1 \input texinfo @c -*-texinfo-*-
2 @setfilename ../../info/tramp
4 @settitle TRAMP User Manual
7 @c This is *so* much nicer :)
10 @c In the Tramp CVS, the version number is auto-frobbed from
11 @c configure.ac, so you should edit that file and run
12 @c "autoconf && ./configure" to change the version number.
14 @c Additionally, flags are set with respect to the Emacs flavor; and
15 @c depending whether Tramp is packaged into (X)Emacs, or standalone.
17 @include trampver.texi
19 @c Macro for formatting a filename according to the repective syntax.
20 @c xxx and yyy are auxiliary macros in order to omit leading and
21 @c trailing whitespace. Not very elegant, but I don't know it better.
27 @macro yyy {one, two}@c
35 @macro trampfn {method, user, host, localname}@c
36 @value{prefix}@yyy{\method\,@value{postfixhop}}@yyy{\user\,@@}\host\@value{postfix}\localname\@c
40 Copyright @copyright{} 1999, 2000, 2001, 2002, 2003, 2004, 2005,
41 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
44 Permission is granted to copy, distribute and/or modify this document
45 under the terms of the GNU Free Documentation License, Version 1.3 or
46 any later version published by the Free Software Foundation; with no
47 Invariant Sections, with the Front-Cover texts being ``A GNU Manual'',
48 and with the Back-Cover Texts as in (a) below. A copy of the license
49 is included in the section entitled ``GNU Free Documentation License''.
51 (a) The FSF's Back-Cover Text is: ``You have the freedom to
52 copy and modify this GNU manual. Buying copies from the FSF
53 supports it in developing GNU and promoting software freedom.''
57 @c Entries for @command{install-info} to use
58 @dircategory @value{emacsname}
60 * TRAMP: (tramp). Transparent Remote Access, Multiple Protocol
61 @value{emacsname} remote file access via rsh and rcp.
65 @title @value{tramp} version @value{trampver} User Manual
66 @author by Daniel Pittman
67 @author based on documentation by Kai Gro@ss{}johann
75 @node Top, Overview, (dir), (dir)
76 @top @value{tramp} version @value{trampver} User Manual
78 This file documents @value{tramp} version @value{trampver}, a remote file
79 editing package for @value{emacsname}.
81 @value{tramp} stands for `Transparent Remote (file) Access, Multiple
82 Protocol'. This package provides remote file editing, similar to
83 @value{ftppackagename}.
85 The difference is that @value{ftppackagename} uses FTP to transfer
86 files between the local and the remote host, whereas @value{tramp} uses a
87 combination of @command{rsh} and @command{rcp} or other work-alike
88 programs, such as @command{ssh}/@command{scp}.
90 You can find the latest version of this document on the web at
91 @uref{http://www.gnu.org/software/tramp/}.
93 @c Pointer to the other Emacs flavor is necessary only in case of
94 @c standalone installation.
96 The manual has been generated for @value{emacsname}.
98 If you want to read the info pages for @value{emacsothername}, you
99 should read in @ref{Installation} how to create them.
102 If you're using the other Emacs flavor, you should read the
103 @uref{@value{emacsotherfilename}, @value{emacsothername}} pages.
109 This manual is also available as a @uref{@value{japanesemanual},
110 Japanese translation}.
113 The latest release of @value{tramp} is available for
114 @uref{ftp://ftp.gnu.org/gnu/tramp/, download}, or you may see
115 @ref{Obtaining Tramp} for more details, including the CVS server
118 @value{tramp} also has a @uref{http://savannah.gnu.org/projects/tramp/,
119 Savannah Project Page}.
122 There is a mailing list for @value{tramp}, available at
123 @email{tramp-devel@@gnu.org}, and archived at
124 @uref{http://lists.gnu.org/archive/html/tramp-devel/, the
125 @value{tramp} Mail Archive}.
127 Older archives are located at
128 @uref{http://sourceforge.net/mailarchive/forum.php?forum=tramp-devel,
129 SourceForge Mail Archive} and
130 @uref{http://www.mail-archive.com/emacs-rcp@@ls6.cs.uni-dortmund.de/,
132 @c in HTML output, there's no new paragraph.
141 * Overview:: What @value{tramp} can and cannot do.
145 * Obtaining Tramp:: How to obtain @value{tramp}.
146 * History:: History of @value{tramp}.
147 @ifset installchapter
148 * Installation:: Installing @value{tramp} with your @value{emacsname}.
150 * Configuration:: Configuring @value{tramp} for use.
151 * Usage:: An overview of the operation of @value{tramp}.
152 * Bug Reports:: Reporting Bugs and Problems.
153 * Frequently Asked Questions:: Questions and answers from the mailing list.
154 * Function Index:: @value{tramp} functions.
155 * Variable Index:: User options and variables.
156 * Concept Index:: An item for each concept.
160 * Files directories and localnames:: How file names, directories and localnames are mangled and managed.
161 * Traces and Profiles:: How to Customize Traces.
162 * Issues:: Debatable Issues and What Was Decided.
164 * GNU Free Documentation License:: The license for this documentation.
167 --- The Detailed Node Listing ---
169 @ifset installchapter
170 Installing @value{tramp} with your @value{emacsname}
172 * Installation parameters:: Parameters in order to control installation.
173 * Load paths:: How to plug-in @value{tramp} into your environment.
174 * Japanese manual:: Japanese manual.
178 Configuring @value{tramp} for use
180 * Connection types:: Types of connections made to remote machines.
181 * Inline methods:: Inline methods.
182 * External methods:: External methods.
184 * GVFS based methods:: GVFS based external methods.
187 * Gateway methods:: Gateway methods.
189 * Default Method:: Selecting a default method.
190 * Default User:: Selecting a default user.
191 * Default Host:: Selecting a default host.
192 * Multi-hops:: Connecting to a remote host using multiple hops.
193 * Customizing Methods:: Using Non-Standard Methods.
194 * Customizing Completion:: Selecting config files for user/host name completion.
195 * Password handling:: Reusing passwords for several connections.
196 * Connection caching:: Reusing connection related information.
197 * Remote Programs:: How @value{tramp} finds and uses programs on the remote machine.
198 * Remote shell setup:: Remote shell setup hints.
199 * Windows setup hints:: Issues with Cygwin ssh.
200 * Auto-save and Backup:: Auto-save and Backup.
204 * Filename Syntax:: @value{tramp} filename conventions.
205 * Alternative Syntax:: URL-like filename syntax.
206 * Filename completion:: Filename completion.
207 * Remote processes:: Integration with other @value{emacsname} packages.
208 * Cleanup remote connections:: Cleanup remote connections.
210 How file names, directories and localnames are mangled and managed
212 * Localname deconstruction:: Breaking a localname into its components.
214 * External packages:: Integration with external Lisp packages.
221 @chapter An overview of @value{tramp}
224 After the installation of @value{tramp} into your @value{emacsname}, you
225 will be able to access files on remote machines as though they were
226 local. Access to the remote file system for editing files, version
227 control, and @code{dired} are transparently enabled.
229 Your access to the remote machine can be with the @command{rsh},
230 @command{rlogin}, @command{telnet} programs or with any similar
231 connection method. This connection must pass @acronym{ASCII}
232 successfully to be usable but need not be 8-bit clean.
234 The package provides support for @command{ssh} connections out of the
235 box, one of the more common uses of the package. This allows
236 relatively secure access to machines, especially if @command{ftp}
239 Under Windows, @value{tramp} is integrated with the PuTTY package,
240 using the @command{plink} program.
242 The majority of activity carried out by @value{tramp} requires only that
243 the remote login is possible and is carried out at the terminal. In
244 order to access remote files @value{tramp} needs to transfer their content
245 to the local machine temporarily.
247 @value{tramp} can transfer files between the machines in a variety of ways.
248 The details are easy to select, depending on your needs and the
249 machines in question.
251 The fastest transfer methods for large files rely on a remote file
252 transfer package such as @command{rcp}, @command{scp}, @command{rsync}
253 or (under Windows) @command{pscp}.
255 If the remote copy methods are not suitable for you, @value{tramp} also
256 supports the use of encoded transfers directly through the shell.
257 This requires that the @command{mimencode} or @command{uuencode} tools
258 are available on the remote machine. These methods are generally
259 faster for small files.
261 @value{tramp} is still under active development and any problems you encounter,
262 trivial or major, should be reported to the @value{tramp} developers.
266 @subsubheading Behind the scenes
267 @cindex behind the scenes
268 @cindex details of operation
271 This section tries to explain what goes on behind the scenes when you
272 access a remote file through @value{tramp}.
274 Suppose you type @kbd{C-x C-f} and enter part of an @value{tramp} file name,
275 then hit @kbd{@key{TAB}} for completion. Suppose further that this is
276 the first time that @value{tramp} is invoked for the host in question. Here's
281 @value{tramp} discovers that it needs a connection to the host. So it
282 invokes @samp{telnet @var{host}} or @samp{rsh @var{host} -l
283 @var{user}} or a similar tool to connect to the remote host.
284 Communication with this process happens through an
285 @value{emacsname} buffer, that is, the output from the remote end
289 The remote host may prompt for a login name (for @command{telnet}).
290 The login name is given in the file name, so @value{tramp} sends the
291 login name and a newline.
294 The remote host may prompt for a password or pass phrase (for
295 @command{rsh} or for @command{telnet} after sending the login name).
296 @value{tramp} displays the prompt in the minibuffer, asking you for the
297 password or pass phrase.
299 You enter the password or pass phrase. @value{tramp} sends it to the remote
300 host, followed by a newline.
303 @value{tramp} now waits for the shell prompt or for a message that the login
306 If @value{tramp} sees neither of them after a certain period of time
307 (a minute, say), then it issues an error message saying that it
308 couldn't find the remote shell prompt and shows you what the remote
311 If @value{tramp} sees a @samp{login failed} message, it tells you so,
312 aborts the login attempt and allows you to try again.
315 Suppose that the login was successful and @value{tramp} sees the shell prompt
316 from the remote host. Now @value{tramp} invokes @command{/bin/sh} because
317 Bourne shells and C shells have different command
318 syntaxes.@footnote{Invoking @command{/bin/sh} will fail if your login
319 shell doesn't recognize @samp{exec /bin/sh} as a valid command.
320 Maybe you use the Scheme shell @command{scsh}@dots{}}
322 After the Bourne shell has come up, @value{tramp} sends a few commands to
323 ensure a good working environment. It turns off echoing, it sets the
324 shell prompt, and a few other things.
327 Now the remote shell is up and it good working order. Remember, what
328 was supposed to happen is that @value{tramp} tries to find out what files exist
329 on the remote host so that it can do filename completion.
331 So, @value{tramp} basically issues @command{cd} and @command{ls} commands and
332 also sometimes @command{echo} with globbing. Another command that is
333 often used is @command{test} to find out whether a file is writable or a
334 directory or the like. The output of each command is parsed for the
338 Suppose you are finished with filename completion, have entered @kbd{C-x
339 C-f}, a full file name and hit @kbd{@key{RET}}. Now comes the time to
340 transfer the file contents from the remote host to the local host so
341 that you can edit them.
343 See above for an explanation of how @value{tramp} transfers the file contents.
345 For inline transfers, @value{tramp} issues a command like @samp{mimencode -b
346 /path/to/remote/file}, waits until the output has accumulated in the
347 buffer that's used for communication, then decodes that output to
348 produce the file contents.
350 For external transfers, @value{tramp} issues a command like the
353 rcp user@@host:/path/to/remote/file /tmp/tramp.4711
355 It then reads the local temporary file @file{/tmp/tramp.4711} into a
356 buffer and deletes the temporary file.
359 You now edit the buffer contents, blithely unaware of what has happened
360 behind the scenes. (Unless you have read this section, that is.) When
361 you are finished, you type @kbd{C-x C-s} to save the buffer.
364 Again, @value{tramp} transfers the file contents to the remote host
365 either inline or external. This is the reverse of what happens when
369 I hope this has provided you with a basic overview of what happens
370 behind the scenes when you open a file with @value{tramp}.
374 @node Obtaining Tramp
375 @chapter Obtaining Tramp.
376 @cindex obtaining Tramp
378 @value{tramp} is freely available on the Internet and the latest
379 release may be downloaded from
380 @uref{ftp://ftp.gnu.org/gnu/tramp/}. This release includes the full
381 documentation and code for @value{tramp}, suitable for installation.
382 But GNU Emacs (22 or later) includes @value{tramp} already, and there
383 is a @value{tramp} package for XEmacs, as well. So maybe it is easier
384 to just use those. But if you want the bleeding edge, read
387 For the especially brave, @value{tramp} is available from CVS. The CVS
388 version is the latest version of the code and may contain incomplete
389 features or new issues. Use these versions at your own risk.
391 Instructions for obtaining the latest development version of @value{tramp}
392 from CVS can be found by going to the Savannah project page at the
393 following URL and then clicking on the CVS link in the navigation bar
397 @uref{http://savannah.gnu.org/projects/tramp/}
400 Or follow the example session below:
403 ] @strong{cd ~/@value{emacsdir}}
404 ] @strong{export CVS_RSH="ssh"}
405 ] @strong{cvs -z3 -d:pserver:anonymous@@cvs.savannah.gnu.org:/sources/tramp co tramp}
409 You should now have a directory @file{~/@value{emacsdir}/tramp}
410 containing the latest version of @value{tramp}. You can fetch the latest
411 updates from the repository by issuing the command:
414 ] @strong{cd ~/@value{emacsdir}/tramp}
415 ] @strong{export CVS_RSH="ssh"}
416 ] @strong{cvs update -d}
420 Once you've got updated files from the CVS repository, you need to run
421 @command{autoconf} in order to get an up-to-date @file{configure}
425 ] @strong{cd ~/@value{emacsdir}/tramp}
431 @chapter History of @value{tramp}
433 @cindex development history
435 Development was started end of November 1998. The package was called
436 @file{rssh.el}, back then. It only provided one method to access a
437 file, using @command{ssh} to log in to a remote host and using
438 @command{scp} to transfer the file contents. After a while, the name
439 was changed to @file{rcp.el}, and now it's @value{tramp}. Along the way,
440 many more methods for getting a remote shell and for transferring the
441 file contents were added. Support for VC was added.
443 After that, there were added the multi-hop methods in April 2000 and
444 the unification of @value{tramp} and Ange-FTP filenames in July 2002.
445 In July 2004, multi-hop methods have been replaced by proxy hosts.
446 Running commands on remote hosts was introduced in December 2005.
448 Support of gateways exists since April 2007.
451 GVFS integration started in February 2009.
454 Storing files into IMAP mailboxes has been added in September 2009.
457 In December 2001, @value{tramp} has been added to the XEmacs package
458 repository. Being part of the GNU Emacs repository happened in June
459 2002, the first release including @value{tramp} was GNU Emacs 22.1.
461 @value{tramp} is also a GNU/Linux Debian package since February 2001.
464 @c Installation chapter is necessary only in case of standalone
465 @c installation. Text taken from trampinst.texi.
466 @ifset installchapter
467 @include trampinst.texi
471 @chapter Configuring @value{tramp} for use
472 @cindex configuration
474 @cindex default configuration
475 @value{tramp} is (normally) fully functional when it is initially
476 installed. It is initially configured to use the @command{scp}
477 program to connect to the remote host. So in the easiest case, you
478 just type @kbd{C-x C-f} and then enter the filename
479 @file{@trampfn{, user, machine, /path/to.file}}.
481 On some hosts, there are problems with opening a connection. These are
482 related to the behavior of the remote shell. See @xref{Remote shell
483 setup}, for details on this.
485 If you do not wish to use these commands to connect to the remote
486 host, you should change the default connection and transfer method
487 that @value{tramp} uses. There are several different methods that @value{tramp}
488 can use to connect to remote machines and transfer files
489 (@pxref{Connection types}).
491 If you don't know which method is right for you, see @xref{Default
496 * Connection types:: Types of connections made to remote machines.
497 * Inline methods:: Inline methods.
498 * External methods:: External methods.
500 * GVFS based methods:: GVFS based external methods.
503 * Gateway methods:: Gateway methods.
505 * Default Method:: Selecting a default method.
506 Here we also try to help those who
507 don't have the foggiest which method
509 * Default User:: Selecting a default user.
510 * Default Host:: Selecting a default host.
511 * Multi-hops:: Connecting to a remote host using multiple hops.
512 * Customizing Methods:: Using Non-Standard Methods.
513 * Customizing Completion:: Selecting config files for user/host name completion.
514 * Password handling:: Reusing passwords for several connections.
515 * Connection caching:: Reusing connection related information.
516 * Remote Programs:: How @value{tramp} finds and uses programs on the remote machine.
517 * Remote shell setup:: Remote shell setup hints.
518 * Windows setup hints:: Issues with Cygwin ssh.
519 * Auto-save and Backup:: Auto-save and Backup.
523 @node Connection types
524 @section Types of connections made to remote machines.
525 @cindex connection types, overview
527 There are two basic types of transfer methods, each with its own
528 advantages and limitations. Both types of connection make use of a
529 remote shell access program such as @command{rsh}, @command{ssh} or
530 @command{telnet} to connect to the remote machine.
532 This connection is used to perform many of the operations that @value{tramp}
533 requires to make the remote file system transparently accessible from
534 the local machine. It is only when visiting files that the methods
537 @cindex inline methods
538 @cindex external methods
539 @cindex methods, inline
540 @cindex methods, external
541 Loading or saving a remote file requires that the content of the file
542 be transfered between the two machines. The content of the file can
543 be transfered using one of two methods: the @dfn{inline method} over
544 the same connection used to log in to the remote machine, or the
545 @dfn{external method} through another connection using a remote copy
546 program such as @command{rcp}, @command{scp} or @command{rsync}.
548 The performance of the external methods is generally better than that
549 of the inline methods, at least for large files. This is caused by
550 the need to encode and decode the data when transferring inline.
552 The one exception to this rule are the @command{scp} based transfer
553 methods. While these methods do see better performance when actually
554 transferring files, the overhead of the cryptographic negotiation at
555 startup may drown out the improvement in file transfer times.
557 External methods should be configured such a way that they don't
558 require a password (with @command{ssh-agent}, or such alike). Modern
559 @command{scp} implementations offer options to reuse existing
560 @command{ssh} connections, see method @command{scpc}. If it isn't
561 possible, you should consider @ref{Password handling}, otherwise you
562 will be prompted for a password every copy action.
566 @section Inline methods
567 @cindex inline methods
568 @cindex methods, inline
570 The inline methods in @value{tramp} are quite powerful and can work in
571 situations where you cannot use an external transfer program to connect.
572 Inline methods are the only methods that work when connecting to the
573 remote machine via telnet. (There are also strange inline methods which
574 allow you to transfer files between @emph{user identities} rather than
577 These methods depend on the existence of a suitable encoding and
578 decoding command on remote machine. Locally, @value{tramp} may be able to
579 use features of @value{emacsname} to decode and encode the files or
580 it may require access to external commands to perform that task.
584 @cindex base-64 encoding
585 @value{tramp} checks the availability and usability of commands like
586 @command{mimencode} (part of the @command{metamail} package) or
587 @command{uuencode} on the remote host. The first reliable command
588 will be used. The search path can be customized, see @ref{Remote
591 If both commands aren't available on the remote host, @value{tramp}
592 transfers a small piece of Perl code to the remote host, and tries to
593 apply it for encoding and decoding.
595 The variable @var{tramp-inline-compress-start-size} controls, whether
596 a file shall be compressed before encoding. This could increase
597 transfer speed for large text files.
605 Connect to the remote host with @command{rsh}. Due to the unsecure
606 connection it is recommended for very local host topology only.
608 On operating systems which provide the command @command{remsh} instead
609 of @command{rsh}, you can use the method @option{remsh}. This is true
610 for HP-UX or Cray UNICOS, for example.
617 Connect to the remote host with @command{ssh}. This is identical to
618 the previous option except that the @command{ssh} package is used,
619 making the connection more secure.
621 There are also two variants, @option{ssh1} and @option{ssh2}, that
622 call @samp{ssh -1} and @samp{ssh -2}, respectively. This way, you can
623 explicitly select whether you want to use the SSH protocol version 1
624 or 2 to connect to the remote host. (You can also specify in
625 @file{~/.ssh/config}, the SSH configuration file, which protocol
626 should be used, and use the regular @option{ssh} method.)
628 Two other variants, @option{ssh1_old} and @option{ssh2_old}, use the
629 @command{ssh1} and @command{ssh2} commands explicitly. If you don't
630 know what these are, you do not need these options.
632 All the methods based on @command{ssh} have an additional feature: you
633 can specify a host name which looks like @file{host#42} (the real host
634 name, then a hash sign, then a port number). This means to connect to
635 the given host but to also pass @code{-p 42} as arguments to the
636 @command{ssh} command.
639 @item @option{telnet}
640 @cindex method telnet
641 @cindex telnet method
643 Connect to the remote host with @command{telnet}. This is as unsecure
644 as the @option{rsh} method.
651 This method does not connect to a remote host at all, rather it uses
652 the @command{su} program to allow you to edit files as another user.
653 That means, the specified host name in the file name must be either
654 @samp{localhost} or the host name as returned by the function
655 @command{(system-name)}. For an exception of this rule see
663 This is similar to the @option{su} method, but it uses @command{sudo}
664 rather than @command{su} to become a different user.
666 Note that @command{sudo} must be configured to allow you to start a
667 shell as the user. It would be nice if it was sufficient if
668 @command{ls} and @command{mimencode} were allowed, but that is not
669 easy to implement, so I haven't got around to it, yet.
676 As you would expect, this is similar to @option{ssh}, only a little
677 different. Whereas @option{ssh} opens a normal interactive shell on
678 the remote host, this option uses @samp{ssh -t -t @var{host} -l
679 @var{user} /bin/sh} to open a connection. This is useful for users
680 where the normal login shell is set up to ask them a number of
681 questions when logging in. This procedure avoids these questions, and
682 just gives @value{tramp} a more-or-less `standard' login shell to work
685 Note that this procedure does not eliminate questions asked by
686 @command{ssh} itself. For example, @command{ssh} might ask ``Are you
687 sure you want to continue connecting?'' if the host key of the remote
688 host is not known. @value{tramp} does not know how to deal with such a
689 question (yet), therefore you will need to make sure that you can log
690 in without such questions.
692 This is also useful for Windows users where @command{ssh}, when
693 invoked from an @value{emacsname} buffer, tells them that it is not
694 allocating a pseudo tty. When this happens, the login shell is wont
695 to not print any shell prompt, which confuses @value{tramp} mightily.
697 This supports the @samp{-p} argument.
700 @item @option{krlogin}
701 @cindex method krlogin
702 @cindex krlogin method
703 @cindex Kerberos (with krlogin method)
705 This method is also similar to @option{ssh}. It only uses the
706 @command{krlogin -x} command to log in to the remote host.
713 This method is mostly interesting for Windows users using the PuTTY
714 implementation of SSH. It uses @samp{plink -ssh} to log in to the
717 This supports the @samp{-P} argument.
719 Additionally, the methods @option{plink1} and @option{plink2} are
720 provided, which call @samp{plink -1 -ssh} or @samp{plink -2 -ssh} in
721 order to use SSH protocol version 1 or 2 explicitly.
723 CCC: Do we have to connect to the remote host once from the command
724 line to accept the SSH key? Maybe this can be made automatic?
726 CCC: Say something about the first shell command failing. This might
727 be due to a wrong setting of @code{tramp-rsh-end-of-line}.
730 @item @option{plinkx}
731 @cindex method plinkx
732 @cindex plinkx method
734 Another method using PuTTY on Windows. Instead of host names, it
735 expects PuTTY session names, calling @samp{plink -load @var{session}
736 -t"}. User names are relevant only in case the corresponding session
737 hasn't defined a user name. Different port numbers must be defined in
745 This is an experimental implementation of the fish protocol, known from
746 the GNU Midnight Commander or the KDE Konqueror. @value{tramp} expects
747 the fish server implementation from the KDE kioslave. That means, the
748 file @file{~/.fishsrv.pl} is expected to reside on the remote host.
750 The implementation lacks good performance. The code is offered anyway,
751 maybe somebody can improve the performance.
756 @node External methods
757 @section External methods
758 @cindex methods, external
759 @cindex external methods
761 The external methods operate through multiple channels, using the
762 remote shell connection for many actions while delegating file
763 transfers to an external transfer utility.
765 This saves the overhead of encoding and decoding that multiplexing the
766 transfer through the one connection has with the inline methods.
768 Since external methods need their own overhead opening a new channel,
769 all files which are smaller than @var{tramp-copy-size-limit} are still
770 transferred with the corresponding inline method. It should provide a
771 fair trade-off between both approaches.
774 @item @option{rcp} --- @command{rsh} and @command{rcp}
777 @cindex rcp (with rcp method)
778 @cindex rsh (with rcp method)
780 This method uses the @command{rsh} and @command{rcp} commands to connect
781 to the remote machine and transfer files. This is probably the fastest
782 connection method available.
784 The alternative method @option{remcp} uses the @command{remsh} and
785 @command{rcp} commands. It should be applied on machines where
786 @command{remsh} is used instead of @command{rsh}.
789 @item @option{scp} --- @command{ssh} and @command{scp}
792 @cindex scp (with scp method)
793 @cindex ssh (with scp method)
795 Using @command{ssh} to connect to the remote host and @command{scp} to
796 transfer files between the machines is the best method for securely
797 connecting to a remote machine and accessing files.
799 The performance of this option is also quite good. It may be slower than
800 the inline methods when you often open and close small files however.
801 The cost of the cryptographic handshake at the start of an @command{scp}
802 session can begin to absorb the advantage that the lack of encoding and
805 There are also two variants, @option{scp1} and @option{scp2}, that
806 call @samp{ssh -1} and @samp{ssh -2}, respectively. This way, you can
807 explicitly select whether you want to use the SSH protocol version 1
808 or 2 to connect to the remote host. (You can also specify in
809 @file{~/.ssh/config}, the SSH configuration file, which protocol
810 should be used, and use the regular @option{scp} method.)
812 Two other variants, @option{scp1_old} and @option{scp2_old}, use the
813 @command{ssh1} and @command{ssh2} commands explicitly. If you don't
814 know what these are, you do not need these options.
816 All the @command{ssh} based methods support the @samp{-p} feature
817 where you can specify a port number to connect to in the host name.
818 For example, the host name @file{host#42} tells @value{tramp} to
819 specify @samp{-p 42} in the argument list for @command{ssh}, and to
820 specify @samp{-P 42} in the argument list for @command{scp}.
823 @item @option{sftp} --- @command{ssh} and @command{sftp}
826 @cindex sftp (with sftp method)
827 @cindex ssh (with sftp method)
829 That is mostly the same method as @option{scp}, but using
830 @command{sftp} as transfer command. So the same remarks are valid.
832 This command does not work like @value{ftppackagename}, where
833 @command{ftp} is called interactively, and all commands are send from
834 within this session. Instead of, @command{ssh} is used for login.
836 This method supports the @samp{-p} argument.
839 @item @option{rsync} --- @command{ssh} and @command{rsync}
842 @cindex rsync (with rsync method)
843 @cindex ssh (with rsync method)
845 Using the @command{ssh} command to connect securely to the remote
846 machine and the @command{rsync} command to transfer files is almost
847 identical to the @option{scp} method.
849 While @command{rsync} performs much better than @command{scp} when
850 transferring files that exist on both hosts, this advantage is lost if
851 the file exists only on one side of the connection. A file can exists
852 on both the remote and local host, when you copy a file from/to a
853 remote host. When you just open a file from the remote host (or write
854 a file there), a temporary file on the local side is kept as long as
855 the corresponding buffer, visiting this file, is alive.
857 This method supports the @samp{-p} argument.
860 @item @option{scpx} --- @command{ssh} and @command{scp}
863 @cindex scp (with scpx method)
864 @cindex ssh (with scpx method)
866 As you would expect, this is similar to @option{scp}, only a little
867 different. Whereas @option{scp} opens a normal interactive shell on
868 the remote host, this option uses @samp{ssh -t -t @var{host} -l
869 @var{user} /bin/sh} to open a connection. This is useful for users
870 where the normal login shell is set up to ask them a number of
871 questions when logging in. This procedure avoids these questions, and
872 just gives @value{tramp} a more-or-less `standard' login shell to work
875 This is also useful for Windows users where @command{ssh}, when
876 invoked from an @value{emacsname} buffer, tells them that it is not
877 allocating a pseudo tty. When this happens, the login shell is wont
878 to not print any shell prompt, which confuses @value{tramp} mightily.
880 This method supports the @samp{-p} argument.
883 @item @option{scpc} --- @command{ssh} and @command{scp}
886 @cindex scp (with scpc method)
887 @cindex ssh (with scpc method)
889 Newer versions of @option{ssh} (for example OpenSSH 4) offer an option
890 @option{ControlMaster}. This allows @option{scp} to reuse an existing
891 @option{ssh} channel, which increases performance.
893 Before you use this method, you shall check whether your @option{ssh}
894 implementation does support this option. Try from the command line
897 ssh localhost -o ControlMaster=yes
900 This method supports the @samp{-p} argument.
903 @item @option{rsyncc} --- @command{ssh} and @command{rsync}
904 @cindex method rsyncc
905 @cindex rsyncc method
906 @cindex rsync (with rsyncc method)
907 @cindex ssh (with rsyncc method)
909 Like the @option{scpc} method, @option{rsyncc} improves the underlying
910 @command{ssh} connection by the option @option{ControlMaster}. This
911 allows @command{rsync} to reuse an existing @command{ssh} channel,
912 which increases performance.
914 This method supports the @samp{-p} argument.
917 @item @option{pscp} --- @command{plink} and @command{pscp}
920 @cindex pscp (with pscp method)
921 @cindex plink (with pscp method)
922 @cindex PuTTY (with pscp method)
924 This method is similar to @option{scp}, but it uses the
925 @command{plink} command to connect to the remote host, and it uses
926 @command{pscp} for transferring the files. These programs are part
927 of PuTTY, an SSH implementation for Windows.
929 This method supports the @samp{-P} argument.
932 @item @option{psftp} --- @command{plink} and @command{psftp}
935 @cindex psftp (with psftp method)
936 @cindex plink (with psftp method)
937 @cindex PuTTY (with psftp method)
939 As you would expect, this method is similar to @option{sftp}, but it
940 uses the @command{plink} command to connect to the remote host, and it
941 uses @command{psftp} for transferring the files. These programs are
942 part of PuTTY, an SSH implementation for Windows.
944 This method supports the @samp{-P} argument.
947 @item @option{fcp} --- @command{fsh} and @command{fcp}
950 @cindex fsh (with fcp method)
951 @cindex fcp (with fcp method)
953 This method is similar to @option{scp}, but it uses the @command{fsh}
954 command to connect to the remote host, and it uses @command{fcp} for
955 transferring the files. @command{fsh/fcp} are a front-end for
956 @command{ssh} which allow for reusing the same @command{ssh} session
957 for submitting several commands. This avoids the startup overhead of
958 @command{scp} (which has to establish a secure connection whenever it
959 is called). Note, however, that you can also use one of the inline
960 methods to achieve a similar effect.
962 This method uses the command @samp{fsh @var{host} -l @var{user}
963 /bin/sh -i} to establish the connection, it does not work to just say
964 @command{fsh @var{host} -l @var{user}}.
969 There is no inline method using @command{fsh} as the multiplexing
970 provided by the program is not very useful in our context. @value{tramp}
971 opens just one connection to the remote host and then keeps it open,
979 This is not a native @value{tramp} method. Instead of, it forwards all
980 requests to @value{ftppackagename}.
982 This works only for unified filenames, see @ref{Issues}.
986 @item @option{smb} --- @command{smbclient}
990 This is another not natural @value{tramp} method. It uses the
991 @command{smbclient} command on different Unices in order to connect to
992 an SMB server. An SMB server might be a Samba (or CIFS) server on
993 another UNIX host or, more interesting, a host running MS Windows. So
994 far, it is tested towards MS Windows NT, MS Windows 2000, and MS
997 The first directory in the localname must be a share name on the remote
998 host. Remember, that the @code{$} character in which default shares
999 usually end, must be written @code{$$} due to environment variable
1000 substitution in file names. If no share name is given (i.e. remote
1001 directory @code{/}), all available shares are listed.
1003 Since authorization is done on share level, you will be prompted
1004 always for a password if you access another share on the same host.
1005 This can be suppressed by @ref{Password handling}.
1007 MS Windows uses for authorization both a user name and a domain name.
1008 Because of this, the @value{tramp} syntax has been extended: you can
1009 specify a user name which looks like @code{user%domain} (the real user
1010 name, then a percent sign, then the domain name). So, to connect to
1011 the machine @code{melancholia} as user @code{daniel} of the domain
1012 @code{BIZARRE}, and edit @file{.emacs} in the home directory (share
1013 @code{daniel$}) I would specify the filename @file{@trampfn{smb,
1014 daniel%BIZARRE, melancholia, /daniel$$/.emacs}}.
1016 Depending on the Windows domain configuration, a Windows user might be
1017 considered as domain user per default. In order to connect as local
1018 user, the WINS name of that machine must be given as domain name.
1019 Usually, it is the machine name in capital letters. In the example
1020 above, the local user @code{daniel} would be specified as
1021 @file{@trampfn{smb, daniel%MELANCHOLIA, melancholia, /daniel$$/.emacs}}.
1023 The domain name as well as the user name are optional. If no user
1024 name is specified at all, the anonymous user (without password
1025 prompting) is assumed. This is different from all other @value{tramp}
1026 methods, where in such a case the local user name is taken.
1028 The @option{smb} method supports the @samp{-p} argument.
1030 @strong{Please note:} If @value{emacsname} runs locally under MS
1031 Windows, this method isn't available. Instead of, you can use UNC
1032 file names like @file{//melancholia/daniel$$/.emacs}. The only
1033 disadvantage is that there's no possibility to specify another user
1040 @cindex method imaps
1042 @cindex imaps method
1044 Accessing an IMAP mailbox is intended to save files there as encrypted
1045 message. It could be used in case there are no other remote file
1048 @value{tramp} supports both @option{imap} and @option{imaps} methods.
1049 The latter one accesses the IMAP server over ssl.
1051 Both methods support the port number specification.
1053 Note, that special handling is needed for declaring a passphrase for
1054 encryption / decryption of the messages (@pxref{Using an
1055 authentication file}).
1062 @node GVFS based methods
1063 @section GVFS based external methods
1064 @cindex methods, gvfs
1065 @cindex gvfs based methods
1068 The connection methods described in this section are based on GVFS
1069 @uref{http://en.wikipedia.org/wiki/GVFS}. Via GVFS, the remote
1070 filesystem is mounted locally through FUSE. @value{tramp} uses
1071 internally this local mounted directory.
1073 The communication with GVFS is implemented via D-Bus messages.
1074 Therefore, your @value{emacsname} must have D-Bus integration,
1075 @pxref{Top, , D-Bus, dbus}.
1084 This method provides access to WebDAV files and directories. There
1085 exists also the external method @option{davs}, which uses SSL
1086 encryption for the access.
1088 Both methods support the port number specification as discussed above.
1095 OBEX is an FTP-like access protocol for simple devices, like cell
1096 phones. Until now @value{tramp} supports only OBEX over Bluetooth.
1099 @item @option{synce}
1100 @cindex method synce
1101 @cindex synce method
1103 The @option{synce} method allows communication with Windows Mobile
1104 devices. Beside GVFS for mounting remote files and directories via
1105 FUSE, it needs also the SYNCE-GVFS plugin.
1108 @defopt tramp-gvfs-methods
1109 This customer option, a list, defines the external methods, which
1110 shall be used with GVFS. Per default, these are @option{dav},
1111 @option{davs}, @option{obex} and @option{synce}. Other possible
1112 values are @option{ftp}, @option{sftp} and @option{smb}.
1118 @node Gateway methods
1119 @section Gateway methods
1120 @cindex methods, gateway
1121 @cindex gateway methods
1123 Gateway methods are not methods to access a remote host directly.
1124 These methods are intended to pass firewalls or proxy servers.
1125 Therefore, they can be used for proxy host declarations
1126 (@pxref{Multi-hops}) only.
1128 A gateway method must come always along with a method who supports
1129 port setting. This is because @value{tramp} targets the accompanied
1130 method to @file{localhost#random_port}, from where the firewall or
1131 proxy server is accessed to.
1133 Gateway methods support user name and password declarations. These
1134 are used to authenticate towards the corresponding firewall or proxy
1135 server. They can be passed only if your friendly administrator has
1136 granted your access.
1139 @item @option{tunnel}
1140 @cindex method tunnel
1141 @cindex tunnel method
1143 This method implements an HTTP tunnel via the @command{CONNECT}
1144 command (see RFC 2616, 2817). Any HTTP 1.1 compliant (proxy) server
1145 shall support this command.
1147 As authentication method, only @option{Basic Authentication} (see RFC
1148 2617) is implemented so far. If no port number is given in the
1149 declaration, port @option{8080} is used for the proxy server.
1152 @item @option{socks}
1153 @cindex method socks
1154 @cindex socks method
1156 The @command{socks} method provides access to SOCKSv5 servers (see
1157 RFC 1928). @option{Username/Password Authentication} according to RFC
1160 The default port number of the socks server is @option{1080}, if not
1161 specified otherwise.
1167 @node Default Method
1168 @section Selecting a default method
1169 @cindex default method
1171 @vindex tramp-default-method
1172 When you select an appropriate transfer method for your typical usage
1173 you should set the variable @code{tramp-default-method} to reflect that
1174 choice. This variable controls which method will be used when a method
1175 is not specified in the @value{tramp} file name. For example:
1178 (setq tramp-default-method "ssh")
1181 @vindex tramp-default-method-alist
1182 You can also specify different methods for certain user/host
1183 combinations, via the variable @code{tramp-default-method-alist}. For
1184 example, the following two lines specify to use the @option{ssh}
1185 method for all user names matching @samp{john} and the @option{rsync}
1186 method for all host names matching @samp{lily}. The third line
1187 specifies to use the @option{su} method for the user @samp{root} on
1188 the machine @samp{localhost}.
1191 (add-to-list 'tramp-default-method-alist '("" "john" "ssh"))
1192 (add-to-list 'tramp-default-method-alist '("lily" "" "rsync"))
1193 (add-to-list 'tramp-default-method-alist
1194 '("\\`localhost\\'" "\\`root\\'" "su"))
1198 See the documentation for the variable
1199 @code{tramp-default-method-alist} for more details.
1201 External methods are normally preferable to inline methods, giving
1204 @xref{Inline methods}.
1205 @xref{External methods}.
1207 Another consideration with the selection of transfer methods is the
1208 environment you will use them in and, especially when used over the
1209 Internet, the security implications of your preferred method.
1211 The @option{rsh} and @option{telnet} methods send your password as
1212 plain text as you log in to the remote machine, as well as
1213 transferring the files in such a way that the content can easily be
1214 read from other machines.
1216 If you need to connect to remote systems that are accessible from the
1217 Internet, you should give serious thought to using @option{ssh} based
1218 methods to connect. These provide a much higher level of security,
1219 making it a non-trivial exercise for someone to obtain your password
1220 or read the content of the files you are editing.
1223 @subsection Which method is the right one for me?
1224 @cindex choosing the right method
1226 Given all of the above, you are probably thinking that this is all fine
1227 and good, but it's not helping you to choose a method! Right you are.
1228 As a developer, we don't want to boss our users around but give them
1229 maximum freedom instead. However, the reality is that some users would
1230 like to have some guidance, so here I'll try to give you this guidance
1231 without bossing you around. You tell me whether it works @dots{}
1233 My suggestion is to use an inline method. For large files, external
1234 methods might be more efficient, but I guess that most people will
1235 want to edit mostly small files. And if you access large text files,
1236 compression (driven by @var{tramp-inline-compress-start-size}) shall
1237 still result in good performance.
1239 I guess that these days, most people can access a remote machine by
1240 using @command{ssh}. So I suggest that you use the @option{ssh}
1241 method. So, type @kbd{C-x C-f @trampfn{ssh, root, otherhost,
1242 /etc/motd} @key{RET}} to edit the @file{/etc/motd} file on the other
1245 If you can't use @option{ssh} to log in to the remote host, then
1246 select a method that uses a program that works. For instance, Windows
1247 users might like the @option{plink} method which uses the PuTTY
1248 implementation of @command{ssh}. Or you use Kerberos and thus like
1251 For the special case of editing files on the local host as another
1252 user, see the @option{su} or @option{sudo} methods. They offer
1253 shortened syntax for the @samp{root} account, like
1254 @file{@trampfn{su, , , /etc/motd}}.
1256 People who edit large files may want to consider @option{scpc} instead
1257 of @option{ssh}, or @option{pscp} instead of @option{plink}. These
1258 external methods are faster than inline methods for large files.
1259 Note, however, that external methods suffer from some limitations.
1260 Please try first whether you really get a noticeable speed advantage
1261 from using an external method! Maybe even for large files, inline
1262 methods are fast enough.
1266 @section Selecting a default user
1267 @cindex default user
1269 The user part of a @value{tramp} file name can be omitted. Usually,
1270 it is replaced by the user name you are logged in. Often, this is not
1271 what you want. A typical use of @value{tramp} might be to edit some
1272 files with root permissions on the local host. This case, you should
1273 set the variable @code{tramp-default-user} to reflect that choice.
1277 (setq tramp-default-user "root")
1280 @code{tramp-default-user} is regarded as obsolete, and will be removed
1283 @vindex tramp-default-user-alist
1284 You can also specify different users for certain method/host
1285 combinations, via the variable @code{tramp-default-user-alist}. For
1286 example, if you always have to use the user @samp{john} in the domain
1287 @samp{somewhere.else}, you can specify the following:
1290 (add-to-list 'tramp-default-user-alist
1291 '("ssh" ".*\\.somewhere\\.else\\'" "john"))
1295 See the documentation for the variable
1296 @code{tramp-default-user-alist} for more details.
1298 One trap to fall in must be known. If @value{tramp} finds a default
1299 user, this user will be passed always to the connection command as
1300 parameter (for example @samp{ssh here.somewhere.else -l john}. If you
1301 have specified another user for your command in its configuration
1302 files, @value{tramp} cannot know it, and the remote access will fail.
1303 If you have specified in the given example in @file{~/.ssh/config} the
1307 Host here.somewhere.else
1312 than you must discard selecting a default user by @value{tramp}. This
1313 will be done by setting it to @code{nil} (or @samp{lily}, likewise):
1316 (add-to-list 'tramp-default-user-alist
1317 '("ssh" "\\`here\\.somewhere\\.else\\'" nil))
1320 The last entry in @code{tramp-default-user-alist} could be your
1321 default user you'll apply predominantly. You shall @emph{append} it
1322 to that list at the end:
1325 (add-to-list 'tramp-default-user-alist '(nil nil "jonas") t)
1330 @section Selecting a default host
1331 @cindex default host
1333 @vindex tramp-default-host
1334 Finally, it is even possible to omit the host name part of a
1335 @value{tramp} file name. This case, the value of the variable
1336 @code{tramp-default-host} is used. Per default, it is initialized
1337 with the host name your local @value{emacsname} is running.
1339 If you, for example, use @value{tramp} mainly to contact the host
1340 @samp{target} as user @samp{john}, you can specify:
1343 (setq tramp-default-user "john"
1344 tramp-default-host "target")
1347 Then the simple file name @samp{@trampfn{ssh, , ,}} will connect you
1348 to John's home directory on target.
1350 Note, however, that the most simplification @samp{/::} won't work,
1351 because @samp{/:} is the prefix for quoted file names.
1356 @section Connecting to a remote host using multiple hops
1360 Sometimes, the methods described before are not sufficient. Sometimes,
1361 it is not possible to connect to a remote host using a simple command.
1362 For example, if you are in a secured network, you might have to log in
1363 to a `bastion host' first before you can connect to the outside world.
1364 Of course, the target host may also require a bastion host.
1366 @vindex tramp-default-proxies-alist
1367 In order to specify such multiple hops, it is possible to define a proxy
1368 host to pass through, via the variable
1369 @code{tramp-default-proxies-alist}. This variable keeps a list of
1370 triples (@var{host} @var{user} @var{proxy}).
1372 The first matching item specifies the proxy host to be passed for a
1373 file name located on a remote target matching @var{user}@@@var{host}.
1374 @var{host} and @var{user} are regular expressions or @code{nil}, which
1375 is interpreted as a regular expression which always matches.
1377 @var{proxy} must be a Tramp filename which localname part is ignored.
1378 Method and user name on @var{proxy} are optional, which is interpreted
1379 with the default values.
1381 The method must be an inline or gateway method (@pxref{Inline
1382 methods}, @pxref{Gateway methods}).
1385 The method must be an inline method (@pxref{Inline methods}).
1387 If @var{proxy} is @code{nil}, no additional hop is required reaching
1388 @var{user}@@@var{host}.
1390 If you, for example, must pass the host @samp{bastion.your.domain} as
1391 user @samp{bird} for any remote host which is not located in your local
1395 (add-to-list 'tramp-default-proxies-alist
1396 '("\\." nil "@trampfn{ssh, bird, bastion.your.domain,}"))
1397 (add-to-list 'tramp-default-proxies-alist
1398 '("\\.your\\.domain\\'" nil nil))
1401 Please note the order of the code. @code{add-to-list} adds elements at the
1402 beginning of a list. Therefore, most relevant rules must be added last.
1404 Proxy hosts can be cascaded. If there is another host called
1405 @samp{jump.your.domain}, which is the only one in your local domain who
1406 is allowed connecting @samp{bastion.your.domain}, you can add another
1410 (add-to-list 'tramp-default-proxies-alist
1411 '("\\`bastion\\.your\\.domain\\'"
1413 "@trampfn{ssh, , jump.your.domain,}"))
1416 @var{proxy} can contain the patterns @code{%h} or @code{%u}. These
1417 patterns are replaced by the strings matching @var{host} or
1418 @var{user}, respectively.
1420 If you, for example, wants to work as @samp{root} on hosts in the
1421 domain @samp{your.domain}, but login as @samp{root} is disabled for
1422 non-local access, you might add the following rule:
1425 (add-to-list 'tramp-default-proxies-alist
1426 '("\\.your\\.domain\\'" "\\`root\\'" "@trampfn{ssh, , %h,}"))
1429 Opening @file{@trampfn{sudo, , randomhost.your.domain,}} would connect
1430 first @samp{randomhost.your.domain} via @code{ssh} under your account
1431 name, and perform @code{sudo -u root} on that host afterwards. It is
1432 important to know that the given method is applied on the host which
1433 has been reached so far. @code{sudo -u root}, applied on your local
1434 host, wouldn't be useful here.
1436 @var{host}, @var{user} and @var{proxy} can also be Lisp forms. These
1437 forms are evaluated, and must return a string, or @code{nil}. The
1438 previous example could be generalized then: For all hosts except my
1439 local one connect via @code{ssh} first, and apply @code{sudo -u root}
1443 (add-to-list 'tramp-default-proxies-alist
1444 '(nil "\\`root\\'" "@trampfn{ssh, , %h,}"))
1445 (add-to-list 'tramp-default-proxies-alist
1446 '((regexp-quote (system-name)) nil nil))
1449 This is the recommended configuration to work as @samp{root} on remote
1453 Finally, @code{tramp-default-proxies-alist} can be used to pass
1454 firewalls or proxy servers. Imagine your local network has a host
1455 @samp{proxy.your.domain} which is used on port 3128 as HTTP proxy to
1456 the outer world. Your friendly administrator has granted you access
1457 under your user name to @samp{host.other.domain} on that proxy
1458 server.@footnote{HTTP tunnels are intended for secure SSL/TLS
1459 communication. Therefore, many proxy server restrict the tunnels to
1460 related target ports. You might need to run your ssh server on your
1461 target host @samp{host.other.domain} on such a port, like 443 (https).
1462 See @uref{http://savannah.gnu.org/maintenance/CvsFromBehindFirewall}
1463 for discussion of ethical issues.} You would need to add the
1467 (add-to-list 'tramp-default-proxies-alist
1468 '("\\`host\\.other\\.domain\\'" nil
1469 "@trampfn{tunnel, , proxy.your.domain#3128,}"))
1472 Gateway methods can be declared as first hop only in a multiple hop
1477 @node Customizing Methods
1478 @section Using Non-Standard Methods
1479 @cindex customizing methods
1480 @cindex using non-standard methods
1481 @cindex create your own methods
1483 There is a variable @code{tramp-methods} which you can change if the
1484 predefined methods don't seem right.
1486 For the time being, I'll refer you to the Lisp documentation of that
1487 variable, accessible with @kbd{C-h v tramp-methods @key{RET}}.
1490 @node Customizing Completion
1491 @section Selecting config files for user/host name completion
1492 @cindex customizing completion
1493 @cindex selecting config files
1494 @vindex tramp-completion-function-alist
1496 The variable @code{tramp-completion-function-alist} is intended to
1497 customize which files are taken into account for user and host name
1498 completion (@pxref{Filename completion}). For every method, it keeps
1499 a set of configuration files, accompanied by a Lisp function able to
1500 parse that file. Entries in @code{tramp-completion-function-alist}
1501 have the form (@var{method} @var{pair1} @var{pair2} ...).
1503 Each @var{pair} is composed of (@var{function} @var{file}).
1504 @var{function} is responsible to extract user names and host names
1505 from @var{file} for completion. There are two functions which access
1508 @defun tramp-get-completion-function method
1509 This function returns the list of completion functions for @var{method}.
1513 (tramp-get-completion-function "rsh")
1515 @result{} ((tramp-parse-rhosts "/etc/hosts.equiv")
1516 (tramp-parse-rhosts "~/.rhosts"))
1520 @defun tramp-set-completion-function method function-list
1521 This function sets @var{function-list} as list of completion functions
1526 (tramp-set-completion-function "ssh"
1527 '((tramp-parse-sconfig "/etc/ssh_config")
1528 (tramp-parse-sconfig "~/.ssh/config")))
1530 @result{} ((tramp-parse-sconfig "/etc/ssh_config")
1531 (tramp-parse-sconfig "~/.ssh/config"))
1535 The following predefined functions parsing configuration files exist:
1538 @item @code{tramp-parse-rhosts}
1539 @findex tramp-parse-rhosts
1541 This function parses files which are syntactical equivalent to
1542 @file{~/.rhosts}. It returns both host names and user names, if
1545 @item @code{tramp-parse-shosts}
1546 @findex tramp-parse-shosts
1548 This function parses files which are syntactical equivalent to
1549 @file{~/.ssh/known_hosts}. Since there are no user names specified
1550 in such files, it can return host names only.
1552 @item @code{tramp-parse-sconfig}
1553 @findex tramp-parse-shosts
1555 This function returns the host nicknames defined by @code{Host} entries
1556 in @file{~/.ssh/config} style files.
1558 @item @code{tramp-parse-shostkeys}
1559 @findex tramp-parse-shostkeys
1561 SSH2 parsing of directories @file{/etc/ssh2/hostkeys/*} and
1562 @file{~/ssh2/hostkeys/*}. Hosts are coded in file names
1563 @file{hostkey_@var{portnumber}_@var{host-name}.pub}. User names
1564 are always @code{nil}.
1566 @item @code{tramp-parse-sknownhosts}
1567 @findex tramp-parse-shostkeys
1569 Another SSH2 style parsing of directories like
1570 @file{/etc/ssh2/knownhosts/*} and @file{~/ssh2/knownhosts/*}. This
1571 case, hosts names are coded in file names
1572 @file{@var{host-name}.@var{algorithm}.pub}. User names are always @code{nil}.
1574 @item @code{tramp-parse-hosts}
1575 @findex tramp-parse-hosts
1577 A function dedicated to @file{/etc/hosts} style files. It returns
1580 @item @code{tramp-parse-passwd}
1581 @findex tramp-parse-passwd
1583 A function which parses @file{/etc/passwd} like files. Obviously, it
1584 can return user names only.
1586 @item @code{tramp-parse-netrc}
1587 @findex tramp-parse-netrc
1589 Finally, a function which parses @file{~/.netrc} like files.
1592 If you want to keep your own data in a file, with your own structure,
1593 you might provide such a function as well. This function must meet
1594 the following conventions:
1596 @defun my-tramp-parse file
1597 @var{file} must be either a file name on your host, or @code{nil}.
1598 The function must return a list of (@var{user} @var{host}), which are
1599 taken as candidates for user and host name completion.
1603 (my-tramp-parse "~/.my-tramp-hosts")
1605 @result{} ((nil "toto") ("daniel" "melancholia"))
1610 @node Password handling
1611 @section Reusing passwords for several connections.
1614 Sometimes it is necessary to connect to the same remote host several
1615 times. Reentering passwords again and again would be annoying, when
1616 the chosen method does not support access without password prompt
1617 through own configuration.
1619 The best recommendation is to use the method's own mechanism for
1620 password handling. Consider @command{ssh-agent} for @option{ssh}-like
1621 methods, or @command{pageant} for @option{plink}-like methods.
1623 However, if you cannot apply such native password handling,
1624 @value{tramp} offers altenatives.
1627 @anchor{Using an authentication file}
1628 @subsection Using an authentication file
1630 @vindex auth-sources
1631 The package @file{auth-source.el}, originally developed in No Gnus,
1632 offers the possibility to read passwords from a file, like FTP does it
1633 from @file{~/.netrc}. The default authentication file is
1634 @file{~/.authinfo.gpg}, this can be changed via the variable
1635 @code{auth-sources}.
1638 A typical entry in the authentication file would be
1641 machine melancholia port scp login daniel password geheim
1644 The port can be any @value{tramp} method (@pxref{Inline methods},
1645 @pxref{External methods}), to match only this method. When you omit
1646 the port, you match all @value{tramp} methods.
1649 A special case are @option{imap}-like methods. Authentication with
1650 the IMAP server is performed via @file{imap.el}, there is no special
1651 need from @value{tramp} point of view. An additional passphrase, used
1652 for symmetric encryption and decryption of the stored messages, should
1653 be given with the special port indication @option{tramp-imap}:
1656 machine melancholia port tramp-imap login daniel password ultrageheim
1660 @anchor{Caching passwords}
1661 @subsection Caching passwords
1663 If there is no authentication file, @value{tramp} caches the passwords
1664 entered by you. They will be reused next time if a connection needs
1665 them for the same user name and host name, independently of the
1668 @vindex password-cache-expiry
1669 Passwords are not saved permanently, that means the password caching
1670 is limited to the lifetime of your @value{emacsname} session. You
1671 can influence the lifetime of password caching by customizing the
1672 variable @code{password-cache-expiry}. The value is the number of
1673 seconds how long passwords are cached. Setting it to @code{nil}
1674 disables the expiration.
1676 @vindex password-cache
1677 If you don't like this feature for security reasons, password caching
1678 can be disabled totally by customizing the variable
1679 @code{password-cache} (setting it to @code{nil}).
1681 Implementation Note: password caching is based on the package
1682 @file{password-cache.el}. For the time being, it is activated only
1683 when this package is seen in the @code{load-path} while loading
1685 @ifset installchapter
1686 If you don't use No Gnus, you can take @file{password.el} from the
1687 @value{tramp} @file{contrib} directory, see @ref{Installation
1692 @node Connection caching
1693 @section Reusing connection related information.
1696 @vindex tramp-persistency-file-name
1697 In order to reduce initial connection time, @value{tramp} stores
1698 connection related information persistently. The variable
1699 @code{tramp-persistency-file-name} keeps the file name where these
1700 information are written. Its default value is
1702 @file{~/.emacs.d/tramp}.
1705 @file{~/.xemacs/tramp}.
1707 It is recommended to choose a local file name.
1709 @value{tramp} reads this file during startup, and writes it when
1710 exiting @value{emacsname}. You can simply remove this file if
1711 @value{tramp} shall be urged to recompute these information next
1712 @value{emacsname} startup time.
1714 Using such persistent information can be disabled by setting
1715 @code{tramp-persistency-file-name} to @code{nil}.
1717 Once consequence of reusing connection related information is that
1718 @var{tramp} needs to distinguish hosts. If you, for example, run a
1719 local @code{sshd} on port 3001, which tunnels @command{ssh} to another
1720 host, you could access both @file{@trampfn{ssh, , localhost,}} and
1721 @file{@trampfn{ssh, , localhost#3001,}}. @var{tramp} would use the
1722 same host related information (like paths, Perl variants, etc) for
1723 both connections, although the information is valid only for one of
1726 In order to avoid trouble, you must use another host name for one of
1727 the connections, like introducing a @option{Host} section in
1728 @file{~/.ssh/config} (@pxref{Frequently Asked Questions}) or applying
1729 multiple hops (@pxref{Multi-hops}).
1731 When @value{tramp} detects a changed operating system version on a
1732 remote host (via the command @command{uname -sr}), it flushes all
1733 connection related information for this host, and opens the
1737 @node Remote Programs
1738 @section How @value{tramp} finds and uses programs on the remote machine.
1740 @value{tramp} depends on a number of programs on the remote host in order to
1741 function, including @command{ls}, @command{test}, @command{find} and
1744 In addition to these required tools, there are various tools that may be
1745 required based on the connection method. See @ref{Inline methods} and
1746 @ref{External methods} for details on these.
1748 Certain other tools, such as @command{perl} (or @command{perl5}) and
1749 @command{grep} will be used if they can be found. When they are
1750 available, they are used to improve the performance and accuracy of
1753 @vindex tramp-remote-path
1754 @vindex tramp-default-remote-path
1755 @vindex tramp-own-remote-path
1756 @defopt tramp-remote-path
1757 When @value{tramp} connects to the remote machine, it searches for the
1758 programs that it can use. The variable @code{tramp-remote-path}
1759 controls the directories searched on the remote machine.
1761 By default, this is set to a reasonable set of defaults for most
1762 machines. The symbol @code{tramp-default-remote-path} is a place
1763 holder, it is replaced by the list of directories received via the
1764 command @command{getconf PATH} on your remote machine. For example,
1765 on GNU Debian this is @file{/bin:/usr/bin}, whereas on Solaris this is
1766 @file{/usr/xpg4/bin:/usr/ccs/bin:/usr/bin:/opt/SUNWspro/bin}. It is
1767 recommended to apply this symbol on top of @code{tramp-remote-path}.
1769 It is possible, however, that your local (or remote ;) system
1770 administrator has put the tools you want in some obscure local
1773 In this case, you can still use them with @value{tramp}. You simply
1774 need to add code to your @file{.emacs} to add the directory to the
1775 remote path. This will then be searched by @value{tramp} when you
1776 connect and the software found.
1778 To add a directory to the remote search path, you could use code such
1782 @i{;; We load @value{tramp} to define the variable.}
1784 @i{;; We have @command{perl} in "/usr/local/perl/bin"}
1785 (add-to-list 'tramp-remote-path "/usr/local/perl/bin")
1788 Another possibility is to reuse the path settings of your remote
1789 account, when you log in. Usually, these settings are overwritten,
1790 because they might not be useful for @value{tramp}. The place holder
1791 @code{tramp-own-remote-path} preserves these settings. You can
1795 (add-to-list 'tramp-remote-path 'tramp-own-remote-path)
1799 @value{tramp} caches several information, like the Perl binary
1800 location. The changed remote search path wouldn't affect these
1801 settings. In order to force @value{tramp} to recompute these values,
1802 you must exit @value{emacsname}, remove your persistency file
1803 (@pxref{Connection caching}), and restart @value{emacsname}.
1806 @node Remote shell setup
1807 @section Remote shell setup hints
1808 @cindex remote shell setup
1809 @cindex @file{.profile} file
1810 @cindex @file{.login} file
1811 @cindex shell init files
1813 As explained in the @ref{Overview} section, @value{tramp} connects to the
1814 remote host and talks to the shell it finds there. Of course, when you
1815 log in, the shell executes its init files. Suppose your init file
1816 requires you to enter the birth date of your mother; clearly @value{tramp}
1817 does not know this and hence fails to log you in to that host.
1819 There are different possible strategies for pursuing this problem. One
1820 strategy is to enable @value{tramp} to deal with all possible situations.
1821 This is a losing battle, since it is not possible to deal with
1822 @emph{all} situations. The other strategy is to require you to set up
1823 the remote host such that it behaves like @value{tramp} expects. This might
1824 be inconvenient because you have to invest a lot of effort into shell
1825 setup before you can begin to use @value{tramp}.
1827 The package, therefore, pursues a combined approach. It tries to
1828 figure out some of the more common setups, and only requires you to
1829 avoid really exotic stuff. For example, it looks through a list of
1830 directories to find some programs on the remote host. And also, it
1831 knows that it is not obvious how to check whether a file exists, and
1832 therefore it tries different possibilities. (On some hosts and
1833 shells, the command @command{test -e} does the trick, on some hosts
1834 the shell builtin doesn't work but the program @command{/usr/bin/test
1835 -e} or @command{/bin/test -e} works. And on still other hosts,
1836 @command{ls -d} is the right way to do this.)
1838 Below you find a discussion of a few things that @value{tramp} does not deal
1839 with, and that you therefore have to set up correctly.
1842 @item @var{shell-prompt-pattern}
1843 @vindex shell-prompt-pattern
1845 After logging in to the remote host, @value{tramp} has to wait for the remote
1846 shell startup to finish before it can send commands to the remote
1847 shell. The strategy here is to wait for the shell prompt. In order to
1848 recognize the shell prompt, the variable @code{shell-prompt-pattern} has
1849 to be set correctly to recognize the shell prompt on the remote host.
1851 Note that @value{tramp} requires the match for @code{shell-prompt-pattern}
1852 to be at the end of the buffer. Many people have something like the
1853 following as the value for the variable: @code{"^[^>$][>$] *"}. Now
1854 suppose your shell prompt is @code{a <b> c $ }. In this case,
1855 @value{tramp} recognizes the @code{>} character as the end of the prompt,
1856 but it is not at the end of the buffer.
1858 @item @var{tramp-shell-prompt-pattern}
1859 @vindex tramp-shell-prompt-pattern
1861 This regular expression is used by @value{tramp} in the same way as
1862 @code{shell-prompt-pattern}, to match prompts from the remote shell.
1863 This second variable exists because the prompt from the remote shell
1864 might be different from the prompt from a local shell --- after all,
1865 the whole point of @value{tramp} is to log in to remote hosts as a
1866 different user. The default value of
1867 @code{tramp-shell-prompt-pattern} is the same as the default value of
1868 @code{shell-prompt-pattern}, which is reported to work well in many
1871 @item @var{tramp-password-prompt-regexp}
1872 @vindex tramp-password-prompt-regexp
1873 @vindex tramp-wrong-passwd-regexp
1875 During login, @value{tramp} might be forced to enter a password or a
1876 passphrase. The difference between both is that a password is
1877 requested from the shell on the remote host, while a passphrase is
1878 needed for accessing local authentication information, like your ssh
1881 @var{tramp-password-prompt-regexp} handles the detection of such
1882 requests for English environments. When you use another localization
1883 of your (local or remote) host, you might need to adapt this. Example:
1887 tramp-password-prompt-regexp
1891 '("passphrase" "Passphrase"
1893 "password" "Password"
1895 "passwort" "Passwort"
1897 "mot de passe" "Mot de passe") t)