tramp.el

;;; tramp.el --- Transparent Remote Access, Multiple Protocol

;; Copyright (C) 1998-2015 Free Software Foundation, Inc.

;; Author: Kai Großjohann <kai.grossjohann@gmx.net>
;;         Michael Albinus <michael.albinus@gmx.de>
;; Keywords: comm, processes
;; Package: tramp

;; This file is part of GNU Emacs.

;; GNU Emacs is free software: you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.

;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.

;;; Commentary:

;; 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.
;;
;; Notes:
;; -----
;;
;; This package only works for Emacs 22.1 and higher, and for XEmacs 21.4
;; and higher.  For XEmacs 21, you need the package `fsf-compat' for
;; the `with-timeout' macro.
;;
;; Also see the todo list at the bottom of this file.
;;
;; The current version of Tramp can be retrieved from the following URL:
;;            http://ftp.gnu.org/gnu/tramp/
;;
;; There's a mailing list for this, as well.  Its name is:
;;            tramp-devel@gnu.org
;; You can use the Web to subscribe, under the following URL:
;;            http://lists.gnu.org/mailman/listinfo/tramp-devel
;;
;; For the adventurous, the current development sources are available
;; via Git.  You can find instructions about this at the following URL:
;;            http://savannah.gnu.org/projects/tramp/
;;
;; Don't forget to put on your asbestos longjohns, first!

;;; Code:

(require 'tramp-compat)

;; Pacify byte-compiler.
(eval-when-compile
  (require 'cl))
(defvar bkup-backup-directory-info)
(defvar directory-sep-char)
(defvar eshell-path-env)
(defvar ls-lisp-use-insert-directory-program)
(defvar outline-regexp)

;;; User Customizable Internal Variables:

(defgroup tramp nil
  "Edit remote files with a combination of ssh, scp, etc."
  :group 'files
  :group 'comm
  :version "22.1")

;; Maybe we need once a real Tramp mode, with key bindings etc.
;;;###autoload
(defcustom tramp-mode t
  "Whether Tramp is enabled.
If it is set to nil, all remote file names are used literally."
  :group 'tramp
  :type 'boolean)

(defcustom tramp-verbose 3
  "Verbosity level for Tramp messages.
Any level x includes messages for all levels 1 .. x-1.  The levels are

 0  silent (no tramp messages at all)
 1  errors
 2  warnings
 3  connection to remote hosts (default level)
 4  activities
 5  internal
 6  sent and received strings
 7  file caching
 8  connection properties
 9  test commands
10  traces (huge)."
  :group 'tramp
  :type 'integer)

;; Emacs case.
(eval-and-compile
  (when (boundp 'backup-directory-alist)
    (defcustom tramp-backup-directory-alist nil
      "Alist of filename patterns and backup directory names.
Each element looks like (REGEXP . DIRECTORY), with the same meaning like
in `backup-directory-alist'.  If a Tramp file is backed up, and DIRECTORY
is a local file name, the backup directory is prepended with Tramp file
name prefix \(method, user, host\) of file.

\(setq tramp-backup-directory-alist backup-directory-alist\)

gives the same backup policy for Tramp files on their hosts like the
policy for local files."
      :group 'tramp
      :type '(repeat (cons (regexp :tag "Regexp matching filename")
			   (directory :tag "Backup directory name"))))))

;; XEmacs case.  We cannot check for `bkup-backup-directory-info', because
;; the package "backup-dir" might not be loaded yet.
(eval-and-compile
  (when (featurep 'xemacs)
    (defcustom tramp-bkup-backup-directory-info nil
      "Alist of (FILE-REGEXP BACKUP-DIR OPTIONS ...))
It has the same meaning like `bkup-backup-directory-info' from package
`backup-dir'.  If a Tramp file is backed up, and BACKUP-DIR is a local
file name, the backup directory is prepended with Tramp file name prefix
\(method, user, host\) of file.

\(setq tramp-bkup-backup-directory-info bkup-backup-directory-info\)

gives the same backup policy for Tramp files on their hosts like the
policy for local files."
      :type '(repeat
	      (list (regexp :tag "File regexp")
		    (string :tag "Backup Dir")
		    (set :inline t
			 (const ok-create)
			 (const full-path)
			 (const prepend-name)
			 (const search-upward))))
      :group 'tramp)))

(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 decoding, 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.

If the shell must be forced to be interactive, see
`tramp-encoding-command-interactive'.

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-command-interactive
  (unless (string-match "cmd\\.exe" tramp-encoding-shell) "-i")
  "Use this switch together with `tramp-encoding-shell' for interactive shells.
See the variable `tramp-encoding-shell' for more information."
  :version "24.1"
  :group 'tramp
  :type '(choice (const nil) string))

;;;###tramp-autoload
(defvar tramp-methods 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-remote-shell'
    This specifies the 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-remote-shell-args'
    For implementation of `shell-command', this specifies the
    arguments to let `tramp-remote-shell' run a single command.
  * `tramp-login-program'
    This specifies the name of the program to use for logging in to the
    remote host.  This may be the name of rsh or a workalike program,
    or the name of telnet or a workalike, or the name of su or a workalike.
  * `tramp-login-args'
    This specifies the list of arguments to pass to the above
    mentioned program.  Please note that this is a list of list of arguments,
    that is, normally you don't want to put \"-a -b\" or \"-f foo\"
    here.  Instead, you want a list (\"-a\" \"-b\"), or (\"-f\" \"foo\").
    There are some patterns: \"%h\" in this list is replaced by the host
    name, \"%u\" is replaced by the user name, \"%p\" is replaced by the
    port number, and \"%%\" can be used to obtain a literal percent character.
    If a list containing \"%h\", \"%u\" or \"%p\" is unchanged during
    expansion (i.e. no host or no user specified), this list is not used as
    argument.  By this, arguments like (\"-l\" \"%u\") are optional.
    \"%t\" is replaced by the temporary file name produced with
    `tramp-make-tramp-temp-file'.  \"%k\" indicates the keep-date
    parameter of a program, if exists.  \"%c\" adds additional
    `tramp-ssh-controlmaster-options' options for the first hop.
  * `tramp-login-env'
     A list of environment variables and their values, which will
     be set when calling `tramp-login-program'.
  * `tramp-async-args'
    When an asynchronous process is started, we know already that
    the connection works.  Therefore, we can pass additional
    parameters to suppress diagnostic messages, in order not to
    tamper the process output.
  * `tramp-copy-program'
    This specifies the name of the program to use for remotely copying
    the file; this might be the absolute filename of scp or the name of
    a workalike program.  It is always applied on the local host.
  * `tramp-copy-args'
    This specifies the list of parameters to pass to the above mentioned
    program, the hints for `tramp-login-args' also apply here.
  * `tramp-copy-env'
     A list of environment variables and their values, which will
     be set when calling `tramp-copy-program'.
  * `tramp-remote-copy-program'
    The listener program to be applied on remote side, if needed.
  * `tramp-remote-copy-args'
    The list of parameters to pass to the listener program, the hints
    for `tramp-login-args' also apply here.  Additionally, \"%r\" could
    be used here and in `tramp-copy-args'.  It denotes a randomly
    chosen port for the remote listener.
  * `tramp-copy-keep-date'
    This specifies whether the copying program when the preserves the
    timestamp of the original file.
  * `tramp-copy-keep-tmpfile'
    This specifies whether a temporary local file shall be kept
    for optimization reasons (useful for \"rsync\" methods).
  * `tramp-copy-recursive'
    Whether the operation copies directories recursively.
  * `tramp-default-port'
    The default port of a method is needed in case of gateway connections.
    Additionally, it is used as indication which method is prepared for
    passing gateways.
  * `tramp-gw-args'
    As the attribute name says, additional arguments are specified here
    when a method is applied via a gateway.
  * `tramp-tmpdir'
    A directory on the remote host for temporary files.  If not
    specified, \"/tmp\" is taken as default.
  * `tramp-connection-timeout'
    This is the maximum time to be spent for establishing a connection.
    In general, the global default value shall be used, but for
    some methods, like \"su\" or \"sudo\", a shorter timeout
    might be desirable.

What does all this mean?  Well, you should specify `tramp-login-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 scp-like program.  If you want
to do this, set `tramp-copy-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-login-program'.  In
this case, the file contents need to be protected since the
`tramp-login-program' might use escape codes or the connection might not
be eight-bit clean.  Therefore, file contents are encoded for transit.
See the variables `tramp-local-coding-commands' and
`tramp-remote-coding-commands' for details.

So, to summarize: if the method is an out-of-band method, then you
must specify `tramp-copy-program' and `tramp-copy-args'.  If it is an
inline method, then these two parameters should be nil.  Methods which
are fit for gateways must have `tramp-default-port' at least.

Notes:

When using `su' or `sudo' 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' or `sudo' is
started on the local host.  You should specify a remote host
`localhost' or the name of the local host.  Another host name is
useful only in combination with `tramp-default-proxies-alist'.")

;;;###tramp-autoload
(defcustom tramp-ssh-controlmaster-options
  (let ((result "")
	(case-fold-search t))
    (ignore-errors
      (when (executable-find "ssh")
	(with-temp-buffer
	  (call-process "ssh" nil t nil "-o" "ControlMaster")
	  (goto-char (point-min))
	  (when (search-forward-regexp "missing.+argument" nil t)
	    (setq result "-o ControlMaster=auto")))
	(unless (zerop (length result))
	  (with-temp-buffer
	    (call-process
	     "ssh" nil t nil "-o" "ControlPath=%C" "host.does.not.exist")
	    (goto-char (point-min))
	    (if (search-forward-regexp "unknown.+key" nil t)
		(setq result
		      (concat result " -o ControlPath='tramp.%%r@%%h:%%p'"))
	      (setq result (concat result " -o ControlPath='tramp.%%C'"))))
	  (with-temp-buffer
	    (call-process "ssh" nil t nil "-o" "ControlPersist")
	    (goto-char (point-min))
	    (when (search-forward-regexp "missing.+argument" nil t)
	      (setq result (concat result " -o ControlPersist=no")))))))
    result)
    "Call ssh to detect whether it supports the Control* arguments.
Return a string to be used in `tramp-methods'."
    :group 'tramp
    :version "24.5"
    :type 'string)

;;;###tramp-autoload
(defcustom tramp-use-ssh-controlmaster-options
  (not (zerop (length tramp-ssh-controlmaster-options)))
  "Whether to use `tramp-ssh-controlmaster-options'."
  :group 'tramp
  :version "24.4"
  :type 'boolean)

(defcustom tramp-default-method
  ;; An external copy method seems to be preferred, because it performs
  ;; much better for large files, and it hasn't too serious delays
  ;; for small files.  But it must be ensured that there aren't
  ;; permanent password queries.  Either a password agent like
  ;; "ssh-agent" or "Pageant" shall run, or the optional
  ;; password-cache.el or auth-sources.el packages shall be active for
  ;; password caching.  If we detect that the user is running OpenSSH
  ;; 4.0 or newer, we could reuse the connection, which calls also for
  ;; an external method.
  (cond
   ;; PuTTY is installed.  We don't take it, if it is installed on a
   ;; non-windows system, or pscp from the pssh (parallel ssh) package
   ;; is found.
   ((and (eq system-type 'windows-nt)
	 (executable-find "pscp"))
    (if	(or (fboundp 'password-read)
	    (fboundp 'auth-source-user-or-password)
	    (fboundp 'auth-source-search)
	    ;; Pageant is running.
	    (tramp-compat-process-running-p "Pageant"))
	"pscp"
      "plink"))
   ;; There is an ssh installation.
   ((executable-find "scp")
    (if	(or (fboundp 'password-read)
	    (fboundp 'auth-source-user-or-password)
	    (fboundp 'auth-source-search)
	    ;; ssh-agent is running.
	    (getenv "SSH_AUTH_SOCK")
	    (getenv "SSH_AGENT_PID")
	    ;; We could reuse the connection.
	    (> (length tramp-ssh-controlmaster-options) 0))
	"scp"
      "ssh"))
   ;; Fallback.
   (t "ftp"))
  "Default method to use for transferring files.
See `tramp-methods' for possibilities.
Also see `tramp-default-method-alist'."
  :group 'tramp
  :type 'string)

;;;###tramp-autoload
(defcustom tramp-default-method-alist nil
  "Default method to use for specific host/user 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 (choice :tag "Host regexp" regexp sexp)
		       (choice :tag "User regexp" regexp sexp)
		       (choice :tag "Method name" string (const nil)))))

(defcustom tramp-default-user nil
  "Default user to use for transferring files.
It is nil by default; otherwise settings in configuration files like
\"~/.ssh/config\" would be overwritten.  Also see `tramp-default-user-alist'.

This variable is regarded as obsolete, and will be removed soon."
  :group 'tramp
  :type '(choice (const nil) string))

;;;###tramp-autoload
(defcustom tramp-default-user-alist nil
  "Default user to use for specific method/host pairs.
This is an alist of items (METHOD HOST USER).  The first matching item
specifies the user to use for a file name which does not specify a
user.  METHOD 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-user' takes effect.

If the file name does not specify the method, lookup is done using the
empty string for the method name."
  :group 'tramp
  :type '(repeat (list (choice :tag "Method regexp" regexp sexp)
		       (choice :tag "  Host regexp" regexp sexp)
		       (choice :tag "    User name" string (const nil)))))

(defcustom tramp-default-host (system-name)
  "Default host to use for transferring files.
Useful for su and sudo methods mostly."
  :group 'tramp
  :type 'string)

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

If the file name does not specify the method, lookup is done using the
empty string for the method name."
  :group 'tramp
  :version "24.4"
  :type '(repeat (list (choice :tag "Method regexp" regexp sexp)
		       (choice :tag "  User regexp" regexp sexp)
		       (choice :tag "    Host name" string (const nil)))))

(defcustom tramp-default-proxies-alist nil
  "Route to be followed for specific host/user pairs.
This is an alist of items (HOST USER PROXY).  The first matching
item specifies the proxy to be passed for a file name located on
a remote target matching USER@HOST.  HOST and USER are regular
expressions.  PROXY must be a Tramp filename without a localname
part.  Method and user name on PROXY are optional, which is
interpreted with the default values.  PROXY can contain the
patterns %h and %u, which are replaced by the strings matching
HOST or USER, respectively.

HOST, USER or PROXY could also be Lisp forms, which will be
evaluated.  The result must be a string or nil, which is
interpreted as a regular expression which always matches."
  :group 'tramp
  :type '(repeat (list (choice :tag "Host regexp" regexp sexp)
		       (choice :tag "User regexp" regexp sexp)
		       (choice :tag " Proxy name" string (const nil)))))

(defcustom tramp-save-ad-hoc-proxies nil
  "Whether to save ad-hoc proxies persistently."
  :group 'tramp
  :version "24.3"
  :type 'boolean)

(defcustom tramp-restricted-shell-hosts-alist
  (when (memq system-type '(windows-nt))
    (list (concat "\\`" (regexp-quote (system-name)) "\\'")))
  "List of hosts, which run a restricted shell.
This is a list of regular expressions, which denote hosts running
a registered shell like \"rbash\".  Those hosts can be used as
proxies only, see `tramp-default-proxies-alist'.  If the local
host runs a registered shell, it shall be added to this list, too."
  :version "24.3"
  :group 'tramp
  :type '(repeat (regexp :tag "Host regexp")))

;;;###tramp-autoload
(defconst tramp-local-host-regexp
  (concat
   "\\`"
   (regexp-opt
    (list "localhost" "localhost6" (system-name) "127\.0\.0\.1" "::1") t)
   "\\'")
  "Host names which are regarded as local host.")

(defvar tramp-completion-function-alist nil
  "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-sconfig'     for \"~/.ssh/config\" like files,
 * `tramp-parse-shostkeys'   for \"~/.ssh2/hostkeys/*\" like files,
 * `tramp-parse-sknownhosts' for \"~/.ssh2/knownhosts/*\" like files,
 * `tramp-parse-hosts'       for \"/etc/hosts\" like files,
 * `tramp-parse-passwd'      for \"/etc/passwd\" like files.
 * `tramp-parse-netrc'       for \"~/.netrc\" like files.
 * `tramp-parse-putty'       for PuTTY registered sessions.

FUNCTION can also be a customer defined function.  For more details see
the info pages.")

(defconst tramp-echo-mark-marker "_echo"
  "String marker to surround echoed commands.")

(defconst tramp-echo-mark-marker-length (length tramp-echo-mark-marker)
  "String length of `tramp-echo-mark-marker'.")

(defconst tramp-echo-mark
  (concat tramp-echo-mark-marker
	  (make-string tramp-echo-mark-marker-length ?\b))
  "String mark to be transmitted around shell commands.
Used to separate their echo from the output they produce.  This
will only be used if we cannot disable remote echo via stty.
This string must have no effect on the remote shell except for
producing some echo which can later be detected by
`tramp-echoed-echo-mark-regexp'.  Using `tramp-echo-mark-marker',
followed by an equal number of backspaces to erase them will
usually suffice.")

(defconst tramp-echoed-echo-mark-regexp
  (format "%s\\(\b\\( \b\\)?\\)\\{%d\\}"
	  tramp-echo-mark-marker tramp-echo-mark-marker-length)
  "Regexp which matches `tramp-echo-mark' as it gets echoed by
the remote shell.")

(defcustom tramp-local-end-of-line
  (if (memq system-type '(windows-nt)) "\r\n" "\n")
  "String used for end of line in local processes."
  :version "24.1"
  :group 'tramp
  :type 'string)

(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."
  :group 'tramp
  :type 'string)

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

Sometimes the prompt is reported to look like \"login as:\"."
  :group 'tramp
  :type 'regexp)

(defcustom tramp-shell-prompt-pattern
  ;; Allow a prompt to start right after a ^M since it indeed would be
  ;; displayed at the beginning of the line (and Zsh uses it).  This
  ;; regexp works only for GNU Emacs.
  ;; Allow also [] style prompts.  They can appear only during
  ;; connection initialization; Tramp redefines the prompt afterwards.
  (concat (if (featurep 'xemacs) "" "\\(?:^\\|\r\\)")
	  "[^]#$%>\n]*#?[]#$%>] *\\(\e\\[[0-9;]*[a-zA-Z] *\\)*")
  "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 similar to the default value of `shell-prompt-pattern',
which should work well in many cases.

This regexp must match both `tramp-initial-end-of-output' and
`tramp-end-of-output'."
  :group 'tramp
  :type 'regexp)

(defcustom tramp-password-prompt-regexp
  (format "^.*\\(%s\\).*:\^@? *"
	  (if (boundp 'password-word-equivalents)
	      (regexp-opt (symbol-value 'password-word-equivalents))
	    "password\\|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."
  :version "24.4"
  :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"
			"Timeout, server not responding."
			"Sorry, try again."
			"Name or service not known"
			"Host key verification failed."
			"No supported authentication methods left to try!") 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)"
		 "Update cached key? (y/n, Return cancels connection)") 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-terminal-prompt-regexp
  (concat "\\("
	  "TERM = (.*)"
	  "\\|"
	  "Terminal type\\? \\[.*\\]"
	  "\\)\\s-*")
  "Regular expression matching all terminal setting prompts.
The regexp should match at end of buffer.
The answer will be provided by `tramp-action-terminal', which see."
  :group 'tramp
  :type 'regexp)

(defcustom tramp-operation-not-permitted-regexp
  (concat "\\(" "preserving times.*" "\\|" "set mode" "\\)" ":\\s-*"
	  (regexp-opt '("Operation not permitted") t))
  "Regular expression matching keep-date problems in (s)cp operations.
Copying has been performed successfully already, so this message can
be ignored safely."
  :group 'tramp
  :type 'regexp)

(defcustom tramp-copy-failed-regexp
  (concat "\\(.+: "
          (regexp-opt '("Permission denied"
                        "not a regular file"
                        "is a directory"
                        "No such file or directory") t)
          "\\)\\s-*")
  "Regular expression matching copy problems in (s)cp operations."
  :group 'tramp
  :type 'regexp)

(defcustom tramp-process-alive-regexp
  ""
  "Regular expression indicating a process has finished.
In fact this expression is empty by intention, it will be used only to
check regularly the status of the associated process.
The answer will be provided by `tramp-action-process-alive',
`tramp-action-out-of-band', which see."
  :group 'tramp
  :type 'regexp)

(defconst 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-compat-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.")

(defconst tramp-temp-buffer-name " *tramp temp*"
  "Buffer name for a temporary buffer.
It shall be used in combination with `generate-new-buffer-name'.")

(defvar tramp-temp-buffer-file-name nil
  "File name of a persistent local temporary file.
Useful for \"rsync\" like methods.")
(make-variable-buffer-local 'tramp-temp-buffer-file-name)
(put 'tramp-temp-buffer-file-name 'permanent-local t)

;; 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.

;; Currently, we have the choice between 'ftp and 'sep.
;;;###autoload
(defcustom tramp-syntax
  (if (featurep 'xemacs) 'sep 'ftp)
  "Tramp filename syntax to be used.

It can have the following values:

  'ftp -- Ange-FTP respective EFS like syntax (GNU Emacs default)
  'sep -- Syntax as defined for XEmacs."
  :group 'tramp
  :version "24.4"
  :type `(choice (const :tag  ,(if (featurep 'xemacs) "EFS" "Ange-FTP") ftp)
		 (const :tag "XEmacs" sep)))

(defconst tramp-prefix-format
  (cond ((equal tramp-syntax 'ftp) "/")
	((equal tramp-syntax 'sep) "/[")
	(t (error "Wrong `tramp-syntax' defined")))
  "String matching the very beginning of Tramp file names.
Used in `tramp-make-tramp-file-name'.")

(defconst 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'.")

(defconst tramp-method-regexp
  "[a-zA-Z_0-9-]+"
  "Regexp matching methods identifiers.")

(defconst tramp-postfix-method-format
  (cond ((equal tramp-syntax 'ftp) ":")
	((equal tramp-syntax 'sep) "/")
	(t (error "Wrong `tramp-syntax' defined")))
  "String matching delimiter between method and user or host names.
Used in `tramp-make-tramp-file-name'.")

(defconst tramp-postfix-method-regexp
  (regexp-quote tramp-postfix-method-format)
  "Regexp matching delimiter between method and user or host names.
Derived from `tramp-postfix-method-format'.")

(defconst tramp-user-regexp "[^/|: \t]+"
  "Regexp matching user names.")

;;;###tramp-autoload
(defconst tramp-prefix-domain-format "%"
  "String matching delimiter between user and domain names.")

;;;###tramp-autoload
(defconst tramp-prefix-domain-regexp
  (regexp-quote tramp-prefix-domain-format)
  "Regexp matching delimiter between user and domain names.
Derived from `tramp-prefix-domain-format'.")

(defconst tramp-domain-regexp "[-a-zA-Z0-9_.]+"
  "Regexp matching domain names.")

(defconst tramp-user-with-domain-regexp
  (concat "\\(" tramp-user-regexp "\\)"
	        tramp-prefix-domain-regexp
	  "\\(" tramp-domain-regexp "\\)")
  "Regexp matching user names with domain names.")

(defconst tramp-postfix-user-format "@"
  "String matching delimiter between user and host names.
Used in `tramp-make-tramp-file-name'.")

(defconst tramp-postfix-user-regexp
  (regexp-quote tramp-postfix-user-format)
  "Regexp matching delimiter between user and host names.
Derived from `tramp-postfix-user-format'.")

(defconst tramp-host-regexp "[a-zA-Z0-9_.-]+"
  "Regexp matching host names.")

(defconst tramp-prefix-ipv6-format
  (cond ((equal tramp-syntax 'ftp) "[")
	((equal tramp-syntax 'sep) "")
	(t (error "Wrong `tramp-syntax' defined")))
  "String matching left hand side of IPv6 addresses.
Used in `tramp-make-tramp-file-name'.")

(defconst tramp-prefix-ipv6-regexp
  (regexp-quote tramp-prefix-ipv6-format)
  "Regexp matching left hand side of IPv6 addresses.
Derived from `tramp-prefix-ipv6-format'.")

;; The following regexp is a bit sloppy.  But it shall serve our
;; purposes.  It covers also IPv4 mapped IPv6 addresses, like in
;; "::ffff:192.168.0.1".
(defconst tramp-ipv6-regexp
  "\\(?:\\(?:[a-zA-Z0-9]+\\)?:\\)+[a-zA-Z0-9.]+"
  "Regexp matching IPv6 addresses.")

(defconst tramp-postfix-ipv6-format
  (cond ((equal tramp-syntax 'ftp) "]")
	((equal tramp-syntax 'sep) "")
	(t (error "Wrong `tramp-syntax' defined")))
  "String matching right hand side of IPv6 addresses.
Used in `tramp-make-tramp-file-name'.")

(defconst tramp-postfix-ipv6-regexp
  (regexp-quote tramp-postfix-ipv6-format)
  "Regexp matching right hand side of IPv6 addresses.
Derived from `tramp-postfix-ipv6-format'.")

(defconst tramp-prefix-port-format
  (cond ((equal tramp-syntax 'ftp) "#")
	((equal tramp-syntax 'sep) "#")
	(t (error "Wrong `tramp-syntax' defined")))
  "String matching delimiter between host names and port numbers.")

(defconst tramp-prefix-port-regexp
  (regexp-quote tramp-prefix-port-format)
  "Regexp matching delimiter between host names and port numbers.
Derived from `tramp-prefix-port-format'.")

(defconst tramp-port-regexp "[0-9]+"
  "Regexp matching port numbers.")

(defconst tramp-host-with-port-regexp
  (concat "\\(" tramp-host-regexp "\\)"
	        tramp-prefix-port-regexp
	  "\\(" tramp-port-regexp "\\)")
  "Regexp matching host names with port numbers.")

(defconst tramp-postfix-hop-format "|"
  "String matching delimiter after ad-hoc hop definitions.")

(defconst tramp-postfix-hop-regexp
  (regexp-quote tramp-postfix-hop-format)
  "Regexp matching delimiter after ad-hoc hop definitions.
Derived from `tramp-postfix-hop-format'.")

(defconst tramp-postfix-host-format
  (cond ((equal tramp-syntax 'ftp) ":")
	((equal tramp-syntax 'sep) "]")
	(t (error "Wrong `tramp-syntax' defined")))
  "String matching delimiter between host names and localnames.
Used in `tramp-make-tramp-file-name'.")

(defconst tramp-postfix-host-regexp
  (regexp-quote tramp-postfix-host-format)
  "Regexp matching delimiter between host names and localnames.
Derived from `tramp-postfix-host-format'.")

(defconst tramp-localname-regexp ".*$"
  "Regexp matching localnames.")

;;; File name format:

(defconst tramp-remote-file-name-spec-regexp
  (concat
   "\\(?:" "\\("   tramp-method-regexp "\\)" tramp-postfix-method-regexp "\\)?"
   "\\(?:" "\\("   tramp-user-regexp   "\\)" tramp-postfix-user-regexp   "\\)?"
   "\\("   "\\(?:" tramp-host-regexp   "\\|"
	           tramp-prefix-ipv6-regexp  "\\(?:" tramp-ipv6-regexp "\\)?"
		 			     tramp-postfix-ipv6-regexp "\\)"
	   "\\(?:" tramp-prefix-port-regexp  tramp-port-regexp "\\)?" "\\)?")
"Regular expression matching a Tramp file name between prefix and postfix.")

(defconst tramp-file-name-structure
  (list
   (concat
    tramp-prefix-regexp
    "\\(" "\\(?:" tramp-remote-file-name-spec-regexp
                  tramp-postfix-hop-regexp "\\)+" "\\)?"
    tramp-remote-file-name-spec-regexp tramp-postfix-host-regexp
    "\\(" tramp-localname-regexp "\\)")
   5 6 7 8 1)
  "List of six elements (REGEXP METHOD USER HOST FILE HOP), detailing \
the Tramp file name structure.

The first element REGEXP is a regular expression matching a Tramp file