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 @value{emacsname} network features
56 * TRAMP: (tramp). Transparent Remote Access, Multiple Protocol
57 @value{emacsname} 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 @value{emacsname}.
78 @value{tramp} stands for ``Transparent Remote (file) Access, Multiple
79 Protocol''. This package provides remote file editing, similar to
80 @value{ftppackagename}.
82 The difference is that @value{ftppackagename} uses FTP to transfer
83 files between the local and the remote host, whereas @value{tramp} uses a
84 combination of @command{rsh} and @command{rcp} or other work-alike
85 programs, such as @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/}.
90 @c Pointer to the other Emacs flavor is necessary only in case of
91 @c standalone installation.
93 The manual has been generated for @value{emacsname}.
95 If you want to read the info pages for @value{emacsothername}, you
96 should read in @ref{Installation} how to create them.
99 If you're using the other Emacs flavor, you should read the
100 @uref{@value{emacsotherfilename}, @value{emacsothername}} pages.
105 The latest release of @value{tramp} is available for
106 @uref{ftp://ftp.gnu.org/gnu/tramp/, download}, or you may see
107 @ref{Obtaining Tramp} for more details, including the Git server
110 @value{tramp} also has a @uref{http://savannah.gnu.org/projects/tramp/,
111 Savannah Project Page}.
114 There is a mailing list for @value{tramp}, available at
115 @email{tramp-devel@@gnu.org}, and archived at
116 @uref{http://lists.gnu.org/archive/html/tramp-devel/, the
117 @value{tramp} Mail Archive}.
119 Older archives are located at
120 @uref{http://sourceforge.net/mailarchive/forum.php?forum=tramp-devel,
121 SourceForge Mail Archive} and
122 @uref{http://www.mail-archive.com/emacs-rcp@@ls6.cs.uni-dortmund.de/,
124 @c in HTML output, there's no new paragraph.
133 * Overview:: What @value{tramp} can and cannot do.
137 * Obtaining Tramp:: How to obtain @value{tramp}.
138 * History:: History of @value{tramp}.
139 @ifset installchapter
140 * Installation:: Installing @value{tramp} with your @value{emacsname}.
142 * Configuration:: Configuring @value{tramp} for use.
143 * Usage:: An overview of the operation of @value{tramp}.
144 * Bug Reports:: Reporting Bugs and Problems.
145 * Frequently Asked Questions:: Questions and answers from the mailing list.
149 * Files directories and localnames::
150 How file names, directories and localnames
151 are mangled and managed.
152 * Traces and Profiles:: How to Customize Traces.
153 * Issues:: Debatable Issues and What Was Decided.
155 * GNU Free Documentation License:: The license for this documentation.
156 * Function Index:: @value{tramp} functions.
157 * Variable Index:: User options and variables.
158 * Concept Index:: An item for each concept.
161 --- The Detailed Node Listing ---
163 @ifset installchapter
164 Installing @value{tramp} with your @value{emacsname}
166 * Installation parameters:: Parameters in order to control installation.
167 * Load paths:: How to plug-in @value{tramp} into your environment.
171 Configuring @value{tramp} for use
173 * Connection types:: Types of connections to remote hosts.
174 * Inline methods:: Inline methods.
175 * External methods:: External methods.
177 * GVFS based methods:: GVFS based external methods.
180 * Gateway methods:: Gateway methods.
182 * Default Method:: Selecting a default method.
183 * Default User:: Selecting a default user.
184 * Default Host:: Selecting a default host.
185 * Multi-hops:: Connecting to a remote host using multiple hops.
186 * Customizing Methods:: Using Non-Standard Methods.
187 * Customizing Completion:: Selecting config files for user/host name completion.
188 * Password handling:: Reusing passwords for several connections.
189 * Connection caching:: Reusing connection related information.
190 * Predefined connection information::
191 Setting own connection related information.
192 * Remote programs:: How @value{tramp} finds and uses programs on the remote host.
193 * Remote shell setup:: Remote shell setup hints.
194 * Android shell setup:: Android shell setup hints.
195 * Auto-save and Backup:: Auto-save and Backup.
196 * Windows setup hints:: Issues with Cygwin ssh.
200 * File name Syntax:: @value{tramp} file name conventions.
201 * File name completion:: File name completion.
202 * Ad-hoc multi-hops:: Declaring multiple hops in the file name.
203 * Remote processes:: Integration with other @value{emacsname} packages.
204 * Cleanup remote connections:: Cleanup remote connections.
206 How file names, directories and localnames are mangled and managed
208 * Localname deconstruction:: Breaking a localname into its components.
210 * External packages:: Integration with external Lisp packages.
218 @chapter An overview of @value{tramp}
221 @value{tramp} is for transparently accessing remote files from within
222 @value{emacsname}. @value{tramp} enables an easy, convenient, and
223 consistent interface to remote files as if they are local files.
224 @value{tramp}'s transparency extends to editing, version control, and
227 @value{tramp} can access remote hosts using any number of access
228 methods, such as @command{rsh}, @command{rlogin}, @command{telnet},
229 and related programs. If these programs can successfully pass
230 @acronym{ASCII]} characters, @value{tramp} can use them.
231 @value{tramp} does not require or mandate 8-bit clean connections.
233 @value{tramp}'s most common access method is through @command{ssh}, a
234 more secure alternative to @command{ftp} and other older access
237 @value{tramp} on Windows operating systems is integrated with the
238 PuTTY package, and uses the @command{plink} program.
240 @value{tramp} mostly operates transparently in the background using
241 the connection programs. As long as these programs enable remote login
242 and can use the terminal, @value{tramp} can adapt them for seamless
243 and transparent access.
245 @value{tramp} temporarily transfers a remote file's contents to the
246 local host editing and related operations. @value{tramp} can also
247 transfer files between hosts using standard Emacs interfaces, a
248 benefit of direct integration of @value{tramp} in @value{emacsname}.
250 @value{tramp} can transfer files using any number of available host
251 programs for remote files, such as @command{rcp}, @command{scp},
252 @command{rsync} or (under Windows) @command{pscp}. @value{tramp}
253 provides easy ways to specify these programs and customize them to
254 specific files, hosts, or access methods.
256 For faster small-size file transfers, @value{tramp} supports encoded
257 transfers directly through the shell using @command{mimencode} or
258 @command{uuencode} provided such tools are available on the remote
262 @subsubheading @value{tramp} behind the scenes
263 @cindex behind the scenes
264 @cindex details of operation
267 Accessing a remote file through @value{tramp} entails a series of
268 actions, many of which are transparent to the user. Yet some actions
269 may require user response (such as entering passwords or completing
270 file names). One typical scenario, opening a file on a remote host, is
271 presented here to illustrate the steps involved:
273 @kbd{C-x C-f} to initiate find-file, enter part of the @value{tramp}
274 file name, then hit @kbd{@key{TAB}} for completion. If this is the
275 first time connection to that host, here's what happens:
279 @value{tramp} invokes @samp{telnet @var{host}} or @samp{rsh @var{host}
280 -l @var{user}} and establishes an external process to connect to the
281 remote host. @value{tramp} communicates with the process through an
282 @value{emacsname} buffer, which also shows output from the remote
286 The remote host may prompt for a login name (for @command{telnet}, for
287 example) in the buffer. If on the other hand, the login name was
288 included in the file name portion, @value{tramp} sends the login name
289 followed by a newline.
292 The remote host may then prompt for a password or pass phrase (for
293 @command{rsh} or for @command{telnet}). @value{tramp} displays the
294 password prompt in the minibuffer. @value{tramp} then sends whatever
295 is entered to the remote host, followed by a newline.
298 @value{tramp} now waits for either the shell prompt or a failed login
301 If @value{tramp} does not receive any messages within a timeout period
302 (a minute, for example), then @value{tramp} responds with an error
303 message about not finding the remote shell prompt. If any messages
304 from the remote host, @value{tramp} displays them in the buffer.
306 For any @samp{login failed} message from the remote host,
307 @value{tramp} aborts the login attempt, and repeats the login steps
311 Upon successful login and @value{tramp} recognizes the shell prompt
312 from the remote host, @value{tramp} prepares the shell environment by
313 turning off echoing, setting shell prompt, and other housekeeping
316 @strong{Note} that for the remote shell, @value{tramp} invokes
317 @command{/bin/sh}. The remote host must recognize @samp{exec /bin/sh}
318 and execute the appropriate shell. This shell must support Bourne
322 @value{tramp} executes @command{cd} and @command{ls} commands to find
323 which files exist on the remote host. @value{tramp} sometimes uses
324 @command{echo} with globbing. @value{tramp} checks if a file or
325 directory is writable with @command{test}. After each command,
326 @value{tramp} parses the output from the remote host for completing
330 After remote file name completion, @value{tramp} transfers the file
331 contents from the remote host.
333 For inline transfers, @value{tramp} sends a command, such as
334 @samp{mimencode -b /path/to/remote/file}, waits until the output has
335 accumulated in the buffer, decodes that output to produce the file's
338 For external transfers, @value{tramp} sends a command as follows:
340 rcp user@@host:/path/to/remote/file /tmp/tramp.4711
342 @value{tramp} reads the local temporary file @file{/tmp/tramp.4711}
343 into a buffer, and then deletes the temporary file.
346 Edit, modify, change the buffer contents as normal, and then save the
347 buffer wth @kbd{C-x C-s}.
350 @value{tramp} transfers the buffer contents to the remote host in
351 a reverse of the process using the appropriate inline or external
355 I hope this has provided you with a basic overview of what happens
356 behind the scenes when you open a file with @value{tramp}.
360 @node Obtaining Tramp
361 @chapter Obtaining Tramp.
362 @cindex obtaining Tramp
364 @value{tramp} is included as part of Emacs (since Emacs version 22.1).
366 @value{tramp} is also freely packaged for download on the Internet at
367 @uref{ftp://ftp.gnu.org/gnu/tramp/}.
369 @value{tramp} development versions are available on Git servers.
370 Development versions contain new and incomplete features.
372 One way to obtain from Git server is to visit the Savannah project
373 page at the following URL and then clicking on the Git link in the
374 navigation bar at the top.
377 @uref{http://savannah.gnu.org/projects/tramp/}
380 Another way is to follow the terminal session below:
383 ] @strong{cd ~/@value{emacsdir}}
384 ] @strong{git clone git://git.savannah.gnu.org/tramp.git}
388 From behind a firewall:
391 ] @strong{git config --global http.proxy http://user:pwd@@proxy.server.com:8080}
392 ] @strong{git clone http://git.savannah.gnu.org/r/tramp.git}
399 ] @strong{git clone login@@git.sv.gnu.org:/srv/git/tramp.git}
403 After one of the above commands, @file{~/@value{emacsdir}/tramp} will
404 containing the latest version of @value{tramp}.
407 To fetch updates from the repository, use git pull:
410 ] @strong{cd ~/@value{emacsdir}/tramp}
415 Run @command{autoconf} as follows to generate an up-to-date
416 @file{configure} script:
419 ] @strong{cd ~/@value{emacsdir}/tramp}
425 @chapter History of @value{tramp}
427 @cindex development history
429 @value{tramp} development started at the end of November 1998 as
430 @file{rssh.el}. It provided only one method of access. It used
431 @command{ssh} for login and @command{scp} to transfer file contents.
432 The name was changed to @file{rcp.el} before it got its preset name
433 @value{tramp}. New methods of remote access were added, so was support
436 April 2000 was the first time when multi-hop methods were added. In
437 July 2002, @value{tramp} unified file names with Ange-FTP@. In July
438 2004, proxy hosts replaced multi-hop methods. Running commands on
439 remote hosts was introduced in December 2005.
441 Support for gateways since April 2007.
444 GVFS integration started in February 2009.
447 Remote commands on Windows hosts since September 2011.
449 Ad-hoc multi-hop methods (with a changed syntax) re-enabled in November
452 In November 2012, added Juergen Hoetzel's @file{tramp-adb.el}.
454 In December 2001, XEmacs package repository adds @value{tramp}.
457 @c Installation chapter is necessary only in case of standalone
458 @c installation. Text taken from trampinst.texi.
459 @ifset installchapter
460 @include trampinst.texi
465 @chapter Configuring @value{tramp}
466 @cindex configuration
467 @cindex default configuration
469 @value{tramp} is initially configured to use the @command{scp} program
470 to connect to the remote host. Just type @kbd{C-x C-f} and then enter
471 file name @file{@trampf{user@@host,/path/to.file}}. For details,
472 see @xref{Default Method}.
474 For problems related to the behavior of remote shell, see @ref{Remote
475 shell setup} for details.
477 For changing the connection type and file access method from the
478 defaults to one of several other options, see (@pxref{Connection
481 @strong{Note} that some user options and variables described in these
482 examples are not auto loaded by @value{emacsname}. All examples
483 require @value{tramp} is installed and loaded:
491 * Connection types:: Types of connections to remote hosts.
492 * Inline methods:: Inline methods.
493 * External methods:: External methods.
495 * GVFS based methods:: GVFS based external methods.
498 * Gateway methods:: Gateway methods.
500 * Default Method:: Selecting a default method.
501 Here we also try to help those who
502 don't have the foggiest which method
504 * Default User:: Selecting a default user.
505 * Default Host:: Selecting a default host.
506 * Multi-hops:: Connecting to a remote host using multiple hops.
507 * Customizing Methods:: Using Non-Standard Methods.
508 * Customizing Completion:: Selecting config files for user/host name completion.
509 * Password handling:: Reusing passwords for several connections.
510 * Connection caching:: Reusing connection related information.
511 * Predefined connection information::
512 Setting own connection related information.
513 * Remote programs:: How @value{tramp} finds and uses programs on the remote host.
514 * Remote shell setup:: Remote shell setup hints.
515 * Android shell setup:: Android shell setup hints.
516 * Auto-save and Backup:: Auto-save and Backup.
517 * Windows setup hints:: Issues with Cygwin ssh.
521 @node Connection types
522 @section Types of connections to remote hosts
523 @cindex connection types, overview
525 @dfn{Inline method} and @dfn{external method} are the two basic types
526 of access methods. While they both use the same remote shell access
527 programs, such as @command{rsh}, @command{ssh}, or @command{telnet},
528 they differ in the file access methods. Choosing the right method
529 becomes important for editing files, transferring large files, or
530 operating on a large number of files.
532 @cindex inline methods
533 @cindex external methods
534 @cindex methods, inline
535 @cindex methods, external
537 The performance of the external methods is generally better than that
538 of the inline methods, at least for large files. This is caused by
539 the need to encode and decode the data when transferring inline.
541 The one exception to this rule are the @option{scp}-based access
542 methods. While these methods do see better performance when actually
543 transferring files, the overhead of the cryptographic negotiation at
544 startup may drown out the improvement in file transfer times.
546 External methods should be configured such a way that they don't
547 require a password (with @command{ssh-agent}, or such alike). Modern
548 @command{scp} implementations offer options to reuse existing
549 @command{ssh} connections, which will be enabled by default if
550 available. If it isn't possible, you should consider @ref{Password
551 handling}, otherwise you will be prompted for a password every copy
556 @section Inline methods
557 @cindex inline methods
558 @cindex methods, inline
560 Inline methods use the same login connection to transfer file
561 contents. Inline methods are quick and easy for small files. They
562 depend on the availability of suitable encoding and decoding programs
563 on the remote host. For local source and destination, @value{tramp}
564 may use built-in equivalents of such programs in @value{emacsname}.
566 Inline methods can work in situations where an external transfer
567 program is unavailable. Inline methods also work when transferring
568 files between different @emph{user identities} on the same host.
572 @cindex base-64 encoding
574 @value{tramp} checks the remote host for the availability and
575 usability of @command{mimencode} (part of the @command{metamail}
576 package) or @command{uuencode}. @value{tramp} uses the first reliable
577 command it finds. @value{tramp}'s search path can be customized, see
578 @ref{Remote programs}.
580 In case both @command{mimencode} and @command{uuencode} are
581 unavailable, @value{tramp} first transfers a small Perl program to the
582 remote host, and then tries that program for encoding and decoding.
584 To increase transfer speeds for large text files, use compression
585 before encoding. The variable @var{tramp-inline-compress-start-size}
586 specifies the file size for such optimization.
593 @command{rsh} is an option for connecting to hosts within local
594 networks since @command{rsh} is not as secure as other methods.
601 @command{ssh} is a more secure option than others to connect to a
604 @command{ssh} can also take extra parameters as port numbers. For
605 example, a host on port 42 is specified as @file{host#42} (the real
606 host name, a hash sign, then a port number). It is the same as passing
607 @code{-p 42} to the @command{ssh} command.
609 @item @option{telnet}
610 @cindex method telnet
611 @cindex telnet method
613 Connecting to a remote host with @command{telnet} is as insecure
614 as the @option{rsh} method.
621 Instead of connecting to a remote host, @command{su} program allows
622 editing as another user. The host can be either @samp{localhost} or
623 the host returned by the function @command{(system-name)}. See
624 @ref{Multi-hops} for an exception to this behavior.
630 Similar to @option{su} method, @option{sudo} uses @command{sudo}.
631 @command{sudo} must have sufficient rights to start a shell.
637 Works like @option{ssh} but without the extra authentication prompts.
638 @option{sshx} uses @samp{ssh -t -t @var{host} -l @var{user} /bin/sh}
639 to open a connection with a ``standard'' login shell.
641 @strong{Note} that @option{sshx} does not bypass authentication
642 questions. For example, if the host key of the remote host is not
643 known, @option{sshx} will still ask ``Are you sure you want to
644 continue connecting?''. @value{tramp} cannot handle such questions.
645 Connections will have to be setup where logins can proceed without
648 @option{sshx} is useful for Windows users when @command{ssh} triggers
649 an error about allocating a pseudo tty. This happens due to missing
650 shell prompts that confuses @value{tramp}.
652 @option{sshx} supports the @samp{-p} argument.
654 @item @option{krlogin}
655 @cindex method krlogin
656 @cindex krlogin method
657 @cindex Kerberos (with krlogin method)
659 This method is also similar to @option{ssh}. It uses the
660 @command{krlogin -x} command only for remote host login.
665 @cindex Kerberos (with ksu method)
667 This is another method from the Kerberos suite. It behaves like @option{su}.
674 @option{plink} method is for Windows users with the PuTTY
675 implementation of SSH@. It uses @samp{plink -ssh} to log in to the
678 Check the @samp{Share SSH connections if possible} control for that
681 @option{plink} method supports the @samp{-P} argument.
684 @item @option{plinkx}
685 @cindex method plinkx
686 @cindex plinkx method
688 Another method using PuTTY on Windows with session names instead of
689 host names. @option{plinkx} calls @samp{plink -load @var{session} -t}.
690 User names and port numbers must be defined in the session.
692 Check the @samp{Share SSH connections if possible} control for that
698 @node External methods
699 @section External methods
700 @cindex methods, external
701 @cindex external methods
703 External methods operate over multiple channels, using the remote
704 shell connection for some actions while delegating file transfers to
705 an external transfer program.
707 External methods save on the overhead of encoding and decoding of
710 Since external methods have the overhead of opening a new channel,
711 files smaller than @var{tramp-copy-size-limit} still use inline
715 @item @option{rcp}---@command{rsh} and @command{rcp}
718 @cindex rcp (with rcp method)
719 @cindex rsh (with rcp method)
721 This method uses the @command{rsh} and @command{rcp} commands to
722 connect to the remote host and transfer files. This is the fastest
723 access method available.
725 The alternative method @option{remcp} uses the @command{remsh} and
726 @command{rcp} commands.
728 @item @option{scp}---@command{ssh} and @command{scp}
731 @cindex scp (with scp method)
732 @cindex ssh (with scp method)
734 Using a combination of @command{ssh} to connect and @command{scp} to
735 transfer is the most secure. While the performance is good, it is
736 slower than the inline methods for smaller files. Though there is no
737 overhead of encoding and decoding of the inline methods,
738 @command{scp}'s cryptographic handshake negates those speed gains.
740 @option{ssh}-based methods support @samp{-p} feature for specifying
741 port numbers. For example, @file{host#42} passes @samp{-p 42} in the
742 argument list to @command{ssh}, and @samp{-P 42} in the argument list
745 @item @option{rsync}---@command{ssh} and @command{rsync}
748 @cindex rsync (with rsync method)
749 @cindex ssh (with rsync method)
751 @command{ssh} command to connect in combination with @command{rsync}
752 command to transfer is similar to the @option{scp} method.
754 @command{rsync} performs much better than @command{scp} when
755 transferring files that exist on both hosts. However, this advantage
756 is lost if the file exists only on one side of the connection.
758 This method supports the @samp{-p} argument.
761 @item @option{scpx}---@command{ssh} and @command{scp}
764 @cindex scp (with scpx method)
765 @cindex ssh (with scpx method)
767 @option{scpx} is useful to avoid login shell questions. It is similar
768 in performance to @option{scp}. @option{scpx} uses @samp{ssh -t -t
769 @var{host} -l @var{user} /bin/sh} to open a connection.
771 @option{sshx} is useful for Windows users when @command{ssh} triggers
772 an error about allocating a pseudo tty. This happens due to missing
773 shell prompts that confuses @value{tramp}.
775 This method supports the @samp{-p} argument.
778 @item @option{pscp}---@command{plink} and @command{pscp}
779 @item @option{psftp}---@command{plink} and @command{psftp}
782 @cindex pscp (with pscp method)
783 @cindex plink (with pscp method)
784 @cindex PuTTY (with pscp method)
787 @cindex pscp (with psftp method)
788 @cindex plink (with psftp method)
789 @cindex PuTTY (with psftp method)
791 These methods are similar to @option{scp} or @option{sftp}, but they
792 use the @command{plink} command to connect to the remote host, and
793 they use @command{pscp} or @command{psftp} for transferring the files.
794 These programs are part of PuTTY, an SSH implementation for Windows.
796 Check the @samp{Share SSH connections if possible} control for that
799 These methods support the @samp{-P} argument.
802 @item @option{fcp}---@command{fsh} and @command{fcp}
805 @cindex fsh (with fcp method)
806 @cindex fcp (with fcp method)
808 This method is similar to @option{scp}, but uses @command{fsh} to
809 connect and @command{fcp} to transfer files. @command{fsh/fcp}, a
810 front-end for @command{ssh}, reuse @command{ssh} session by
811 submitting several commands. This avoids the startup overhead due to
812 @command{scp}'s secure connection. Inline methods have similar
815 The command used for this connection is: @samp{fsh @var{host} -l
816 @var{user} /bin/sh -i}
821 @option{fsh} has no inline method since the multiplexing it offers is
822 not useful for @value{tramp}. @command{fsh} connects to remote host
823 and @value{tramp} keeps that one connection open.
825 @item @option{nc}---@command{telnet} and @command{nc}
828 @cindex nc (with nc method)
829 @cindex telnet (with nc method)
831 Using @command{telnet} to connect and @command{nc} to transfer files
832 is sometimes the only combination suitable for accessing routers or
833 NAS hosts. These dumb devices have severely restricted local shells,
834 such as the @command{busybox} and do not host any other encode or
841 When @value{tramp} uses @option{ftp}, it forwards requests to whatever
842 ftp program is specified by @value{ftppackagename}. This external
843 program must be capable of servicing requests from @value{tramp}.
846 This method works only for unified file names, see @ref{Issues}.
850 @item @option{smb}---@command{smbclient}
854 This non-native @value{tramp} method connects via the Server Message
855 Block (SMB) networking protocol to hosts running file servers that are
856 typically based on @url{https://www.samba.org/,,Samba} or MS Windows.
858 Using @command{smbclient} requires a few tweaks when working with
861 The first directory in the localname must be a share name on the
864 Since SMB shares end in the @code{$} character, @value{tramp} must use
865 @code{$$} when specifying those shares to avoid environment variable
868 When @value{tramp} is not specific about the share name or uses the
869 generic remote directory @code{/}, @command{smbclient} returns all
872 Since SMB authentication is based on each SMB share, @value{tramp}
873 prompts for a password even when accessing a different share on the
874 same SMB host. This prompting can be suppressed by @ref{Password
877 To accommodate user name/domain name syntax required by MS Windows
878 authorization, @value{tramp} provides for an extended syntax in
879 @code{user%domain} format (where user is username, @code{%} is the
880 percent symbol, and domain is the windows domain name). An example:
883 @trampfn{smb,daniel%BIZARRE@@melancholia,/daniel$$/.emacs}
886 where user @code{daniel} connects as a domain user to the SMB host
887 @code{melancholia} in the windows domain @code{BIZARRE} to edit
888 @file{.emacs} located in the home directory (share @code{daniel$}).
890 Alternatively, for local WINS users (as opposed to domain users),
891 substitute the domain name with the name of the local host in
892 UPPERCASE as shown here:
895 @trampfn{smb,daniel%MELANCHOLIA@@melancholia,/daniel$$/.emacs}
898 where user @code{daniel} connects as local user to the SMB host
899 @code{melancholia} in the local domain @code{MELANCHOLIA} to edit
900 @file{.emacs} located in the home directory (share @code{daniel$}).
902 The domain name and user name are optional for @command{smbclient}
903 authentication. When user name is not specified, @command{smbclient}
904 uses the anonymous user (without prompting for password). This
905 behavior is unlike other @value{tramp} methods, where local user name
908 The @option{smb} method is unavailable if @value{emacsname} is run under a
909 local user authentication context in MS Windows. However such users
910 can still access remote files using UNC file names instead of @value{tramp}:
913 //melancholia/daniel$$/.emacs
916 UNC file name specification does not allow the specification of a
917 different user name for authentication like the @command{smbclient}
925 This method uses Android Debug Bridge program for accessing Android
926 devices. The Android Debug Bridge must be installed locally for
927 @value{tramp} to work. Some GNU/Linux distributions provide Android
928 Debug Bridge as an installation package. Alternatively, the program is
929 installed as part of the Android SDK@. @value{tramp} finds the
930 @command{adb} program either via the @env{PATH} environment variable
931 or the absolute path set in the variable @var{tramp-adb-program}.
933 @value{tramp} connects to Android devices with @option{adb} only when
934 the custom option @option{tramp-adb-connect-if-not-connected} is not
935 @code{nil}. Otherwise, the connection must be established outside
938 @value{tramp} does not require a host name part of the remote file
939 name when a single Android device is connected to @command{adb}.
940 @value{tramp} instead uses @file{@trampfn{adb,,}} as the default
941 name. @command{adb devices} shows available host names.
943 @option{adb} method normally does not need user name to authenticate
944 on the Android device because it runs under the @command{adbd}
945 process. But when a user name is specified, however, @value{tramp}
946 applies an @command{su} in the syntax. When authentication does not
947 succeed, especially on un-rooted Android devices, @value{tramp}
948 displays login errors.
950 For Android devices connected through TCP/IP, a port number can be
951 specified using @file{device#42} host name syntax or @value{tramp} can
952 use the default value as declared in @command{adb} command. Port
953 numbers are not applicable to Android devices connected through USB@.
959 @node GVFS based methods
960 @section GVFS based external methods
961 @cindex methods, gvfs
962 @cindex gvfs based methods
965 GVFS is the virtual file system for the Gnome Desktop,
966 @uref{http://en.wikipedia.org/wiki/GVFS}. Remote files on GVFS are
967 mounted locally through FUSE and @value{tramp} uses this locally
968 mounted directory internally.
970 @value{emacsname} uses the D-Bus mechanism to communicate with GVFS@.
971 @value{emacsname} must have the message bus system, D-Bus integration
972 active, @pxref{Top, , D-Bus, dbus}.
979 This method is for connecting to remote hosts with the Apple Filing
980 Protocol for accessing files on Mac OS X volumes. @value{tramp} access
981 syntax requires a leading volume (share) name, for example:
982 @file{@trampfn{afp,user@@host,/volume}}.
991 @option{dav} method provides access to WebDAV files and directories
992 based on standard protocols, such as HTTP@. @option{davs} does the same
993 but with SSL encryption. Both methods support the port numbers.
999 OBEX is an FTP-like access protocol for cell phones and similar simple
1000 devices. @value{tramp} supports OBEX over Bluetooth.
1007 This method uses @command{sftp} in order to securely access remote
1008 hosts. @command{sftp} is a more secure option for connecting to hosts
1009 that for security reasons refuse @command{ssh} connections.
1011 @item @option{synce}
1012 @cindex method synce
1013 @cindex synce method
1015 @option{synce} method allows connecting to Windows Mobile devices. It
1016 uses GVFS for mounting remote files and directories via FUSE and
1017 requires the SYNCE-GVFS plugin.
1021 @defopt tramp-gvfs-methods
1022 @vindex tramp-gvfs-methods
1023 This custom option is a list of external methods for GVFS@. By
1024 default, this list includes @option{afp}, @option{dav}, @option{davs},
1025 @option{obex}, @option{sftp} and @option{synce}. Other methods to
1026 include are: @option{ftp} and @option{smb}.
1032 @node Gateway methods
1033 @section Gateway methods
1034 @cindex methods, gateway
1035 @cindex gateway methods
1037 Gateway methods are for proxy host declarations (@pxref{Multi-hops})
1038 so as to pass through firewalls and proxy servers. They are not like
1039 the other methods that declare direct connections to a remote host.
1041 A gateway method always comes with a port setting. @value{tramp}
1042 targets the port number with the gateway method
1043 @file{localhost#random_port} from where the firewall or proxy server
1046 Gateway methods support user name and password declarations for
1047 authenticating the corresponding firewall or proxy server. Such
1048 authentication can be passed through only if granted access by system
1052 @item @option{tunnel}
1053 @cindex method tunnel
1054 @cindex tunnel method
1056 This method implements an HTTP tunnel via the @command{CONNECT}
1057 command (conforming to RFC 2616, 2817 specifications). Proxy servers
1058 using HTTP version 1.1 or later protocol support this command.
1060 For authentication, this protocol uses only @option{Basic
1061 Authentication} (see RFC 2617). When no port number is specified, this
1062 protocol defaults to @option{8080}.
1065 @item @option{socks}
1066 @cindex method socks
1067 @cindex socks method
1069 The @option{socks} method connects to SOCKSv5 servers (see RFC 1928)
1070 and supports @option{Username/Password Authentication}.
1072 The default port number for the socks server is @option{1080}, if not
1073 specified otherwise.
1079 @node Default Method
1080 @section Selecting a default method
1081 @cindex default method
1082 @vindex tramp-default-method
1083 @vindex tramp-default-method-alist
1085 Default method is for transferring files. The variable
1086 @code{tramp-default-method} sets it. @value{tramp} uses this variable
1087 to determine the default method for tramp file names that do not have
1091 (setq tramp-default-method "ssh")
1094 Default methods for transferring files can be customized for specific
1095 user and host combinations through the alist variable
1096 @code{tramp-default-method-alist}.
1098 For example, the following two lines specify to use the @option{ssh}
1099 method for all user names matching @samp{john} and the @option{rsync}
1100 method for all host names matching @samp{lily}. The third line
1101 specifies to use the @option{su} method for the user @samp{root} on
1102 the host @samp{localhost}.
1105 (add-to-list 'tramp-default-method-alist '("" "john" "ssh"))
1106 (add-to-list 'tramp-default-method-alist '("lily" "" "rsync"))
1107 (add-to-list 'tramp-default-method-alist
1108 '("\\`localhost\\'" "\\`root\\'" "su"))
1112 See the documentation for the variable
1113 @code{tramp-default-method-alist} for details.
1116 External methods performance faster for large files.
1119 @xref{Inline methods}.
1120 @xref{External methods}.
1122 Choosing the access method also depends on the security environment.
1123 For example, @option{rsh} and @option{telnet} methods that use clear
1124 text password transfers are inappropriate for over the Internet
1125 connections. Secure remote connections should use @option{ssh} that
1129 @subsection Which method to use?
1130 @cindex choosing the right method
1132 @value{tramp} provides maximum number of choices for maximum
1133 flexibility. Choosing which method depends on the hosts, clients,
1134 network speeds, and the security context.
1136 Start by using an inline method.
1138 External methods might be more efficient for large files, but most
1139 @value{tramp} users edit small files more often than large files.
1141 Enable compression, @var{tramp-inline-compress-start-size}, for a
1142 performance boost for large files.
1144 Since @command{ssh} has become the most common method of remote host
1145 access and it has the most reasonable security protocols, use
1146 @option{ssh} method. Typical @option{ssh} usage to edit the
1147 @file{/etc/motd} file on the otherhost:
1150 @kbd{C-x C-f @trampfn{ssh,root@@otherhost,/etc/motd} @key{RET}}
1153 If @option{ssh} is unavailable for whatever reason, look for other
1154 obvious options. For Windows, try the @option{plink} method. For
1155 Kerberos, try @option{krlogin}.
1157 For editing local files as @option{su} or @option{sudo} methods, try
1158 the shortened syntax of @samp{root}:
1161 @kbd{C-x C-f @trampfn{su,,/etc/motd} @key{RET}}
1164 For editing large files, @option{scp} is faster than @option{ssh}.
1165 @option{pscp} is faster than @option{plink}. But this speed
1166 improvement is not always true.
1170 @section Selecting a default user
1171 @cindex default user
1172 @vindex tramp-default-user
1173 @vindex tramp-default-user-alist
1175 @value{tramp} file name can omit the user name part since
1176 @value{tramp} substitutes the currently logged-in user name. However
1177 this substitution can be overridden with @code{tramp-default-user}.
1181 (setq tramp-default-user "root")
1184 Instead of a single default user, @code{tramp-default-user-alist}
1185 allows multiple default user values based on access method or host
1186 name combinations. The alist can hold multiple values. For example, to
1187 use the @samp{john} as the default user for the domain
1188 @samp{somewhere.else} only:
1191 (add-to-list 'tramp-default-user-alist
1192 '("ssh" ".*\\.somewhere\\.else\\'" "john"))
1196 See the documentation for the variable @code{tramp-default-user-alist}
1199 A Caution: @value{tramp} will override any default user specified in
1200 the configuration files outside @value{emacsname}, such as
1201 @file{~/.ssh/config}. To stop @value{tramp} from applying the default
1202 value, set the corresponding alist entry to nil:
1205 (add-to-list 'tramp-default-user-alist
1206 '("ssh" "\\`here\\.somewhere\\.else\\'" nil))
1209 The last entry in @code{tramp-default-user-alist} should be reserved
1210 for catch-all or most often used login.
1213 (add-to-list 'tramp-default-user-alist
1214 '(nil nil "jonas") t)
1219 @section Selecting a default host
1220 @cindex default host
1221 @vindex tramp-default-host
1222 @vindex tramp-default-host-alist
1224 When host name is omitted, @value{tramp} substitutes the value from
1225 the @code{tramp-default-host} variable. It is initially populated with
1226 the local hostname where @value{emacsname} is running. Both the
1227 default user and default host can be overridden as follows:
1230 (setq tramp-default-user "john"
1231 tramp-default-host "target")
1234 With both defaults set, @samp{@trampfn{ssh,,}} will connect
1235 @value{tramp} to John's home directory on target.
1238 @strong{Note} @samp{/::} won't work, because @samp{/:} is the prefix
1239 for quoted file names.
1242 Instead of a single default host, @code{tramp-default-host-alist}
1243 allows multiple default host values based on access method or user
1244 name combinations. The alist can hold multiple values. While
1245 @code{tramp-default-host} is sufficient in most cases, some methods,
1246 like @option{adb}, require defaults overwritten.
1249 See the documentation for the variable @code{tramp-default-host-alist}
1254 @section Connecting to a remote host using multiple hops
1258 Multi-hops are methods to reach hosts behind firewalls or to reach the
1259 outside world from inside a bastion host. With multi-hops,
1260 @value{tramp} can negotiate these hops with the appropriate user/host
1261 authentication at each hop. All methods until now have been the single
1262 hop kind, where the start and end points of the connection did not
1263 have intermediate check points.
1265 @defopt tramp-default-proxies-alist
1266 @vindex tramp-default-proxies-alist
1267 @option{tramp-default-proxies-alist} specifies proxy hosts to pass
1268 through. This variable is list of triples consisting of (@var{host}
1269 @var{user} @var{proxy}).
1271 The first match is the proxy host through which passes the file name
1272 and the target host matching @var{user}@@@var{host}. @var{host} and
1273 @var{user} are regular expressions or @code{nil}, interpreted as a
1274 regular expression which always matches.
1276 @var{proxy} is a literal @value{tramp} file name whose local name part
1277 is ignored, and the method and user name parts are optional.
1280 The method must be an inline or gateway method (@pxref{Inline
1281 methods}, @pxref{Gateway methods}).
1284 The method must be an inline method (@pxref{Inline methods}).
1286 If @var{proxy} is @code{nil}, no additional hop is required reaching
1287 @var{user}@@@var{host}.
1289 For example, to pass through the host @samp{bastion.your.domain} as
1290 user @samp{bird} to reach remote hosts outside the local domain:
1293 (add-to-list 'tramp-default-proxies-alist
1294 '("\\." nil "@trampfn{ssh,bird@@bastion.your.domain,}"))
1295 (add-to-list 'tramp-default-proxies-alist
1296 '("\\.your\\.domain\\'" nil nil))
1299 @strong{Note}: @code{add-to-list} adds elements at the beginning of a
1300 list. Therefore, most relevant rules must come last in the list.
1302 Proxy hosts can be cascaded in the alist. If there is another host
1303 called @samp{jump.your.domain}, which is the only host allowed to
1304 connect to @samp{bastion.your.domain}, then:
1307 (add-to-list 'tramp-default-proxies-alist
1308 '("\\`bastion\\.your\\.domain\\'"
1310 "@trampfn{ssh,jump.your.domain,}"))
1313 @var{proxy} can take patterns @code{%h} or @code{%u} for @var{host} or
1314 @var{user} respectively.
1316 To login as @samp{root} on remote hosts in the domain
1317 @samp{your.domain}, but login as @samp{root} is disabled for non-local
1318 access, then use this alist entry:
1321 (add-to-list 'tramp-default-proxies-alist
1322 '("\\.your\\.domain\\'" "\\`root\\'" "@trampfn{ssh,%h,}"))
1325 Opening @file{@trampfn{sudo,randomhost.your.domain,}} first
1326 connects to @samp{randomhost.your.domain} via @code{ssh} under your
1327 account name, and then perform @code{sudo -u root} on that host.
1329 It is key for the sudo method in the above example to be applied on
1330 the host after reaching it and not on the local host.
1332 @var{host}, @var{user} and @var{proxy} can also take Lisp forms. These
1333 forms when evaluated must return either a string or @code{nil}.
1335 To generalize (from the previous example): For all hosts, except my
1336 local one, first connect via @command{ssh}, and then apply
1337 @command{sudo -u root}:
1340 (add-to-list 'tramp-default-proxies-alist
1341 '(nil "\\`root\\'" "@trampfn{ssh,%h,}"))
1342 (add-to-list 'tramp-default-proxies-alist
1343 '((regexp-quote (system-name)) nil nil))
1346 The above configuration allows @value{tramp} connection as @samp{root}
1347 to remote Ubuntu hosts.
1350 @code{tramp-default-proxies-alist} is also used for passing through
1351 firewalls or proxy servers.
1353 For example, the local host @samp{proxy.your.domain} on port 3128
1354 serves as HTTP proxy to the outer world. User has access rights to
1355 another proxy server on @samp{host.other.domain}.@footnote{HTTP tunnels
1356 are intended for secure SSL/TLS communication. Therefore, many proxy
1357 servers restrict the tunnels to related target ports. You might need
1358 to run your ssh server on your target host @samp{host.other.domain} on
1359 such a port, like 443 (https). See
1360 @uref{http://savannah.gnu.org/maintenance/CvsFromBehindFirewall} for
1361 discussion of ethical issues.} Then the configuration is:
1364 (add-to-list 'tramp-default-proxies-alist
1365 '("\\`host\\.other\\.domain\\'" nil
1366 "@trampfn{tunnel,proxy.your.domain#3128,}"))
1369 Gateway methods in a multiple hop chain can be declared only as the first hop.
1373 Passing through hops involves dealing with restricted shells, such as
1374 @command{rbash}. If @value{tramp} is made aware, then it would use
1375 them for proxies only.
1377 @defopt tramp-restricted-shell-hosts-alist
1378 @vindex tramp-restricted-shell-hosts-alist
1379 An alist of regular expressions of hosts running restricted shells,
1380 such as @command{rbash}. @value{tramp} will then use them only as
1383 To specify the bastion host from the example above as running a
1387 (add-to-list 'tramp-restricted-shell-hosts-alist
1388 "\\`bastion\\.your\\.domain\\'")
1393 @node Customizing Methods
1394 @section Using Non-Standard Methods
1395 @cindex customizing methods
1396 @cindex using non-standard methods
1397 @cindex create your own methods
1399 The @code{tramp-methods} variable currently has an exhaustive list of
1400 predefined methods. Any part of this list can be modified with more
1401 suitable settings. Refer to the Lisp documentation of that variable,
1402 accessible with @kbd{C-h v tramp-methods @key{RET}}.
1405 @node Customizing Completion
1406 @section Selecting config files for user/host name completion
1407 @cindex customizing completion
1408 @cindex selecting config files
1409 @vindex tramp-completion-function-alist
1411 @code{tramp-completion-function-alist} uses predefined files for user
1412 and host name completion (@pxref{File name completion}). For each
1413 method, it keeps a set of configuration files and a function that can
1414 parse that file. Each entry in @code{tramp-completion-function-alist}
1415 is of the form (@var{method} @var{pair1} @var{pair2} @dots{}).
1417 Each @var{pair} is composed of (@var{function} @var{file}).
1418 @var{function} is responsible for extracting user names and host names
1419 from @var{file} for completion. There are two functions which access
1422 @defun tramp-get-completion-function method
1423 This function returns the list of completion functions for @var{method}.
1427 (tramp-get-completion-function "rsh")
1429 @result{} ((tramp-parse-rhosts "/etc/hosts.equiv")
1430 (tramp-parse-rhosts "~/.rhosts"))
1434 @defun tramp-set-completion-function method function-list
1435 This function sets @var{function-list} as list of completion functions
1440 (tramp-set-completion-function "ssh"
1441 '((tramp-parse-sconfig "/etc/ssh_config")
1442 (tramp-parse-sconfig "~/.ssh/config")))
1444 @result{} ((tramp-parse-sconfig "/etc/ssh_config")
1445 (tramp-parse-sconfig "~/.ssh/config"))
1449 The following predefined functions parsing configuration files exist:
1452 @item @code{tramp-parse-rhosts}
1453 @findex tramp-parse-rhosts
1455 This function parses files which are syntactical equivalent to
1456 @file{~/.rhosts}. It returns both host names and user names, if
1459 @item @code{tramp-parse-shosts}
1460 @findex tramp-parse-shosts
1462 This function parses files which are syntactical equivalent to
1463 @file{~/.ssh/known_hosts}. Since there are no user names specified
1464 in such files, it can return host names only.
1466 @item @code{tramp-parse-sconfig}
1467 @findex tramp-parse-shosts
1469 This function returns the host nicknames defined by @code{Host} entries
1470 in @file{~/.ssh/config} style files.
1472 @item @code{tramp-parse-shostkeys}
1473 @findex tramp-parse-shostkeys
1475 SSH2 parsing of directories @file{/etc/ssh2/hostkeys/*} and
1476 @file{~/ssh2/hostkeys/*}. Hosts are coded in file names
1477 @file{hostkey_@var{portnumber}_@var{host-name}.pub}. User names
1478 are always @code{nil}.
1480 @item @code{tramp-parse-sknownhosts}
1481 @findex tramp-parse-shostkeys
1483 Another SSH2 style parsing of directories like
1484 @file{/etc/ssh2/knownhosts/*} and @file{~/ssh2/knownhosts/*}. This
1485 case, hosts names are coded in file names
1486 @file{@var{host-name}.@var{algorithm}.pub}. User names are always @code{nil}.
1488 @item @code{tramp-parse-hosts}
1489 @findex tramp-parse-hosts
1491 A function dedicated to @file{/etc/hosts} for host names.
1493 @item @code{tramp-parse-passwd}
1494 @findex tramp-parse-passwd
1496 A function which parses @file{/etc/passwd} files for user names.
1498 @item @code{tramp-parse-netrc}
1499 @findex tramp-parse-netrc
1501 A function which parses @file{~/.netrc} and @file{~/.authinfo}-style files.
1505 To keep a custom file with custom data in a custom structure, a custom
1506 function has to be provided. This function must meet the following
1509 @defun my-tramp-parse file
1510 @var{file} must be either a file on the host, or @code{nil}. The
1511 function must return a list of (@var{user} @var{host}), which are
1512 taken as candidates for completion for user and host names.
1516 (my-tramp-parse "~/.my-tramp-hosts")
1518 @result{} ((nil "toto") ("daniel" "melancholia"))
1523 @node Password handling
1524 @section Reusing passwords for several connections
1527 To avoid repeated prompts for passwords, consider native caching
1528 mechanisms, such as @command{ssh-agent} for @option{ssh}-like
1529 methods, or @command{pageant} for @option{plink}-like methods.
1531 @value{tramp} offers alternatives when native solutions cannot meet
1535 @anchor{Using an authentication file}
1536 @subsection Using an authentication file
1537 @vindex auth-sources
1539 The package @file{auth-source.el}, originally developed for No Gnus,
1540 reads passwords from different sources, @xref{Help for users, ,
1541 auth-source, auth}. The default authentication file is
1542 @file{~/.authinfo.gpg}, but this can be changed via the variable
1543 @code{auth-sources}.
1546 A typical entry in the authentication file:
1549 machine melancholia port scp login daniel password geheim
1552 The port can take any @value{tramp} method (@pxref{Inline methods},
1553 @pxref{External methods}). Omitting port values matches all
1554 @value{tramp} methods.
1556 Setting @code{auth-source-debug} to @code{t} to debug messages.
1559 @anchor{Caching passwords}
1560 @subsection Caching passwords
1562 @value{tramp} can cache passwords as entered and reuse when needed for
1563 the same user or host name independent of the access method.
1565 @vindex password-cache-expiry
1567 @code{password-cache-expiry} sets the duration (in seconds) the
1568 passwords are remembered. Passwords are never saved permanently nor
1569 can they extend beyond the lifetime of the current @value{emacsname}
1570 session. Set @code{password-cache-expiry} to @code{nil} to disable
1573 @vindex password-cache
1575 Set @code{password-cache} to @code{nil} to disable password caching.
1577 @strong{Implementation Note}: password caching depends on
1578 @file{password-cache.el} package. @value{tramp} activates password
1579 caching only if @value{tramp} can discover, while @value{emacsname} is
1580 loading, the package through @code{load-path}.
1582 @ifset installchapter
1583 @file{password.el} is available from No Gnus or from the @value{tramp}
1584 @file{contrib} directory, see @ref{Installation parameters}.
1588 @node Connection caching
1589 @section Reusing connection related information
1591 @vindex tramp-persistency-file-name
1593 For faster initial connection times, @value{tramp} stores previous
1594 connection properties in a file specified by the variable
1595 @code{tramp-persistency-file-name}.
1597 The default file name for @code{tramp-persistency-file-name} is:
1599 @file{~/.emacs.d/tramp}.
1602 @file{~/.xemacs/tramp}.
1605 @value{tramp} reads this file during @value{emacsname} startup, and
1606 writes to it when exiting @value{emacsname}. Delete this file for
1607 @value{tramp} to recreate a new one on next @value{emacsname} startup.
1609 Set @code{tramp-persistency-file-name} to @code{nil} to disable
1610 storing connections persistently.
1612 To reuse connection information from the persistent list,
1613 @value{tramp} needs to uniquely identify every host. However in some
1614 cases, two different connections may result in the same persistent
1615 information. For example, connecting to a host using @command{ssh} and
1616 connecting to the same host through @code{sshd} on port 3001. Both
1617 access methods result in nearly identical persistent specifications
1618 @file{@trampfn{ssh,localhost,}} and @file{@trampfn{ssh,localhost#3001,}}.
1620 Changing host names could avoid duplicates. One way is to add a
1621 @option{Host} section in @file{~/.ssh/config} (@pxref{Frequently Asked
1622 Questions}). Another way is to apply multiple hops (@pxref{Multi-hops}).
1624 When @value{tramp} detects a change in the operating system version in
1625 a remote host (via the command @command{uname -sr}), it flushes all
1626 connection related information for that host and creates a new entry.
1629 @node Predefined connection information
1630 @section Setting own connection related information
1631 @vindex tramp-connection-properties
1633 For more precise customization, parameters specified by
1634 @code{tramp-methods} can be overwritten manually.
1636 Set @code{tramp-connection-properties} to manually override
1637 @code{tramp-methods}. Properties in this list are in the form
1638 @code{(@var{regexp} @var{property} @var{value})}. @var{regexp} matches
1639 remote file names. Use @code{nil} to match all. @var{property} is the
1640 property's name, and @var{value} is the property's value.
1642 @var{property} is any method specific parameter contained in
1643 @code{tramp-methods}. The parameter key in @code{tramp-methods} is a
1644 symbol name @code{tramp-<foo>}. To overwrite that property, use the
1645 string @samp{<foo>} for @var{property}. For example, this changes the
1649 (add-to-list 'tramp-connection-properties
1650 (list (regexp-quote "@trampfn{ssh,user@@randomhost.your.domain,}")
1651 "remote-shell" "/bin/ksh"))
1652 (add-to-list 'tramp-connection-properties
1653 (list (regexp-quote "@trampfn{ssh,user@@randomhost.your.domain,}")
1654 "remote-shell-login" '("-")))
1657 The parameters @code{tramp-remote-shell} and
1658 @code{tramp-remote-shell-login} in @code{tramp-methods} now have new
1659 values for the remote host.
1661 @var{property} could also be any property found in
1662 @code{tramp-persistency-file-name}.
1664 To get around how restricted shells randomly drop connections, set the
1665 special property @samp{busybox}. For example:
1668 (add-to-list 'tramp-connection-properties
1669 (list (regexp-quote "@trampfn{ssh,user@@randomhost.your.domain,}")
1674 @node Remote programs
1675 @section How @value{tramp} finds and uses programs on the remote host
1677 @value{tramp} requires access to and rights to several commands on
1678 remote hosts: @command{ls}, @command{test}, @command{find} and
1681 Besides there are other required programs for @ref{Inline methods} and
1682 @ref{External methods} of connection.
1684 To improve performance and accuracy of remote file access,
1685 @value{tramp} uses @command{perl} (or @command{perl5}) and
1686 @command{grep} when available.
1688 @defopt tramp-remote-path
1689 @vindex tramp-remote-path
1690 @vindex tramp-default-remote-path
1691 @vindex tramp-own-remote-path
1692 @option{tramp-remote-path} specifies which remote directory paths
1693 @value{tramp} can search for @ref{Remote programs}.
1695 @value{tramp} uses standard defaults, such as @file{/bin} and
1696 @file{/usr/bin}, which are reasonable for most hosts. To accommodate
1697 differences in hosts and paths, for example, @file{/bin:/usr/bin} on
1699 @file{/usr/xpg4/bin:/usr/ccs/bin:/usr/bin:/opt/SUNWspro/bin} on
1700 Solaris, @value{tramp} queries the remote host with @command{getconf
1701 PATH} and updates the symbol @code{tramp-default-remote-path}.
1703 For instances where hosts keep obscure locations for paths for
1704 security reasons, manually add such paths to local @file{.emacs} as
1705 shown below for @value{tramp} to use when connecting.
1708 (add-to-list 'tramp-remote-path "/usr/local/perl/bin")
1711 Another way to find the remote path is to use the path assigned to the
1712 remote user by the remote host. @value{tramp} does not normally retain
1713 this remote path after logging. However, @code{tramp-own-remote-path}
1714 preserves the path value, which can be used to update
1715 @code{tramp-remote-path}.
1718 (add-to-list 'tramp-remote-path 'tramp-own-remote-path)
1722 When remote search paths are changed, local @value{tramp} caches must
1723 be recomputed. To force @value{tramp} to recompute afresh, exit
1724 @value{emacsname}, remove the persistent file (@pxref{Connection
1725 caching}), and restart @value{emacsname}.
1728 @node Remote shell setup
1729 @section Remote shell setup hints
1730 @cindex remote shell setup
1731 @cindex @file{.profile} file
1732 @cindex @file{.login} file
1733 @cindex shell init files
1735 @value{tramp} checks for the availability of standard programs in the
1736 usual locations. Common tactics include successively trying
1737 @command{test -e}, @command{/usr/bin/test -e}, and @command{/bin/test
1738 -e}. @command{ls -d} is another approach. But these approaches do not
1739 help with these new login patterns.
1741 When @value{tramp} encounters two-factor logins or additional challenge
1742 questions, such as entering birth date or security code or passphrase,
1743 @value{tramp} needs a few more configuration steps to accommodate
1746 The difference between a password prompt and a passphrase prompt is
1747 that the password for completing the login while the passphrase is
1748 for authorizing access to local authentication information, such as
1751 There is no one configuration to accommodate all the variations in
1752 login security, especially not the exotic ones. However, @value{tramp}
1753 provides a few tweaks to address the most common ones.
1756 @item @var{tramp-shell-prompt-pattern}
1757 @vindex tramp-shell-prompt-pattern
1759 @code{tramp-shell-prompt-pattern} is for remote login shell prompt,
1760 which may not be the same as the local login shell prompt,
1761 @code{shell-prompt-pattern}. Since most hosts use identical prompts,
1762 @value{tramp} sets a similar default value for both prompts.
1764 @item @var{tramp-password-prompt-regexp}
1765 @item @var{tramp-wrong-passwd-regexp}
1766 @vindex tramp-password-prompt-regexp
1767 @vindex tramp-wrong-passwd-regexp
1769 @value{tramp} uses @var{tramp-password-prompt-regexp} to distinguish
1770 between prompts for passwords and prompts for passphrases. By default,
1771 @var{tramp-password-prompt-regexp} handles the detection in English
1772 language environments. See a localization example below:
1776 tramp-password-prompt-regexp
1780 '("passphrase" "Passphrase"
1782 "password" "Password"
1784 "passwort" "Passwort"
1786 "mot de passe" "Mot de passe") t)
1790 Similar localization may be necessary for handling wrong password
1791 prompts, for which @value{tramp} uses @var{tramp-wrong-passwd-regexp}.
1793 @item @command{tset} and other questions
1794 @cindex Unix command tset
1795 @cindex tset Unix command
1796 @vindex tramp-terminal-type
1798 To suppress inappropriate prompts for terminal type, @value{tramp}
1799 sets the @env{TERM} to @code{dumb} before the remote login process
1800 begins via the variable @code{tramp-terminal-type}. This will silence
1801 common @command{tset} related prompts.
1803 @value{tramp}'s strategy for handling such prompts (commonly triggered
1804 from login scripts on remote hosts) is to set the environment
1805 variables so that no prompts interrupt the shell initialization
1808 @vindex tramp-actions-before-shell
1810 An alternative approach is to configure @value{tramp} with strings
1811 that can identify such questions using
1812 @code{tramp-actions-before-shell}. Example:
1815 (defconst my-tramp-prompt-regexp
1816 (concat (regexp-opt '("Enter the birth date of your mother:") t)
1818 "Regular expression matching my login prompt question.")
1820 (defun my-tramp-action (proc vec)
1821 "Enter \"19000101\" in order to give a correct answer."
1822 (save-window-excursion
1823 (with-current-buffer (tramp-get-connection-buffer vec)
1824 (tramp-message vec 6 "\n%s" (buffer-string))
1825 (tramp-send-string vec "19000101"))))
1827 (add-to-list 'tramp-actions-before-shell
1828 '(my-tramp-prompt-regexp my-tramp-action))
1832 @item Conflicting names for users and variables in @file{.profile}
1834 When a user name is the same as a variable name in a local file, such
1835 as @file{.profile}, then @value{tramp} may send incorrect values for
1836 environment variables. To avoid incorrect values, change the local
1837 variable name to something different from the user name. For example,
1838 if the user name is @env{FRUMPLE}, then change the variable name to
1842 @item Non-Bourne commands in @file{.profile}
1844 When the remote host's @file{.profile} is also used for shells other
1845 than Bourne shell, then some incompatible syntaxes for commands in
1846 @file{.profile} may trigger errors in Bourne shell on the host and may
1847 not complete client's @value{tramp} connections.
1849 One example of a Bourne shell incompatible syntax in @file{.profile}:
1850 using @command{export FOO=bar} instead of @command{FOO=bar; export
1851 FOO}. After remote login, @value{tramp} will trigger an error during
1852 its execution of @command{/bin/sh} on the remote host because Bourne
1853 shell does not recognize the export command as entered in
1856 Likewise, (@code{~}) character in paths will cause errors because
1857 Bourne shell does not do (@code{~}) character expansions.
1859 One approach to avoiding these incompatibilities is to make all
1860 commands in @file{~/.shrc} and @file{~/.profile} Bourne shell
1861 compatible so @value{tramp} can complete connections to that remote.
1862 To accommodate using non-Bourne shells on that remote, use other
1863 shell-specific config files. For example, bash can use
1864 @file{~/.bash_profile} and ignore @file{.profile}.
1867 @item Interactive shell prompt
1869 @value{tramp} redefines the remote shell prompt internally for robust
1870 parsing. This redefinition affects the looks of a prompt in an
1871 interactive remote shell through commands, such as @kbd{M-x
1872 shell}. Such prompts, however, can be reset to something more readable
1873 and recognizable using these @value{tramp} variables.
1875 @value{tramp} sets the @env{INSIDE_EMACS} variable in the startup
1876 script file @file{~/.emacs_SHELLNAME}.
1878 @env{SHELLNAME} is @code{bash} or equivalent shell names. Change it by
1879 setting the environment variable @env{ESHELL} in the @file{.emacs} as
1883 (setenv "ESHELL" "bash")
1886 Then re-set the prompt string in @file{~/.emacs_SHELLNAME} as follows:
1889 # Reset the prompt for remote Tramp shells.
1890 if [ "$@{INSIDE_EMACS/*tramp*/tramp@}" == "tramp" ] ; then
1897 @xref{Interactive Shell, , , @value{emacsdir}}.
1901 @item @command{busybox} / @command{nc}
1902 @cindex Unix command nc
1903 @cindex nc Unix command
1905 @value{tramp}'s @option{nc} method uses the @command{nc} command to
1906 install and execute a listener as follows (see @code{tramp-methods}):
1912 The above command-line syntax has changed with @command{busybox}
1913 versions. If @command{nc} refuses the @command{-p} parameter, then
1914 overwrite as follows:
1918 'tramp-connection-properties
1919 `(,(regexp-quote "192.168.0.1") "remote-copy-args" (("-l") ("%r"))))
1923 where @samp{192.168.0.1} is the remote host IP address
1924 (@pxref{Predefined connection information}).
1929 @node Android shell setup
1930 @section Android shell setup hints
1931 @cindex android shell setup
1933 @value{tramp} uses the @option{adb} method to access Android
1934 devices. Android devices provide a restricted shell access through an
1935 USB connection. The local host must have the Android SDK installed.
1937 Applications such as @code{SSHDroid} that run @command{sshd} process
1938 on the Android device can accept any @option{ssh}-based methods
1939 provided these settings are adjusted:
1941 @code{sh} must be specified for remote shell since Android devices do
1942 not provide @code{/bin/sh}. @code{sh} will then invoke whatever shell is
1943 installed on the device with this setting:
1946 (add-to-list 'tramp-connection-properties
1947 (list (regexp-quote "192.168.0.26") "remote-shell" "sh"))
1951 where @samp{192.168.0.26} is the Android device's IP address.
1952 (@pxref{Predefined connection information}).
1954 @value{tramp} requires preserving @env{PATH} environment variable from
1955 user settings. Android devices prefer @file{/system/xbin} path over
1956 @file{/system/bin}. Both of these are set as follows:
1959 (add-to-list 'tramp-remote-path 'tramp-own-remote-path)
1960 (add-to-list 'tramp-remote-path "/system/xbin")
1964 When the Android device is not @samp{rooted}, specify a writable
1965 directory for temporary files:
1968 (add-to-list 'tramp-remote-process-environment "TMPDIR=$HOME")
1972 Open a remote connection with the command @kbd{C-x C-f
1973 @trampfn{ssh,192.168.0.26#2222,}}, where @command{sshd} is listening on port
1976 To add a corresponding entry to the @file{~/.ssh/config} file
1977 (recommended), use this:
1981 HostName 192.168.0.26
1987 To use the host name @samp{android} instead of the IP address shown in
1988 the previous example, fix the connection properties as follows:
1991 (add-to-list 'tramp-connection-properties
1992 (list (regexp-quote "android") "remote-shell" "sh"))
1996 Open a remote connection with a more concise command @kbd{C-x C-f
1997 @trampfn{ssh,android,}}.
2000 @node Auto-save and Backup
2001 @section Auto-save and Backup configuration
2005 @vindex backup-directory-alist
2008 @vindex bkup-backup-directory-info
2011 To avoid @value{tramp} from saving backup files owned by root to
2012 locations accessible to others, default backup settings in
2014 @code{backup-directory-alist}
2017 @code{bkup-backup-directory-info}
2021 Here's a scenario where files could be inadvertently
2022 exposed. @value{emacsname} by default writes backup files to the same
2023 directory as the original files unless changed to another location,
2024 such as @file{~/.emacs.d/backups/}. Such a directory will also be used
2025 by default by @value{tramp} when using, say, a restricted file
2026 @file{@trampfn{su,root@@localhost,/etc/secretfile}}. The backup file
2027 of the secretfile is now owned by the user logged in from tramp and
2032 @code{backup-directory-alist}
2035 @code{bkup-backup-directory-info}
2037 is @code{nil} (the default), such problems do not occur.
2039 To ``turn off'' the backup feature for @value{tramp} files and stop
2040 @value{tramp} from saving to the backup directory, use this:
2044 (add-to-list 'backup-directory-alist
2045 (cons tramp-file-name-regexp nil))
2050 (require 'backup-dir)
2051 (add-to-list 'bkup-backup-directory-info
2052 (list tramp-file-name-regexp ""))
2058 Disabling backups can be targeted to just the @option{su} and
2059 @option{sudo} methods:
2062 (setq backup-enable-predicate
2064 (and (normal-backup-enable-predicate name)
2066 (let ((method (file-remote-p name 'method)))
2067 (when (stringp method)
2068 (member method '("su" "sudo"))))))))
2072 Another option is to create better backup file naming with user and
2073 host names prefixed to the file name. For example, transforming
2074 @file{/etc/secretfile} to
2075 @file{~/.emacs.d/backups/!su:root@@localhost:!etc!secretfile}, set the
2076 @value{tramp} variable
2078 @code{tramp-backup-directory-alist}
2081 @code{tramp-bkup-backup-directory-info}
2083 from the existing variable
2085 @code{backup-directory-alist}.
2088 @code{bkup-backup-directory-info}.
2091 Then @value{tramp} backs up to a file name that is transformed with a
2092 prefix consisting of the DIRECTORY name. This file name prefixing
2093 happens only when the DIRECTORY is an absolute local file name.
2100 (add-to-list 'backup-directory-alist
2101 (cons "." "~/.emacs.d/backups/"))
2102 (setq tramp-backup-directory-alist backup-directory-alist)
2107 (require 'backup-dir)
2108 (add-to-list 'bkup-backup-directory-info
2109 (list "." "~/.emacs.d/backups/" 'full-path))
2110 (setq tramp-bkup-backup-directory-info bkup-backup-directory-info)
2115 The backup file name of
2116 @file{@trampfn{su,root@@localhost,/etc/secretfile}} would be
2118 @file{@trampfn{su,root@@localhost,~/.emacs.d/backups/!su:root@@localhost:!etc!secretfile~}}
2121 @file{@trampfn{su,root@@localhost,~/.emacs.d/backups/![su!root@@localhost]!etc!secretfile~}}
2124 Just as for backup files, similar issues of file naming affect
2125 auto-saving @value{tramp} files.
2127 Auto-saved files are saved in the directory specified by the variable
2128 @code{auto-save-file-name-transforms}. By default this is set to the
2129 local temporary directory. But in some versions of Debian GNU/Linux,
2130 this points to the source directory where the @value{emacsname} was
2131 compiled. Reset such values to a valid directory.
2133 Set @code{auto-save-file-name-transforms} to @code{nil} to save
2134 auto-saved files to the same directory as the original file.
2136 Alternatively, set the variable @code{tramp-auto-save-directory} to
2137 direct all auto saves to that location.
2140 @code{auto-save-directory} can also be used here instead of other
2141 locations specified above.
2144 @node Windows setup hints
2145 @section Issues with Cygwin ssh
2146 @cindex Cygwin, issues
2148 This section is incomplete. Please share your solutions.
2150 @cindex method sshx with Cygwin
2151 @cindex sshx method with Cygwin
2153 Cygwin's @command{ssh} works only with a Cygwin version of
2154 @value{emacsname}. To check for compatibility: type @kbd{M-x eshell}, and
2155 start @kbd{ssh test.host}. Incompatibilities trigger this message:
2158 Pseudo-terminal will not be allocated because stdin is not a terminal.
2161 Some older versions of Cygwin's @command{ssh} work with the
2162 @option{sshx} access method. Consult Cygwin's FAQ at
2163 @uref{http://cygwin.com/faq/} for details.
2166 @cindex method scpx with Cygwin
2167 @cindex scpx method with Cygwin
2169 When using the @option{scpx} access method, @value{emacsname} may call
2170 @command{scp} with Windows file naming, such as @code{c:/foo}. But
2171 the version of @command{scp} that is installed with Cygwin does not
2172 know about Windows file naming, which causes it to incorrectly look
2173 for a host named @code{c}.
2175 A workaround: write a wrapper script for @option{scp} to convert
2176 Windows file names to Cygwin file names.
2178 @cindex Cygwin and ssh-agent
2179 @cindex SSH_AUTH_SOCK and @value{emacsname} on Windows
2181 When using the @command{ssh-agent} on Windows for password-less
2182 interaction, @option{ssh} methods depend on the environment variable
2183 @env{SSH_AUTH_SOCK}. But this variable is not set when
2184 @value{emacsname} is started from a Desktop shortcut and
2185 authentication fails.
2187 One workaround is to use a Windows based SSH Agent, such as
2188 Pageant. It is part of the Putty Suite of tools.
2190 The fallback is to start @value{emacsname} from a shell.
2194 @chapter Using @value{tramp}
2195 @cindex using @value{tramp}
2197 @value{tramp} operates transparently, accessing remote files as if
2198 they are local. However, @value{tramp} employs a formalized remote
2199 file naming syntax to perform its functions transparently. This
2200 syntax consists of many parts specifying access methods,
2201 authentication, host names, and file names.
2203 @value{ftppackagename} uses a similar syntax.
2208 Unlike opening local files in @value{emacsname}, which are
2209 instantaneous, opening remote files in @value{tramp} is slower at
2210 first. Sometimes there is a noticeable delay before the prompts for
2211 passwords or authentication appear in the minibuffer. Hitting
2212 @kbd{@key{RET}} or other keys during this gap will be processed by
2213 @value{emacsname}. This type-ahead facility is a feature of
2214 @value{emacsname} that may cause missed prompts when using
2218 * File name Syntax:: @value{tramp} file name conventions.
2219 * File name completion:: File name completion.
2220 * Ad-hoc multi-hops:: Declaring multiple hops in the file name.
2221 * Remote processes:: Integration with other @value{emacsname} packages.
2222 * Cleanup remote connections:: Cleanup remote connections.
2226 @node File name Syntax
2227 @section @value{tramp} file name conventions
2228 @cindex file name syntax
2229 @cindex file name examples
2231 @file{@trampf{host,localfilename}}
2232 opens file @var{localfilename} on the remote host @var{host}, using
2233 the default method. @xref{Default Method}.
2236 @item @value{prefix}melancholia@value{postfix}.emacs
2237 For the file @file{.emacs} located in the home directory, on the host
2240 @item @value{prefix}melancholia.danann.net@value{postfix}.emacs
2241 For the file @file{.emacs} specified using the fully qualified domain name of
2244 @item @value{prefix}melancholia@value{postfix}~/.emacs
2245 For the file @file{.emacs} specified using the @file{~}, which is expanded.
2247 @item @value{prefix}melancholia@value{postfix}~daniel/.emacs
2248 For the file @file{.emacs} located in @code{daniel}'s home directory
2249 on the host, @code{melancholia}. The @file{~<user>} construct is
2250 expanded to the home directory of that user on the remote host.
2252 @item @value{prefix}melancholia@value{postfix}/etc/squid.conf
2253 For the file @file{/etc/squid.conf} on the host @code{melancholia}.
2257 @var{host} can take IPv4 or IPv6 address, as in
2258 @file{@trampf{127.0.0.1,.emacs}} or
2259 @file{@trampf{@value{ipv6prefix}::1@value{ipv6postfix},.emacs}}.
2261 For syntactical reasons, IPv6 addresses must be embedded in square
2262 brackets @file{@value{ipv6prefix}} and @file{@value{ipv6postfix}}.
2265 By default, @value{tramp} will use the current local user name as the
2266 remote user name for log in to the remote host. Specifying a different
2267 name using the proper syntax will override this default behavior:
2270 @trampf{user@@host,path/to.file}
2273 @file{@trampf{daniel@@melancholia,.emacs}} is for file
2274 @file{.emacs} in @code{daniel}'s home directory on the host,
2277 Specify other file access methods (@pxref{Inline methods},
2278 @pxref{External methods}) as part of the file name.
2281 Method name comes before user name, as in
2282 @file{@value{prefix}@var{method}@value{postfixhop}} (Note the trailing
2286 This is done by replacing the initial @file{@value{prefix}} with
2287 @file{@value{prefix}@var{method}@value{postfixhop}} (Note the trailing
2290 The syntax specifications for user, host, and file do not change.
2292 To connect to the host @code{melancholia} as @code{daniel}, using
2293 @option{ssh} method for @file{.emacs} in @code{daniel}'s home
2294 directory, the full specification is:
2295 @file{@trampfn{ssh,daniel@@melancholia,.emacs}}.
2297 A remote file name containing a host name, which is the same string as
2298 a method name, is not allowed.
2300 For specifying port numbers, affix @file{#<port>} to the host
2301 name. For example: @file{@trampfn{ssh,daniel@@melancholia#42,.emacs}}.
2304 @node File name completion
2305 @section File name completion
2306 @cindex file name completion
2308 @value{tramp} can complete the following @value{tramp} file name
2309 components: method names, user names, host names, and file names
2310 located on remote hosts.
2312 Enable this by activating partial completion in @file{.emacs}.
2314 @xref{Completion Options, , , @value{emacsdir}}.
2318 For example, type @kbd{C-x C-f @value{prefix}t @key{TAB}},
2319 @value{tramp} completion choices show up as
2322 @c @multitable {@trampfn{telnet,melancholia.danann.net,}} {@trampfn{telnet,192.168.0.1,}}
2323 @multitable @columnfractions .5 .5
2325 @item @value{prefixhop}telnet@value{postfixhop} @tab tmp/
2326 @item @value{prefixhop}toto@value{postfix} @tab
2329 @item @value{prefixhop}telnet@value{postfixhop} @tab @value{prefixhop}toto@value{postfix}
2334 @samp{@value{prefixhop}telnet@value{postfixhop}}
2335 is a possible completion for the respective method,
2337 @samp{tmp/} stands for the directory @file{/tmp} on your local host,
2339 and @samp{@value{prefixhop}toto@value{postfix}}
2340 might be a host @value{tramp} has detected in your @file{~/.ssh/known_hosts}
2341 file (when using @option{ssh} as default method).
2343 Type @kbd{e @key{TAB}} for the minibuffer completion to
2344 @samp{@value{prefix}telnet@value{postfixhop}}. Typing @kbd{@key{TAB}}
2345 shows host names @value{tramp} from @file{/etc/hosts} file, for example.
2348 @multitable @columnfractions .5 .5
2349 @c @multitable {@trampfn{telnet,melancholia.danann.net,}} {@trampfn{telnet,192.168.0.1,}}
2350 @item @trampfn{telnet,127.0.0.1,} @tab @trampfn{telnet,192.168.0.1,}
2351 @c @item @trampfn{telnet,@value{ipv6prefix}::1@value{ipv6postfix},} @tab @trampfn{telnet,localhost,}
2352 @item @value{prefix}telnet@value{postfixhop}@value{ipv6prefix}::1@value{ipv6postfix}@value{postfix} @tab @trampfn{telnet,localhost,}
2353 @item @trampfn{telnet,melancholia.danann.net,} @tab @trampfn{telnet,melancholia,}
2357 Choose a host from the above list and then continue to complete file
2360 When the configuration (@pxref{Customizing Completion}) includes user
2361 names, then the completion lists will account for the user names as well.
2363 Remote hosts previously visited or hosts whose connections are kept
2364 persistently (@pxref{Connection caching}) will be included in the
2367 After remote host name completion comes completion of file names on
2368 the remote host. It works the same as with local host file completion,
2369 except that killing with double-slash @file{//} kills only the file
2370 name part of the @value{tramp} file name syntax.
2372 A triple-slash stands for the default behavior.
2375 @xref{Minibuffer File, , , @value{emacsdir}}.
2383 @kbd{C-x C-f @trampfn{telnet,melancholia,/usr/local/bin//etc} @key{TAB}}
2384 @print{} @trampfn{telnet,melancholia,/etc}
2386 @kbd{C-x C-f @trampfn{telnet,melancholia,//etc} @key{TAB}}
2389 @kbd{C-x C-f @trampfn{telnet,melancholia,/usr/local/bin///etc} @key{TAB}}
2394 @kbd{C-x C-f @trampfn{telnet,melancholia,/usr/local/bin//}}
2395 @print{} @trampfn{telnet,melancholia,/}
2397 @kbd{C-x C-f @trampfn{telnet,melancholia,//}}
2402 During file name completion, remote directory contents are re-read
2403 regularly to account for any changes in the filesystem that may affect
2404 the completion candidates. Such re-reads can account for changes to
2405 the file system by applications outside @value{emacsname}
2406 (@pxref{Connection caching}).
2408 @defopt tramp-completion-reread-directory-timeout
2409 @vindex tramp-completion-reread-directory-timeout
2410 The timeout is number of seconds since last remote command for
2411 rereading remote directory contents. 0 re-reads immediately during
2412 file name completion, @code{nil} uses cached directory contents.
2416 @node Ad-hoc multi-hops
2417 @section Declaring multiple hops in the file name
2418 @cindex multi-hop, ad-hoc
2419 @cindex proxy hosts, ad-hoc
2421 @value{tramp} file name syntax can accommodate ad hoc specification of
2422 multiple proxies without using @code{tramp-default-proxies-alist}
2423 configuration setup(@pxref{Multi-hops}).
2425 Each proxy is specified using the same syntax as the remote host
2426 specification minus the file name part. Each hop is separated by a
2427 @samp{|}. Chain the proxies from the starting host to the destination
2428 remote host name and file name. For example, hopping over a single
2429 proxy @samp{bird@@bastion} to a remote file on @samp{you@@remotehost}:
2432 @c @kbd{C-x C-f @trampfn{ssh@value{postfixhop}bird@@bastion|ssh,you,remotehost,/path}}
2433 @kbd{C-x C-f @value{prefix}ssh@value{postfixhop}bird@@bastion|ssh@value{postfixhop}you@@remotehost@value{postfix}/path}
2436 Proxies can take patterns @code{%h} or @code{%u}.
2438 @value{tramp} adds the ad-hoc definitions on the fly to
2439 @code{tramp-default-proxies-alist} and is available for re-use during
2440 that @value{emacsname} session. Subsequent @value{tramp} connections
2441 to the same remote host can then use the shortcut form:
2442 @samp{@trampfn{ssh,you@@remotehost,/path}}.
2444 @defopt tramp-save-ad-hoc-proxies
2445 @vindex tramp-save-ad-hoc-proxies
2446 For ad-hoc definitions to be saved automatically in
2447 @option{tramp-default-proxies-alist} for future @value{emacsname}
2448 sessions, set @option{tramp-save-ad-hoc-proxies}.
2451 (setq tramp-save-ad-hoc-proxies t)
2456 @node Remote processes
2457 @section Integration with other @value{emacsname} packages
2461 @value{tramp} supports starting new running processes on the remote
2462 host for discovering remote file names. @value{emacsname} packages on
2463 the remote host need no specific modifications for @value{tramp}'s
2466 This type of integration does not work with the @option{ftp} method,
2467 and does not support the pty association as specified in
2468 @code{start-file-process}.
2470 @code{process-file} and @code{start-file-process} work on the remote
2471 host when the variable @code{default-directory} is remote:
2474 (let ((default-directory "/ssh:remote.host:"))
2475 (start-file-process "grep" (get-buffer-create "*grep*")
2476 "/bin/sh" "-c" "grep -e tramp *"))
2481 Remote processes do not apply to GVFS (see @ref{GVFS based methods})
2482 because the remote file system is mounted on the local host and
2483 @value{tramp} just accesses by changing the @code{default-directory}.
2486 @value{tramp} starts a remote process when a command is executed in a
2487 remote file or directory buffer. As of now, these packages have been
2488 integrated to work with @value{tramp}: @file{compile.el} (commands
2489 like @code{compile} and @code{grep}) and @file{gud.el} (@code{gdb} or
2492 For @value{tramp} to find the command on the remote, it must be
2493 accessible through the default search path as setup by @value{tramp}
2494 upon first connection. Alternatively, use an absolute path or extend
2495 @code{tramp-remote-path} (see @ref{Remote programs}):
2498 (add-to-list 'tramp-remote-path "~/bin")
2499 (add-to-list 'tramp-remote-path "/appli/pub/bin")
2502 Customize @code{tramp-remote-process-environment} to suit the remote
2503 program's environment for the remote host.
2504 @code{tramp-remote-process-environment} is a list of strings
2505 structured similar to @code{process-environment}, where each element
2506 is a string of the form @samp{ENVVARNAME=VALUE}.
2508 To avoid any conflicts with local host variables set through local
2509 configuration files, such as @file{~/.profile}, use @samp{ENVVARNAME=}
2510 to unset them for the remote environment.
2513 Use @code{add-to-list} to add entries:
2516 (add-to-list 'tramp-remote-process-environment "JAVA_HOME=/opt/java")
2519 Modifying or deleting already existing values in the
2520 @code{tramp-remote-process-environment} list may not be feasible on
2521 restricted remote hosts. For example, some system administrators
2522 disallow changing @env{HISTORY} variable. To accommodate such
2523 restrictions when using @value{tramp}, fix the
2524 @code{tramp-remote-process-environment} by the following code in the
2525 local @file{.emacs} file:
2528 (let ((process-environment tramp-remote-process-environment))
2529 (setenv "HISTORY" nil)
2530 (setq tramp-remote-process-environment process-environment))
2533 @value{tramp} does not use the defaults specified in
2534 @code{process-environment} for running @code{process-file} or
2535 @code{start-file-process} on remote hosts. When values from
2536 @code{process-environment} are needed for remote processes, then set
2540 (let ((process-environment (cons "HGPLAIN=1" process-environment)))
2541 (process-file @dots{}))
2544 This works only for environment variables not already set in the
2545 @code{process-environment}.
2547 For integrating other @value{emacsname} packages so @value{tramp} can
2548 execute remotely, please file a bug report. @xref{Bug Reports}.
2551 @subsection Running remote programs that create local X11 windows
2553 To allow a remote program to create an X11 window on the local host,
2554 set the @env{DISPLAY} environment variable for the remote host as
2555 follows in the local @file{.emacs} file:
2558 (add-to-list 'tramp-remote-process-environment
2559 (format "DISPLAY=%s" (getenv "DISPLAY")))
2563 @code{(getenv "DISPLAY")} should return a recognizable name for the
2564 local host that the remote host can redirect X11 window
2565 interactions. If querying for a recognizable name is not possible for
2566 whatever reason, then replace @code{(getenv "DISPLAY")} with a
2567 hard-coded, fixed name. Note that using @code{:0} for X11 display name
2568 here will not work as expected.
2570 An alternate approach is specify @code{ForwardX11 yes} or
2571 @code{ForwardX11Trusted yes} in the file @file{~/.ssh/config} on the
2575 @subsection Running @code{shell} on a remote host
2578 Set @option{explicit-shell-file-name} to the appropriate shell name
2579 when using @value{tramp} between two hosts with different operating
2580 systems, such as @samp{windows-nt} and @samp{gnu/linux}. This option
2581 ensures the correct name of the remote shell program.
2584 Starting with Emacs 24, when @option{explicit-shell-file-name} is
2585 equal to @code{nil}, calling @code{shell} interactively will prompt
2590 @subsection Running @code{shell-command} on a remote host
2591 @cindex shell-command
2593 @code{shell-command} executes commands synchronously or asynchronously
2594 on remote hosts and displays output in buffers on the local
2598 @kbd{C-x C-f @trampfn{sudo,,} @key{RET}}
2599 @kbd{M-! tail -f /var/log/syslog.log & @key{RET}}
2602 @command{tail} command outputs continuously to the local buffer,
2603 @file{*Async Shell Command*}
2606 @kbd{M-x auto-revert-tail-mode} runs similarly showing continuous output.
2610 @subsection Running @code{eshell} on a remote host
2613 @value{tramp} is integrated into @file{eshell.el}, which enables
2614 interactive eshell sessions on remote hosts at the command prompt.
2615 You must add the module @code{eshell-tramp} to
2616 @code{eshell-modules-list}. Here's a sample interaction after opening
2617 @kbd{M-x eshell} on a remote host:
2620 @b{~ $} cd @trampfn{sudo,,/etc} @key{RET}
2621 @b{@trampfn{sudo,root@@host,/etc} $} hostname @key{RET}
2623 @b{@trampfn{sudo,root@@host,/etc} $} id @key{RET}
2624 uid=0(root) gid=0(root) groups=0(root)
2625 @b{@trampfn{sudo,root@@host,/etc} $} find-file shadow @key{RET}
2627 @b{@trampfn{sudo,root@@host,/etc} $}
2631 @code{eshell} in @value{emacsname} 23.2 added custom @code{su} and
2632 @code{sudo} commands that set the default directory correctly for the
2633 @file{*eshell*} buffer. @value{tramp} silently updates
2634 @code{tramp-default-proxies-alist} with an entry for this directory
2635 (@pxref{Multi-hops}):
2638 @b{~ $} cd @trampfn{ssh,user@@remotehost,/etc} @key{RET}
2639 @b{@trampfn{ssh,user@@remotehost,/etc} $} find-file shadow @key{RET}
2640 File is not readable: @trampfn{ssh,user@@remotehost,/etc/shadow}
2641 @b{@trampfn{ssh,user@@remotehost,/etc} $} sudo find-file shadow @key{RET}
2644 @b{@trampfn{ssh,user@@remotehost,/etc} $} su - @key{RET}
2645 @b{@trampfn{su,root@@remotehost,/root} $} id @key{RET}
2646 uid=0(root) gid=0(root) groups=0(root)
2647 @b{@trampfn{su,root@@remotehost,/root} $}
2652 @anchor{Running a debugger on a remote host}
2653 @subsection Running a debugger on a remote host
2658 @file{gud.el} provides a unified interface to symbolic debuggers
2661 (@ref{Debuggers, , , @value{emacsdir}}).
2664 @value{tramp} can run debug on remote hosts by calling @code{gdb}
2665 with a remote file name:
2668 @kbd{M-x gdb @key{RET}}
2669 @b{Run gdb (like this):} gdb --annotate=3 @trampfn{ssh,host,~/myprog} @key{RET}
2672 Relative file names are based on the remote default directory. When
2673 @file{myprog.pl} exists in @file{@trampfn{ssh,host,/home/user}},
2674 valid calls include:
2677 @kbd{M-x perldb @key{RET}}
2678 @b{Run perldb (like this):} perl -d myprog.pl @key{RET}
2681 Just the local part of a remote file name, such as @kbd{perl -d
2682 /home/user/myprog.pl}, is not possible.
2684 Arguments of the program to be debugged must be literal, can take
2685 relative or absolute paths, but not remote paths.
2688 @subsection Running remote processes on Windows hosts
2692 @command{winexe} runs processes on a remote Windows host, and
2693 @value{tramp} can use it for @code{process-file} and
2694 @code{start-file-process}.
2696 @code{tramp-smb-winexe-program} specifies the local @command{winexe}
2697 command. Powershell V2.0 on the remote host is required to run
2698 processes triggered from @value{tramp}.
2700 @option{explicit-shell-file-name} and @option{explicit-*-args} have to
2701 be set properly so @kbd{M-x shell} can open a proper remote shell on a
2702 Windows host. To open @command{cmd}, set it as follows:
2705 (setq explicit-shell-file-name "cmd"
2706 explicit-cmd-args '("/q"))
2710 To open @command{powershell} as a remote shell, use this:
2713 (setq explicit-shell-file-name "powershell"
2714 explicit-powershell-args '("-file" "-"))
2718 @node Cleanup remote connections
2719 @section Cleanup remote connections
2722 @value{tramp} provides several ways to flush remote connections.
2724 @deffn Command tramp-cleanup-connection vec
2725 This command flushes all connection related objects. @option{vec} is
2726 the internal representation of a remote connection. When called
2727 interactively, this command lists active remote connections in the
2728 minibuffer. Each connection is of the format
2729 @file{@trampfn{method,user@@host,}}. Flushing remote connections also
2731 cache (@pxref{Password handling}), file cache, connection cache
2732 (@pxref{Connection caching}), and connection buffers.
2735 @deffn Command tramp-cleanup-this-connection
2736 Flushes only the current buffer's remote connection objects, the same
2737 as in @code{tramp-cleanup-connection}.
2740 @deffn Command tramp-cleanup-all-connections
2741 Flushes all active remote connection objects, the same as in
2742 @code{tramp-cleanup-connection}.
2745 @deffn Command tramp-cleanup-all-buffers
2746 Just as for @code{tramp-cleanup-all-connections}, all remote
2747 connections are cleaned up in addition to killing buffers related to
2748 that remote connection.
2753 @chapter Reporting Bugs and Problems
2756 @value{tramp}'s development team is actively engaged in solving bugs
2757 and problems and looks to feature requests and suggestions.
2759 @value{tramp}'s mailing list is the place for more advice and
2760 information on working with @value{tramp}, solving problems,
2761 discussing, and general discussions about @value{tramp}.
2763 @value{tramp}'s mailing list is moderated but even non-subscribers can
2764 post for moderator approval. Sometimes this approval step may take as
2765 long as 48 hours due to public holidays.
2767 @email{tramp-devel@@gnu.org} is the mailing list. Messages sent to
2768 this address go to all the subscribers. This is @emph{not} the
2769 address to send subscription requests to.
2771 To subscribe to the mailing list, visit:
2772 @uref{http://lists.gnu.org/mailman/listinfo/tramp-devel/, the
2773 @value{tramp} Mail Subscription Page}.
2776 @ifset installchapter
2777 Before sending a bug report, run the test suite first @ref{Testing}.
2782 Check if the bug or problem is already addressed in @xref{Frequently
2785 Run @kbd{M-x tramp-bug} to generate a buffer with details of the
2786 system along with the details of the @value{tramp}
2787 installation. Please include these details with the bug report.
2789 The bug report must describe in as excruciating detail as possible the
2790 steps required to reproduce the problem. These details must include
2791 the setup of the remote host and any special or unique conditions that
2794 Include a minimal test case that reproduces the problem. This will
2795 help the development team find the best solution and avoid unrelated
2798 To exclude cache-related problems, flush all caches before running the
2799 test, @ref{Cleanup remote connections}.
2801 When including @value{tramp}'s messages in the bug report, increase
2802 the verbosity level to 6 (@pxref{Traces and Profiles, Traces}) in the
2803 @file{~/.emacs} file before repeating steps to the bug. Include the
2804 contents of the @file{*tramp/foo*} and @file{*debug tramp/foo*}
2805 buffers with the bug report.
2807 @strong{Note} that a verbosity level greater than 6 is not necessary
2808 at this stage. Also note that a verbosity level of 6 or greater, the
2809 contents of files and directories will be included in the debug
2810 buffer. Passwords typed in @value{tramp} will never be included
2814 @node Frequently Asked Questions
2815 @chapter Frequently Asked Questions
2816 @cindex frequently asked questions
2821 Where is the latest @value{tramp}?
2823 @value{tramp} is available at the GNU URL:
2826 @uref{ftp://ftp.gnu.org/gnu/tramp/}
2829 @value{tramp}'s GNU project page is located here:
2832 @uref{http://savannah.gnu.org/projects/tramp/}
2836 Which systems does it work on?
2838 The package works successfully on Emacs 22, Emacs 23, Emacs 24, Emacs
2839 25, XEmacs 21 (starting with 21.4), and SXEmacs 22.
2841 While Unix and Unix-like systems are the primary remote targets,
2842 @value{tramp} has equal success connecting to other platforms, such as
2843 MS Windows XP/Vista/7.
2847 How to speed up @value{tramp}?
2849 @value{tramp} does many things in the background, some of which
2850 depends on network speeds, response speeds of remote hosts, and
2851 authentication delays. During these operations, @value{tramp}'s
2852 responsiveness slows down. Some suggestions within the scope of
2853 @value{tramp}'s settings include:
2855 Use an external method, such as @option{scp}, which are faster than
2858 Keep the file @code{tramp-persistency-file-name}, which is where
2859 @value{tramp} caches remote information about hosts and files. Caching
2860 is enabled by default. Don't disable it.
2862 Set @code{remote-file-name-inhibit-cache} to @code{nil} if remote
2863 files are not independently updated outside @value{tramp}'s control.
2864 That cache cleanup will be necessary if the remote directories or
2865 files are updated independent of @value{tramp}.
2867 Set @code{tramp-completion-reread-directory-timeout} to @code{nil} to
2868 speed up completions, @ref{File name completion}.
2870 Disable version control to avoid delays:
2873 (setq vc-ignore-dir-regexp
2874 (format "\\(%s\\)\\|\\(%s\\)"
2875 vc-ignore-dir-regexp
2876 tramp-file-name-regexp))
2879 Disable excessive traces. Set @code{tramp-verbose} to 3 or lower,
2880 default being 3. Increase trace levels temporarily when hunting for
2884 @value{tramp} does not connect to the remote host
2886 Three main reasons for why @value{tramp} does not connect to the remote host:
2890 Unknown characters in the prompt
2892 @value{tramp} needs a clean recognizable prompt on the remote host for
2893 accurate parsing. Shell prompts that contain escape sequences for
2894 coloring cause parsing problems. @ref{Remote shell setup} for
2895 customizing prompt detection using regular expressions.
2897 To check if the remote host's prompt is being recognized, use this
2898 test: switch to @value{tramp} connection buffer @file{*tramp/foo*},
2899 put the cursor at the top of the buffer, and then apply the following
2903 @kbd{M-: (re-search-forward (concat tramp-shell-prompt-pattern "$"))}
2906 If the cursor has not moved to the prompt at the bottom of the buffer,
2907 then @value{tramp} has failed to recognize the prompt.
2909 When using zsh on remote hosts, disable zsh line editor because zsh
2910 uses left-hand side and right-hand side prompts in parallel. Add the
2911 following line to @file{~/.zshrc}:
2914 [ $TERM = "dumb" ] && unsetopt zle && PS1='$ '
2917 When using fish shell on remote hosts, disable fancy formatting by
2918 adding the following to @file{~/.config/fish/config.fish}:
2921 function fish_prompt
2922 if test $TERM = "dumb"
2930 When using WinSSHD on remote hosts, @value{tramp} do not recognize the
2931 strange prompt settings.
2934 Echoed characters after login
2936 @value{tramp} suppresses echos from remote hosts with the
2937 @command{stty -echo} command. But sometimes it is too late to suppress
2938 welcome messages from the remote host containing harmful control
2939 characters. Using @option{sshx} or @option{scpx} methods can avoid
2940 this problem because they allocate a pseudo tty. @xref{Inline
2944 @value{tramp} stops transferring strings longer than 500 characters
2946 Set @code{tramp-chunksize} to 500 to get around this problem, which is
2947 related to faulty implementation of @code{process-send-string} on
2948 HP-UX, FreeBSD and Tru64 Unix systems. Consult the documentation for
2949 @code{tramp-chunksize} to see when this is necessary.
2951 Set @code{file-precious-flag} to @code{t} for files accessed by
2952 @value{tramp} so the file contents are checked using checksum by
2953 first saving to a temporary file.
2955 @pxref{Saving Buffers, , , elisp}
2962 (when (file-remote-p default-directory)
2963 (set (make-local-variable 'file-precious-flag) t))))
2969 @value{tramp} does not recognize if a @command{ssh} session hangs
2971 @command{ssh} sessions on the local host hang when the network is
2972 down. @value{tramp} cannot safely detect such hangs. The network
2973 configuration for @command{ssh} can be configured to kill such hangs
2974 with the following command in the @file{~/.ssh/config}:
2978 ServerAliveInterval 5
2983 @value{tramp} does not use default @command{ssh} @code{ControlPath}
2985 @value{tramp} overwrites @code{ControlPath} settings when initiating
2986 @command{ssh} sessions. @value{tramp} does this to fend off a stall
2987 if a master session opened outside the @value{emacsname} session is no
2988 longer open. That is why @value{tramp} prompts for the password again
2989 even if there is an @command{ssh} already open.
2991 Some @command{ssh} versions support a @code{ControlPersist} option,
2992 which allows you to set the @code{ControlPath} provided the variable
2993 @code{tramp-ssh-controlmaster-options} is customized as follows:
2996 (setq tramp-ssh-controlmaster-options
2998 "-o ControlPath=/tmp/ssh-ControlPath-%%r@@%%h:%%p "
2999 "-o ControlMaster=auto -o ControlPersist=yes"))
3002 Note how "%r", "%h" and "%p" must be encoded as "%%r", "%%h" and
3005 If the @file{~/.ssh/config} is configured appropriately for the above
3006 behavior, then any changes to @command{ssh} can be suppressed with
3007 this @code{nil} setting:
3010 (setq tramp-use-ssh-controlmaster-options nil)
3015 File name completion does not work with @value{tramp}
3017 @acronym{ANSI} escape sequences from the remote shell may cause errors
3018 in @value{tramp}'s parsing of remote buffers.
3020 To test if this is the case, open a remote shell and check if the output
3021 of @command{ls} is in color.
3023 To disable @acronym{ANSI} escape sequences from the remote hosts,
3024 disable @option{--color=yes} or @option{--color=auto} in the remote
3025 host's @file{.bashrc} or @file{.profile}. Turn this alias on and off
3026 to see if file name completion works.
3029 File name completion does not work in directories with large number of
3032 This may be related to globbing, which is the use of shell's ability
3033 to expand wild card specifications, such as @samp{*.c}. For
3034 directories with large number of files, globbing might exceed the
3035 shell's limit on length of command lines and hang. @value{tramp} uses
3038 To test if globbing hangs, open a shell on the remote host and then
3039 run @samp{ls -d * ..?* > /dev/null}.
3041 When testing, ensure the remote shell is the same shell
3042 (@command{/bin/sh}, @command{ksh} or @command{bash}), that
3043 @value{tramp} uses when connecting to that host.
3047 How to get notified after @value{tramp} completes file transfers?
3049 Make @value{emacsname} beep after reading from or writing to the
3050 remote host with the following code in @file{~/.emacs} file.
3053 (defadvice tramp-handle-write-region
3054 (after tramp-write-beep-advice activate)
3055 "Make tramp beep after writing a file."
3059 (defadvice tramp-handle-do-copy-or-rename-file
3060 (after tramp-copy-beep-advice activate)
3061 "Make tramp beep after copying a file."
3065 (defadvice tramp-handle-insert-file-contents
3066 (after tramp-insert-beep-advice activate)
3067 "Make tramp beep after inserting a file."
3075 How to get a Visual Warning when working with @samp{root} privileges
3077 Get a modeline indication when working with @samp{root} privileges
3078 with the following code (tested with @value{emacsname} 22.1) in
3079 @file{~/.emacs} file:
3082 (defun my-mode-line-function ()
3083 (when (string-match "^/su\\(do\\)?:" default-directory)
3084 (setq mode-line-format
3085 (format-mode-line mode-line-format 'font-lock-warning-face))))
3087 (add-hook 'find-file-hook 'my-mode-line-function)
3088 (add-hook 'dired-mode-hook 'my-mode-line-function)
3095 How to get host indication in the mode line?
3097 The following code (tested with @value{emacsname} 22.1) in
3098 @file{~/.emacs} file shows it:
3101 (defconst my-mode-line-buffer-identification
3105 (if (file-remote-p default-directory)
3106 (tramp-file-name-host
3107 (tramp-dissect-file-name default-directory))
3109 (if (string-match "^[^0-9][^.]*\\(\\..*\\)" host-name)
3110 (substring host-name 0 (match-beginning 1))
3115 mode-line-buffer-identification
3116 my-mode-line-buffer-identification)
3122 mode-line-buffer-identification
3123 my-mode-line-buffer-identification)))
3126 The mode line in @value{emacsname} 23.1 and later versions now
3127 contains an indication if @code{default-directory} for the current
3128 buffer is on a remote host. Moreover, the corresponding tool-tip
3129 shows the remote host name. The above @code{:eval} clause can also be
3130 simplified to show the host name in the mode line:
3135 (or (file-remote-p default-directory 'host)
3137 (if (string-match "^[^0-9][^.]*\\(\\..*\\)" host-name)
3138 (substring host-name 0 (match-beginning 1))
3146 Remote host does not understand default options for directory listing
3148 @value{emacsname} computes the @command{dired} options based on the
3149 local host but if the remote host cannot understand the same
3150 @command{ls} command, then set them with a hook as follows:
3154 'dired-before-readin-hook
3156 (when (file-remote-p default-directory)
3157 (setq dired-actual-switches "-al"))))
3163 Why is @file{~/.sh_history} file on the remote host growing?
3165 Due to @command{ksh} saving tilde expansions triggered by
3166 @value{tramp}, the history file is probably growing rapidly. To fix,
3167 turn off saving history by putting this shell code in the
3171 if [ -f $HOME/.sh_history ] ; then
3172 /bin/rm $HOME/.sh_history
3174 if [ "$@{HISTFILE-unset@}" != "unset" ] ; then
3177 if [ "$@{HISTSIZE-unset@}" != "unset" ] ; then
3182 For @option{ssh}-based method, add the following line to your
3183 @file{~/.ssh/environment} file:
3191 How to shorten long file names when typing in @value{tramp}?
3193 Adapt several of these approaches to reduce typing. If the full name
3194 is @file{@trampfn{ssh,news@@news.my.domain,/opt/news/etc}}, then:
3199 Use default values for method name and user name:
3201 You can define default methods and user names for hosts,
3202 (@pxref{Default Method}, @pxref{Default User}):
3205 (setq tramp-default-method "ssh"
3206 tramp-default-user "news")
3209 The reduced typing: @kbd{C-x C-f @trampf{news.my.domain,/opt/news/etc}}.
3211 @strong{Note} that there are some useful shortcuts already. Accessing
3212 your local host as @samp{root} user, is possible just by @kbd{C-x C-f
3216 Use configuration options of the access method:
3218 Programs used for access methods already offer powerful configurations
3219 (@pxref{Customizing Completion}). For @option{ssh}, configure the
3220 file @file{~/.ssh/config}:
3224 HostName news.my.domain
3228 The reduced typing: @kbd{C-x C-f @trampfn{ssh,xy,/opt/news/etc}}.
3230 Depending on the number of files in the directories, host names
3231 completion can further reduce key strokes: @kbd{C-x C-f
3232 @value{prefix}ssh@value{postfixhop}x @key{TAB}}.
3235 Use environment variables to expand long strings
3237 For long file names, set up environment variables that are expanded in
3238 the minibuffer. Environment variables are set either outside
3239 @value{emacsname} or inside @value{emacsname} with Lisp:
3242 (setenv "xy" "@trampfn{ssh,news@@news.my.domain,/opt/news/etc/}")
3245 The reduced typing: @kbd{C-x C-f $xy @key{RET}}.
3247 @strong{Note} that file name cannot be edited here because the
3248 environment variables are not expanded during editing in the
3251 @item Define own keys:
3253 Redefine another key sequence in @value{emacsname} for @kbd{C-x C-f}:
3257 [(control x) (control y)]
3263 "@trampfn{ssh,news@@news.my.domain,/opt/news/etc/}"))))
3266 Simply typing @kbd{C-x C-y} would prepare minibuffer editing of file
3269 See @uref{http://www.emacswiki.org/cgi-bin/wiki/TrampMode, the Emacs
3270 Wiki} for a more comprehensive example.
3273 Define own abbreviation (1):
3275 Abbreviation list expansion can be used to reduce typing long file names:
3279 'directory-abbrev-alist
3280 '("^/xy" . "@trampfn{ssh,news@@news.my.domain,/opt/news/etc/}"))
3283 The reduced typing: @kbd{C-x C-f /xy @key{RET}}.
3285 @strong{Note} that file name cannot be edited here because the
3286 environment variables are not expanded during editing in the
3290 Define own abbreviation (2):
3292 The @code{abbrev-mode} gives additional flexibility for editing in the
3296 (define-abbrev-table 'my-tramp-abbrev-table
3297 '(("xy" "@trampfn{ssh,news@@news.my.domain,/opt/news/etc/}")))
3300 'minibuffer-setup-hook
3303 (setq local-abbrev-table my-tramp-abbrev-table)))
3305 (defadvice minibuffer-complete
3306 (before my-minibuffer-complete activate)
3309 ;; If you use partial-completion-mode
3310 (defadvice PC-do-completion
3311 (before my-PC-do-completion activate)
3315 The reduced typing: @kbd{C-x C-f xy @key{TAB}}.
3317 The minibuffer expands for further editing.
3319 @item Use bookmarks:
3321 Use bookmarks to save Tramp file names.
3323 @pxref{Bookmarks, , , @value{emacsdir}}.
3326 Upon visiting a location with @value{tramp}, save it as a bookmark with
3328 @kbd{@key{menu-bar} @key{edit} @key{bookmarks} @key{set}}.
3331 @kbd{@key{menu-bar} @key{view} @key{bookmarks} @key{set}}.
3334 To revisit that bookmark:
3336 @kbd{@key{menu-bar} @key{edit} @key{bookmarks} @key{jump}}.
3339 @kbd{@key{menu-bar} @key{view} @key{bookmarks} @key{jump}}.
3342 @item Use recent files:
3350 remembers visited places.
3353 @pxref{File Conveniences, , , @value{emacsdir}}.
3356 @pxref{recent-files, , , edit-utils}.
3360 Keep remote file names in the recent list without have to check for
3361 their accessibility through remote access:
3368 (recent-files-initialize)
3372 (when (file-remote-p (buffer-file-name))
3373 (recent-files-make-permanent)))
3378 Reaching recently opened files:
3380 @kbd{@key{menu-bar} @key{file} @key{Open Recent}}.
3383 @kbd{@key{menu-bar} @key{Recent Files}}.
3387 @item Use filecache:
3389 Since @file{filecache} remembers visited places, add the remote
3390 directory to the cache:
3393 (eval-after-load "filecache"
3394 '(file-cache-add-directory
3395 "@trampfn{ssh,news@@news.my.domain,/opt/news/etc/}"))
3398 Then use directory completion in the minibuffer with @kbd{C-x C-f
3405 @file{bbdb} has a built-in feature for @value{ftppackagename} files,
3406 which also works for @value{tramp} file names.
3408 @pxref{bbdb-ftp, Storing FTP sites in the BBDB, , bbdb}.
3411 Load @file{bbdb} in @value{emacs}:
3418 Create a BBDB entry with @kbd{M-x bbdb-create-ftp-site}. Then specify
3419 a method and user name where needed. Examples:
3422 @kbd{M-x bbdb-create-ftp-site @key{RET}}
3423 @b{Ftp Site:} news.my.domain @key{RET}
3424 @b{Ftp Directory:} /opt/news/etc/ @key{RET}
3425 @b{Ftp Username:} ssh@value{postfixhop}news @key{RET}
3426 @b{Company:} @key{RET}
3427 @b{Additional Comments:} @key{RET}
3430 In BBDB buffer, access an entry by pressing the key @key{F}.
3435 Thanks to @value{tramp} users for contributing to these recipes.
3438 Why saved multi-hop file names do not work in a new @value{emacsname}
3441 When saving ad-hoc multi-hop @value{tramp} file names (@pxref{Ad-hoc
3442 multi-hops}) via bookmarks, recent files,
3446 or another package, use the full ad-hoc file name including all hops,
3448 @file{@trampfn{ssh,bird@@bastion|ssh@value{postfixhop}news.my.domain,/opt/news/etc}}.
3450 Alternatively, when saving abbreviated multi-hop file names
3451 @file{@trampfn{ssh,news@@news.my.domain,/opt/news/etc}}, the custom
3452 option @code{tramp-save-ad-hoc-proxies} must be set non-@code{nil}
3458 How to connect to a remote @value{emacsname} session using @value{tramp}?
3460 Configure Emacs Client
3462 (@pxref{Emacs Server, , , @value{emacsdir}}).
3465 Then on the remote host, start the Emacs Server:
3469 (setq server-host (system-name)
3474 If @code{(system-name)} of the remote host cannot be resolved on the
3475 local host, use IP address instead.
3477 Copy from the remote host the resulting file
3478 @file{~/.emacs.d/server/server} to the local host, to the same
3481 Then start Emacs Client from the command line:
3484 emacsclient @trampfn{ssh,user@@host,/file/to/edit}
3487 @code{user} and @code{host} refer to the local host.
3489 To make Emacs Client an editor for other programs, use a wrapper
3490 script @file{emacsclient.sh}:
3494 emacsclient @trampfn{ssh,$(whoami)@@$(hostname --fqdn),$1}
3497 Then change the environment variable @env{EDITOR} to point to the
3501 export EDITOR=/path/to/emacsclient.sh
3507 How to disable other packages from calling @value{tramp}?
3509 There are packages that call @value{tramp} without the user ever
3510 entering a remote file name. Even without applying a remote file
3511 syntax, some packages enable @value{tramp} on their own. How can users
3512 disable such features.
3518 Disable @value{tramp} file name completion:
3521 (custom-set-variables
3522 '(ido-enable-tramp-completion nil))
3528 Disable remote directory tracking mode:
3531 (rlogin-directory-tracking-mode -1)
3537 How to disable @value{tramp}?
3542 To keep @value{ftppackagename} as default the remote files access
3543 package, set this in @file{.emacs}:
3546 (setq tramp-default-method "ftp")
3553 @value{tramp} (and @value{ftppackagename}),
3558 set @code{tramp-mode} to @code{nil} in @file{.emacs}.
3561 (setq tramp-mode nil)
3565 To unload @value{tramp}, type @kbd{M-x tramp-unload-tramp}.
3567 Unloading @value{tramp} resets @value{ftppackagename} plugins also.
3573 @c For the developer
3574 @node Files directories and localnames
3575 @chapter How file names, directories and localnames are mangled and managed.
3578 * Localname deconstruction:: Splitting a localname into its component parts.
3580 * External packages:: Integrating with external Lisp packages.
3585 @node Localname deconstruction
3586 @section Splitting a localname into its component parts
3588 @value{tramp} package redefines lisp functions
3589 @code{file-name-directory} and @code{file-name-nondirectory} to
3590 accommodate the unique file naming syntax that @value{tramp} requires.
3592 The replacements dissect the file name, use the original handler for
3593 the localname, take that result, and then re-build the @value{tramp}
3594 file name. By relying on the original handlers for localnames,
3595 @value{tramp} benefits from platform specific hacks to the original
3600 @node External packages
3601 @section Integrating with external Lisp packages
3602 @subsection File name completion.
3604 For name completions in the minibuffer, @value{tramp} depends on the
3605 last input character to decide whether to look for method name
3606 completion or host name completion. For example, @kbd{C-x C-f
3607 @value{prefix}ssh@value{postfixhop} @key{TAB}} is not entirely clear
3608 if @option{ssh} is a method or a host name. But if the last input
3609 character was either @key{TAB}, @key{SPACE} or @kbd{?}, then
3610 @value{tramp} favors file name completion over host name completion.
3612 What about external packages using other characters to trigger file
3613 name completions? They must somehow signal this to @value{tramp}. Use
3614 the variable @code{non-essential} temporarily and bind it to
3615 non-@code{nil} value.
3618 (let ((non-essential t))
3623 @subsection File attributes cache.
3625 Keeping a local cache of remote file attributes in sync with the
3626 remote host is a time-consuming operation. Flushing and re-querying
3627 these attributes can tax @value{tramp} to a grinding halt on busy
3630 To get around these types of slow-downs in @value{tramp}'s
3631 responsiveness, set the @code{process-file-side-effects} to @code{nil}
3632 to stop @value{tramp} from flushing the cache. This is helpful in
3633 situations where callers to @code{process-file} know there are no file
3634 attribute changes. The let-bind form to accomplish this:
3637 (let (process-file-side-effects)
3641 For asynchronous processes, @value{tramp} uses a process sentinel to
3642 flush file attributes cache. When callers to @code{start-file-process}
3643 know beforehand no file attribute changes are expected, then the
3644 process sentinel should be set to the default state. In cases where
3645 the caller defines its own process sentinel, @value{tramp}'s process
3646 sentinel is overwritten. The caller can still flush the file
3647 attributes cache in its process sentinel with this code:
3650 (unless (memq (process-status proc) '(run open))
3651 (dired-uncache remote-directory))
3654 Since @value{tramp} traverses subdirectories starting with the
3655 root-directory, it is most likely sufficient to make the
3656 @code{default-directory} of the process buffer as the root directory.
3660 @node Traces and Profiles
3661 @chapter How to Customize Traces
3663 @value{tramp} messages are raised with verbosity levels ranging from 0
3664 to 10. @value{tramp} does not display all messages; only those with a
3665 verbosity level less than or equal to @code{tramp-verbose}.
3667 The verbosity levels are
3669 @w{ 0} silent (no @value{tramp} messages at all)
3670 @*@indent @w{ 1} errors
3671 @*@indent @w{ 2} warnings
3672 @*@indent @w{ 3} connection to remote hosts (default verbosity)
3673 @*@indent @w{ 4} activities
3674 @*@indent @w{ 5} internal
3675 @*@indent @w{ 6} sent and received strings
3676 @*@indent @w{ 7} file caching
3677 @*@indent @w{ 8} connection properties
3678 @*@indent @w{ 9} test commands
3679 @*@indent @w{10} traces (huge)
3681 With @code{tramp-verbose} greater than or equal to 4, messages are
3682 also written to a @value{tramp} debug buffer. Such debug buffers are
3683 essential to bug and problem analyses. For @value{tramp} bug reports,
3684 set the @code{tramp-verbose} level to 6 (@pxref{Bug Reports}).
3686 The debug buffer is in
3688 @ref{Outline Mode, , , @value{emacsdir}}.
3693 In this buffer, messages can be filtered by their level. To see
3694 messages up to verbosity level 5, enter @kbd{C-u 6 C-c C-q}.
3696 Other navigation keys are described in
3697 @ref{Outline Visibility, , , @value{emacsdir}}.
3700 @value{tramp} handles errors internally. But to get a Lisp backtrace,
3701 both the error and the signal have to be set as follows:
3704 (setq debug-on-error t
3708 To enable stepping through @value{tramp} function call traces, they
3709 have to be specifically enabled as shown in this code:
3713 (dolist (elt (all-completions "tramp-" obarray 'functionp))
3714 (trace-function-background (intern elt)))
3715 (untrace-function 'tramp-read-passwd)
3716 (untrace-function 'tramp-gw-basic-authentication)
3719 The buffer @file{*trace-output*} contains the output from the function
3720 call traces. Disable @code{tramp-read-passwd} and
3721 @code{tramp-gw-basic-authentication} to stop password strings from
3722 being written to @file{*trace-output*}.
3726 @chapter Debatable Issues and What Was Decided
3729 @item The uuencode method does not always work.
3731 @command{uudecode} on some systems cannot write to stdout, but
3732 @value{tramp} depends on encoding and decoding programs to be able to
3733 read from stdin and write to stdout.
3735 We can find ways to circumvent @command{uudecode}'s ability to write
3736 to stdout, such as writing to a temporary file and then piping that to
3739 But I have decided not to implement workarounds as they are too
3740 fragile to work reliably. Some on systems, @value{tramp} will not have
3743 @item The @value{tramp} file name syntax differs between Emacs and XEmacs.
3745 The Emacs maintainers wish to use a unified file name syntax for
3746 Ange-FTP and @value{tramp} so that users don't have to learn yet
3747 another syntax though it is okay to learn new extensions.
3749 For the XEmacs maintainers, the disruption from a unified file name
3750 syntax are not worth the gains. Firstly, the XEmacs package system
3751 relies on EFS for downloading new packages and therefore is already
3752 installed. On the other hand, @value{tramp} is not installed by
3753 default in XEmacs. Unifying will require @value{tramp} installed from
3757 @strong{Note:} To make the syntax similar to @value{ftppackagename},
3758 make this change to the init file:
3761 (setq tramp-unified-filenames t)
3765 To disable auto loading @value{emacsname} @value{tramp} package, set
3767 @file{@dots{}/xemacs-packages/lisp/tramp/auto-autoloads.el*} to
3770 When using unified file names, @value{emacsname} download sites are
3771 added to @code{tramp-default-method-alist} with default method of
3772 @option{ftp} @xref{Default Method} for proper working of the
3773 @value{emacsname} package system.
3775 The syntax for unified file names is described in the @value{tramp} manual
3776 for @value{emacsothername}.
3781 @node GNU Free Documentation License
3782 @appendix GNU Free Documentation License
3783 @include doclicense.texi
3786 @node Function Index
3787 @unnumbered Function Index
3791 @node Variable Index
3792 @unnumbered Variable Index
3797 @unnumbered Concept Index
3804 @c * Say something about the .login and .profile files of the remote
3806 @c * Explain how tramp.el works in principle: open a shell on a remote
3807 @c host and then send commands to it.
3808 @c * Consistent small or capitalized words especially in menus.
3809 @c * Make a unique declaration of @trampfn.