1 \input texinfo @c -*- mode: texinfo; coding: utf-8 -*-
2 @setfilename ../../info/tramp.info
4 @settitle TRAMP User Manual
8 @c This is *so* much nicer :)
11 @c In the Tramp repository, the version number is auto-frobbed from
12 @c configure.ac, so you should edit that file and run
13 @c "autoconf && ./configure" to change the version number.
15 @c Additionally, flags are set with respect to the Emacs flavor; and
16 @c depending whether Tramp is packaged into (X)Emacs, or standalone.
18 @include trampver.texi
20 @c Macro for formatting a file name according to the respective syntax.
21 @c Macro arguments should not have any leading or
22 @c trailing whitespace. Not very elegant, but I don't know it better.
24 @macro trampfn {method, userhost, localname}
26 \method\@value{postfixhop}@c
27 \userhost\@value{postfix}\localname\
30 @c Similar, but without a method prefix.
32 @macro trampf {userhost, localname}
34 \userhost\@value{postfix}\localname\
38 Copyright @copyright{} 1999--2016 Free Software Foundation, Inc.
41 Permission is granted to copy, distribute and/or modify this document
42 under the terms of the GNU Free Documentation License, Version 1.3 or
43 any later version published by the Free Software Foundation; with no
44 Invariant Sections, with the Front-Cover Texts being ``A GNU Manual'',
45 and with the Back-Cover Texts as in (a) below. A copy of the license
46 is included in the section entitled ``GNU Free Documentation License''.
48 (a) The FSF's Back-Cover Text is: ``You have the freedom to
49 copy and modify this GNU manual.''
53 @c Entries for @command{install-info} to use
54 @dircategory Emacs network features
56 * TRAMP: (tramp). Transparent Remote Access, Multiple Protocol
57 Emacs remote file access via ssh and scp.
61 @title @value{tramp} version @value{trampver} User Manual
62 @author by Daniel Pittman
63 @author based on documentation by Kai Großjohann
72 @node Top, Overview, (dir), (dir)
73 @top @value{tramp} version @value{trampver} User Manual
75 This file documents @value{tramp} version @value{trampver}, a remote file
76 editing package for Emacs.
78 @value{tramp} stands for ``Transparent Remote (file) Access, Multiple
79 Protocol''. This package provides remote file editing, similar to
82 The difference is that Ange FTP uses FTP to transfer files between the
83 local and the remote host, whereas @value{tramp} uses a combination of
84 @command{rsh} and @command{rcp} or other work-alike programs, such as
85 @command{ssh}/@command{scp}.
87 You can find the latest version of this document on the web at
88 @uref{http://www.gnu.org/software/tramp/}.
91 The latest release of @value{tramp} is available for
92 @uref{ftp://ftp.gnu.org/gnu/tramp/, download}, or you may see
93 @ref{Obtaining Tramp} for more details, including the Git server
96 @value{tramp} also has a @uref{http://savannah.gnu.org/projects/tramp/,
97 Savannah Project Page}.
100 There is a mailing list for @value{tramp}, available at
101 @email{tramp-devel@@gnu.org}, and archived at
102 @uref{http://lists.gnu.org/archive/html/tramp-devel/, the
103 @value{tramp} Mail Archive}.
105 Older archives are located at
106 @uref{http://sourceforge.net/mailarchive/forum.php?forum=tramp-devel,
107 SourceForge Mail Archive} and
108 @uref{http://www.mail-archive.com/emacs-rcp@@ls6.cs.uni-dortmund.de/,
110 @c in HTML output, there's no new paragraph.
119 * Overview:: What @value{tramp} can and cannot do.
123 * Obtaining Tramp:: How to obtain @value{tramp}.
124 * History:: History of @value{tramp}.
125 @ifset installchapter
126 * Installation:: Installing @value{tramp} with your Emacs.
128 * Configuration:: Configuring @value{tramp} for use.
129 * Usage:: An overview of the operation of @value{tramp}.
130 * Bug Reports:: Reporting Bugs and Problems.
131 * Frequently Asked Questions:: Questions and answers from the mailing list.
135 * Files directories and localnames::
136 How file names, directories and localnames
137 are mangled and managed.
138 * Traces and Profiles:: How to Customize Traces.
140 * GNU Free Documentation License:: The license for this documentation.
141 * Function Index:: @value{tramp} functions.
142 * Variable Index:: User options and variables.
143 * Concept Index:: An item for each concept.
146 --- The Detailed Node Listing ---
148 @ifset installchapter
149 Installing @value{tramp} with your Emacs
151 * Installation parameters:: Parameters in order to control installation.
152 * Load paths:: How to plug-in @value{tramp} into your environment.
156 Configuring @value{tramp} for use
158 * Connection types:: Types of connections to remote hosts.
159 * Inline methods:: Inline methods.
160 * External methods:: External methods.
161 * GVFS based methods:: GVFS based external methods.
162 * Gateway methods:: Gateway methods.
163 * Default Method:: Selecting a default method.
164 * Default User:: Selecting a default user.
165 * Default Host:: Selecting a default host.
166 * Multi-hops:: Connecting to a remote host using multiple hops.
167 * Customizing Methods:: Using Non-Standard Methods.
168 * Customizing Completion:: Selecting config files for user/host name completion.
169 * Password handling:: Reusing passwords for several connections.
170 * Connection caching:: Reusing connection related information.
171 * Predefined connection information::
172 Setting own connection related information.
173 * Remote programs:: How @value{tramp} finds and uses programs on the remote host.
174 * Remote shell setup:: Remote shell setup hints.
175 * Android shell setup:: Android shell setup hints.
176 * Auto-save and Backup:: Auto-save and Backup.
177 * Windows setup hints:: Issues with Cygwin ssh.
181 * File name Syntax:: @value{tramp} file name conventions.
182 * File name completion:: File name completion.
183 * Ad-hoc multi-hops:: Declaring multiple hops in the file name.
184 * Remote processes:: Integration with other Emacs packages.
185 * Cleanup remote connections:: Cleanup remote connections.
187 How file names, directories and localnames are mangled and managed
189 * Localname deconstruction:: Breaking a localname into its components.
190 * External packages:: Integration with external Lisp packages.
197 @chapter An overview of @value{tramp}
200 @value{tramp} is for transparently accessing remote files from within
201 Emacs. @value{tramp} enables an easy, convenient, and consistent
202 interface to remote files as if they are local files. @value{tramp}'s
203 transparency extends to editing, version control, and @code{dired}.
205 @value{tramp} can access remote hosts using any number of access
206 methods, such as @command{rsh}, @command{rlogin}, @command{telnet},
207 and related programs. If these programs can successfully pass
208 @acronym{ASCII]} characters, @value{tramp} can use them.
209 @value{tramp} does not require or mandate 8-bit clean connections.
211 @value{tramp}'s most common access method is through @command{ssh}, a
212 more secure alternative to @command{ftp} and other older access
215 @value{tramp} on Windows operating systems is integrated with the
216 PuTTY package, and uses the @command{plink} program.
218 @value{tramp} mostly operates transparently in the background using
219 the connection programs. As long as these programs enable remote login
220 and can use the terminal, @value{tramp} can adapt them for seamless
221 and transparent access.
223 @value{tramp} temporarily transfers a remote file's contents to the
224 local host editing and related operations. @value{tramp} can also
225 transfer files between hosts using standard Emacs interfaces, a
226 benefit of direct integration of @value{tramp} in Emacs.
228 @value{tramp} can transfer files using any number of available host
229 programs for remote files, such as @command{rcp}, @command{scp},
230 @command{rsync} or (under Windows) @command{pscp}. @value{tramp}
231 provides easy ways to specify these programs and customize them to
232 specific files, hosts, or access methods.
234 For faster small-size file transfers, @value{tramp} supports encoded
235 transfers directly through the shell using @command{mimencode} or
236 @command{uuencode} provided such tools are available on the remote
240 @subsubheading @value{tramp} behind the scenes
241 @cindex behind the scenes
242 @cindex details of operation
245 Accessing a remote file through @value{tramp} entails a series of
246 actions, many of which are transparent to the user. Yet some actions
247 may require user response (such as entering passwords or completing
248 file names). One typical scenario, opening a file on a remote host, is
249 presented here to illustrate the steps involved:
251 @kbd{C-x C-f} to initiate find-file, enter part of the @value{tramp}
252 file name, then hit @kbd{@key{TAB}} for completion. If this is the
253 first time connection to that host, here's what happens:
257 @value{tramp} invokes @samp{telnet @var{host}} or @samp{rsh @var{host}
258 -l @var{user}} and establishes an external process to connect to the
259 remote host. @value{tramp} communicates with the process through an
260 Emacs buffer, which also shows output from the remote host.
263 The remote host may prompt for a login name (for @command{telnet}, for
264 example) in the buffer. If on the other hand, the login name was
265 included in the file name portion, @value{tramp} sends the login name
266 followed by a newline.
269 The remote host may then prompt for a password or pass phrase (for
270 @command{rsh} or for @command{telnet}). @value{tramp} displays the
271 password prompt in the minibuffer. @value{tramp} then sends whatever
272 is entered to the remote host, followed by a newline.
275 @value{tramp} now waits for either the shell prompt or a failed login
278 If @value{tramp} does not receive any messages within a timeout period
279 (a minute, for example), then @value{tramp} responds with an error
280 message about not finding the remote shell prompt. If any messages
281 from the remote host, @value{tramp} displays them in the buffer.
283 For any @samp{login failed} message from the remote host,
284 @value{tramp} aborts the login attempt, and repeats the login steps
288 Upon successful login and @value{tramp} recognizes the shell prompt
289 from the remote host, @value{tramp} prepares the shell environment by
290 turning off echoing, setting shell prompt, and other housekeeping
293 @strong{Note} that for the remote shell, @value{tramp} invokes
294 @command{/bin/sh}. The remote host must recognize @samp{exec /bin/sh}
295 and execute the appropriate shell. This shell must support Bourne
299 @value{tramp} executes @command{cd} and @command{ls} commands to find
300 which files exist on the remote host. @value{tramp} sometimes uses
301 @command{echo} with globbing. @value{tramp} checks if a file or
302 directory is writable with @command{test}. After each command,
303 @value{tramp} parses the output from the remote host for completing
307 After remote file name completion, @value{tramp} transfers the file
308 contents from the remote host.
310 For inline transfers, @value{tramp} sends a command, such as
311 @samp{mimencode -b /path/to/remote/file}, waits until the output has
312 accumulated in the buffer, decodes that output to produce the file's
315 For external transfers, @value{tramp} sends a command as follows:
317 rcp user@@host:/path/to/remote/file /tmp/tramp.4711
319 @value{tramp} reads the local temporary file @file{/tmp/tramp.4711}
320 into a buffer, and then deletes the temporary file.
323 Edit, modify, change the buffer contents as normal, and then save the
324 buffer wth @kbd{C-x C-s}.
327 @value{tramp} transfers the buffer contents to the remote host in
328 a reverse of the process using the appropriate inline or external
332 I hope this has provided you with a basic overview of what happens
333 behind the scenes when you open a file with @value{tramp}.
337 @node Obtaining Tramp
338 @chapter Obtaining @value{tramp}
339 @cindex obtaining Tramp
341 @value{tramp} is included as part of Emacs (since Emacs version 22.1).
343 @value{tramp} is also freely packaged for download on the Internet at
344 @uref{ftp://ftp.gnu.org/gnu/tramp/}.
346 @value{tramp} development versions are available on Git servers.
347 Development versions contain new and incomplete features.
349 One way to obtain from Git server is to visit the Savannah project
350 page at the following URL and then clicking on the Git link in the
351 navigation bar at the top.
354 @uref{http://savannah.gnu.org/projects/tramp/}
357 Another way is to follow the terminal session below:
360 ] @strong{cd ~/emacs}
361 ] @strong{git clone git://git.savannah.gnu.org/tramp.git}
365 From behind a firewall:
368 ] @strong{git config --global http.proxy http://user:pwd@@proxy.server.com:8080}
369 ] @strong{git clone http://git.savannah.gnu.org/r/tramp.git}
376 ] @strong{git clone login@@git.sv.gnu.org:/srv/git/tramp.git}
380 After one of the above commands, @file{~/emacs/tramp} will
381 containing the latest version of @value{tramp}.
384 To fetch updates from the repository, use git pull:
387 ] @strong{cd ~/emacs/tramp}
392 Run @command{autoconf} as follows to generate an up-to-date
393 @file{configure} script:
396 ] @strong{cd ~/emacs/tramp}
402 @chapter History of @value{tramp}
404 @cindex development history
406 @value{tramp} development started at the end of November 1998 as
407 @file{rssh.el}. It provided only one method of access. It used
408 @command{ssh} for login and @command{scp} to transfer file contents.
409 The name was changed to @file{rcp.el} before it got its preset name
410 @value{tramp}. New methods of remote access were added, so was support
413 April 2000 was the first time when multi-hop methods were added. In
414 July 2002, @value{tramp} unified file names with Ange-FTP@. In July
415 2004, proxy hosts replaced multi-hop methods. Running commands on
416 remote hosts was introduced in December 2005. Support for gateways
419 GVFS integration started in February 2009.
421 Remote commands on Windows hosts since September 2011. Ad-hoc
422 multi-hop methods (with a changed syntax) re-enabled in November 2011.
424 In November 2012, added Juergen Hoetzel's @file{tramp-adb.el}.
427 @c Installation chapter is necessary only in case of standalone
428 @c installation. Text taken from trampinst.texi.
429 @ifset installchapter
430 @include trampinst.texi
435 @chapter Configuring @value{tramp}
436 @cindex configuration
437 @cindex default configuration
439 @value{tramp} is initially configured to use the @command{scp} program
440 to connect to the remote host. Just type @kbd{C-x C-f} and then enter
441 file name @file{@trampf{user@@host,/path/to.file}}. For details,
442 see @xref{Default Method}.
444 For problems related to the behavior of remote shell, see @ref{Remote
445 shell setup} for details.
447 For changing the connection type and file access method from the
448 defaults to one of several other options, see (@pxref{Connection
451 @strong{Note} that some user options and variables described in these
452 examples are not auto loaded by Emacs. All examples require
453 @value{tramp} is installed and loaded:
461 * Connection types:: Types of connections to remote hosts.
462 * Inline methods:: Inline methods.
463 * External methods:: External methods.
464 * GVFS based methods:: GVFS based external methods.
465 * Gateway methods:: Gateway methods.
466 * Default Method:: Selecting a default method.
467 Here we also try to help those who
468 don't have the foggiest which method
470 * Default User:: Selecting a default user.
471 * Default Host:: Selecting a default host.
472 * Multi-hops:: Connecting to a remote host using multiple hops.
473 * Customizing Methods:: Using Non-Standard Methods.
474 * Customizing Completion:: Selecting config files for user/host name completion.
475 * Password handling:: Reusing passwords for several connections.
476 * Connection caching:: Reusing connection related information.
477 * Predefined connection information::
478 Setting own connection related information.
479 * Remote programs:: How @value{tramp} finds and uses programs on the remote host.
480 * Remote shell setup:: Remote shell setup hints.
481 * Android shell setup:: Android shell setup hints.
482 * Auto-save and Backup:: Auto-save and Backup.
483 * Windows setup hints:: Issues with Cygwin ssh.
487 @node Connection types
488 @section Types of connections to remote hosts
489 @cindex connection types, overview
491 @dfn{Inline method} and @dfn{external method} are the two basic types
492 of access methods. While they both use the same remote shell access
493 programs, such as @command{rsh}, @command{ssh}, or @command{telnet},
494 they differ in the file access methods. Choosing the right method
495 becomes important for editing files, transferring large files, or
496 operating on a large number of files.
498 @cindex inline methods
499 @cindex external methods
500 @cindex methods, inline
501 @cindex methods, external
503 The performance of the external methods is generally better than that
504 of the inline methods, at least for large files. This is caused by
505 the need to encode and decode the data when transferring inline.
507 The one exception to this rule are the @option{scp}-based access
508 methods. While these methods do see better performance when actually
509 transferring files, the overhead of the cryptographic negotiation at
510 startup may drown out the improvement in file transfer times.
512 External methods should be configured such a way that they don't
513 require a password (with @command{ssh-agent}, or such alike). Modern
514 @command{scp} implementations offer options to reuse existing
515 @command{ssh} connections, which will be enabled by default if
516 available. If it isn't possible, you should consider @ref{Password
517 handling}, otherwise you will be prompted for a password every copy
522 @section Inline methods
523 @cindex inline methods
524 @cindex methods, inline
526 Inline methods use the same login connection to transfer file
527 contents. Inline methods are quick and easy for small files. They
528 depend on the availability of suitable encoding and decoding programs
529 on the remote host. For local source and destination, @value{tramp}
530 may use built-in equivalents of such programs in Emacs.
532 Inline methods can work in situations where an external transfer
533 program is unavailable. Inline methods also work when transferring
534 files between different @emph{user identities} on the same host.
538 @cindex base-64 encoding
540 @value{tramp} checks the remote host for the availability and
541 usability of @command{mimencode} (part of the @command{metamail}
542 package) or @command{uuencode}. @value{tramp} uses the first reliable
543 command it finds. @value{tramp}'s search path can be customized, see
544 @ref{Remote programs}.
546 In case both @command{mimencode} and @command{uuencode} are
547 unavailable, @value{tramp} first transfers a small Perl program to the
548 remote host, and then tries that program for encoding and decoding.
550 To increase transfer speeds for large text files, use compression
551 before encoding. The variable @var{tramp-inline-compress-start-size}
552 specifies the file size for such optimization.
559 @command{rsh} is an option for connecting to hosts within local
560 networks since @command{rsh} is not as secure as other methods.
566 @command{ssh} is a more secure option than others to connect to a
569 @command{ssh} can also take extra parameters as port numbers. For
570 example, a host on port 42 is specified as @file{host#42} (the real
571 host name, a hash sign, then a port number). It is the same as passing
572 @code{-p 42} to the @command{ssh} command.
574 @item @option{telnet}
575 @cindex method telnet
576 @cindex telnet method
578 Connecting to a remote host with @command{telnet} is as insecure
579 as the @option{rsh} method.
585 Instead of connecting to a remote host, @command{su} program allows
586 editing as another user. The host can be either @samp{localhost} or
587 the host returned by the function @command{(system-name)}. See
588 @ref{Multi-hops} for an exception to this behavior.
594 Similar to @option{su} method, @option{sudo} uses @command{sudo}.
595 @command{sudo} must have sufficient rights to start a shell.
601 The @command{sg} program allows editing as different group. The host
602 can be either @samp{localhost} or the host returned by the function
603 @command{(system-name)}. The user name must be specified, but it
604 denotes a group name. See @ref{Multi-hops} for an exception to this
611 Works like @option{ssh} but without the extra authentication prompts.
612 @option{sshx} uses @samp{ssh -t -t @var{host} -l @var{user} /bin/sh}
613 to open a connection with a ``standard'' login shell.
615 @strong{Note} that @option{sshx} does not bypass authentication
616 questions. For example, if the host key of the remote host is not
617 known, @option{sshx} will still ask ``Are you sure you want to
618 continue connecting?''. @value{tramp} cannot handle such questions.
619 Connections will have to be setup where logins can proceed without
622 @option{sshx} is useful for Windows users when @command{ssh} triggers
623 an error about allocating a pseudo tty. This happens due to missing
624 shell prompts that confuses @value{tramp}.
626 @option{sshx} supports the @samp{-p} argument.
628 @item @option{krlogin}
629 @cindex method krlogin
630 @cindex krlogin method
631 @cindex Kerberos (with krlogin method)
633 This method is also similar to @option{ssh}. It uses the
634 @command{krlogin -x} command only for remote host login.
639 @cindex Kerberos (with ksu method)
641 This is another method from the Kerberos suite. It behaves like @option{su}.
647 @option{plink} method is for Windows users with the PuTTY
648 implementation of SSH@. It uses @samp{plink -ssh} to log in to the
651 Check the @samp{Share SSH connections if possible} control for that
654 @option{plink} method supports the @samp{-P} argument.
656 @item @option{plinkx}
657 @cindex method plinkx
658 @cindex plinkx method
660 Another method using PuTTY on Windows with session names instead of
661 host names. @option{plinkx} calls @samp{plink -load @var{session} -t}.
662 User names and port numbers must be defined in the session.
664 Check the @samp{Share SSH connections if possible} control for that
670 @node External methods
671 @section External methods
672 @cindex methods, external
673 @cindex external methods
675 External methods operate over multiple channels, using the remote
676 shell connection for some actions while delegating file transfers to
677 an external transfer program.
679 External methods save on the overhead of encoding and decoding of
682 Since external methods have the overhead of opening a new channel,
683 files smaller than @var{tramp-copy-size-limit} still use inline
687 @item @option{rcp}---@command{rsh} and @command{rcp}
690 @cindex rcp (with rcp method)
691 @cindex rsh (with rcp method)
693 This method uses the @command{rsh} and @command{rcp} commands to
694 connect to the remote host and transfer files. This is the fastest
695 access method available.
697 The alternative method @option{remcp} uses the @command{remsh} and
698 @command{rcp} commands.
700 @item @option{scp}---@command{ssh} and @command{scp}
703 @cindex scp (with scp method)
704 @cindex ssh (with scp method)
706 Using a combination of @command{ssh} to connect and @command{scp} to
707 transfer is the most secure. While the performance is good, it is
708 slower than the inline methods for smaller files. Though there is no
709 overhead of encoding and decoding of the inline methods,
710 @command{scp}'s cryptographic handshake negates those speed gains.
712 @option{ssh}-based methods support @samp{-p} feature for specifying
713 port numbers. For example, @file{host#42} passes @samp{-p 42} in the
714 argument list to @command{ssh}, and @samp{-P 42} in the argument list
717 @item @option{rsync}---@command{ssh} and @command{rsync}
720 @cindex rsync (with rsync method)
721 @cindex ssh (with rsync method)
723 @command{ssh} command to connect in combination with @command{rsync}
724 command to transfer is similar to the @option{scp} method.
726 @command{rsync} performs much better than @command{scp} when
727 transferring files that exist on both hosts. However, this advantage
728 is lost if the file exists only on one side of the connection.
730 This method supports the @samp{-p} argument.
732 @item @option{scpx}---@command{ssh} and @command{scp}
735 @cindex scp (with scpx method)
736 @cindex ssh (with scpx method)
738 @option{scpx} is useful to avoid login shell questions. It is similar
739 in performance to @option{scp}. @option{scpx} uses @samp{ssh -t -t
740 @var{host} -l @var{user} /bin/sh} to open a connection.
742 @option{sshx} is useful for Windows users when @command{ssh} triggers
743 an error about allocating a pseudo tty. This happens due to missing
744 shell prompts that confuses @value{tramp}.
746 This method supports the @samp{-p} argument.
748 @item @option{pscp}---@command{plink} and @command{pscp}
749 @item @option{psftp}---@command{plink} and @command{psftp}
752 @cindex pscp (with pscp method)
753 @cindex plink (with pscp method)
754 @cindex PuTTY (with pscp method)
757 @cindex pscp (with psftp method)
758 @cindex plink (with psftp method)
759 @cindex PuTTY (with psftp method)
761 These methods are similar to @option{scp} or @option{sftp}, but they
762 use the @command{plink} command to connect to the remote host, and
763 they use @command{pscp} or @command{psftp} for transferring the files.
764 These programs are part of PuTTY, an SSH implementation for Windows.
766 Check the @samp{Share SSH connections if possible} control for that
769 These methods support the @samp{-P} argument.
771 @item @option{fcp}---@command{fsh} and @command{fcp}
774 @cindex fsh (with fcp method)
775 @cindex fcp (with fcp method)
777 This method is similar to @option{scp}, but uses @command{fsh} to
778 connect and @command{fcp} to transfer files. @command{fsh/fcp}, a
779 front-end for @command{ssh}, reuse @command{ssh} session by
780 submitting several commands. This avoids the startup overhead due to
781 @command{scp}'s secure connection. Inline methods have similar
784 The command used for this connection is: @samp{fsh @var{host} -l
785 @var{user} /bin/sh -i}
790 @option{fsh} has no inline method since the multiplexing it offers is
791 not useful for @value{tramp}. @command{fsh} connects to remote host
792 and @value{tramp} keeps that one connection open.
794 @item @option{nc}---@command{telnet} and @command{nc}
797 @cindex nc (with nc method)
798 @cindex telnet (with nc method)
800 Using @command{telnet} to connect and @command{nc} to transfer files
801 is sometimes the only combination suitable for accessing routers or
802 NAS hosts. These dumb devices have severely restricted local shells,
803 such as the @command{busybox} and do not host any other encode or
810 When @value{tramp} uses @option{ftp}, it forwards requests to whatever
811 ftp program is specified by Ange FTP. This external program must be
812 capable of servicing requests from @value{tramp}.
814 @item @option{smb}---@command{smbclient}
818 This non-native @value{tramp} method connects via the Server Message
819 Block (SMB) networking protocol to hosts running file servers that are
820 typically based on @url{https://www.samba.org/,,Samba} or MS Windows.
822 Using @command{smbclient} requires a few tweaks when working with
825 The first directory in the localname must be a share name on the
828 Since SMB shares end in the @code{$} character, @value{tramp} must use
829 @code{$$} when specifying those shares to avoid environment variable
832 When @value{tramp} is not specific about the share name or uses the
833 generic remote directory @code{/}, @command{smbclient} returns all
836 Since SMB authentication is based on each SMB share, @value{tramp}
837 prompts for a password even when accessing a different share on the
838 same SMB host. This prompting can be suppressed by @ref{Password
841 To accommodate user name/domain name syntax required by MS Windows
842 authorization, @value{tramp} provides for an extended syntax in
843 @code{user%domain} format (where user is username, @code{%} is the
844 percent symbol, and domain is the windows domain name). An example:
847 @trampfn{smb,daniel%BIZARRE@@melancholia,/daniel$$/.emacs}
850 where user @code{daniel} connects as a domain user to the SMB host
851 @code{melancholia} in the windows domain @code{BIZARRE} to edit
852 @file{.emacs} located in the home directory (share @code{daniel$}).
854 Alternatively, for local WINS users (as opposed to domain users),
855 substitute the domain name with the name of the local host in
856 UPPERCASE as shown here:
859 @trampfn{smb,daniel%MELANCHOLIA@@melancholia,/daniel$$/.emacs}
862 where user @code{daniel} connects as local user to the SMB host
863 @code{melancholia} in the local domain @code{MELANCHOLIA} to edit
864 @file{.emacs} located in the home directory (share @code{daniel$}).
866 The domain name and user name are optional for @command{smbclient}
867 authentication. When user name is not specified, @command{smbclient}
868 uses the anonymous user (without prompting for password). This
869 behavior is unlike other @value{tramp} methods, where local user name
872 The @option{smb} method is unavailable if Emacs is run under a
873 local user authentication context in MS Windows. However such users
874 can still access remote files using UNC file names instead of @value{tramp}:
877 //melancholia/daniel$$/.emacs
880 UNC file name specification does not allow the specification of a
881 different user name for authentication like the @command{smbclient}
888 This method uses Android Debug Bridge program for accessing Android
889 devices. The Android Debug Bridge must be installed locally for
890 @value{tramp} to work. Some GNU/Linux distributions provide Android
891 Debug Bridge as an installation package. Alternatively, the program is
892 installed as part of the Android SDK@. @value{tramp} finds the
893 @command{adb} program either via the @env{PATH} environment variable
894 or the absolute path set in the variable @var{tramp-adb-program}.
896 @value{tramp} connects to Android devices with @option{adb} only when
897 the custom option @option{tramp-adb-connect-if-not-connected} is not
898 @code{nil}. Otherwise, the connection must be established outside
901 @value{tramp} does not require a host name part of the remote file
902 name when a single Android device is connected to @command{adb}.
903 @value{tramp} instead uses @file{@trampfn{adb,,}} as the default
904 name. @command{adb devices} shows available host names.
906 @option{adb} method normally does not need user name to authenticate
907 on the Andriod device because it runs under the @command{adbd}
908 process. But when a user name is specified, however, @value{tramp}
909 applies an @command{su} in the syntax. When authentication does not
910 succeed, especially on un-rooted Android devices, @value{tramp}
911 displays login errors.
913 For Andriod devices connected through TCP/IP, a port number can be
914 specified using @file{device#42} host name syntax or @value{tramp} can
915 use the default value as declared in @command{adb} command. Port
916 numbers are not applicable to Android devices connected through USB@.
922 @node GVFS based methods
923 @section GVFS based external methods
924 @cindex methods, gvfs
925 @cindex gvfs based methods
928 GVFS is the virtual file system for the Gnome Desktop,
929 @uref{http://en.wikipedia.org/wiki/GVFS}. Remote files on GVFS are
930 mounted locally through FUSE and @value{tramp} uses this locally
931 mounted directory internally.
933 Emacs uses the D-Bus mechanism to communicate with GVFS@. Emacs must
934 have the message bus system, D-Bus integration active, @pxref{Top, ,
942 This method is for connecting to remote hosts with the Apple Filing
943 Protocol for accessing files on Mac OS X volumes. @value{tramp} access
944 syntax requires a leading volume (share) name, for example:
945 @file{@trampfn{afp,user@@host,/volume}}.
954 @option{dav} method provides access to WebDAV files and directories
955 based on standard protocols, such as HTTP@. @option{davs} does the same
956 but with SSL encryption. Both methods support the port numbers.
962 OBEX is an FTP-like access protocol for cell phones and similar simple
963 devices. @value{tramp} supports OBEX over Bluetooth.
969 This method uses @command{sftp} in order to securely access remote
970 hosts. @command{sftp} is a more secure option for connecting to hosts
971 that for security reasons refuse @command{ssh} connections.
977 @option{synce} method allows connecting to Windows Mobile devices. It
978 uses GVFS for mounting remote files and directories via FUSE and
979 requires the SYNCE-GVFS plugin.
983 @defopt tramp-gvfs-methods
984 @vindex tramp-gvfs-methods
985 This custom option is a list of external methods for GVFS@. By
986 default, this list includes @option{afp}, @option{dav}, @option{davs},
987 @option{obex}, @option{sftp} and @option{synce}. Other methods to
988 include are: @option{ftp} and @option{smb}.
993 @node Gateway methods
994 @section Gateway methods
995 @cindex methods, gateway
996 @cindex gateway methods
998 Gateway methods are for proxy host declarations (@pxref{Multi-hops})
999 so as to pass through firewalls and proxy servers. They are not like
1000 the other methods that declare direct connections to a remote host.
1002 A gateway method always comes with a port setting. @value{tramp}
1003 targets the port number with the gateway method
1004 @file{localhost#random_port} from where the firewall or proxy server
1007 Gateway methods support user name and password declarations for
1008 authenticating the corresponding firewall or proxy server. Such
1009 authentication can be passed through only if granted access by system
1013 @item @option{tunnel}
1014 @cindex method tunnel
1015 @cindex tunnel method
1017 This method implements an HTTP tunnel via the @command{CONNECT}
1018 command (conforming to RFC 2616, 2817 specifications). Proxy servers
1019 using HTTP version 1.1 or later protocol support this command.
1021 For authentication, this protocol uses only @option{Basic
1022 Authentication} (see RFC 2617). When no port number is specified, this
1023 protocol defaults to @option{8080}.
1025 @item @option{socks}
1026 @cindex method socks
1027 @cindex socks method
1029 The @option{socks} method connects to SOCKSv5 servers (see RFC 1928)
1030 and supports @option{Username/Password Authentication}.
1032 The default port number for the socks server is @option{1080}, if not
1033 specified otherwise.
1038 @node Default Method
1039 @section Selecting a default method
1040 @cindex default method
1041 @vindex tramp-default-method
1042 @vindex tramp-default-method-alist
1044 Default method is for transferring files. The variable
1045 @code{tramp-default-method} sets it. @value{tramp} uses this variable
1046 to determine the default method for tramp file names that do not have
1050 (setq tramp-default-method "ssh")
1053 Default methods for transferring files can be customized for specific
1054 user and host combinations through the alist variable
1055 @code{tramp-default-method-alist}.
1057 For example, the following two lines specify to use the @option{ssh}
1058 method for all user names matching @samp{john} and the @option{rsync}
1059 method for all host names matching @samp{lily}. The third line
1060 specifies to use the @option{su} method for the user @samp{root} on
1061 the host @samp{localhost}.
1064 (add-to-list 'tramp-default-method-alist '("" "john" "ssh"))
1065 (add-to-list 'tramp-default-method-alist '("lily" "" "rsync"))
1066 (add-to-list 'tramp-default-method-alist
1067 '("\\`localhost\\'" "\\`root\\'" "su"))
1071 See the documentation for the variable
1072 @code{tramp-default-method-alist} for details.
1075 External methods performance faster for large files.
1078 @xref{Inline methods}.
1079 @xref{External methods}.
1081 Choosing the access method also depends on the security environment.
1082 For example, @option{rsh} and @option{telnet} methods that use clear
1083 text password transfers are inappropriate for over the Internet
1084 connections. Secure remote connections should use @option{ssh} that
1088 @subsection Which method to use?
1089 @cindex choosing the right method
1091 @value{tramp} provides maximum number of choices for maximum
1092 flexibility. Choosing which method depends on the hosts, clients,
1093 network speeds, and the security context.
1095 Start by using an inline method.
1097 External methods might be more efficient for large files, but most
1098 @value{tramp} users edit small files more often than large files.
1100 Enable compression, @var{tramp-inline-compress-start-size}, for a
1101 performance boost for large files.
1103 Since @command{ssh} has become the most common method of remote host
1104 access and it has the most reasonable security protocols, use
1105 @option{ssh} method. Typical @option{ssh} usage to edit the
1106 @file{/etc/motd} file on the otherhost:
1109 @kbd{C-x C-f @trampfn{ssh,root@@otherhost,/etc/motd} @key{RET}}
1112 If @option{ssh} is unavailable for whatever reason, look for other
1113 obvious options. For Windows, try the @option{plink} method. For
1114 Kerberos, try @option{krlogin}.
1116 For editing local files as @option{su} or @option{sudo} methods, try
1117 the shortened syntax of @samp{root}:
1120 @kbd{C-x C-f @trampfn{su,,/etc/motd} @key{RET}}
1123 For editing large files, @option{scp} is faster than @option{ssh}.
1124 @option{pscp} is faster than @option{plink}. But this speed
1125 improvement is not always true.
1129 @section Selecting a default user
1130 @cindex default user
1131 @vindex tramp-default-user
1132 @vindex tramp-default-user-alist
1134 @value{tramp} file name can omit the user name part since
1135 @value{tramp} substitutes the currently logged-in user name. However
1136 this substitution can be overridden with @code{tramp-default-user}.
1140 (setq tramp-default-user "root")
1143 Instead of a single default user, @code{tramp-default-user-alist}
1144 allows multiple default user values based on access method or host
1145 name combinations. The alist can hold multiple values. For example, to
1146 use the @samp{john} as the default user for the domain
1147 @samp{somewhere.else} only:
1150 (add-to-list 'tramp-default-user-alist
1151 '("ssh" ".*\\.somewhere\\.else\\'" "john"))
1155 See the documentation for the variable @code{tramp-default-user-alist}
1158 A Caution: @value{tramp} will override any default user specified in
1159 the configuration files outside Emacs, such as @file{~/.ssh/config}.
1160 To stop @value{tramp} from applying the default value, set the
1161 corresponding alist entry to nil:
1164 (add-to-list 'tramp-default-user-alist
1165 '("ssh" "\\`here\\.somewhere\\.else\\'" nil))
1168 The last entry in @code{tramp-default-user-alist} should be reserved
1169 for catch-all or most often used login.
1172 (add-to-list 'tramp-default-user-alist
1173 '(nil nil "jonas") t)
1178 @section Selecting a default host
1179 @cindex default host
1180 @vindex tramp-default-host
1181 @vindex tramp-default-host-alist
1183 When host name is omitted, @value{tramp} substitutes the value from
1184 the @code{tramp-default-host} variable. It is initially populated
1185 with the local hostname where Emacs is running. Both the default user
1186 and default host can be overridden as follows:
1189 (setq tramp-default-user "john"
1190 tramp-default-host "target")
1193 With both defaults set, @samp{@trampfn{ssh,,}} will connect
1194 @value{tramp} to John's home directory on target.
1196 @strong{Note} @samp{/::} won't work, because @samp{/:} is the prefix
1197 for quoted file names.
1199 Instead of a single default host, @code{tramp-default-host-alist}
1200 allows multiple default host values based on access method or user
1201 name combinations. The alist can hold multiple values. While
1202 @code{tramp-default-host} is sufficient in most cases, some methods,
1203 like @option{adb}, require defaults overwritten.
1206 See the documentation for the variable @code{tramp-default-host-alist}
1211 @section Connecting to a remote host using multiple hops
1215 Multi-hops are methods to reach hosts behind firewalls or to reach the
1216 outside world from inside a bastion host. With multi-hops,
1217 @value{tramp} can negotiate these hops with the appropriate user/host
1218 authentication at each hop. All methods until now have been the single
1219 hop kind, where the start and end points of the connection did not
1220 have intermediate check points.
1222 @defopt tramp-default-proxies-alist
1223 @vindex tramp-default-proxies-alist
1224 @option{tramp-default-proxies-alist} specifies proxy hosts to pass
1225 through. This variable is list of triples consisting of (@var{host}
1226 @var{user} @var{proxy}).
1228 The first match is the proxy host through which passes the file name
1229 and the target host matching @var{user}@@@var{host}. @var{host} and
1230 @var{user} are regular expressions or @code{nil}, interpreted as a
1231 regular expression which always matches.
1233 @var{proxy} is a literal @value{tramp} file name whose local name part
1234 is ignored, and the method and user name parts are optional.
1236 The method must be an inline or gateway method (@pxref{Inline
1237 methods}, @pxref{Gateway methods}).
1238 If @var{proxy} is @code{nil}, no additional hop is required reaching
1239 @var{user}@@@var{host}.
1241 For example, to pass through the host @samp{bastion.your.domain} as
1242 user @samp{bird} to reach remote hosts outside the local domain:
1245 (add-to-list 'tramp-default-proxies-alist
1246 '("\\." nil "@trampfn{ssh,bird@@bastion.your.domain,}"))
1247 (add-to-list 'tramp-default-proxies-alist
1248 '("\\.your\\.domain\\'" nil nil))
1251 @strong{Note}: @code{add-to-list} adds elements at the beginning of a
1252 list. Therefore, most relevant rules must come last in the list.
1254 Proxy hosts can be cascaded in the alist. If there is another host
1255 called @samp{jump.your.domain}, which is the only host allowed to
1256 connect to @samp{bastion.your.domain}, then:
1259 (add-to-list 'tramp-default-proxies-alist
1260 '("\\`bastion\\.your\\.domain\\'"
1262 "@trampfn{ssh,jump.your.domain,}"))
1265 @var{proxy} can take patterns @code{%h} or @code{%u} for @var{host} or
1266 @var{user} respectively.
1268 To login as @samp{root} on remote hosts in the domain
1269 @samp{your.domain}, but login as @samp{root} is disabled for non-local
1270 access, then use this alist entry:
1273 (add-to-list 'tramp-default-proxies-alist
1274 '("\\.your\\.domain\\'" "\\`root\\'" "@trampfn{ssh,%h,}"))
1277 Opening @file{@trampfn{sudo,randomhost.your.domain,}} first
1278 connects to @samp{randomhost.your.domain} via @code{ssh} under your
1279 account name, and then perform @code{sudo -u root} on that host.
1281 It is key for the sudo method in the above example to be applied on
1282 the host after reaching it and not on the local host.
1284 @var{host}, @var{user} and @var{proxy} can also take Lisp forms. These
1285 forms when evaluated must return either a string or @code{nil}.
1287 To generalize (from the previous example): For all hosts, except my
1288 local one, first connect via @command{ssh}, and then apply
1289 @command{sudo -u root}:
1292 (add-to-list 'tramp-default-proxies-alist
1293 '(nil "\\`root\\'" "@trampfn{ssh,%h,}"))
1294 (add-to-list 'tramp-default-proxies-alist
1295 '((regexp-quote (system-name)) nil nil))
1298 The above configuration allows @value{tramp} connection as @samp{root}
1299 to remote Ubuntu hosts.
1301 @code{tramp-default-proxies-alist} is also used for passing through
1302 firewalls or proxy servers.
1304 For example, the local host @samp{proxy.your.domain} on port 3128
1305 serves as HTTP proxy to the outer world. User has access rights to
1306 another proxy server on @samp{host.other.domain}.@footnote{HTTP tunnels
1307 are intended for secure SSL/TLS communication. Therefore, many proxy
1308 servers restrict the tunnels to related target ports. You might need
1309 to run your ssh server on your target host @samp{host.other.domain} on
1310 such a port, like 443 (https). See
1311 @uref{http://savannah.gnu.org/maintenance/CvsFromBehindFirewall} for
1312 discussion of ethical issues.} Then the configuration is:
1315 (add-to-list 'tramp-default-proxies-alist
1316 '("\\`host\\.other\\.domain\\'" nil
1317 "@trampfn{tunnel,proxy.your.domain#3128,}"))
1320 Gateway methods in a multiple hop chain can be declared only as the first hop.
1323 Passing through hops involves dealing with restricted shells, such as
1324 @command{rbash}. If @value{tramp} is made aware, then it would use
1325 them for proxies only.
1327 @defopt tramp-restricted-shell-hosts-alist
1328 @vindex tramp-restricted-shell-hosts-alist
1329 An alist of regular expressions of hosts running restricted shells,
1330 such as @command{rbash}. @value{tramp} will then use them only as
1333 To specify the bastion host from the example above as running a
1337 (add-to-list 'tramp-restricted-shell-hosts-alist
1338 "\\`bastion\\.your\\.domain\\'")
1343 @node Customizing Methods
1344 @section Using Non-Standard Methods
1345 @cindex customizing methods
1346 @cindex using non-standard methods
1347 @cindex create your own methods
1349 The @code{tramp-methods} variable currently has an exhaustive list of
1350 predefined methods. Any part of this list can be modified with more
1351 suitable settings. Refer to the Lisp documentation of that variable,
1352 accessible with @kbd{C-h v tramp-methods @key{RET}}.
1355 @node Customizing Completion
1356 @section Selecting config files for user/host name completion
1357 @cindex customizing completion
1358 @cindex selecting config files
1359 @vindex tramp-completion-function-alist
1361 @code{tramp-completion-function-alist} uses predefined files for user
1362 and host name completion (@pxref{File name completion}). For each
1363 method, it keeps a set of configuration files and a function that can
1364 parse that file. Each entry in @code{tramp-completion-function-alist}
1365 is of the form (@var{method} @var{pair1} @var{pair2} @dots{}).
1367 Each @var{pair} is composed of (@var{function} @var{file}).
1368 @var{function} is responsible for extracting user names and host names
1369 from @var{file} for completion. There are two functions which access
1372 @defun tramp-get-completion-function method
1373 This function returns the list of completion functions for @var{method}.
1377 (tramp-get-completion-function "rsh")
1379 @result{} ((tramp-parse-rhosts "/etc/hosts.equiv")
1380 (tramp-parse-rhosts "~/.rhosts"))
1384 @defun tramp-set-completion-function method function-list
1385 This function sets @var{function-list} as list of completion functions
1390 (tramp-set-completion-function "ssh"
1391 '((tramp-parse-sconfig "/etc/ssh_config")
1392 (tramp-parse-sconfig "~/.ssh/config")))
1394 @result{} ((tramp-parse-sconfig "/etc/ssh_config")
1395 (tramp-parse-sconfig "~/.ssh/config"))
1399 The following predefined functions parsing configuration files exist:
1402 @item @code{tramp-parse-rhosts}
1403 @findex tramp-parse-rhosts
1405 This function parses files which are syntactical equivalent to
1406 @file{~/.rhosts}. It returns both host names and user names, if
1409 @item @code{tramp-parse-shosts}
1410 @findex tramp-parse-shosts
1412 This function parses files which are syntactical equivalent to
1413 @file{~/.ssh/known_hosts}. Since there are no user names specified
1414 in such files, it can return host names only.
1416 @item @code{tramp-parse-sconfig}
1417 @findex tramp-parse-shosts
1419 This function returns the host nicknames defined by @code{Host} entries
1420 in @file{~/.ssh/config} style files.
1422 @item @code{tramp-parse-shostkeys}
1423 @findex tramp-parse-shostkeys
1425 SSH2 parsing of directories @file{/etc/ssh2/hostkeys/*} and
1426 @file{~/ssh2/hostkeys/*}. Hosts are coded in file names
1427 @file{hostkey_@var{portnumber}_@var{host-name}.pub}. User names
1428 are always @code{nil}.
1430 @item @code{tramp-parse-sknownhosts}
1431 @findex tramp-parse-shostkeys
1433 Another SSH2 style parsing of directories like
1434 @file{/etc/ssh2/knownhosts/*} and @file{~/ssh2/knownhosts/*}. This
1435 case, hosts names are coded in file names
1436 @file{@var{host-name}.@var{algorithm}.pub}. User names are always @code{nil}.
1438 @item @code{tramp-parse-hosts}
1439 @findex tramp-parse-hosts
1441 A function dedicated to @file{/etc/hosts} for host names.
1443 @item @code{tramp-parse-passwd}
1444 @findex tramp-parse-passwd
1446 A function which parses @file{/etc/passwd} files for user names.
1448 @item @code{tramp-parse-etc-group}
1449 @findex tramp-parse-etc-group
1451 A function which parses @file{/etc/group} files for group names.
1453 @item @code{tramp-parse-netrc}
1454 @findex tramp-parse-netrc
1456 A function which parses @file{~/.netrc} and @file{~/.authinfo}-style files.
1460 To keep a custom file with custom data in a custom structure, a custom
1461 function has to be provided. This function must meet the following
1464 @defun my-tramp-parse file
1465 @var{file} must be either a file on the host, or @code{nil}. The
1466 function must return a list of (@var{user} @var{host}), which are
1467 taken as candidates for completion for user and host names.
1471 (my-tramp-parse "~/.my-tramp-hosts")
1473 @result{} ((nil "toto") ("daniel" "melancholia"))
1478 @node Password handling
1479 @section Reusing passwords for several connections
1482 To avoid repeated prompts for passwords, consider native caching
1483 mechanisms, such as @command{ssh-agent} for @option{ssh}-like
1484 methods, or @command{pageant} for @option{plink}-like methods.
1486 @value{tramp} offers alternatives when native solutions cannot meet
1490 @anchor{Using an authentication file}
1491 @subsection Using an authentication file
1492 @vindex auth-sources
1494 The package @file{auth-source.el}, originally developed for No Gnus,
1495 reads passwords from different sources, @xref{Help for users, ,
1496 auth-source, auth}. The default authentication file is
1497 @file{~/.authinfo.gpg}, but this can be changed via the variable
1498 @code{auth-sources}.
1501 A typical entry in the authentication file:
1504 machine melancholia port scp login daniel password geheim
1507 The port can take any @value{tramp} method (@pxref{Inline methods},
1508 @pxref{External methods}). Omitting port values matches all
1509 @value{tramp} methods.
1511 Setting @code{auth-source-debug} to @code{t} to debug messages.
1514 @anchor{Caching passwords}
1515 @subsection Caching passwords
1517 @value{tramp} can cache passwords as entered and reuse when needed for
1518 the same user or host name independent of the access method.
1520 @vindex password-cache-expiry
1522 @code{password-cache-expiry} sets the duration (in seconds) the
1523 passwords are remembered. Passwords are never saved permanently nor
1524 can they extend beyond the lifetime of the current Emacs session. Set
1525 @code{password-cache-expiry} to @code{nil} to disable expiration.
1527 @vindex password-cache
1529 Set @code{password-cache} to @code{nil} to disable password caching.
1531 @strong{Implementation Note}: password caching depends on
1532 @file{password-cache.el} package. @value{tramp} activates password
1533 caching only if @value{tramp} can discover, while Emacs is loading,
1534 the package through @code{load-path}.
1536 @ifset installchapter
1537 @file{password.el} is available from No Gnus or from the @value{tramp}
1538 @file{contrib} directory, see @ref{Installation parameters}.
1542 @node Connection caching
1543 @section Reusing connection related information
1545 @vindex tramp-persistency-file-name
1547 For faster initial connection times, @value{tramp} stores previous
1548 connection properties in a file specified by the variable
1549 @code{tramp-persistency-file-name}.
1551 The default file name for @code{tramp-persistency-file-name} is
1552 @file{~/.emacs.d/tramp}.
1554 @value{tramp} reads this file during Emacs startup, and writes to it
1555 when exiting Emacs. Delete this file for @value{tramp} to recreate a
1556 new one on next Emacs startup.
1558 Set @code{tramp-persistency-file-name} to @code{nil} to disable
1559 storing connections persistently.
1561 To reuse connection information from the persistent list,
1562 @value{tramp} needs to uniquely identify every host. However in some
1563 cases, two different connections may result in the same persistent
1564 information. For example, connecting to a host using @command{ssh} and
1565 connecting to the same host through @code{sshd} on port 3001. Both
1566 access methods result in nearly identical persistent specifications
1567 @file{@trampfn{ssh,localhost,}} and @file{@trampfn{ssh,localhost#3001,}}.
1569 Changing host names could avoid duplicates. One way is to add a
1570 @option{Host} section in @file{~/.ssh/config} (@pxref{Frequently Asked
1571 Questions}). Another way is to apply multiple hops (@pxref{Multi-hops}).
1573 When @value{tramp} detects a change in the operating system version in
1574 a remote host (via the command @command{uname -sr}), it flushes all
1575 connection related information for that host and creates a new entry.
1578 @node Predefined connection information
1579 @section Setting own connection related information
1580 @vindex tramp-connection-properties
1582 For more precise customization, parameters specified by
1583 @code{tramp-methods} can be overwritten manually.
1585 Set @code{tramp-connection-properties} to manually override
1586 @code{tramp-methods}. Properties in this list are in the form
1587 @code{(@var{regexp} @var{property} @var{value})}. @var{regexp} matches
1588 remote file names. Use @code{nil} to match all. @var{property} is the
1589 property's name, and @var{value} is the property's value.
1591 @var{property} is any method specific parameter contained in
1592 @code{tramp-methods}. The parameter key in @code{tramp-methods} is a
1593 symbol name @code{tramp-<foo>}. To overwrite that property, use the
1594 string @samp{<foo>} for @var{property}. For example, this changes the
1598 (add-to-list 'tramp-connection-properties
1599 (list (regexp-quote "@trampfn{ssh,user@@randomhost.your.domain,}")
1600 "remote-shell" "/bin/ksh"))
1601 (add-to-list 'tramp-connection-properties
1602 (list (regexp-quote "@trampfn{ssh,user@@randomhost.your.domain,}")
1603 "remote-shell-login" '("-")))
1606 The parameters @code{tramp-remote-shell} and
1607 @code{tramp-remote-shell-login} in @code{tramp-methods} now have new
1608 values for the remote host.
1610 @var{property} could also be any property found in
1611 @code{tramp-persistency-file-name}.
1613 To get around how restricted shells randomly drop connections, set the
1614 special property @samp{busybox}. For example:
1617 (add-to-list 'tramp-connection-properties
1618 (list (regexp-quote "@trampfn{ssh,user@@randomhost.your.domain,}")
1623 @node Remote programs
1624 @section How @value{tramp} finds and uses programs on the remote host
1626 @value{tramp} requires access to and rights to several commands on
1627 remote hosts: @command{ls}, @command{test}, @command{find} and
1630 Besides there are other required programs for @ref{Inline methods} and
1631 @ref{External methods} of connection.
1633 To improve performance and accuracy of remote file access,
1634 @value{tramp} uses @command{perl} (or @command{perl5}) and
1635 @command{grep} when available.
1637 @defopt tramp-remote-path
1638 @vindex tramp-remote-path
1639 @vindex tramp-default-remote-path
1640 @vindex tramp-own-remote-path
1641 @option{tramp-remote-path} specifies which remote directory paths
1642 @value{tramp} can search for @ref{Remote programs}.
1644 @value{tramp} uses standard defaults, such as @file{/bin} and
1645 @file{/usr/bin}, which are reasonable for most hosts. To accommodate
1646 differences in hosts and paths, for example, @file{/bin:/usr/bin} on
1648 @file{/usr/xpg4/bin:/usr/ccs/bin:/usr/bin:/opt/SUNWspro/bin} on
1649 Solaris, @value{tramp} queries the remote host with @command{getconf
1650 PATH} and updates the symbol @code{tramp-default-remote-path}.
1652 For instances where hosts keep obscure locations for paths for
1653 security reasons, manually add such paths to local @file{.emacs} as
1654 shown below for @value{tramp} to use when connecting.
1657 (add-to-list 'tramp-remote-path "/usr/local/perl/bin")
1660 Another way to find the remote path is to use the path assigned to the
1661 remote user by the remote host. @value{tramp} does not normally retain
1662 this remote path after logging. However, @code{tramp-own-remote-path}
1663 preserves the path value, which can be used to update
1664 @code{tramp-remote-path}.
1667 (add-to-list 'tramp-remote-path 'tramp-own-remote-path)
1671 When remote search paths are changed, local @value{tramp} caches must
1672 be recomputed. To force @value{tramp} to recompute afresh, exit
1673 Emacs, remove the persistent file (@pxref{Connection caching}), and
1677 @node Remote shell setup
1678 @section Remote shell setup hints
1679 @cindex remote shell setup
1680 @cindex @file{.profile} file
1681 @cindex @file{.login} file
1682 @cindex shell init files
1684 @value{tramp} checks for the availability of standard programs in the
1685 usual locations. Common tactics include successively trying
1686 @command{test -e}, @command{/usr/bin/test -e}, and @command{/bin/test
1687 -e}. @command{ls -d} is another approach. But these approaches do not
1688 help with these new login patterns.
1690 When @value{tramp} encounters two-factor logins or additional challenge
1691 questions, such as entering birth date or security code or passphrase,
1692 @value{tramp} needs a few more configuration steps to accommodate
1695 The difference between a password prompt and a passphrase prompt is
1696 that the password for completing the login while the passphrase is
1697 for authorizing access to local authentication information, such as
1700 There is no one configuration to accommodate all the variations in
1701 login security, especially not the exotic ones. However, @value{tramp}
1702 provides a few tweaks to address the most common ones.
1705 @item @var{tramp-shell-prompt-pattern}
1706 @vindex tramp-shell-prompt-pattern
1708 @code{tramp-shell-prompt-pattern} is for remote login shell prompt,
1709 which may not be the same as the local login shell prompt,
1710 @code{shell-prompt-pattern}. Since most hosts use identical prompts,
1711 @value{tramp} sets a similar default value for both prompts.
1713 @item @var{tramp-password-prompt-regexp}
1714 @item @var{tramp-wrong-passwd-regexp}
1715 @vindex tramp-password-prompt-regexp
1716 @vindex tramp-wrong-passwd-regexp
1718 @value{tramp} uses @var{tramp-password-prompt-regexp} to distinguish
1719 between prompts for passwords and prompts for passphrases. By default,
1720 @var{tramp-password-prompt-regexp} handles the detection in English
1721 language environments. See a localization example below:
1725 tramp-password-prompt-regexp
1729 '("passphrase" "Passphrase"
1731 "password" "Password"
1733 "passwort" "Passwort"
1735 "mot de passe" "Mot de passe") t)
1739 Similar localization may be necessary for handling wrong password
1740 prompts, for which @value{tramp} uses @var{tramp-wrong-passwd-regexp}.
1742 @item @command{tset} and other questions
1743 @cindex Unix command tset
1744 @cindex tset Unix command
1745 @vindex tramp-terminal-type
1747 To suppress inappropriate prompts for terminal type, @value{tramp}
1748 sets the @env{TERM} to @code{dumb} before the remote login process
1749 begins via the variable @code{tramp-terminal-type}. This will silence
1750 common @command{tset} related prompts.
1752 @value{tramp}'s strategy for handling such prompts (commonly triggered
1753 from login scripts on remote hosts) is to set the environment
1754 variables so that no prompts interrupt the shell initialization
1757 @vindex tramp-actions-before-shell
1759 An alternative approach is to configure @value{tramp} with strings
1760 that can identify such questions using
1761 @code{tramp-actions-before-shell}. Example:
1764 (defconst my-tramp-prompt-regexp
1765 (concat (regexp-opt '("Enter the birth date of your mother:") t)
1767 "Regular expression matching my login prompt question.")
1769 (defun my-tramp-action (proc vec)
1770 "Enter \"19000101\" in order to give a correct answer."
1771 (save-window-excursion
1772 (with-current-buffer (tramp-get-connection-buffer vec)
1773 (tramp-message vec 6 "\n%s" (buffer-string))
1774 (tramp-send-string vec "19000101"))))
1776 (add-to-list 'tramp-actions-before-shell
1777 '(my-tramp-prompt-regexp my-tramp-action))
1781 @item Conflicting names for users and variables in @file{.profile}
1783 When a user name is the same as a variable name in a local file, such
1784 as @file{.profile}, then @value{tramp} may send incorrect values for
1785 environment variables. To avoid incorrect values, change the local
1786 variable name to something different from the user name. For example,
1787 if the user name is @env{FRUMPLE}, then change the variable name to
1791 @item Non-Bourne commands in @file{.profile}
1793 When the remote host's @file{.profile} is also used for shells other
1794 than Bourne shell, then some incompatible syntaxes for commands in
1795 @file{.profile} may trigger errors in Bourne shell on the host and may
1796 not complete client's @value{tramp} connections.
1798 One example of a Bourne shell incompatible syntax in @file{.profile}:
1799 using @command{export FOO=bar} instead of @command{FOO=bar; export
1800 FOO}. After remote login, @value{tramp} will trigger an error during
1801 its execution of @command{/bin/sh} on the remote host because Bourne
1802 shell does not recognize the export command as entered in
1805 Likewise, (@code{~}) character in paths will cause errors because
1806 Bourne shell does not do (@code{~}) character expansions.
1808 One approach to avoiding these incompatibilities is to make all
1809 commands in @file{~/.shrc} and @file{~/.profile} Bourne shell
1810 compatible so @value{tramp} can complete connections to that remote.
1811 To accommodate using non-Bourne shells on that remote, use other
1812 shell-specific config files. For example, bash can use
1813 @file{~/.bash_profile} and ignore @file{.profile}.
1816 @item Interactive shell prompt
1818 @value{tramp} redefines the remote shell prompt internally for robust
1819 parsing. This redefinition affects the looks of a prompt in an
1820 interactive remote shell through commands, such as @kbd{M-x
1821 shell}. Such prompts, however, can be reset to something more readable
1822 and recognizable using these @value{tramp} variables.
1824 @value{tramp} sets the @env{INSIDE_EMACS} variable in the startup
1825 script file @file{~/.emacs_SHELLNAME}.
1827 @env{SHELLNAME} is @code{bash} or equivalent shell names. Change it by
1828 setting the environment variable @env{ESHELL} in the @file{.emacs} as
1832 (setenv "ESHELL" "bash")
1835 Then re-set the prompt string in @file{~/.emacs_SHELLNAME} as follows:
1838 # Reset the prompt for remote Tramp shells.
1839 if [ "$@{INSIDE_EMACS/*tramp*/tramp@}" == "tramp" ] ; then
1845 @xref{Interactive Shell, , , emacs}.
1848 @item @command{busybox} / @command{nc}
1849 @cindex Unix command nc
1850 @cindex nc Unix command
1852 @value{tramp}'s @option{nc} method uses the @command{nc} command to
1853 install and execute a listener as follows (see @code{tramp-methods}):
1859 The above command-line syntax has changed with @command{busybox}
1860 versions. If @command{nc} refuses the @command{-p} parameter, then
1861 overwrite as follows:
1865 'tramp-connection-properties
1866 `(,(regexp-quote "192.168.0.1") "remote-copy-args" (("-l") ("%r"))))
1870 where @samp{192.168.0.1} is the remote host IP address
1871 (@pxref{Predefined connection information}).
1876 @node Android shell setup
1877 @section Android shell setup hints
1878 @cindex android shell setup
1880 @value{tramp} uses the @option{adb} method to access Android
1881 devices. Android devices provide a restricted shell access through an
1882 USB connection. The local host must have Andriod SDK installed.
1884 Applications such as @code{SSHDroid} that run @command{sshd} process
1885 on the Android device can accept any @option{ssh}-based methods
1886 provided these settings are adjusted:
1888 @code{sh} must be specified for remote shell since Android devices do
1889 not provide @code{/bin/sh}. @code{sh} will then invoke whatever shell is
1890 installed on the device with this setting:
1893 (add-to-list 'tramp-connection-properties
1894 (list (regexp-quote "192.168.0.26") "remote-shell" "sh"))
1898 where @samp{192.168.0.26} is the Android device's IP address.
1899 (@pxref{Predefined connection information}).
1901 @value{tramp} requires preserving @env{PATH} environment variable from
1902 user settings. Android devices prefer @file{/system/xbin} path over
1903 @file{/system/bin}. Both of these are set as follows:
1906 (add-to-list 'tramp-remote-path 'tramp-own-remote-path)
1907 (add-to-list 'tramp-remote-path "/system/xbin")
1911 When the Android device is not @samp{rooted}, specify a writable
1912 directory for temporary files:
1915 (add-to-list 'tramp-remote-process-environment "TMPDIR=$HOME")
1919 Open a remote connection with the command @kbd{C-x C-f
1920 @trampfn{ssh,192.168.0.26#2222,}}, where @command{sshd} is listening on port
1923 To add a corresponding entry to the @file{~/.ssh/config} file
1924 (recommended), use this:
1928 HostName 192.168.0.26
1934 To use the host name @samp{android} instead of the IP address shown in
1935 the previous example, fix the connection properties as follows:
1938 (add-to-list 'tramp-connection-properties
1939 (list (regexp-quote "android") "remote-shell" "sh"))
1943 Open a remote connection with a more concise command @kbd{C-x C-f
1944 @trampfn{ssh,android,}}.
1947 @node Auto-save and Backup
1948 @section Auto-save and Backup configuration
1951 @vindex backup-directory-alist
1953 To avoid @value{tramp} from saving backup files owned by root to
1954 locations accessible to others, default backup settings in
1955 @code{backup-directory-alist} have to be altered.
1957 Here's a scenario where files could be inadvertently exposed. Emacs
1958 by default writes backup files to the same directory as the original
1959 files unless changed to another location, such as
1960 @file{~/.emacs.d/backups/}. Such a directory will also be used by
1961 default by @value{tramp} when using, say, a restricted file
1962 @file{@trampfn{su,root@@localhost,/etc/secretfile}}. The backup
1963 file of the secretfile is now owned by the user logged in from tramp
1966 When @code{backup-directory-alist} is @code{nil} (the default), such
1967 problems do not occur.
1969 To ``turns off'' the backup feature for @value{tramp} files and stop
1970 @value{tramp} from saving to the backup directory, use this:
1973 (add-to-list 'backup-directory-alist
1974 (cons tramp-file-name-regexp nil))
1978 Disabling backups can be targetted to just @option{su} and
1979 @option{sudo} methods:
1982 (setq backup-enable-predicate
1984 (and (normal-backup-enable-predicate name)
1986 (let ((method (file-remote-p name 'method)))
1987 (when (stringp method)
1988 (member method '("su" "sudo"))))))))
1991 Another option is to create better backup file naming with user and
1992 host names prefixed to the file name. For example, transforming
1993 @file{/etc/secretfile} to
1994 @file{~/.emacs.d/backups/!su:root@@localhost:!etc!secretfile}, set the
1995 @value{tramp} variable @code{tramp-backup-directory-alist} from the
1996 existing variable @code{backup-directory-alist}.
1998 Then @value{tramp} backs up to a file name that is transformed with a
1999 prefix consisting of the DIRECTORY name. This file name prefixing
2000 happens only when the DIRECTORY is an absolute local file name.
2006 (add-to-list 'backup-directory-alist
2007 (cons "." "~/.emacs.d/backups/"))
2008 (setq tramp-backup-directory-alist backup-directory-alist)
2012 The backup file name of
2013 @file{@trampfn{su,root@@localhost,/etc/secretfile}} would be
2014 @file{@trampfn{su,root@@localhost,~/.emacs.d/backups/!su:root@@localhost:!etc!secretfile~}}.
2016 Just as for backup files, similar issues of file naming affect
2017 auto-saving @value{tramp} files. Auto-saved files are saved in the
2018 directory specified by the variable
2019 @code{auto-save-file-name-transforms}. By default this is set to the
2020 local temporary directory. But in some versions of Debian GNU/Linux,
2021 this points to the source directory where the Emacs was compiled.
2022 Reset such values to a valid directory.
2024 Set @code{auto-save-file-name-transforms} to @code{nil} to save
2025 auto-saved files to the same directory as the original file.
2027 Alternatively, set the variable @code{tramp-auto-save-directory} to
2028 direct all auto saves to that location.
2030 @node Windows setup hints
2031 @section Issues with Cygwin ssh
2032 @cindex Cygwin, issues
2034 This section is incomplete. Please share your solutions.
2036 @cindex method sshx with Cygwin
2037 @cindex sshx method with Cygwin
2039 Cygwin's @command{ssh} works only with a Cygwin version of Emacs. To
2040 check for compatibility: type @kbd{M-x eshell}, and start @kbd{ssh
2041 test.host}. Incompatbilities trigger this message:
2044 Pseudo-terminal will not be allocated because stdin is not a terminal.
2047 Some older versions of Cygwin's @command{ssh} work with the
2048 @option{sshx} access method. Consult Cygwin's FAQ at
2049 @uref{http://cygwin.com/faq/} for details.
2052 @cindex method scpx with Cygwin
2053 @cindex scpx method with Cygwin
2055 When using the @option{scpx} access method, Emacs may call
2056 @command{scp} with Windows file naming, such as @code{c:/foo}. But
2057 the version of @command{scp} that is installed with Cygwin does not
2058 know about Windows file naming, which causes it to incorrectly look
2059 for a host named @code{c}.
2061 A workaround: write a wrapper script for @option{scp} to convert
2062 Windows file names to Cygwin file names.
2064 @cindex Cygwin and ssh-agent
2065 @cindex SSH_AUTH_SOCK and Emacs on Windows
2067 When using the @command{ssh-agent} on Windows for password-less
2068 interaction, @option{ssh} methods depend on the environment variable
2069 @env{SSH_AUTH_SOCK}. But this variable is not set when Emacs is
2070 started from a Desktop shortcut and authentication fails.
2072 One workaround is to use a Windows based SSH Agent, such as
2073 Pageant. It is part of the Putty Suite of tools.
2075 The fallback is to start Emacs from a shell.
2079 @chapter Using @value{tramp}
2080 @cindex using @value{tramp}
2082 @value{tramp} operates transparently, accessing remote files as if
2083 they are local. However, @value{tramp} employs a formalized remote
2084 file naming syntax to perform its functions transparently. This
2085 syntax consists of many parts specifying access methods,
2086 authentication, host names, and file names. Ange FTP uses a similar
2091 Unlike opening local files in Emacs, which are instantaneous, opening
2092 remote files in @value{tramp} is slower at first. Sometimes there is
2093 a noticable delay before the prompts for passwords or authentication
2094 appear in the minibuffer. Hitting @kbd{@key{RET}} or other keys
2095 during this gap will be processed by Emacs. This type-ahead facility
2096 is a feature of Emacs that may cause missed prompts when using
2100 * File name Syntax:: @value{tramp} file name conventions.
2101 * File name completion:: File name completion.
2102 * Ad-hoc multi-hops:: Declaring multiple hops in the file name.
2103 * Remote processes:: Integration with other Emacs packages.
2104 * Cleanup remote connections:: Cleanup remote connections.
2108 @node File name Syntax
2109 @section @value{tramp} file name conventions
2110 @cindex file name syntax
2111 @cindex file name examples
2113 @file{@trampf{host,localfilename}}
2114 opens file @var{localfilename} on the remote host @var{host}, using
2115 the default method. @xref{Default Method}.
2118 @item @value{prefix}melancholia@value{postfix}.emacs
2119 For the file @file{.emacs} located in the home directory, on the host
2122 @item @value{prefix}melancholia.danann.net@value{postfix}.emacs
2123 For the file @file{.emacs} specified using the fully qualified domain name of
2126 @item @value{prefix}melancholia@value{postfix}~/.emacs
2127 For the file @file{.emacs} specified using the @file{~}, which is expanded.
2129 @item @value{prefix}melancholia@value{postfix}~daniel/.emacs
2130 For the file @file{.emacs} located in @code{daniel}'s home directory
2131 on the host, @code{melancholia}. The @file{~<user>} construct is
2132 expanded to the home directory of that user on the remote host.
2134 @item @value{prefix}melancholia@value{postfix}/etc/squid.conf
2135 For the file @file{/etc/squid.conf} on the host @code{melancholia}.
2139 @var{host} can take IPv4 or IPv6 address, as in
2140 @file{@trampf{127.0.0.1,.emacs}} or
2141 @file{@trampf{@value{ipv6prefix}::1@value{ipv6postfix},.emacs}}.
2142 For syntactical reasons, IPv6 addresses must be embedded in square
2143 brackets @file{@value{ipv6prefix}} and @file{@value{ipv6postfix}}.
2145 By default, @value{tramp} will use the current local user name as the
2146 remote user name for log in to the remote host. Specifying a different
2147 name using the proper syntax will override this default behavior:
2150 @trampf{user@@host,path/to.file}
2153 @file{@trampf{daniel@@melancholia,.emacs}} is for file
2154 @file{.emacs} in @code{daniel}'s home directory on the host,
2157 Specify other file access methods (@pxref{Inline methods},
2158 @pxref{External methods}) as part of the file name.
2160 Method name comes before user name, as in
2161 @file{@value{prefix}@var{method}@value{postfixhop}} (Note the trailing
2162 colon). The syntax specificaton for user, host, and file do not
2165 To connect to the host @code{melancholia} as @code{daniel}, using
2166 @option{ssh} method for @file{.emacs} in @code{daniel}'s home
2167 directory, the full specification is:
2168 @file{@trampfn{ssh,daniel@@melancholia,.emacs}}.
2170 A remote file name containing a host name, which is the same string as
2171 a method name, is not allowed.
2173 For specifying port numbers, affix @file{#<port>} to the host
2174 name. For example: @file{@trampfn{ssh,daniel@@melancholia#42,.emacs}}.
2177 @node File name completion
2178 @section File name completion
2179 @cindex file name completion
2181 @value{tramp} can complete the following @value{tramp} file name
2182 components: method names, user names, host names, and file names
2183 located on remote hosts. Enable this by activating partial completion
2186 @xref{Completion Options, , , emacs}.
2189 For example, type @kbd{C-x C-f @value{prefix}t @key{TAB}},
2190 @value{tramp} completion choices show up as
2193 @c @multitable {@trampfn{telnet,melancholia.danann.net,}} {@trampfn{telnet,192.168.0.1,}}
2194 @multitable @columnfractions .5 .5
2195 @item @value{prefixhop}telnet@value{postfixhop} @tab tmp/
2196 @item @value{prefixhop}toto@value{postfix} @tab
2200 @samp{@value{prefixhop}telnet@value{postfixhop}} is a possible
2201 completion for the respective method, @samp{tmp/} stands for the
2202 directory @file{/tmp} on your local host, and
2203 @samp{@value{prefixhop}toto@value{postfix}} might be a host
2204 @value{tramp} has detected in your @file{~/.ssh/known_hosts} file
2205 (when using @option{ssh} as default method).
2207 Type @kbd{e @key{TAB}} for the minibuffer completion to
2208 @samp{@value{prefix}telnet@value{postfixhop}}. Typing @kbd{@key{TAB}}
2209 shows host names @value{tramp} from @file{/etc/hosts} file, for example.
2212 @multitable @columnfractions .5 .5
2213 @c @multitable {@trampfn{telnet,melancholia.danann.net,}} {@trampfn{telnet,192.168.0.1,}}
2214 @item @trampfn{telnet,127.0.0.1,} @tab @trampfn{telnet,192.168.0.1,}
2215 @c @item @trampfn{telnet,@value{ipv6prefix}::1@value{ipv6postfix},} @tab @trampfn{telnet,localhost,}
2216 @item @value{prefix}telnet@value{postfixhop}@value{ipv6prefix}::1@value{ipv6postfix}@value{postfix} @tab @trampfn{telnet,localhost,}
2217 @item @trampfn{telnet,melancholia.danann.net,} @tab @trampfn{telnet,melancholia,}
2221 Choose a host from the above list and then continue to complete file
2224 When the configuration (@pxref{Customizing Completion}) includes user
2225 names, then the completion lists will account for the user names as well.
2227 Remote hosts previously visited or hosts whose connections are kept
2228 persistently (@pxref{Connection caching}) will be included in the
2231 After remote host name completion comes completion of file names on
2232 the remote host. It works the same as on loal host file completion
2233 except when killing with double-slash @file{//} kills only the file
2234 name part of the @value{tramp} file name syntax. A triple-slash
2235 stands for the default behavior.
2237 @xref{Minibuffer File, , , emacs}.
2244 @kbd{C-x C-f @trampfn{telnet,melancholia,/usr/local/bin//etc} @key{TAB}}
2245 @print{} @trampfn{telnet,melancholia,/etc}
2247 @kbd{C-x C-f @trampfn{telnet,melancholia,//etc} @key{TAB}}
2250 @kbd{C-x C-f @trampfn{telnet,melancholia,/usr/local/bin///etc} @key{TAB}}
2254 During file name completion, remote directory contents are re-read
2255 regularly to account for any changes in the filesystem that may affect
2256 the completion candidates. Such re-reads can account for changes to
2257 the file system by applications outside Emacs (@pxref{Connection
2260 @defopt tramp-completion-reread-directory-timeout
2261 @vindex tramp-completion-reread-directory-timeout
2262 The timeout is number of seconds since last remote command for
2263 rereading remote directory contents. 0 re-reads immediately during
2264 file name completion, @code{nil} uses cached directory contents.
2268 @node Ad-hoc multi-hops
2269 @section Declaring multiple hops in the file name
2270 @cindex multi-hop, ad-hoc
2271 @cindex proxy hosts, ad-hoc
2273 @value{tramp} file name syntax can accommodate ad hoc specification of
2274 multiple proxies without using @code{tramp-default-proxies-alist}
2275 configuration setup(@pxref{Multi-hops}).
2277 Each proxy is specified using the same syntax as the remote host
2278 specification minus the file name part. Each hop is separated by a
2279 @samp{|}. Chain the proxies from the starting host to the destination
2280 remote host name and file name. For example, hopping over a single
2281 proxy @samp{bird@@bastion} to a remote file on @samp{you@@remotehost}:
2284 @c @kbd{C-x C-f @trampfn{ssh@value{postfixhop}bird@@bastion|ssh,you,remotehost,/path}}
2285 @kbd{C-x C-f @value{prefix}ssh@value{postfixhop}bird@@bastion|ssh@value{postfixhop}you@@remotehost@value{postfix}/path}
2288 Proxies can take patterns @code{%h} or @code{%u}.
2290 @value{tramp} adds the ad-hoc definitions on the fly to
2291 @code{tramp-default-proxies-alist} and is available for re-use during
2292 that Emacs session. Subsequent @value{tramp} connections to the same
2293 remote host can then use the shortcut form:
2294 @samp{@trampfn{ssh,you@@remotehost,/path}}.
2296 @defopt tramp-save-ad-hoc-proxies
2297 @vindex tramp-save-ad-hoc-proxies
2298 For ad-hoc definitions to be saved automatically in
2299 @option{tramp-default-proxies-alist} for future Emacs sessions, set
2300 @option{tramp-save-ad-hoc-proxies}.
2303 (setq tramp-save-ad-hoc-proxies t)
2308 @node Remote processes
2309 @section Integration with other Emacs packages
2313 @value{tramp} supports starting new running processes on the remote
2314 host for discovering remote file names. Emacs packages on the remote
2315 host need no specific modifications for @value{tramp}'s use.
2317 This type of integration does not work with the @option{ftp} method,
2318 and does not support the pty association as specified in
2319 @code{start-file-process}.
2321 @code{process-file} and @code{start-file-process} work on the remote
2322 host when the variable @code{default-directory} is remote:
2325 (let ((default-directory "/ssh:remote.host:"))
2326 (start-file-process "grep" (get-buffer-create "*grep*")
2327 "/bin/sh" "-c" "grep -e tramp *"))
2332 Remote processes do not apply to GVFS (see @ref{GVFS based methods})
2333 because the remote file system is mounted on the local host and
2334 @value{tramp} just accesses by changing the @code{default-directory}.
2337 @value{tramp} starts a remote process when a command is executed in a
2338 remote file or directory buffer. As of now, these packages have been
2339 integrated to work with @value{tramp}: @file{compile.el} (commands
2340 like @code{compile} and @code{grep}) and @file{gud.el} (@code{gdb} or
2343 For @value{tramp} to find the command on the remote, it must be
2344 accessible through the default search path as setup by @value{tramp}
2345 upon first connection. Alternatively, use an absolute path or extend
2346 @code{tramp-remote-path} (see @ref{Remote programs}):
2349 (add-to-list 'tramp-remote-path "~/bin")
2350 (add-to-list 'tramp-remote-path "/appli/pub/bin")
2353 Customize @code{tramp-remote-process-environment} to suit the remote
2354 program's environment for the remote host.
2355 @code{tramp-remote-process-environment} is a list of strings
2356 structured similar to @code{process-environment}, where each element
2357 is a string of the form @samp{ENVVARNAME=VALUE}.
2359 To avoid any conflicts with local host variables set through local
2360 configuration files, such as @file{~/.profile}, use @samp{ENVVARNAME=}
2361 to unset them for the remote environment.
2364 Use @code{add-to-list} to add entries:
2367 (add-to-list 'tramp-remote-process-environment "JAVA_HOME=/opt/java")
2370 Modifying or deleting already existing values in the
2371 @code{tramp-remote-process-environment} list may not be feasible on
2372 restricted remote hosts. For example, some system administrators
2373 disallow changing @env{HISTORY} variable. To accommodate such
2374 restrictions when using @value{tramp}, fix the
2375 @code{tramp-remote-process-environment} by the following code in the
2376 local @file{.emacs} file:
2379 (let ((process-environment tramp-remote-process-environment))
2380 (setenv "HISTORY" nil)
2381 (setq tramp-remote-process-environment process-environment))
2384 @value{tramp} does not use the defaults specified in
2385 @code{process-environment} for running @code{process-file} or
2386 @code{start-file-process} on remote hosts. When values from
2387 @code{process-environment} are needed for remote processes, then set
2391 (let ((process-environment (cons "HGPLAIN=1" process-environment)))
2392 (process-file @dots{}))
2395 This works only for environment variables not already set in the
2396 @code{process-environment}.
2398 For integrating other Emacs packages so @value{tramp} can execute
2399 remotely, please file a bug report. @xref{Bug Reports}.
2402 @subsection Running remote programs that create local X11 windows
2404 To allow a remote program to create an X11 window on the local host,
2405 set the @env{DISPLAY} environment variable for the remote host as
2406 follows in the local @file{.emacs} file:
2409 (add-to-list 'tramp-remote-process-environment
2410 (format "DISPLAY=%s" (getenv "DISPLAY")))
2414 @code{(getenv "DISPLAY")} should return a recognizable name for the
2415 local host that the remote host can redirect X11 window
2416 interactions. If querying for a recognizable name is not possible for
2417 whatever reason, then replace @code{(getenv "DISPLAY")} with a
2418 hard-coded, fixed name. Note that using @code{:0} for X11 display name
2419 here will not work as expected.
2421 An alternate approach is specify @code{ForwardX11 yes} or
2422 @code{ForwardX11Trusted yes} in the file @file{~/.ssh/config} on the
2426 @subsection Running @code{shell} on a remote host
2429 Set @option{explicit-shell-file-name} to the appropriate shell name
2430 when using @value{tramp} between two hosts with different operating
2431 systems, such as @samp{windows-nt} and @samp{gnu/linux}. This option
2432 ensures the correct name of the remote shell program.
2434 Starting with Emacs 24, when @option{explicit-shell-file-name} is
2435 equal to @code{nil}, calling @code{shell} interactively will prompt
2439 @subsection Running @code{shell-command} on a remote host
2440 @cindex shell-command
2442 @code{shell-command} executes commands synchronously or asynchronously
2443 on remote hosts and displays output in buffers on the local
2447 @kbd{C-x C-f @trampfn{sudo,,} @key{RET}}
2448 @kbd{M-! tail -f /var/log/syslog.log & @key{RET}}
2451 @command{tail} command outputs continuously to the local buffer,
2452 @file{*Async Shell Command*}
2454 @kbd{M-x auto-revert-tail-mode} runs similarly showing continuous output.
2457 @subsection Running @code{eshell} on a remote host
2460 @value{tramp} is integrated into @file{eshell.el}, which enables
2461 interactive eshell sessions on remote hosts at the command prompt.
2462 You must add the module @code{eshell-tramp} to
2463 @code{eshell-modules-list}. Here's a sample interaction after opening
2464 @kbd{M-x eshell} on a remote host:
2467 @b{~ $} cd @trampfn{sudo,,/etc} @key{RET}
2468 @b{@trampfn{sudo,root@@host,/etc} $} hostname @key{RET}
2470 @b{@trampfn{sudo,root@@host,/etc} $} id @key{RET}
2471 uid=0(root) gid=0(root) groups=0(root)
2472 @b{@trampfn{sudo,root@@host,/etc} $} find-file shadow @key{RET}
2474 @b{@trampfn{sudo,root@@host,/etc} $}
2477 @code{eshell} in Emacs 23.2 added custom @code{su} and @code{sudo}
2478 commands that set the default directory correctly for the
2479 @file{*eshell*} buffer. @value{tramp} silently updates
2480 @code{tramp-default-proxies-alist} with an entry for this directory
2481 (@pxref{Multi-hops}):
2484 @b{~ $} cd @trampfn{ssh,user@@remotehost,/etc} @key{RET}
2485 @b{@trampfn{ssh,user@@remotehost,/etc} $} find-file shadow @key{RET}
2486 File is not readable: @trampfn{ssh,user@@remotehost,/etc/shadow}
2487 @b{@trampfn{ssh,user@@remotehost,/etc} $} sudo find-file shadow @key{RET}
2490 @b{@trampfn{ssh,user@@remotehost,/etc} $} su - @key{RET}
2491 @b{@trampfn{su,root@@remotehost,/root} $} id @key{RET}
2492 uid=0(root) gid=0(root) groups=0(root)
2493 @b{@trampfn{su,root@@remotehost,/root} $}
2497 @anchor{Running a debugger on a remote host}
2498 @subsection Running a debugger on a remote host
2503 @file{gud.el} provides a unified interface to symbolic debuggers
2505 (@ref{Debuggers, , , emacs}).
2507 @value{tramp} can run debug on remote hosts by calling @code{gdb}
2508 with a remote file name:
2511 @kbd{M-x gdb @key{RET}}
2512 @b{Run gdb (like this):} gdb --annotate=3 @trampfn{ssh,host,~/myprog} @key{RET}
2515 Relative file names are based on the remote default directory. When
2516 @file{myprog.pl} exists in @file{@trampfn{ssh,host,/home/user}},
2517 valid calls include:
2520 @kbd{M-x perldb @key{RET}}
2521 @b{Run perldb (like this):} perl -d myprog.pl @key{RET}
2524 Just the local part of a remote file name, such as @kbd{perl -d
2525 /home/user/myprog.pl}, is not possible.
2527 Arguments of the program to be debugged must be literal, can take
2528 relative or absolute paths, but not remote paths.
2531 @subsection Running remote processes on Windows hosts
2535 @command{winexe} runs processes on a remote Windows host, and
2536 @value{tramp} can use it for @code{process-file} and
2537 @code{start-file-process}.
2539 @code{tramp-smb-winexe-program} specifies the local @command{winexe}
2540 command. Powershell V2.0 on the remote host is required to run
2541 processes triggered from @value{tramp}.
2543 @option{explicit-shell-file-name} and @option{explicit-*-args} have to
2544 be set properly so @kbd{M-x shell} can open a proper remote shell on a
2545 Windows host. To open @command{cmd}, set it as follows:
2548 (setq explicit-shell-file-name "cmd"
2549 explicit-cmd-args '("/q"))
2553 To open @command{powershell} as a remote shell, use this:
2556 (setq explicit-shell-file-name "powershell"
2557 explicit-powershell-args '("-file" "-"))
2561 @node Cleanup remote connections
2562 @section Cleanup remote connections
2565 @value{tramp} provides several ways to flush remote connections.
2567 @deffn Command tramp-cleanup-connection vec
2568 This command flushes all connection related objects. @option{vec} is
2569 the internal representation of a remote connection. When called
2570 interactively, this command lists active remote connections in the
2571 minibuffer. Each connection is of the format
2572 @file{@trampfn{method,user@@host,}}. Flushing remote connections also
2574 cache (@pxref{Password handling}), file cache, connection cache
2575 (@pxref{Connection caching}), and connection buffers.
2578 @deffn Command tramp-cleanup-this-connection
2579 Flushes only the current buffer's remote connection objects, the same
2580 as in @code{tramp-cleanup-connection}.
2583 @deffn Command tramp-cleanup-all-connections
2584 Flushes all active remote connection objects, the same as in
2585 @code{tramp-cleanup-connection}.
2588 @deffn Command tramp-cleanup-all-buffers
2589 Just as for @code{tramp-cleanup-all-connections}, all remote
2590 connections are cleaned up in addition to killing buffers related to
2591 that remote connection.
2596 @chapter Reporting Bugs and Problems
2599 @value{tramp}'s development team is actively engaged in solving bugs
2600 and problems and looks to feature requests and suggestions.
2602 @value{tramp}'s mailing list is the place for more advice and
2603 information on working with @value{tramp}, solving problems,
2604 discussing, and general discussions about @value{tramp}.
2606 @value{tramp}'s mailing list is moderated but even non-subscribers can
2607 post for moderator approval. Sometimes this approval step may take as
2608 long as 48 hours due to public holidays.
2610 @email{tramp-devel@@gnu.org} is the mailing list. Messages sent to
2611 this address go to all the subscribers. This is @emph{not} the
2612 address to send subscription requests to.
2614 To subscribe to the mailing list, visit:
2615 @uref{http://lists.gnu.org/mailman/listinfo/tramp-devel/, the
2616 @value{tramp} Mail Subscription Page}.
2618 @ifset installchapter
2619 Before sending a bug report, run the test suite first @ref{Testing}.
2623 Check if the bug or problem is already addressed in @xref{Frequently
2626 Run @kbd{M-x tramp-bug} to generate a buffer with details of the
2627 system along with the details of the @value{tramp}
2628 installation. Please include these details with the bug report.
2630 The bug report must describe in as excruciating detail as possible the
2631 steps required to reproduce the problem. These details must include
2632 the setup of the remote host and any special or unique conditions that
2635 Include a minimal test case that reproduces the problem. This will
2636 help the development team find the best solution and avoid unrelated
2639 To exclude cache-related problems, flush all caches before running the
2640 test, @ref{Cleanup remote connections}.
2642 When including @value{tramp}'s messages in the bug report, increase
2643 the verbosity level to 6 (@pxref{Traces and Profiles, Traces}) in the
2644 @file{~/.emacs} file before repeating steps to the bug. Include the
2645 contents of the @file{*tramp/foo*} and @file{*debug tramp/foo*}
2646 buffers with the bug report.
2648 @strong{Note} that a verbosity level greater than 6 is not necessary
2649 at this stage. Also note that a verbosity level of 6 or greater, the
2650 contents of files and directories will be included in the debug
2651 buffer. Passwords typed in @value{tramp} will never be included
2655 @node Frequently Asked Questions
2656 @chapter Frequently Asked Questions
2657 @cindex frequently asked questions
2662 Where is the latest @value{tramp}?
2664 @value{tramp} is available at the GNU URL:
2667 @uref{ftp://ftp.gnu.org/gnu/tramp/}
2670 @value{tramp}'s GNU project page is located here:
2673 @uref{http://savannah.gnu.org/projects/tramp/}
2677 Which systems does it work on?
2679 The package works successfully on Emacs 23, Emacs 24, and Emacs 25.
2681 While Unix and Unix-like systems are the primary remote targets,
2682 @value{tramp} has equal success connecting to other platforms, such as
2683 MS Windows XP/Vista/7.
2687 How to speed up @value{tramp}?
2689 @value{tramp} does many things in the background, some of which
2690 depends on network speeds, response speeds of remote hosts, and
2691 authentication delays. During these operations, @value{tramp}'s
2692 responsiveness slows down. Some suggestions within the scope of
2693 @value{tramp}'s settings include:
2695 Use an external method, such as @option{scp}, which are faster than
2698 Keep the file @code{tramp-persistency-file-name}, which is where
2699 @value{tramp} caches remote information about hosts and files. Caching
2700 is enabled by default. Don't disable it.
2702 Set @code{remote-file-name-inhibit-cache} to @code{nil} if remote
2703 files are not independently updated outside @value{tramp}'s control.
2704 That cache cleanup will be necessary if the remote directories or
2705 files are updated independent of @value{tramp}.
2707 Set @code{tramp-completion-reread-directory-timeout} to @code{nil} to
2708 speed up completions, @ref{File name completion}.
2710 Disable version control to avoid delays:
2713 (setq vc-ignore-dir-regexp
2714 (format "\\(%s\\)\\|\\(%s\\)"
2715 vc-ignore-dir-regexp
2716 tramp-file-name-regexp))
2719 Disable excessive traces. Set @code{tramp-verbose} to 3 or lower,
2720 default being 3. Increase trace levels temporarily when hunting for
2724 @value{tramp} does not connect to the remote host
2726 Three main reasons for why @value{tramp} does not connect to the remote host:
2730 Unknown characters in the prompt
2732 @value{tramp} needs a clean recognizable prompt on the remote host for
2733 accurate parsing. Shell prompts that contain escape sequences for
2734 coloring cause parsing problems. @ref{Remote shell setup} for
2735 customizing prompt detection using regular expressions.
2737 To check if the remote host's prompt is being recognized, use this
2738 test: switch to @value{tramp} connection buffer @file{*tramp/foo*},
2739 put the cursor at the top of the buffer, and then apply the following
2743 @kbd{M-: (re-search-forward (concat tramp-shell-prompt-pattern "$"))}
2746 If the cursor has not moved to the prompt at the bottom of the buffer,
2747 then @value{tramp} has failed to recognize the prompt.
2749 When using zsh on remote hosts, disable zsh line editor because zsh
2750 uses left-hand side and right-hand side prompts in parallel. Add the
2751 following line to @file{~/.zshrc}:
2754 [ $TERM = "dumb" ] && unsetopt zle && PS1='$ '
2757 When using fish shell on remote hosts, disable fancy formatting by
2758 adding the following to @file{~/.config/fish/config.fish}:
2761 function fish_prompt
2762 if test $TERM = "dumb"
2770 When using WinSSHD on remote hosts, @value{tramp} do not recognize the
2771 strange prompt settings.
2774 Echoed characters after login
2776 @value{tramp} suppresses echos from remote hosts with the
2777 @command{stty -echo} command. But sometimes it is too late to suppress
2778 welcome messages from the remote host containing harmful control
2779 characters. Using @option{sshx} or @option{scpx} methods can avoid
2780 this problem because they allocate a pseudo tty. @xref{Inline
2784 @value{tramp} stops transferring strings longer than 500 characters
2786 Set @code{tramp-chunksize} to 500 to get around this problem, which is
2787 related to faulty implementation of @code{process-send-string} on
2788 HP-UX, FreeBSD and Tru64 Unix systems. Consult the documentation for
2789 @code{tramp-chunksize} to see when this is necessary.
2791 Set @code{file-precious-flag} to @code{t} for files accessed by
2792 @value{tramp} so the file contents are checked using checksum by
2793 first saving to a temporary file.
2795 @pxref{Saving Buffers, , , elisp}
2802 (when (file-remote-p default-directory)
2803 (set (make-local-variable 'file-precious-flag) t))))
2809 @value{tramp} does not recognize if a @command{ssh} session hangs
2811 @command{ssh} sessions on the local host hang when the network is
2812 down. @value{tramp} cannot safely detect such hangs. The network
2813 configuration for @command{ssh} can be configured to kill such hangs
2814 with the following command in the @file{~/.ssh/config}:
2818 ServerAliveInterval 5
2823 @value{tramp} does not use default @command{ssh} @code{ControlPath}
2825 @value{tramp} overwrites @code{ControlPath} settings when initiating
2826 @command{ssh} sessions. @value{tramp} does this to fend off a stall
2827 if a master session opened outside the Emacs session is no longer
2828 open. That is why @value{tramp} prompts for the password again even
2829 if there is an @command{ssh} already open.
2831 Some @command{ssh} versions support a @code{ControlPersist} option,
2832 which allows you to set the @code{ControlPath} provided the variable
2833 @code{tramp-ssh-controlmaster-options} is customized as follows:
2836 (setq tramp-ssh-controlmaster-options
2838 "-o ControlPath=/tmp/ssh-ControlPath-%%r@@%%h:%%p "
2839 "-o ControlMaster=auto -o ControlPersist=yes"))
2842 Note how "%r", "%h" and "%p" must be encoded as "%%r", "%%h" and
2845 If the @file{~/.ssh/config} is configured appropriately for the above
2846 behavior, then any changes to @command{ssh} can be suppressed with
2847 this @code{nil} setting:
2850 (setq tramp-use-ssh-controlmaster-options nil)
2855 File name completion does not work with @value{tramp}
2857 @acronym{ANSI} escape sequences from the remote shell may cause errors
2858 in @value{tramp}'s parsing of remote buffers.
2860 To test if this is the case, open a remote shell and check if the output
2861 of @command{ls} is in color.
2863 To disable @acronym{ANSI} escape sequences from the remote hosts,
2864 disable @option{--color=yes} or @option{--color=auto} in the remote
2865 host's @file{.bashrc} or @file{.profile}. Turn this alias on and off
2866 to see if file name completion works.
2869 File name completion does not work in directories with large number of
2872 This may be related to globbing, which is the use of shell's ability
2873 to expand wild card specifications, such as @samp{*.c}. For
2874 directories with large number of files, globbing might exceed the
2875 shell's limit on length of command lines and hang. @value{tramp} uses
2878 To test if globbing hangs, open a shell on the remote host and then
2879 run @samp{ls -d * ..?* > /dev/null}.
2881 When testing, ensure the remote shell is the same shell
2882 (@command{/bin/sh}, @command{ksh} or @command{bash}), that
2883 @value{tramp} uses when connecting to that host.
2887 How to get notified after @value{tramp} completes file transfers?
2889 Make Emacs beep after reading from or writing to the remote host with
2890 the following code in @file{~/.emacs} file.
2893 (defadvice tramp-handle-write-region
2894 (after tramp-write-beep-advice activate)
2895 "Make tramp beep after writing a file."
2899 (defadvice tramp-handle-do-copy-or-rename-file
2900 (after tramp-copy-beep-advice activate)
2901 "Make tramp beep after copying a file."
2905 (defadvice tramp-handle-insert-file-contents
2906 (after tramp-insert-beep-advice activate)
2907 "Make tramp beep after inserting a file."
2914 How to get a Visual Warning when working with @samp{root} privileges
2916 Get a modeline indication when working with @samp{root} privileges
2917 with the following code (tested with Emacs 22.1) in @file{~/.emacs}
2921 (defun my-mode-line-function ()
2922 (when (string-match "^/su\\(do\\)?:" default-directory)
2923 (setq mode-line-format
2924 (format-mode-line mode-line-format 'font-lock-warning-face))))
2926 (add-hook 'find-file-hook 'my-mode-line-function)
2927 (add-hook 'dired-mode-hook 'my-mode-line-function)
2932 How to get host indication in the mode line?
2934 The following code (tested with Emacs 22.1) in @file{~/.emacs} file
2938 (defconst my-mode-line-buffer-identification
2942 (if (file-remote-p default-directory)
2943 (tramp-file-name-host
2944 (tramp-dissect-file-name default-directory))
2946 (if (string-match "^[^0-9][^.]*\\(\\..*\\)" host-name)
2947 (substring host-name 0 (match-beginning 1))
2952 mode-line-buffer-identification
2953 my-mode-line-buffer-identification)
2959 mode-line-buffer-identification
2960 my-mode-line-buffer-identification)))
2963 The mode line in Emacs 23.1 and later versions now contains an
2964 indication if @code{default-directory} for the current buffer is on a
2965 remote host. Moreover, the corresponding tool-tip shows the remote
2966 host name. The above @code{:eval} clause can also be simplified to
2967 show the host name in the mode line:
2972 (or (file-remote-p default-directory 'host)
2974 (if (string-match "^[^0-9][^.]*\\(\\..*\\)" host-name)
2975 (substring host-name 0 (match-beginning 1))
2981 Remote host does not understand default options for directory listing
2983 Emacs computes the @command{dired} options based on the local host but
2984 if the remote host cannot understand the same @command{ls} command,
2985 then set them with a hook as follows:
2989 'dired-before-readin-hook
2991 (when (file-remote-p default-directory)
2992 (setq dired-actual-switches "-al"))))
2997 Why is @file{~/.sh_history} file on the remote host growing?
2999 Due to @command{ksh} saving tilde expansions triggered by
3000 @value{tramp}, the history file is probably growing rapidly. To fix,
3001 turn off saving history by putting this shell code in the
3005 if [ -f $HOME/.sh_history ] ; then
3006 /bin/rm $HOME/.sh_history
3008 if [ "$@{HISTFILE-unset@}" != "unset" ] ; then
3011 if [ "$@{HISTSIZE-unset@}" != "unset" ] ; then
3016 For @option{ssh}-based method, add the following line to your
3017 @file{~/.ssh/environment} file:
3025 How to shorten long file names when typing in @value{tramp}?
3027 Adapt several of these approaches to reduce typing. If the full name
3028 is @file{@trampfn{ssh,news@@news.my.domain,/opt/news/etc}}, then:
3033 Use default values for method name and user name:
3035 You can define default methods and user names for hosts,
3036 (@pxref{Default Method}, @pxref{Default User}):
3039 (setq tramp-default-method "ssh"
3040 tramp-default-user "news")
3043 The reduced typing: @kbd{C-x C-f @trampf{news.my.domain,/opt/news/etc}}.
3045 @strong{Note} that there are some useful shortcuts already. Accessing
3046 your local host as @samp{root} user, is possible just by @kbd{C-x C-f
3050 Use configuration options of the access method:
3052 Programs used for access methods already offer powerful configurations
3053 (@pxref{Customizing Completion}). For @option{ssh}, configure the
3054 file @file{~/.ssh/config}:
3058 HostName news.my.domain
3062 The reduced typing: @kbd{C-x C-f @trampfn{ssh,xy,/opt/news/etc}}.
3064 Depending on the number of files in the directories, host names
3065 completion can further reduce key strokes: @kbd{C-x C-f
3066 @value{prefix}ssh@value{postfixhop}x @key{TAB}}.
3069 Use environment variables to expand long strings
3071 For long file names, set up environment variables that are expanded in
3072 the minibuffer. Environment variables are set either outside Emacs or
3073 inside Emacs with Lisp:
3076 (setenv "xy" "@trampfn{ssh,news@@news.my.domain,/opt/news/etc/}")
3079 The reduced typing: @kbd{C-x C-f $xy @key{RET}}.
3081 @strong{Note} that file name cannot be edited here because the
3082 environment variables are not expanded during editing in the
3085 @item Define own keys:
3087 Redefine another key sequence in Emacs for @kbd{C-x C-f}:
3091 [(control x) (control y)]
3097 "@trampfn{ssh,news@@news.my.domain,/opt/news/etc/}"))))
3100 Simply typing @kbd{C-x C-y} would prepare minibuffer editing of file
3103 See @uref{http://www.emacswiki.org/cgi-bin/wiki/TrampMode, the Emacs
3104 Wiki} for a more comprehensive example.
3107 Define own abbreviation (1):
3109 Abbreviation list expansion can be used to reduce typing long file names:
3113 'directory-abbrev-alist
3114 '("^/xy" . "@trampfn{ssh,news@@news.my.domain,/opt/news/etc/}"))
3117 The reduced typing: @kbd{C-x C-f /xy @key{RET}}.
3119 @strong{Note} that file name cannot be edited here because the
3120 environment variables are not expanded during editing in the
3124 Define own abbreviation (2):
3126 The @code{abbrev-mode} gives additional flexibility for editing in the
3130 (define-abbrev-table 'my-tramp-abbrev-table
3131 '(("xy" "@trampfn{ssh,news@@news.my.domain,/opt/news/etc/}")))
3134 'minibuffer-setup-hook
3137 (setq local-abbrev-table my-tramp-abbrev-table)))
3139 (defadvice minibuffer-complete
3140 (before my-minibuffer-complete activate)
3143 ;; If you use partial-completion-mode
3144 (defadvice PC-do-completion
3145 (before my-PC-do-completion activate)
3149 The reduced typing: @kbd{C-x C-f xy @key{TAB}}.
3151 The minibuffer expands for further editing.
3153 @item Use bookmarks:
3155 Use bookmarks to save Tramp file names.
3157 @pxref{Bookmarks, , , emacs}.
3160 Upon visiting a location with @value{tramp}, save it as a bookmark with
3161 @kbd{@key{menu-bar} @key{edit} @key{bookmarks} @key{set}}.
3163 To revisit that bookmark:
3164 @kbd{@key{menu-bar} @key{edit} @key{bookmarks} @key{jump}}.
3166 @item Use recent files:
3168 @file{recentf} remembers visited places.
3170 @pxref{File Conveniences, , , emacs}.
3173 Keep remote file names in the recent list without have to check for
3174 their accessibility through remote access:
3180 Reaching recently opened files: @kbd{@key{menu-bar} @key{file}
3183 @item Use filecache:
3185 Since @file{filecache} remembers visited places, add the remote
3186 directory to the cache:
3189 (eval-after-load "filecache"
3190 '(file-cache-add-directory
3191 "@trampfn{ssh,news@@news.my.domain,/opt/news/etc/}"))
3194 Then use directory completion in the minibuffer with @kbd{C-x C-f
3199 @file{bbdb} has a built-in feature for Ange FTP files, which also
3200 works for @value{tramp} file names.
3202 @pxref{bbdb-ftp, Storing FTP sites in the BBDB, , bbdb}.
3205 Load @file{bbdb} in Emacs:
3212 Create a BBDB entry with @kbd{M-x bbdb-create-ftp-site}. Then specify
3213 a method and user name where needed. Examples:
3216 @kbd{M-x bbdb-create-ftp-site @key{RET}}
3217 @b{Ftp Site:} news.my.domain @key{RET}
3218 @b{Ftp Directory:} /opt/news/etc/ @key{RET}
3219 @b{Ftp Username:} ssh@value{postfixhop}news @key{RET}
3220 @b{Company:} @key{RET}
3221 @b{Additional Comments:} @key{RET}
3224 In BBDB buffer, access an entry by pressing the key @key{F}.
3228 Thanks to @value{tramp} users for contributing to these recipes.
3231 Why saved multi-hop file names do not work in a new Emacs session?
3233 When saving ad-hoc multi-hop @value{tramp} file names (@pxref{Ad-hoc
3234 multi-hops}) via bookmarks, recent files, filecache, bbdb, or another
3235 package, use the full ad-hoc file name including all hops, like
3236 @file{@trampfn{ssh,bird@@bastion|ssh@value{postfixhop}news.my.domain,/opt/news/etc}}.
3238 Alternatively, when saving abbreviated multi-hop file names
3239 @file{@trampfn{ssh,news@@news.my.domain,/opt/news/etc}}, the custom
3240 option @code{tramp-save-ad-hoc-proxies} must be set non-@code{nil}
3245 How to connect to a remote Emacs session using @value{tramp}?
3247 Configure Emacs Client
3249 (@pxref{Emacs Server, , , emacs}).
3252 Then on the remote host, start the Emacs Server:
3256 (setq server-host (system-name)
3261 If @code{(system-name)} of the remote host cannot be resolved on the
3262 local host, use IP address instead.
3264 Copy from the remote host the resulting file
3265 @file{~/.emacs.d/server/server} to the local host, to the same
3268 Then start Emacs Client from the command line:
3271 emacsclient @trampfn{ssh,user@@host,/file/to/edit}
3274 @code{user} and @code{host} refer to the local host.
3276 To make Emacs Client an editor for other programs, use a wrapper
3277 script @file{emacsclient.sh}:
3281 emacsclient @trampfn{ssh,$(whoami)@@$(hostname --fqdn),$1}
3284 Then change the environment variable @env{EDITOR} to point to the
3288 export EDITOR=/path/to/emacsclient.sh
3293 How to disable other packages from calling @value{tramp}?
3295 There are packages that call @value{tramp} without the user ever
3296 entering a remote file name. Even without applying a remote file
3297 syntax, some packages enable @value{tramp} on their own. How can users
3298 disable such features.
3304 Disable @value{tramp} file name completion:
3307 (custom-set-variables
3308 '(ido-enable-tramp-completion nil))
3314 Disable remote directory tracking mode:
3317 (rlogin-directory-tracking-mode -1)
3323 How to disable @value{tramp}?
3327 To keep Ange FTP as default the remote files access package, set this
3331 (setq tramp-default-method "ftp")
3335 To disable both @value{tramp} (and Ange FTP), set @code{tramp-mode} to
3336 @code{nil} in @file{.emacs}.
3339 (setq tramp-mode nil)
3343 To unload @value{tramp}, type @kbd{M-x tramp-unload-tramp}. Unloading
3344 @value{tramp} resets Ange FTP plugins also.
3349 @c For the developer
3350 @node Files directories and localnames
3351 @chapter How file names, directories and localnames are mangled and managed.
3354 * Localname deconstruction:: Splitting a localname into its component parts.
3355 * External packages:: Integrating with external Lisp packages.
3359 @node Localname deconstruction
3360 @section Splitting a localname into its component parts
3362 @value{tramp} package redefines lisp functions
3363 @code{file-name-directory} and @code{file-name-nondirectory} to
3364 accommodate the unique file naming syntax that @value{tramp} requires.
3366 The replacements dissect the file name, use the original handler for
3367 the localname, take that result, and then re-build the @value{tramp}
3368 file name. By relying on the original handlers for localnames,
3369 @value{tramp} benefits from platform specific hacks to the original
3373 @node External packages
3374 @section Integrating with external Lisp packages
3375 @subsection File name completion.
3377 For name completions in the minibuffer, @value{tramp} depends on the
3378 last input character to decide whether to look for method name
3379 completion or host name completion. For example, @kbd{C-x C-f
3380 @value{prefix}ssh@value{postfixhop} @key{TAB}} is not entirely clear
3381 if @option{ssh} is a method or a host name. But if the last input
3382 character was either @key{TAB}, @key{SPACE} or @kbd{?}, then
3383 @value{tramp} favors file name completion over host name completion.
3385 What about external packages using other characters to trigger file
3386 name completions? They must somehow signal this to @value{tramp}. Use
3387 the variable @code{non-essential} temporarily and bind it to
3388 non-@code{nil} value.
3391 (let ((non-essential t))
3396 @subsection File attributes cache.
3398 Keeping a local cache of remote file attributes in sync with the
3399 remote host is a time-consuming operation. Flushing and re-querying
3400 these attributes can tax @value{tramp} to a grinding halt on busy
3403 To get around these types of slow-downs in @value{tramp}'s
3404 responsiveness, set the @code{process-file-side-effects} to @code{nil}
3405 to stop @value{tramp} from flushing the cache. This is helpful in
3406 situations where callers to @code{process-file} know there are no file
3407 attribute changes. The let-bind form to accomplish this:
3410 (let (process-file-side-effects)
3414 For asynchronous processes, @value{tramp} uses a process sentinel to
3415 flush file attributes cache. When callers to @code{start-file-process}
3416 know beforehand no file attribute changes are expected, then the
3417 process sentinel should be set to the default state. In cases where
3418 the caller defines its own process sentinel, @value{tramp}'s process
3419 sentinel is overwritten. The caller can still flush the file
3420 attributes cache in its process sentinel with this code:
3423 (unless (memq (process-status proc) '(run open))
3424 (dired-uncache remote-directory))
3427 Since @value{tramp} traverses subdirectories starting with the
3428 root-directory, it is most likely sufficient to make the
3429 @code{default-directory} of the process buffer as the root directory.
3432 @node Traces and Profiles
3433 @chapter How to Customize Traces
3435 @value{tramp} messages are raised with verbosity levels ranging from 0
3436 to 10. @value{tramp} does not display all messages; only those with a
3437 verbosity level less than or equal to @code{tramp-verbose}.
3439 The verbosity levels are
3441 @w{ 0} silent (no @value{tramp} messages at all)
3442 @*@indent @w{ 1} errors
3443 @*@indent @w{ 2} warnings
3444 @*@indent @w{ 3} connection to remote hosts (default verbosity)
3445 @*@indent @w{ 4} activities
3446 @*@indent @w{ 5} internal
3447 @*@indent @w{ 6} sent and received strings
3448 @*@indent @w{ 7} file caching
3449 @*@indent @w{ 8} connection properties
3450 @*@indent @w{ 9} test commands
3451 @*@indent @w{10} traces (huge)
3453 With @code{tramp-verbose} greater than or equal to 4, messages are
3454 also written to a @value{tramp} debug buffer. Such debug buffers are
3455 essential to bug and problem analyses. For @value{tramp} bug reports,
3456 set the @code{tramp-verbose} level to 6 (@pxref{Bug Reports}).
3458 The debug buffer is in
3460 @ref{Outline Mode, , , emacs}.
3465 In this buffer, messages can be filtered by their level. To see
3466 messages up to verbosity level 5, enter @kbd{C-u 6 C-c C-q}.
3468 Other navigation keys are described in
3469 @ref{Outline Visibility, , , emacs}.
3472 @value{tramp} handles errors internally. But to get a Lisp backtrace,
3473 both the error and the signal have to be set as follows:
3476 (setq debug-on-error t
3480 To enable stepping through @value{tramp} function call traces, they
3481 have to be specifically enabled as shown in this code:
3485 (dolist (elt (all-completions "tramp-" obarray 'functionp))
3486 (trace-function-background (intern elt)))
3487 (untrace-function 'tramp-read-passwd)
3488 (untrace-function 'tramp-gw-basic-authentication)
3491 The buffer @file{*trace-output*} contains the output from the function
3492 call traces. Disable @code{tramp-read-passwd} and
3493 @code{tramp-gw-basic-authentication} to stop password strings from
3494 being written to @file{*trace-output*}.
3497 @node GNU Free Documentation License
3498 @appendix GNU Free Documentation License
3499 @include doclicense.texi
3502 @node Function Index
3503 @unnumbered Function Index
3507 @node Variable Index
3508 @unnumbered Variable Index
3513 @unnumbered Concept Index
3520 @c * Say something about the .login and .profile files of the remote
3522 @c * Explain how tramp.el works in principle: open a shell on a remote
3523 @c host and then send commands to it.
3524 @c * Consistent small or capitalized words especially in menus.
3525 @c * Make a unique declaration of @trampfn.