal percent character.
Note that the interpretation of the percent escapes also depends on
the FUNCTION.  For example, the `%u' escape is forbidden with the
function `tramp-multi-connect-telnet'.  See the documentation of the
various functions for details."
  :group 'tramp
  :type '(repeat (list string function string)))

(defcustom tramp-default-method "ssh"
  "*Default method to use for transferring files.
See `tramp-methods' for possibilities.
Also see `tramp-default-method-alist'.

Emacs uses a unified filename syntax for Tramp and Ange-FTP.
For backward compatibility, the default value of this variable
is \"ftp\" on Emacs.  But XEmacs uses a separate filename syntax
for Tramp and EFS, so there the default method is \"sm\"."
  :group 'tramp
  :type 'string)

(defcustom tramp-default-method-alist
  (when tramp-unified-filenames
    '(("\\`ftp\\." "" "ftp")
      ("" "\\`\\(anonymous\\|ftp\\)\\'" "ftp")
      ("\\`localhost\\'" "\\`root\\'" "su")))
  "*Default method to use for specific user/host pairs.
This is an alist of items (HOST USER METHOD).  The first matching item
specifies the method to use for a file name which does not specify a
method.  HOST and USER are regular expressions or nil, which is
interpreted as a regular expression which always matches.  If no entry
matches, the variable `tramp-default-method' takes effect.

If the file name does not specify the user, lookup is done using the
empty string for the user name.

See `tramp-methods' for a list of possibilities for METHOD."
  :group 'tramp
  :type '(repeat (list (regexp :tag "Host regexp")
		       (regexp :tag "User regexp")
		       (string :tag "Method"))))

(defcustom tramp-ftp-method "ftp"
  "*When this method name is used, forward all calls to Ange-FTP."
  :group 'tramp
  :type 'string)

;; Default values for non-Unices seeked
(defconst tramp-completion-function-alist-rsh
  (unless (memq system-type '(windows-nt))
    '((tramp-parse-rhosts "/etc/hosts.equiv")
      (tramp-parse-rhosts "~/.rhosts")))
  "Default list of (FUNCTION FILE) pairs to be examined for rsh methods."
)

;; Default values for non-Unices seeked
(defconst tramp-completion-function-alist-ssh
  (unless (memq system-type '(windows-nt))
    '((tramp-parse-rhosts "/etc/hosts.equiv")
      (tramp-parse-rhosts "/etc/shosts.equiv")
      (tramp-parse-shosts "/etc/ssh_known_hosts")
      (tramp-parse-rhosts "~/.rhosts")
      (tramp-parse-rhosts "~/.shosts")
      (tramp-parse-shosts "~/.ssh/known_hosts")))
  "Default list of (FUNCTION FILE) pairs to be examined for ssh methods."
)

;; Default values for non-Unices seeked
(defconst tramp-completion-function-alist-telnet
  (unless (memq system-type '(windows-nt))
    '((tramp-parse-hosts "/etc/hosts")))
  "Default list of (FUNCTION FILE) pairs to be examined for telnet methods."
)

;; Default values for non-Unices seeked
(defconst tramp-completion-function-alist-su
  (unless (memq system-type '(windows-nt))
    '((tramp-parse-passwd "/etc/passwd")))
  "Default list of (FUNCTION FILE) pairs to be examined for su methods."
)

;; Default values for non-Unices seeked
(defconst tramp-completion-function-alist-ftp
  (unless (memq system-type '(windows-nt))
    '((tramp-parse-netrc "~/.netrc")))
  "Default list of (FUNCTION FILE) pairs to be examined for ftp methods."
)

(defcustom tramp-completion-function-alist
  (list (cons "rcp"      tramp-completion-function-alist-rsh)
	(cons "scp"      tramp-completion-function-alist-ssh)
	(cons "scp1"     tramp-completion-function-alist-ssh)
	(cons "scp2"     tramp-completion-function-alist-ssh)
	(cons "scp1_old" tramp-completion-function-alist-ssh)
	(cons "scp2_old" tramp-completion-function-alist-ssh)
	(cons "rsync"    tramp-completion-function-alist-rsh)
	(cons "rsh"      tramp-completion-function-alist-rsh)
 	(cons "ssh"      tramp-completion-function-alist-ssh)
 	(cons "ssh1"     tramp-completion-function-alist-ssh)
 	(cons "ssh2"     tramp-completion-function-alist-ssh)
 	(cons "ssh1_old" tramp-completion-function-alist-ssh)
 	(cons "ssh2_old" tramp-completion-function-alist-ssh)
 	(cons "telnet"   tramp-completion-function-alist-telnet)
 	(cons "su"       tramp-completion-function-alist-su)
 	(cons "sudo"     tramp-completion-function-alist-su)
 	(cons "multi"    nil)
 	(cons "scpx"     tramp-completion-function-alist-ssh)
 	(cons "sshx"     tramp-completion-function-alist-ssh)
	(cons "krlogin"  tramp-completion-function-alist-rsh)
 	(cons "plink"    tramp-completion-function-alist-ssh)
 	(cons "pscp"     tramp-completion-function-alist-ssh)
 	(cons "fcp"      tramp-completion-function-alist-ssh)
 	(cons "ftp"      tramp-completion-function-alist-ftp)
     )
  "*Alist of methods for remote files.
This is a list of entries of the form (NAME PAIR1 PAIR2 ...).
Each NAME stands for a remote access method.  Each PAIR is of the form
\(FUNCTION FILE).  FUNCTION is responsible to extract user names and host
names from FILE for completion.  The following predefined FUNCTIONs exists:

 * `tramp-parse-rhosts' for \".rhosts\" like files,
 * `tramp-parse-shosts' for \"ssh_known_hosts\" like files,
 * `tramp-parse-hosts'  for \"/etc/hosts\" like files, and
 * `tramp-parse-passwd' for \"/etc/passwd\" like files.
 * `tramp-parse-netrc ' for \".netrc\" like files.

FUNCTION can also see a customer defined function.  For more details see
the info pages."
  :group 'tramp
  :type '(repeat
          (cons string
                (choice (const nil) (repeat (list function file))))))

(defcustom tramp-rsh-end-of-line "\n"
  "*String used for end of line in rsh connections.
I don't think this ever needs to be changed, so please tell me about it
if you need to change this.
Also see `tramp-password-end-of-line'."
  :group 'tramp
  :type 'string)

(defcustom tramp-password-end-of-line tramp-rsh-end-of-line
  "*String used for end of line after sending a password.
It seems that people using plink under Windows need to send
\"\\r\\n\" (carriage-return, then newline) after a password, but just
\"\\n\" after all other lines.  This variable can be used for the
password, see `tramp-rsh-end-of-line' for the other cases.

The default value is to use the same value as `tramp-rsh-end-of-line'."
  :group 'tramp
  :type 'string)

(defcustom tramp-remote-path
  '("/bin" "/usr/bin" "/usr/sbin" "/usr/local/bin" "/usr/ccs/bin"
    "/local/bin" "/local/freeware/bin" "/local/gnu/bin"
    "/usr/freeware/bin" "/usr/pkg/bin" "/usr/contrib/bin")
  "*List of directories to search for executables on remote host.
Please notify me about other semi-standard directories to include here.

You can use `~' in this list, but when searching for a shell which groks
tilde expansion, all directory names starting with `~' will be ignored."
  :group 'tramp
  :type '(repeat string))

(defcustom tramp-login-prompt-regexp
  ".*ogin: *"
  "*Regexp matching login-like prompts.
The regexp should match at end of buffer."
  :group 'tramp
  :type 'regexp)

(defcustom tramp-shell-prompt-pattern
  "^[^#$%>\n]*[#$%>] *"
  "Regexp to match prompts from remote shell.
Normally, Tramp expects you to configure `shell-prompt-pattern'
correctly, but sometimes it happens that you are connecting to a
remote host which sends a different kind of shell prompt.  Therefore,
Tramp recognizes things matched by `shell-prompt-pattern' as prompt,
and also things matched by this variable.  The default value of this
variable is the same as the default value of `shell-prompt-pattern',
which should work well in many cases."
  :group 'tramp
  :type 'regexp)

(defcustom tramp-password-prompt-regexp
  "^.*\\([pP]assword\\|passphrase.*\\):\^@? *"
  "*Regexp matching password-like prompts.
The regexp should match at end of buffer.

The `sudo' program appears to insert a `^@' character into the prompt."
  :group 'tramp
  :type 'regexp)

(defcustom tramp-wrong-passwd-regexp
  (concat "^.*"
	  ;; These strings should be on the last line
	  (regexp-opt '("Permission denied."
			"Login incorrect"
			"Login Incorrect"
			"Connection refused"
			"Connection closed"
			"Sorry, try again."
			"Name or service not known"
			"Host key verification failed.") t)
	  ".*"
	  "\\|"
	  "^.*\\("
	  ;; Here comes a list of regexes, separated by \\|
	  "Received signal [0-9]+"
	  "\\).*")
  "*Regexp matching a `login failed' message.
The regexp should match at end of buffer."
  :group 'tramp
  :type 'regexp)

(defcustom tramp-yesno-prompt-regexp
  (concat
   (regexp-opt '("Are you sure you want to continue connecting (yes/no)?") t)
   "\\s-*")
  "Regular expression matching all yes/no queries which need to be confirmed.
The confirmation should be done with yes or no.
The regexp should match at end of buffer.
See also `tramp-yn-prompt-regexp'."
  :group 'tramp
  :type 'regexp)

(defcustom tramp-yn-prompt-regexp
  (concat (regexp-opt '("Store key in cache? (y/n)") t)
	  "\\s-*")
  "Regular expression matching all y/n queries which need to be confirmed.
The confirmation should be done with y or n.
The regexp should match at end of buffer.
See also `tramp-yesno-prompt-regexp'."
  :group 'tramp
  :type 'regexp)
  

(defcustom tramp-temp-name-prefix "tramp."
  "*Prefix to use for temporary files.
If this is a relative file name (such as \"tramp.\"), it is considered
relative to the directory name returned by the function
`tramp-temporary-file-directory' (which see).  It may also be an
absolute file name; don't forget to include a prefix for the filename
part, though."
  :group 'tramp
  :type 'string)

(defcustom tramp-discard-garbage nil
  "*If non-nil, try to discard garbage sent by remote shell.
Some shells send such garbage upon connection setup."
  :group 'tramp
  :type 'boolean)

(defcustom tramp-sh-extra-args '(("/bash\\'" . "--norc"))
  "*Alist specifying extra arguments to pass to the remote shell.
Entries are (REGEXP . ARGS) where REGEXP is a regular expression
matching the shell file name and ARGS is a string specifying the
arguments.

This variable is only used when Tramp needs to start up another shell
for tilde expansion.  The extra arguments should typically prevent the
shell from reading its init file."
  :group 'tramp
  :type '(alist :key-type string :value-type string))

(defcustom tramp-prefix-format
  (if tramp-unified-filenames "/" "/[")
  "*String matching the very beginning of tramp file names.
Used in `tramp-make-tramp-file-name' and `tramp-make-tramp-multi-file-name'."
  :group 'tramp
  :type 'string)

(defcustom tramp-prefix-regexp
  (concat "^" (regexp-quote tramp-prefix-format))
  "*Regexp matching the very beginning of tramp file names.
Should always start with \"^\". Derived from `tramp-prefix-format'."
  :group 'tramp
  :type 'regexp)

(defcustom tramp-method-regexp
  "[a-zA-Z_0-9-]+"
  "*Regexp matching methods identifiers."
  :group 'tramp
  :type 'regexp)

;; It is a little bit annoying that in XEmacs case this delimeter is different
;; for single-hop and multi-hop cases.
(defcustom tramp-postfix-single-method-format
  (if tramp-unified-filenames ":" "/")
  "*String matching delimeter between method and user or host names.
Applicable for single-hop methods.
Used in `tramp-make-tramp-file-name'."
  :group 'tramp
  :type 'string)

(defcustom tramp-postfix-single-method-regexp
  (regexp-quote tramp-postfix-single-method-format)
  "*Regexp matching delimeter between method and user or host names.
Applicable for single-hop methods.
Derived from `tramp-postfix-single-method-format'."
  :group 'tramp
  :type 'regexp)

(defcustom tramp-postfix-multi-method-format
  ":"
  "*String matching delimeter between method and user or host names.
Applicable for multi-hop methods.
Used in `tramp-make-tramp-multi-file-name'."
  :group 'tramp
  :type 'string)

(defcustom tramp-postfix-multi-method-regexp
  (regexp-quote tramp-postfix-multi-method-format)
  "*Regexp matching delimeter between method and user or host names.
Applicable for multi-hop methods.
Derived from `tramp-postfix-multi-method-format'."
  :group 'tramp
  :type 'regexp)

(defcustom tramp-postfix-multi-hop-format
  (if tramp-unified-filenames ":" "/")
  "*String matching delimeter between path and next method.
Applicable for multi-hop methods.
Used in `tramp-make-tramp-multi-file-name'."
  :group 'tramp
  :type 'string)

(defcustom tramp-postfix-multi-hop-regexp
  (regexp-quote tramp-postfix-multi-hop-format)
  "*Regexp matching delimeter between path and next method.
Applicable for multi-hop methods.
Derived from `tramp-postfix-multi-hop-format'."
  :group 'tramp
  :type 'regexp)

(defcustom tramp-user-regexp
  "[^:@/ \t]*"
  "*Regexp matching user names."
  :group 'tramp
  :type 'regexp)

(defcustom tramp-postfix-user-format
  "@"
  "*String matching delimeter between user and host names.
Used in `tramp-make-tramp-file-name' and `tramp-make-tramp-multi-file-name'."
  :group 'tramp
  :type 'string)

(defcustom tramp-postfix-user-regexp
  (regexp-quote tramp-postfix-user-format)
  "*Regexp matching delimeter between user and host names.
Derived from `tramp-postfix-user-format'."
  :group 'tramp
  :type 'regexp)

(defcustom tramp-host-regexp
  "[a-zA-Z0-9_.#-]*"
  "*Regexp matching host names."
  :group 'tramp
  :type 'regexp)

(defcustom tramp-postfix-host-format
  (if tramp-unified-filenames ":" "]")
  "*String matching delimeter between host names and paths.
Used in `tramp-make-tramp-file-name' and `tramp-make-tramp-multi-file-name'."
  :group 'tramp
  :type 'string)

(defcustom tramp-postfix-host-regexp
  (regexp-quote tramp-postfix-host-format)
  "*Regexp matching delimeter between host names and paths.
Derived from `tramp-postfix-host-format'."
  :group 'tramp
  :type 'regexp)

(defcustom tramp-path-regexp
  ".*$"
  "*Regexp matching paths."
  :group 'tramp
  :type 'regexp)

;; File name format.

(defcustom tramp-file-name-structure
  (list
   (concat
    tramp-prefix-regexp
    "\\(" "\\(" tramp-method-regexp "\\)" tramp-postfix-single-method-regexp "\\)?"
    "\\(" "\\(" tramp-user-regexp   "\\)" tramp-postfix-user-regexp   "\\)?"
          "\\(" tramp-host-regexp   "\\)" tramp-postfix-host-regexp
	  "\\(" tramp-path-regexp   "\\)")
   2 4 5 6)

  "*List of five elements (REGEXP METHOD USER HOST FILE), detailing \
the tramp file name structure.

The first element REGEXP is a regular expression matching a tramp file
name.  The regex should contain parentheses around the method name,
the user name, the host name, and the file name parts.

The second element METHOD is a number, saying which pair of
parentheses matches the method name.  The third element USER is
similar, but for the user name.  The fourth element HOST is similar,
but for the host name.  The fifth element FILE is for the file name.
These numbers are passed directly to `match-string', which see.  That
means the opening parentheses are counted to identify the pair.

See also `tramp-file-name-regexp'."
  :group 'tramp
  :type '(list (regexp :tag "File name regexp")
               (integer :tag "Paren pair for method name")
               (integer :tag "Paren pair for user name  ")
               (integer :tag "Paren pair for host name  ")
               (integer :tag "Paren pair for file name  ")))

;;;###autoload
(defconst tramp-file-name-regexp-unified
  "\\`/[^/:]+:"
  "Value for `tramp-file-name-regexp' for unified remoting.
Emacs (not XEmacs) uses a unified filename syntax for Ange-FTP and
Tramp.  See `tramp-file-name-structure-unified' for more explanations.")

;;;###autoload
(defconst tramp-file-name-regexp-separate
  "\\`/\\[.*\\]"
  "Value for `tramp-file-name-regexp' for separate remoting.
XEmacs uses a separate filename syntax for Tramp and EFS.
See `tramp-file-name-structure-separate' for more explanations.")

;;;###autoload
(defcustom tramp-file-name-regexp
  (if tramp-unified-filenames
      tramp-file-name-regexp-unified
    tramp-file-name-regexp-separate)
  "*Regular expression matching file names handled by tramp.
This regexp should match tramp file names but no other file names.
\(When tramp.el is loaded, this regular expression is prepended to
`file-name-handler-alist', and that is searched sequentially.  Thus,
if the tramp entry appears rather early in the `file-name-handler-alist'
and is a bit too general, then some files might be considered tramp
files which are not really tramp files.

Please note that the entry in `file-name-handler-alist' is made when
this file (tramp.el) is loaded.  This means that this variable must be set
before loading tramp.el.  Alternatively, `file-name-handler-alist' can be
updated after changing this variable.

Also see `tramp-file-name-structure'."
  :group 'tramp
  :type 'regexp)

;;;###autoload
(defconst tramp-completion-file-name-regexp-unified
  "^/[^/]*$"
  "Value for `tramp-completion-file-name-regexp' for unified remoting.
Emacs (not XEmacs) uses a unified filename syntax for Ange-FTP and
Tramp.  See `tramp-file-name-structure-unified' for more explanations.")

;;;###autoload
(defconst tramp-completion-file-name-regexp-separate
  "^/\\([[][^]]*\\)?$"
  "Value for `tramp-completion-file-name-regexp' for separate remoting.
XEmacs uses a separate filename syntax for Tramp and EFS.
See `tramp-file-name-structure-separate' for more explanations.")

;;;###autoload
(defcustom tramp-completion-file-name-regexp
  (if tramp-unified-filenames
      tramp-completion-file-name-regexp-unified
    tramp-completion-file-name-regexp-separate)
  "*Regular expression matching file names handled by tramp completion.
This regexp should match partial tramp file names only.

Please note that the entry in `file-name-handler-alist' is made when
this file (tramp.el) is loaded.  This means that this variable must be set
before loading tramp.el.  Alternatively, `file-name-handler-alist' can be
updated after changing this variable.

Also see `tramp-file-name-structure'."
  :group 'tramp
  :type 'regexp)

(defcustom tramp-multi-file-name-structure
  (list
   (concat
    tramp-prefix-regexp
    "\\(" "\\(" tramp-method-regexp "\\)" "\\)?"
    "\\(" "\\(" tramp-postfix-multi-hop-regexp "%s" "\\)+" "\\)?"
    tramp-postfix-host-regexp "\\(" tramp-path-regexp "\\)")
   2 3 -1)
  "*Describes the file name structure of `multi' files.
Multi files allow you to contact a remote host in several hops.
This is a list of four elements (REGEXP METHOD HOP PATH).

The first element, REGEXP, gives a regular expression to match against
the file name.  In this regular expression, `%s' is replaced with the
value of `tramp-multi-file-name-hop-structure'.  (Note: in order to
allow multiple hops, you normally want to use something like
\"\\\\(\\\\(%s\\\\)+\\\\)\" in the regular expression.  The outer pair
of parentheses is used for the HOP element, see below.)

All remaining elements are numbers.  METHOD gives the number of the
paren pair which matches the method name.  HOP gives the number of the
paren pair which matches the hop sequence.  PATH gives the number of
the paren pair which matches the path name on the remote host.

PATH can also be negative, which means to count from the end.  Ie, a
value of -1 means the last paren pair.

I think it would be good if the regexp matches the whole of the
string, but I haven't actually tried what happens if it doesn't..."
  :group 'tramp
  :type '(list (regexp :tag "File name regexp")
               (integer :tag "Paren pair for method name")
               (integer :tag "Paren pair for hops")
               (integer :tag "Paren pair to match path")))

(defcustom tramp-multi-file-name-hop-structure
  (list
   (concat
    "\\(" tramp-method-regexp "\\)" tramp-postfix-multi-method-regexp
    "\\(" tramp-user-regexp   "\\)" tramp-postfix-user-regexp
    "\\(" tramp-host-regexp   "\\)")
   1 2 3)
  "*Describes the structure of a hop in multi files.
This is a list of four elements (REGEXP METHOD USER HOST).  First
element REGEXP is used to match against the hop.  Pair number METHOD
matches the method of one hop, pair number USER matches the user of
one hop, pair number HOST matches the host of one hop.

This regular expression should match exactly all of one hop."
  :group 'tramp
  :type '(list (regexp :tag "Hop regexp")
               (integer :tag "Paren pair for method name")
               (integer :tag "Paren pair for user name")
               (integer :tag "Paren pair for host name")))

(defcustom tramp-make-multi-tramp-file-format
  (list
   (concat tramp-prefix-format "%m")
   (concat tramp-postfix-multi-hop-format
    "%m" tramp-postfix-multi-method-format
    "%u" tramp-postfix-user-format
    "%h")
   (concat tramp-postfix-host-format "%p"))
  "*Describes how to construct a `multi' file name.
This is a list of three elements PREFIX, HOP and PATH.

The first element PREFIX says how to construct the prefix, the second
element HOP specifies what each hop looks like, and the final element
PATH says how to construct the path name.

In PREFIX, `%%' means `%' and `%m' means the method name.

In HOP, `%%' means `%' and `%m', `%u', `%h' mean the hop method, hop
user and hop host, respectively.

In PATH, `%%' means `%' and `%p' means the path name.

The resulting file name always contains one copy of PREFIX and one
copy of PATH, but there is one copy of HOP for each hop in the file
name.

Note: the current implementation requires the prefix to contain the
method name, followed by all the hops, and the path name must come
last."
  :group 'tramp
  :type '(list string string string))

(defcustom tramp-terminal-type "dumb"
  "*Value of TERM environment variable for logging in to remote host.
Because Tramp wants to parse the output of the remote shell, it is easily
confused by ANSI color escape sequences and suchlike.  Often, shell init
files conditionalize this setup based on the TERM environment variable."
  :group 'tramp
  :type 'string)

(defcustom tramp-completion-without-shell-p nil
  "*If nil, use shell wildcards for completion, else rely on Lisp only.
Using shell wildcards for completions has the advantage that it can be
fast even in large directories, but completion is always
case-sensitive.  Relying on Lisp only means that case-insensitive
completion is possible (subject to the variable `completion-ignore-case'),
but it might be slow on large directories."
  :group 'tramp
  :type 'boolean)

(defcustom tramp-actions-before-shell
  '((tramp-password-prompt-regexp tramp-action-password)
    (tramp-login-prompt-regexp tramp-action-login)
    (shell-prompt-pattern tramp-action-succeed)
    (tramp-shell-prompt-pattern tramp-action-succeed)
    (tramp-wrong-passwd-regexp tramp-action-permission-denied)
    (tramp-yesno-prompt-regexp tramp-action-yesno)
    (tramp-yn-prompt-regexp tramp-action-yn))
  "List of pattern/action pairs.
Whenever a pattern matches, the corresponding action is performed.
Each item looks like (PATTERN ACTION).

The PATTERN should be a symbol, a variable.  The value of this
variable gives the regular expression to search for.  Note that the
regexp must match at the end of the buffer, \"\\'\" is implicitly
appended to it.

The ACTION should also be a symbol, but a function.  When the
corresponding PATTERN matches, the ACTION function is called."
  :group 'tramp
  :type '(repeat (list variable function)))

(defcustom tramp-multi-actions
  '((tramp-password-prompt-regexp tramp-multi-action-password)
    (tramp-login-prompt-regexp tramp-multi-action-login)
    (shell-prompt-pattern tramp-multi-action-succeed)
    (tramp-shell-prompt-pattern tramp-multi-action-succeed)
    (tramp-wrong-passwd-regexp tramp-multi-action-permission-denied))
  "List of pattern/action pairs.
This list is used for each hop in multi-hop connections.
See `tramp-actions-before-shell' for more info."
  :group 'tramp
  :type '(repeat (list variable function)))

;;; Internal Variables:

(defvar tramp-buffer-file-attributes nil
  "Holds the `ls -ild' output for the current buffer.
This variable is local to each buffer.  It is not used if the remote
machine groks Perl.  If it is used, it's used as an emulation for
the visited file modtime.")
(make-variable-buffer-local 'tramp-buffer-file-attributes)

(defvar tramp-end-of-output "/////"
  "String used to recognize end of output.")

(defvar tramp-connection-function nil
  "This internal variable holds a parameter for `tramp-methods'.
In the connection buffer, this variable has the value of the like-named
method parameter, as specified in `tramp-methods' (which see).")

(defvar tramp-remote-sh nil
  "This internal variable holds a parameter for `tramp-methods'.
In the connection buffer, this variable has the value of the like-named
method parameter, as specified in `tramp-methods' (which see).")

(defvar tramp-rsh-program nil
  "This internal variable holds a parameter for `tramp-methods'.
In the connection buffer, this variable has the value of the like-named
method parameter, as specified in `tramp-methods' (which see).")

(defvar tramp-rsh-args nil
  "This internal variable holds a parameter for `tramp-methods'.
In the connection buffer, this variable has the value of the like-named
method parameter, as specified in `tramp-methods' (which see).")

(defvar tramp-rcp-program nil
  "This internal variable holds a parameter for `tramp-methods'.
In the connection buffer, this variable has the value of the like-named
method parameter, as specified in `tramp-methods' (which see).")

(defvar tramp-rcp-args nil
  "This internal variable holds a parameter for `tramp-methods'.
In the connection buffer, this variable has the value of the like-named
method parameter, as specified in `tramp-methods' (which see).")

(defvar tramp-rcp-keep-date-arg nil
  "This internal variable holds a parameter for `tramp-methods'.
In the connection buffer, this variable has the value of the like-named
method parameter, as specified in `tramp-methods' (which see).")

(defvar tramp-encoding-command nil
  "This internal variable holds a parameter for `tramp-methods'.
In the connection buffer, this variable has the value of the like-named
method parameter, as specified in `tramp-methods' (which see).")

(defvar tramp-decoding-command nil
  "This internal variable holds a parameter for `tramp-methods'.
In the connection buffer, this variable has the value of the like-named
method parameter, as specified in `tramp-methods' (which see).")

(defvar tramp-encoding-function nil
  "This internal variable holds a parameter for `tramp-methods'.
In the connection buffer, this variable has the value of the like-named
method parameter, as specified in `tramp-methods' (which see).")

(defvar tramp-decoding-function nil
  "This internal variable holds a parameter for `tramp-methods'.
In the connection buffer, this variable has the value of the like-named
method parameter, as specified in `tramp-methods' (which see).")

(defvar tramp-telnet-program nil
  "This internal variable holds a parameter for `tramp-methods'.
In the connection buffer, this variable has the value of the like-named
method parameter, as specified in `tramp-methods' (which see).")

(defvar tramp-telnet-args nil
  "This internal variable holds a parameter for `tramp-methods'.
In the connection buffer, this variable has the value of the like-named
method parameter, as specified in `tramp-methods' (which see).")

(defvar tramp-su-program nil
  "This internal variable holds a parameter for `tramp-methods'.
In the connection buffer, this variable has the value of the like-named
method parameter, as specified in `tramp-methods' (which see).")

;; CCC `local in each buffer'?
(defvar tramp-ls-command nil
  "This command is used to get a long listing with numeric user and group ids.
This variable is automatically made buffer-local to each rsh process buffer
upon opening the connection.")

(defvar tramp-current-multi-method nil
  "Name of `multi' connection method for this *tramp* buffer, or nil if not multi.
This variable is automatically made buffer-local to each rsh process buffer
upon opening the connection.")

(defvar tramp-current-method nil
  "Connection method for this *tramp* buffer.
This variable is automatically made buffer-local to each rsh process buffer
upon opening the connection.")

(defvar tramp-current-user nil
  "Remote login name for this *tramp* buffer.
This variable is automatically made buffer-local to each rsh process buffer
upon opening the connection.")

(defvar tramp-current-host nil
  "Remote host for this *tramp* buffer.
This variable is automatically made buffer-local to each rsh process buffer
upon opening the connection.")

(defvar tramp-test-groks-nt nil
  "Whether the `test' command groks the `-nt' switch.
\(`test A -nt B' tests if file A is newer than file B.)
This variable is automatically made buffer-local to each rsh process buffer
upon opening the connection.")

(defvar tramp-file-exists-command nil
  "Command to use for checking if a file exists.
This variable is automatically made buffer-local to each rsh process buffer
upon opening the connection.")

(defconst tramp-uudecode "\
tramp_uudecode () {
\(echo begin 600 /tmp/tramp.$$; tail +2) | uudecode
cat /tmp/tramp.$$
rm -f /tmp/tramp.$$
}"
  "Shell function to implement `uudecode' to standard output.
Many systems support `uudecode -o -' for this or `uudecode -p', but
some systems don't, and for them we have this shell function.")

;; Perl script to implement `file-attributes' in a Lisp `read'able
;; output.  If you are hacking on this, note that you get *no* output
;; unless this spits out a complete line, including the '\n' at the
;; end.
(defconst tramp-perl-file-attributes "\
$f = $ARGV[0];
@s = lstat($f);
if (($s[2] & 0170000) == 0120000) { $l = readlink($f); $l = \"\\\"$l\\\"\"; }
elsif (($s[2] & 0170000) == 040000) { $l = \"t\"; }
else { $l = \"nil\" };
printf(\"(%s %u %d %d (%u %u) (%u %u) (%u %u) %u %u t (%u . %u) (%u %u))\\n\",
$l, $s[3], $s[4], $s[5], $s[8] >> 16 & 0xffff, $s[8] & 0xffff,
$s[9] >> 16 & 0xffff, $s[9] & 0xffff, $s[10] >> 16 & 0xffff, $s[10] & 0xffff,
$s[7], $s[2], $s[1] >> 16 & 0xffff, $s[1] & 0xffff, $s[0] >> 16 & 0xffff, $s[0] & 0xffff);"
  "Perl script to produce output suitable for use with `file-attributes'
on the remote file system.")

;; ;; These two use uu encoding.
;; (defvar tramp-perl-encode "%s -e'\
;; print qq(begin 644 xxx\n);
;; my $s = q();
;; my $res = q();
;; while (read(STDIN, $s, 45)) {
;;     print pack(q(u), $s);
;; }
;; print qq(`\n);
;; print qq(end\n);
;; '"
;;   "Perl program to use for encoding a file.
;; Escape sequence %s is replaced with name of Perl binary.")

;; (defvar tramp-perl-decode "%s -ne '
;; print unpack q(u), $_;
;; '"
;;   "Perl program to use for decoding a file.
;; Escape sequence %s is replaced with name of Perl binary.")

;; These two use base64 encoding.
(defvar tramp-perl-encode-with-module
  "perl -MMIME::Base64 -0777 -ne 'print encode_base64($_)'"
  "Perl program to use for encoding a file.
Escape sequence %s is replaced with name of Perl binary.
This string is passed to `format', so percent characters need to be doubled.
This implementation requires the MIME::Base64 Perl module to be installed
on the remote host.")

(defvar tramp-perl-decode-with-module
  "perl -MMIME::Base64 -0777 -ne 'print decode_base64($_)'"
  "Perl program to use for decoding a file.
Escape sequence %s is replaced with name of Perl binary.
This string is passed to `format', so percent characters need to be doubled.
This implementation requires the MIME::Base64 Perl module to be installed
on the remote host.")

(defvar tramp-perl-encode
  "%s -e '
# This script contributed by Juanma Barranquero <lektu@terra.es>.
# Copyright (C) 2002 Free Software Foundation, Inc.
use strict;

my %%trans = do {
    my $i = 0;
    map {(substr(unpack(q(B8), chr $i++), 2, 6), $_)}
      split //, q(ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/);
};

binmode(\\*STDIN);

# We read in chunks of 54 bytes, to generate output lines
# of 72 chars (plus end of line)
$/ = \\54;

while (my $data = <STDIN>) {
    my $pad = q();

    # Only for the last chunk, and only if did not fill the last three-byte packet
    if (eof) {
        my $mod = length($data) %% 3;
        $pad = q(=) x (3 - $mod) if $mod;
    }

    # Not the fastest method, but it is simple: unpack to binary string, split
    # by groups of 6 bits and convert back from binary to byte; then map into
    # the translation table
    print
      join q(),
        map($trans{$_},
            (substr(unpack(q(B*), $data) . q(00000), 0, 432) =~ /....../g)),
              $pad,
                qq(\\n);
}
'"
  "Perl program to use for encoding a file.
Escape sequence %s is replaced with name of Perl binary.
This string is passed to `format', so percent characters need to be doubled.")

(defvar tramp-perl-decode
  "%s -e '
# This script contributed by Juanma Barranquero <lektu@terra.es>.
# Copyright (C) 2002 Free Software Foundation, Inc.
use strict;

my %%trans = do {
    my $i = 0;
    map {($_, substr(unpack(q(B8), chr $i++), 2, 6))}
      split //, q(ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/)
};

my %%bytes = map {(unpack(q(B8), chr $_), chr $_)} 0 .. 255;

binmode(\\*STDOUT);

# We are going to accumulate into $pending to accept any line length
# (we do not check they are <= 76 chars as the RFC says)
my $pending = q();

while (my $data = <STDIN>) {
    chomp $data;

    # If we find one or two =, we have reached the end and
    # any following data is to be discarded
    my $finished = $data =~ s/(==?).*/$1/;
    $pending .= $data;

    my $len = length($pending);
    my $chunk = substr($pending, 0, $len & ~3);

    # Easy method: translate from chars to (pregenerated) six-bit packets, join,
    # split in 8-bit chunks and convert back to char.
    print join q(),
      map $bytes{$_},
        ((join q(), map {$trans{$_} || q()} split //, $chunk) =~ /......../g);

    last if $finished;
}
'"
  "Perl program to use for decoding a file.
Escape sequence %s is replaced with name of Perl binary.
This string is passed to `format', so percent characters need to be doubled.")

; These values conform to `file-attributes' from XEmacs 21.2.
; GNU Emacs and other tools not checked.
(defconst tramp-file-mode-type-map '((0  . "-")  ; Normal file (SVID-v2 and XPG2)
				     (1  . "p")  ; fifo
				     (2  . "c")  ; character device
				     (3  . "m")  ; multiplexed character device (v7)
				     (4  . "d")  ; directory
				     (5  . "?")  ; Named special file (XENIX)
				     (6  . "b")  ; block device
				     (7  . "?")  ; multiplexed block device (v7)
				     (8  . "-")  ; regular file
				     (9  . "n")  ; network special file (HP-UX)
				     (10 . "l")  ; symlink
				     (11 . "?")  ; ACL shadow inode (Solaris, not userspace)
				     (12 . "s")  ; socket
				     (13 . "D")  ; door special (Solaris)
				     (14 . "w")) ; whiteout (BSD)
  "A list of file types returned from the `stat' system call.
This is used to map a mode number to a permission string.")

(defvar tramp-dos-coding-system
  (if (and (fboundp 'coding-system-p)
           (funcall 'coding-system-p '(dos)))
      'dos
    'undecided-dos)
  "Some Emacsen know the `dos' coding system, others need `undecided-dos'.")

(defvar tramp-last-cmd-time nil
  "Internal Tramp variable recording the time when the last cmd was sent.
This variable is buffer-local in every buffer.")
(make-variable-buffer-local 'tramp-last-cmd-time)

;; This variable does not have the right value in XEmacs.  What should
;; I use instead of find-operation-coding-system in XEmacs?
(defvar tramp-feature-write-region-fix
  (when (fboundp 'find-operation-coding-system)
    (let ((file-coding-system-alist '(("test" emacs-mule))))
      (find-operation-coding-system 'write-region 0 0 "" nil "test")))
    "Internal variable to say if `write-region' chooses the right coding.
Older versions of Emacs chose the coding system for `write-region' based
on the FILENAME argument, even if VISIT was a string.")

;; New handlers should be added here.  The following operations can be
;; handled using the normal primitives: file-name-as-directory,
;; file-name-directory, file-name-nondirectory,
;; file-name-sans-versions, get-file-buffer.
(defconst tramp-file-name-handler-alist
  '(
    (load . tramp-handle-load)
    (make-symbolic-link . tramp-handle-make-symbolic-link)
    (file-name-directory . tramp-handle-file-name-directory)
    (file-name-nondirectory . tramp-handle-file-name-nondirectory)
    (file-truename . tramp-handle-file-truename)
    (file-exists-p . tramp-handle-file-exists-p)
    (file-directory-p . tramp-handle-file-directory-p)
    (file-executable-p . tramp-handle-file-executable-p)
    (file-accessible-directory-p . tramp-handle-file-accessible-directory-p)
    (file-readable-p . tramp-handle-file-readable-p)
    (file-regular-p . tramp-handle-file-regular-p)
    (file-symlink-p . tramp-handle-file-symlink-p)
    (file-writable-p . tramp-handle-file-writable-p)
    (file-ownership-preserved-p . tramp-handle-file-ownership-preserved-p)
    (file-newer-than-file-p . tramp-handle-file-newer-than-file-p)
    (file-attributes . tramp-handle-file-attributes)
    (file-modes . tramp-handle-file-modes)
    (file-directory-files . tramp-handle-file-directory-files)
    (directory-files . tramp-handle-directory-files)
    (file-name-all-completions . tramp-handle-file-name-all-completions)
    (file-name-completion . tramp-handle-file-name-completion)
    (add-name-to-file . tramp-handle-add-name-to-file)
    (copy-file . tramp-handle-copy-file)
    (rename-file . tramp-handle-rename-file)
    (set-file-modes . tramp-handle-set-file-modes)
    (make-directory . tramp-handle-make-directory)
    (delete-directory . tramp-handle-delete-directory)
    (delete-file . tramp-handle-delete-file)
    (directory-file-name . tramp-handle-directory-file-name)
    (shell-command . tramp-handle-shell-command)
    (insert-directory . tramp-handle-insert-directory)
    (expand-file-name . tramp-handle-expand-file-name)
    (file-local-copy . tramp-handle-file-local-copy)
    (insert-file-contents . tramp-handle-insert-file-contents)
    (write-region . tramp-handle-write-region)
    (unhandled-file-name-directory . tramp-handle-unhandled-file-name-directory)
    (dired-call-process . tramp-handle-dired-call-process)
    (dired-recursive-delete-directory
     . tramp-handle-dired-recursive-delete-directory)
    (set-visited-file-modtime . tramp-handle-set-visited-file-modtime)
    (verify-visited-file-modtime . tramp-handle-verify-visited-file-modtime))
        "Alist of handler functions.
Operations not mentioned here will be handled by the normal Emacs functions.")

;; Handlers for partial tramp file names. For GNU Emacs just
;; `file-name-all-completions' is needed. The other ones are necessary
;; for XEmacs.
(defconst tramp-completion-file-name-handler-alist
  '(
    (file-name-directory . tramp-completion-handle-file-name-directory)
    (file-name-nondirectory . tramp-completion-handle-file-name-nondirectory)
    (file-exists-p . tramp-completion-handle-file-exists-p)
    (file-name-all-completions . tramp-completion-handle-file-name-all-completions)
    (file-name-completion . tramp-completion-handle-file-name-completion)
    (expand-file-name . tramp-completion-handle-expand-file-name))
  "Alist of completion handler functions.
Used for file names matching `tramp-file-name-regexp'. Operations not
mentioned here will be handled by `tramp-file-name-handler-alist' or the
normal Emacs functions.")

;;; Internal functions which must come first.

(defsubst tramp-message (level fmt-string &rest args)
  "Emit a message depending on verbosity level.
First arg LEVEL says to be quiet if `tramp-verbose' is less than LEVEL.  The
message is emitted only if `tramp-verbose' is greater than or equal to LEVEL.
Calls function `message' with FMT-STRING as control string and the remaining
ARGS to actually emit the message (if applicable).

This function expects to be called from the tramp buffer only!"
  (when (<= level tramp-verbose)
    (apply #'message (concat "tramp: " fmt-string) args)
    (when tramp-debug-buffer
      (save-excursion
        (set-buffer
         (tramp-get-debug-buffer
	  tramp-current-multi-method tramp-current-method
	  tramp-current-user tramp-current-host))
        (goto-char (point-max))
        (tramp-insert-with-face
         'italic
         (concat "# " (apply #'format fmt-string args) "\n"))))))

(defun tramp-message-for-buffer
  (multi-method method user host level fmt-string &rest args)
  "Like `tramp-message' but temporarily switches to the tramp buffer.
First three args METHOD, USER, and HOST identify the tramp buffer to use,
remaining args passed to `tramp-message'."
  (save-excursion
    (set-buffer (tramp-get-buffer multi-method method user host))
    (apply 'tramp-message level fmt-string args)))

(defsubst tramp-line-end-position nil
  "Return point at end of line.
Calls `line-end-position' or `point-at-eol' if defined, else
own implementation."
  (cond
   ((fboundp 'line-end-position) (funcall 'line-end-position))
   ((fboundp 'point-at-eol) 	 (funcall 'point-at-eol))
   (t (save-excursion (end-of-line) (point)))))

(defmacro with-parsed-tramp-file-name (filename var &rest body)
  "Parse a Tramp filename and make components available in the body.

First arg FILENAME is evaluated and dissected into its components.
Second arg VAR is a symbol.  It is used as a variable name to hold
the filename structure.  It is also used as a prefix for the variables
holding the components.  For example, if VAR is the symbol `foo', then
`foo' will be bound to the whole structure, `foo-multi-method' will
be bound to the multi-method component, and so on for `foo-method',
`foo-user', `foo-host', `foo-path'.

Remaining args are Lisp expressions to be evaluated (inside an implicit
`progn').

If VAR is nil, then we bind `v' to the structure and `multi-method',
`method', `user', `host', `path' to the components."
  `(let* ((,(or var 'v) (tramp-dissect-file-name ,filename))
	  (,(if var (intern (concat (symbol-name var) "-multi-method")) 'multi-method)
	   (tramp-file-name-multi-method ,(or var 'v)))
	  (,(if var (intern (concat (symbol-name var) "-method")) 'method)
	   (tramp-file-name-method ,(or var 'v)))
	  (,(if var (intern (concat (symbol-name var) "-user")) 'user)
	   (tramp-file-name-user ,(or var 'v)))
	  (,(if var (intern (concat (symbol-name var) "-host")) 'host)
	   (tramp-file-name-host ,(or var 'v)))
	  (,(if var (intern (concat (symbol-name var) "-path")) 'path)
	   (tramp-file-name-path ,(or var 'v))))
     ,@body))

(put 'with-parsed-tramp-file-name 'lisp-indent-function 2)

;;; Config Manipulation Functions:

(defun tramp-set-completion-function (method function-list)
  "Sets the list of completion functions for METHOD.
FUNCTION-LIST is a list of entries of the form (FUNCTION FILE).
The FUNCTION is intended to parse FILE according its syntax.
It might be a predefined FUNCTION, or a user defined FUNCTION.
Predefined FUNCTIONs are `tramp-parse-rhosts', `tramp-parse-shosts',
`tramp-parse-hosts', and `tramp-parse-passwd'.
Example:

    (tramp-set-completion-function
     \"ssh\"
     '((tramp-parse-shosts \"/etc/ssh_known_hosts\")
       (tramp-parse-shosts \"~/.ssh/known_hosts\")))"

  (let ((v (cdr (assoc method tramp-completion-function-alist))))
    (when v (setcdr v function-list))))

(defun tramp-get-completion-function (method)
  "Returns list of completion functions for METHOD.
For definition of that list see `tramp-set-completion-function'."
 (cdr (assoc method tramp-completion-function-alist)))

;;; File Name Handler Functions:

(defun tramp-handle-make-symbolic-link
  (filename linkname &optional ok-if-already-exists)
  "Like `make-symbolic-link' for tramp files.
If LINKNAME is a non-Tramp file, it is used verbatim as the target of
the symlink.  If LINKNAME is a Tramp file, only the path component is
used as the target of the symlink.

If LINKNAME is a Tramp file and the path component is relative, then
it is expanded first, before the path component is taken.  Note that
this can give surprising results if the user/host for the source and
target of the symlink differ."
  (with-parsed-tramp-file-name linkname l
    (when (tramp-ange-ftp-file-name-p l-multi-method l-method l-user l-host)
      (tramp-invoke-ange-ftp 'make-symbolic-link
			     filename linkname ok-if-already-exists))
    (let ((ln (tramp-get-remote-ln l-multi-method l-method l-user l-host))
	  (cwd (file-name-directory l-path)))
      (unless ln
	(signal 'file-error
		(list "Making a symbolic link."
		      "ln(1) does not exist on the remote host.")))

      ;; Do the 'confirm if exists' thing.
      (when (file-exists-p linkname)
	;; What to do?
	(if (or (null ok-if-already-exists) ; not allowed to exist
		(and (numberp ok-if-already-exists)
		     (not (yes-or-no-p
			   (format
			    "File %s already exists; make it a link anyway? "
			    l-path)))))
	    (signal 'file-already-exists (list "File already exists" l-path))
	  (delete-file linkname)))

      ;; If FILENAME is a Tramp name, use just the path component.
      (when (tramp-tramp-file-p filename)
	(setq filename (tramp-file-name-path
			(tramp-dissect-file-name
			 (expand-file-name filename)))))
    
      ;; Right, they are on the same host, regardless of user, method, etc.
      ;; We now make the link on the remote machine. This will occur as the user
      ;; that FILENAME belongs to.
      (zerop
       (tramp-send-command-and-check
	l-multi-method l-method l-user l-host
	(format "cd %s && %s -sf %s %s"
		cwd ln
		filename 
		l-path)
	t)))))


(defun tramp-handle-load (file &optional noerror nomessage nosuffix must-suffix)
  "Like `load' for tramp files.  Not implemented!"
  (unless (file-name-absolute-p file)
    (error "Tramp cannot `load' files without absolute path name"))
  (with-parsed-tramp-file-name file nil
    (when (tramp-ange-ftp-file-name-p multi-method method user host)
      (tramp-invoke-ange-ftp 'load
			     file noerror nomessage nosuffix must-suffix))
    (unless nosuffix
      (cond ((file-exists-p (concat file ".elc"))
	     (setq file (concat file ".elc")))
	    ((file-exists-p (concat file ".el"))
	     (setq file (concat file ".el")))))
    (when must-suffix
      ;; The first condition is always true for absolute file names.
      ;; Included for safety's sake.
      (unless (or (file-name-directory file)
		  (string-match "\\.elc?\\'" file))
	(error "File `%s' does not include a `.el' or `.elc' suffix"
	       file)))
    (unless noerror
      (when (not (file-exists-p file))
	(error "Cannot load nonexistant file `%s'" file)))
    (if (not (file-exists-p file))
	nil
      (unless nomessage
	(message "Loading %s..." file))
      (let ((local-copy (file-local-copy file)))
	;; MUST-SUFFIX doesn't exist on XEmacs, so let it default to nil.
	(load local-copy noerror t t)
	(delete-file local-copy))
      (unless nomessage
	(message "Loading %s...done" file))
      t)))

;; Path manipulation functions that grok TRAMP paths...
(defun tramp-handle-file-name-directory (file)
  "Like `file-name-directory' but aware of TRAMP files."
  ;; everything except the last filename thing is the directory
  (with-parsed-tramp-file-name file nil
    (when (tramp-ange-ftp-file-name-p multi-method method user host)
      (tramp-invoke-ange-ftp 'file-name-directory file))
    ;; For the following condition, two possibilities should be tried:
    ;; (1) (string= path "")
    ;; (2) (or (string= path "") (string= path "/"))
    ;; The second variant fails when completing a "/" directory on
    ;; the remote host, that is a filename which looks like
    ;; "/user@host:/".  But maybe wildcards fail with the first variant.
    ;; We should do some investigation.
    (if (string= path "")
	;; For a filename like "/[foo]", we return "/".  The `else'
	;; case would return "/[foo]" unchanged.  But if we do that,
	;; then `file-expand-wildcards' ceases to work.  It's not
	;; quite clear to me what's the intuition that tells that this
	;; behavior is the right behavior, but oh, well.
	"/"
      ;; run the command on the path portion only
      ;; CCC: This should take into account the remote machine type, no?
      ;;  --daniel <daniel@danann.net>
      (tramp-make-tramp-file-name multi-method method user host
				  ;; This will not recurse...
				  (or (file-name-directory path) "")))))

(defun tramp-handle-file-name-nondirectory (file)
  "Like `file-name-nondirectory' but aware of TRAMP files."
  (with-parsed-tramp-file-name file nil
    (when (tramp-ange-ftp-file-name-p multi-method method user host)
      (tramp-invoke-ange-ftp 'file-name-nondirectory file))
    (file-name-nondirectory path)))

(defun tramp-handle-file-truename (filename &optional counter prev-dirs)
  "Like `file-truename' for tramp files."
  (with-parsed-tramp-file-name filename nil
    ;; Ange-FTP does not support truename processing, but for
    ;; convenience we pretend it did and forward the call to Ange-FTP
    ;; anyway.  Ange-FTP then just invokes `identity'.
    (when (tramp-ange-ftp-file-name-p multi-method method user host)
      (tramp-invoke-ange-ftp 'file-truename filename))
    (let* ((steps        (tramp-split-string path "/"))
	   (pathdir (let ((directory-sep-char ?/))
		      (file-name-as-directory path)))
	   (is-dir (string= path pathdir))
	   (thisstep nil)
	   (numchase 0)
	   ;; Don't make the following value larger than necessary.
	   ;; People expect an error message in a timely fashion when
	   ;; something is wrong; otherwise they might think that Emacs
	   ;; is hung.  Of course, correctness has to come first.
	   (numchase-limit 20)
	   (result nil)			;result steps in reverse order
	   symlink-target)
      (tramp-message-for-buffer
       multi-method method user host
       10 "Finding true name for `%s'" filename)
      (while (and steps (< numchase numchase-limit))
	(setq thisstep (pop steps))
	(tramp-message-for-buffer
	 multi-method method user host
	 10 "Check %s"
	 (mapconcat 'identity
		    (append '("") (reverse result) (list thisstep))
		    "/"))
	(setq symlink-target
	      (nth 0 (tramp-handle-file-attributes
		      (tramp-make-tramp-file-name
		       multi-method method user host
		       (mapconcat 'identity
				  (append '("")
					  (reverse result)
					  (list thisstep))
				  "/")))))
	(cond ((string= "." thisstep)
	       (tramp-message-for-buffer multi-method method user host
					 10 "Ignoring step `.'"))
	      ((string= ".." thisstep)
	       (tramp-message-for-buffer multi-method method user host
					 10 "Processing step `..'")
	       (pop result))
	      ((stringp symlink-target)
	       ;; It's a symlink, follow it.
	       (tramp-message-for-buffer
		multi-method method user host
		10 "Follow symlink to %s" symlink-target)
	       (setq numchase (1+ numchase))
	       (when (file-name-absolute-p symlink-target)
		 (setq result nil))
	       (setq steps
		     (append (tramp-split-string symlink-target "/") steps)))
	      (t
	       ;; It's a file.
	       (setq result (cons thisstep result)))))
      (when (>= numchase numchase-limit)
	(error "Maximum number (%d) of symlinks exceeded" numchase-limit))
      (setq result (reverse result))
      (tramp-message-for-buffer
       multi-method method user host
       10 "True name of `%s' is `%s'"
       filename (mapconcat 'identity (cons "" result) "/"))
      (tramp-make-tramp-file-name
       multi-method method user host
       (concat (mapconcat 'identity (cons "" result) "/")
	       (if is-dir "/" ""))))))

;; Basic functions.

(defun tramp-handle-file-exists-p (filename)
  "Like `file-exists-p' for tramp files."
  (with-parsed-tramp-file-name filename nil
    (when (tramp-ange-ftp-file-name-p multi-method method user host)
      (tramp-invoke-ange-ftp 'file-exists-p filename))
    (save-excursion
      (zerop (tramp-send-command-and-check
	      multi-method method user host
	      (format
	       (tramp-get-file-exists-command multi-method method user host)
	       (tramp-shell-quote-argument path)))))))

;; CCC: This should check for an error condition and signal failure
;;      when something goes wrong.
;; Daniel Pittman <daniel@danann.net>
(defun tramp-handle-file-attributes (filename &optional nonnumeric)
  "Like `file-attributes' for tramp files.
Optional argument NONNUMERIC means return user and group name
rather than as numbers."
  (let (result)
    (with-parsed-tramp-file-name filename nil
      (when (tramp-ange-ftp-file-name-p multi-method method user host)
	(tramp-invoke-ange-ftp 'file-attributes filename))
      (when (tramp-handle-file-exists-p filename)
	;; file exists, find out stuff
	(save-excursion
	  (if (tramp-get-remote-perl multi-method method user host)
	      (setq result
		    (tramp-handle-file-attributes-with-perl
		     multi-method method user host path nonnumeric))
	    (setq result
		  (tramp-handle-file-attributes-with-ls
		   multi-method method user host path nonnumeric))))))
    result))


(defun tramp-handle-file-attributes-with-ls
  (multi-method method user host path &optional nonnumeric)
  "Implement `file-attributes' for tramp files using the ls(1) command."
  (let (symlinkp dirp
		 res-inode res-filemodes res-numlinks
		 res-uid res-gid res-size res-symlink-target)
    (tramp-message-for-buffer multi-method method user host 10
			      "file attributes with ls: %s"
			      (tramp-make-tramp-file-name
			       multi-method method user host path))
    (tramp-send-command
     multi-method method user host
     (format "%s %s %s"
	     (tramp-get-ls-command multi-method method user host)
	     (if nonnumeric "-ild" "-ildn")
	     (tramp-shell-quote-argument path)))
    (tramp-wait-for-output)
    ;; parse `ls -l' output ...
    ;; ... inode
    (setq res-inode
	  (condition-case err
	      (read (current-buffer))
	    (invalid-read-syntax
	     (when (and (equal (cadr err)
			       "Integer constant overflow in reader")
			(string-match
			 "^[0-9]+\\([0-9][0-9][0-9][0-9][0-9]\\)\\'"
			 (caddr err)))
	       (let* ((big (read (substring (caddr err) 0
					    (match-beginning 1))))
		      (small (read (match-string 1 (caddr err))))
		      (twiddle (/ small 65536)))
		 (cons (+ big twiddle)
		       (- small (* twiddle 65536))))))))
    ;; ... file mode flags
    (setq res-filemodes (symbol-name (read (current-buffer))))
    ;; ... number links
    (setq res-numlinks (read (current-buffer)))
    ;; ... uid and gid
    (setq res-uid (read (current-buffer)))
    (setq res-gid (read (current-buffer)))
    (unless nonnumeric
      (unless (numberp res-uid) (setq res-uid -1))
      (unless (numberp res-gid) (setq res-gid -1)))
    ;; ... size
    (setq res-size (read (current-buffer)))
    ;; From the file modes, figure out other stuff.
    (setq symlinkp (eq ?l (aref res-filemodes 0)))
    (setq dirp (eq ?d (aref res-filemodes 0)))
    ;; if symlink, find out file name pointed to
    (when symlinkp
      (search-forward "-> ")
      (setq res-symlink-target
	    (buffer-substring (point)
			      (tramp-line-end-position))))
    ;; return data gathered
    (list
     ;; 0. t for directory, string (name linked to) for symbolic
     ;; link, or nil.
     (or dirp res-symlink-target nil)
     ;; 1. Number of links to file.
     res-numlinks
     ;; 2. File uid.
     res-uid
     ;; 3. File gid.
     res-gid
     ;; 4. Last access time, as a list of two integers. First
     ;; integer has high-order 16 bits of time, second has low 16
     ;; bits.
     ;; 5. Last modification time, likewise.
     ;; 6. Last status change time, likewise.
     '(0 0) '(0 0) '(0 0)		;CCC how to find out?
     ;; 7. Size in bytes (-1, if number is out of range).
     res-size
     ;; 8. File modes, as a string of ten letters or dashes as in ls -l.
     res-filemodes
     ;; 9. t iff file's gid would change if file were deleted and
     ;; recreated.
     nil				;hm?
     ;; 10. inode number.
     res-inode
     ;; 11. Device number.
     -1					;hm?
     )))

(defun tramp-handle-file-attributes-with-perl
  (multi-method method user host path &optional nonnumeric)
  "Implement `file-attributes' for tramp files using a Perl script.

The Perl command is sent to the remote machine when the connection
is initially created and is kept cached by the remote shell."
  (tramp-message-for-buffer multi-method method user host 10
			    "file attributes with perl: %s"
			    (tramp-make-tramp-file-name
			     multi-method method user host path))
  (tramp-send-command
   multi-method method user host
   (format "tramp_file_attributes %s" 
	   (tramp-shell-quote-argument path)))
  (tramp-wait-for-output)
  (let ((result (read (current-buffer))))
    (setcar (nthcdr 8 result)
	    (tramp-file-mode-from-int (nth 8 result)))
    result))

(defun tramp-handle-set-visited-file-modtime (&optional time-list)
  "Like `set-visited-file-modtime' for tramp files."
  (unless (buffer-file-name)
    (error "Can't set-visited-file-modtime: buffer `%s' not visiting a file"
	   (buffer-name)))
  (when time-list
    (tramp-run-real-handler 'set-visited-file-modtime (list time-list)))
  (let ((f (buffer-file-name))
	(coding-system-used nil))
    (with-parsed-tramp-file-name f nil
      ;; This operation is not handled by Ange-FTP!  Compare this
      ;; behavior with `file-truename' which Ange-FTP does not really
      ;; handle, either, but at least it pretends to.  I wonder if
      ;; Ange-FTP should also pretend to grok
      ;; `set-visited-file-modtime', for consistency?
      (when (tramp-ange-ftp-file-name-p multi-method method user host)
	(throw 'tramp-forward-to-ange-ftp
	       (tramp-run-real-handler 'set-visited-file-modtime
				       (list time-list))))
      (let* ((attr (file-attributes f))
	     (modtime (nth 5 attr)))
	;; We use '(0 0) as a don't-know value.  See also
	;; `tramp-handle-file-attributes-with-ls'.
	(when (boundp 'last-coding-system-used)
	  (setq coding-system-used last-coding-system-used))
	(if (not (equal modtime '(0 0)))
	    (tramp-run-real-handler 'set-visited-file-modtime (list modtime))
	  (save-excursion
	    (tramp-send-command
	     multi-method method user host
	     (format "%s -ild %s"
		     (tramp-get-ls-command multi-method method user host)
		     (tramp-shell-quote-argument path)))
	    (tramp-wait-for-output)
	    (setq attr (buffer-substring (point)
					 (progn (end-of-line) (point)))))
	  (setq tramp-buffer-file-attributes attr))
	(when (boundp 'last-coding-system-used)
	  (setq last-coding-system-used coding-system-used))
	nil))))

;; CCC continue here

;; This function makes the same assumption as
;; `tramp-handle-set-visited-file-modtime'.
(defun tramp-handle-verify-visited-file-modtime (buf)
  "Like `verify-visited-file-modtime' for tramp files."
  (with-current-buffer buf
    (let ((f (buffer-file-name)))
      (with-parsed-tramp-file-name f nil
	(when (tramp-ange-ftp-file-name-p multi-method method user host)
	  ;; This one requires a hack since the file name is not passed
	  ;; on the arg list.
	  (let ((buffer-file-name (tramp-make-ange-ftp-file-name
				   user host path)))
	    (tramp-invoke-ange-ftp 'verify-visited-file-modtime buf)))
	(let* ((attr (file-attributes f))
	       (modtime (nth 5 attr)))
	  (cond ((and attr (not (equal modtime '(0 0))))
		 ;; Why does `file-attributes' return a list (HIGH
		 ;; LOW), but `visited-file-modtime' returns a cons
		 ;; (HIGH . LOW)?
		 (let ((mt (visited-file-modtime)))
		   (< (abs (tramp-time-diff
			    modtime (list (car mt) (cdr mt)))) 2)))
		(attr
		 (save-excursion
		   (tramp-send-command
		    multi-method method user host
		    (format "%s -ild %s"
			    (tramp-get-ls-command multi-method method
						  user host)
			    (tramp-shell-quote-argument path)))
		   (tramp-wait-for-output)
		   (setq attr (buffer-substring
			       (point) (progn (end-of-line) (point)))))
		 (equal tramp-buffer-file-attributes attr))
		;; If file does not exist, say it is not modified.
		(t nil)))))))

(defadvice clear-visited-file-modtime (after tramp activate)
  "Set `tramp-buffer-file-attributes' back to nil.
Tramp uses this variable as an emulation for the actual modtime of the file,
if the remote host can't provide the modtime."
  (setq tramp-buffer-file-attributes nil))

(defun tramp-handle-set-file-modes (filename mode)
  "Like `set-file-modes' for tramp files."
  (with-parsed-tramp-file-name filename nil
    (when (tramp-ange-ftp-file-name-p multi-method method user host)
      (tramp-invoke-ange-ftp 'set-file-modes mode filename))
    (save-excursion
      (unless (zerop (tramp-send-command-and-check
		      multi-method method user host
		      (format "chmod %s %s"
			      (tramp-decimal-to-octal mode)
			      (tramp-shell-quote-argument path))))
	(signal 'file-error
		(list "Doing chmod"
		      ;; FIXME: extract the proper text from chmod's stderr.
		      "error while changing file's mode"
		      filename))))))

;; Simple functions using the `test' command.

(defun tramp-handle-file-executable-p (filename)
  "Like `file-executable-p' for tramp files."
  (with-parsed-tramp-file-name filename nil
    (when (tramp-ange-ftp-file-name-p multi-method method user host)
      (tramp-invoke-ange-ftp 'file-executable-p filename))
    (zerop (tramp-run-test "-x" filename))))

(defun tramp-handle-file-readable-p (filename)
  "Like `file-readable-p' for tramp files."
  (with-parsed-tramp-file-name filename nil
    (when (tramp-ange-ftp-file-name-p multi-method method user host)
      (tramp-invoke-ange-ftp 'file-readable-p filename))
    (zerop (tramp-run-test "-r" filename))))

(defun tramp-handle-file-accessible-directory-p (filename)
  "Like `file-accessible-directory-p' for tramp files."
  (with-parsed-tramp-file-name filename nil
    (when (tramp-ange-ftp-file-name-p multi-method method user host)
      (tramp-invoke-ange-ftp 'file-accessible-directory-p filename))
    (and (zerop (tramp-run-test "-d" filename))
	 (zerop (tramp-run-test "-r" filename))
	 (zerop (tramp-run-test "-x" filename)))))

;; When the remote shell is started, it looks for a shell which groks
;; tilde expansion.  Here, we assume that all shells which grok tilde
;; expansion will also provide a `test' command which groks `-nt' (for
;; newer than).  If this breaks, tell me about it and I'll try to do
;; something smarter about it.
(defun tramp-handle-file-newer-than-file-p (file1 file2)
  "Like `file-newer-than-file-p' for tramp files."
  (cond ((not (file-exists-p file1))
         nil)
        ((not (file-exists-p file2))
         t)
        ;; We are sure both files exist at this point.
        (t
         (save-excursion
	   ;; We try to get the mtime of both files.  If they are not
	   ;; equal to the "dont-know" value, then we subtract the times
	   ;; and obtain the result.
	   (let ((fa1 (file-attributes file1))
		 (fa2 (file-attributes file2)))
	     (if (and (not (equal (nth 5 fa1) '(0 0)))
		      (not (equal (nth 5 fa2) '(0 0))))
		 (> 0 (car (subtract-time (nth 5 fa1) (nth 5 fa2))))
	       ;; If one of them is the dont-know value, then we can
	       ;; still try to run a shell command on the remote host.
	       ;; However, this only works if both files are Tramp
	       ;; files and both have the same method, same user, same
	       ;; host.
	       (unless (and (tramp-tramp-file-p file1)
			    (tramp-tramp-file-p file2))
		 (signal
		  'file-error
		  (list
		   "Cannot check if Tramp file is newer than non-Tramp file"
		   file1 file2)))
	       (with-parsed-tramp-file-name file1 v1
		 (with-parsed-tramp-file-name file2 v2
		   (when (and (tramp-ange-ftp-file-name-p
			       v1-multi-method v1-method v1-user v1-host)
			      (tramp-ange-ftp-file-name-p
			       v2-multi-method v2-method v2-user v2-host))
		     (tramp-invoke-ange-ftp 'file-newer-than-file-p
					    file1 file2))
		   (unless (and (equal v1-multi-method v2-multi-method)
				(equal v1-method v2-method)
				(equal v1-user v2-user)
				(equal v1-host v2-host))
		     (signal 'file-error
			     (list "Files must have same method, user, host"
				   file1 file2)))
		   (unless (and (tramp-tramp-file-p file1)
				(tramp-tramp-file-p file2))
		     (signal 'file-error
			     (list "Files must be tramp files on same host"
				   file1 file2)))
		   (if (tramp-get-test-groks-nt
			v1-multi-method v1-method v1-user v1-host)
		       (zerop (tramp-run-test2 "test" file1 file2 "-nt"))
		     (zerop (tramp-run-test2
			     "tramp_test_nt" file1 file2)))))))))))

;; Functions implemented using the basic functions above.

(defun tramp-handle-file-modes (filename)
  "Like `file-modes' for tramp files."
  (with-parsed-tramp-file-name filename nil
    (when (tramp-ange-ftp-file-name-p multi-method method user host)
      (tramp-invoke-ange-ftp 'file-modes filename))
    (when (file-exists-p filename)
      (tramp-mode-string-to-int
       (nth 8 (tramp-handle-file-attributes filename))))))

(defun tramp-handle-file-directory-p (filename)
  "Like `file-directory-p' for tramp files."
  ;; Care must be taken that this function returns `t' for symlinks
  ;; pointing to directories.  Surely the most obvious implementation
  ;; would be `test -d', but that returns false for such symlinks.
  ;; CCC: Stefan Monnier says that `test -d' follows symlinks.  And
  ;; I now think he's right.  So we could be using `test -d', couldn't
  ;; we?
  ;;
  ;; Alternatives: `cd %s', `test -d %s'
  (with-parsed-tramp-file-name filename nil
    (when (tramp-ange-ftp-file-name-p multi-method method user host)
      (tramp-invoke-ange-ftp 'file-directory-p filename))
    (save-excursion
      (zerop
       (tramp-send-command-and-check
	multi-method method user host
	(format "test -d %s"
		(tramp-shell-quote-argument path))
	t)))))				;run command in subshell

(defun tramp-handle-file-regular-p (filename)
  "Like `file-regular-p' for tramp files."
  (with-parsed-tramp-file-name filename nil
    (when (tramp-ange-ftp-file-name-p multi-method method user host)
      (tramp-invoke-ange-ftp 'file-regular-p filename))
    (and (tramp-handle-file-exists-p filename)
	 (eq ?- (aref (nth 8 (tramp-handle-file-attributes filename)) 0)))))

(defun tramp-handle-file-symlink-p (filename)
  "Like `file-symlink-p' for tramp files."
  (with-parsed-tramp-file-name filename nil
    (when (tramp-ange-ftp-file-name-p multi-method method user host)
      (tramp-invoke-ange-ftp 'file-symlink-p filename))
    (let ((x (car (tramp-handle-file-attributes filename))))
      (when (stringp x) x))))

(defun tramp-handle-file-writable-p (filename)
  "Like `file-writable-p' for tramp files."
  (with-parsed-tramp-file-name filename nil
    (when (tramp-ange-ftp-file-name-p multi-method method user host)
      (tramp-invoke-ange-ftp 'file-writable-p filename))
    (if (tramp-handle-file-exists-p filename)
	;; Existing files must be writable.
	(zerop (tramp-run-test "-w" filename))
      ;; If file doesn't exist, check if directory is writable.
      (and (zerop (tramp-run-test
		   "-d" (tramp-handle-file-name-directory filename)))
	   (zerop (tramp-run-test
		   "-w" (tramp-handle-file-name-directory filename)))))))

(defun tramp-handle-file-ownership-preserved-p (filename)
  "Like `file-ownership-preserved-p' for tramp files."
  (with-parsed-tramp-file-name filename nil
    (when (tramp-ange-ftp-file-name-p multi-method method user host)
      (tramp-invoke-ange-ftp 'file-ownership-preserved-p filename))
    (or (not (tramp-handle-file-exists-p filename))
	;; Existing files must be writable.
	(zerop (tramp-run-test "-O" filename)))))

;; Other file name ops.