1 \input texinfo @c -*-texinfo-*-
2 @setfilename ../../info/tramp
4 @settitle TRAMP User Manual
8 @c This is *so* much nicer :)
11 @c In the Tramp CVS, 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 filename according to the repective syntax.
21 @c xxx and yyy are auxiliary macros in order to omit leading and
22 @c trailing whitespace. Not very elegant, but I don't know it better.
28 @macro yyy {one, two}@c
36 @macro trampfn {method, user, host, localname}@c
37 @value{prefix}@yyy{\method\,@value{postfixhop}}@yyy{\user\,@@}\host\@value{postfix}\localname\@c
41 Copyright @copyright{} 1999, 2000, 2001, 2002, 2003, 2004, 2005,
42 2006, 2007, 2008 Free Software Foundation, Inc.
45 Permission is granted to copy, distribute and/or modify this document
46 under the terms of the GNU Free Documentation License, Version 1.2 or
47 any later version published by the Free Software Foundation; with no
48 Invariant Sections, with the Front-Cover texts being ``A GNU
49 Manual'', and with the Back-Cover Texts as in (a) below. A copy of the
50 license is included in the section entitled ``GNU Free Documentation
51 License'' in the Emacs manual.
53 (a) The FSF's Back-Cover Text is: ``You have the freedom to
54 copy and modify this GNU manual. Buying copies from the FSF
55 supports it in developing GNU and promoting software freedom.''
57 This document is part of a collection distributed under the GNU Free
58 Documentation License. If you want to distribute this document
59 separately from the collection, you can do so by adding a copy of the
60 license to the document, as described in section 6 of the license.
64 @c Entries for @command{install-info} to use
65 @dircategory @value{emacsname}
67 * TRAMP: (tramp). Transparent Remote Access, Multiple Protocol
68 @value{emacsname} remote file access via rsh and rcp.
74 @title @value{tramp} version @value{trampver} User Manual
76 @author by Daniel Pittman
77 @author based on documentation by Kai Gro@ss{}johann
88 @node Top, Overview, (dir), (dir)
89 @top @value{tramp} version @value{trampver} User Manual
91 This file documents @value{tramp} version @value{trampver}, a remote file
92 editing package for @value{emacsname}.
94 @value{tramp} stands for `Transparent Remote (file) Access, Multiple
95 Protocol'. This package provides remote file editing, similar to
96 @value{ftppackagename}.
98 The difference is that @value{ftppackagename} uses FTP to transfer
99 files between the local and the remote host, whereas @value{tramp} uses a
100 combination of @command{rsh} and @command{rcp} or other work-alike
101 programs, such as @command{ssh}/@command{scp}.
103 You can find the latest version of this document on the web at
104 @uref{http://www.gnu.org/software/tramp/}.
106 @c Pointer to the other Emacs flavor is necessary only in case of
107 @c standalone installation.
108 @ifset installchapter
109 The manual has been generated for @value{emacsname}.
111 If you want to read the info pages for @value{emacsothername}, you
112 should read in @ref{Installation} how to create them.
115 If you're using the other Emacs flavor, you should read the
116 @uref{@value{emacsotherfilename}, @value{emacsothername}} pages.
122 This manual is also available as a @uref{@value{japanesemanual},
123 Japanese translation}.
126 The latest release of @value{tramp} is available for
127 @uref{ftp://ftp.gnu.org/gnu/tramp/, download}, or you may see
128 @ref{Obtaining Tramp} for more details, including the CVS server
131 @value{tramp} also has a @uref{http://savannah.gnu.org/projects/tramp/,
132 Savannah Project Page}.
135 There is a mailing list for @value{tramp}, available at
136 @email{tramp-devel@@gnu.org}, and archived at
137 @uref{http://lists.gnu.org/archive/html/tramp-devel/, the
138 @value{tramp} Mail Archive}.
140 Older archives are located at
141 @uref{http://sourceforge.net/mailarchive/forum.php?forum=tramp-devel,
142 SourceForge Mail Archive} and
143 @uref{http://www.mail-archive.com/emacs-rcp@@ls6.cs.uni-dortmund.de/,
145 @c in HTML output, there's no new paragraph.
154 * Overview:: What @value{tramp} can and cannot do.
158 * Obtaining Tramp:: How to obtain @value{tramp}.
159 * History:: History of @value{tramp}.
160 @ifset installchapter
161 * Installation:: Installing @value{tramp} with your @value{emacsname}.
163 * Configuration:: Configuring @value{tramp} for use.
164 * Usage:: An overview of the operation of @value{tramp}.
165 * Bug Reports:: Reporting Bugs and Problems.
166 * Frequently Asked Questions:: Questions and answers from the mailing list.
167 * Function Index:: @value{tramp} functions.
168 * Variable Index:: User options and variables.
169 * Concept Index:: An item for each concept.
173 * Version Control:: The inner workings of remote version control.
174 * Files directories and localnames:: How file names, directories and localnames are mangled and managed.
175 * Traces and Profiles:: How to Customize Traces.
176 * Issues:: Debatable Issues and What Was Decided.
178 * GNU Free Documentation License:: The license for this documentation.
181 --- The Detailed Node Listing ---
183 @ifset installchapter
184 Installing @value{tramp} with your @value{emacsname}
186 * Installation parameters:: Parameters in order to control installation.
187 * Load paths:: How to plug-in @value{tramp} into your environment.
188 * Japanese manual:: Japanese manual.
192 Configuring @value{tramp} for use
194 * Connection types:: Types of connections made to remote machines.
195 * Inline methods:: Inline methods.
196 * External transfer methods:: External transfer methods.
198 * Gateway methods:: Gateway methods.
200 * Default Method:: Selecting a default method.
201 * Default User:: Selecting a default user.
202 * Default Host:: Selecting a default host.
203 * Multi-hops:: Connecting to a remote host using multiple hops.
204 * Customizing Methods:: Using Non-Standard Methods.
205 * Customizing Completion:: Selecting config files for user/host name completion.
206 * Password caching:: Reusing passwords for several connections.
207 * Connection caching:: Reusing connection related information.
208 * Remote Programs:: How @value{tramp} finds and uses programs on the remote machine.
209 * Remote shell setup:: Remote shell setup hints.
210 * Windows setup hints:: Issues with Cygwin ssh.
211 * Auto-save and Backup:: Auto-save and Backup.
215 * Filename Syntax:: @value{tramp} filename conventions.
216 * Alternative Syntax:: URL-like filename syntax.
217 * Filename completion:: Filename completion.
218 * Remote processes:: Integration with other @value{emacsname} packages.
219 * Cleanup remote connections:: Cleanup remote connections.
221 The inner workings of remote version control
223 * Version Controlled Files:: Determining if a file is under version control.
224 * Remote Commands:: Executing the version control commands on the remote machine.
225 * Changed workfiles:: Detecting if the working file has changed.
226 * Checking out files:: Bringing the workfile out of the repository.
227 * Miscellaneous Version Control:: Things related to Version Control that don't fit elsewhere.
229 Things related to Version Control that don't fit elsewhere
231 * Remote File Ownership:: How VC determines who owns a workfile.
232 * Back-end Versions:: How VC determines what release your RCS is.
234 How file names, directories and localnames are mangled and managed
236 * Localname deconstruction:: Breaking a localname into its components.
238 * External packages:: Integration with external Lisp packages.
245 @chapter An overview of @value{tramp}
248 After the installation of @value{tramp} into your @value{emacsname}, you
249 will be able to access files on remote machines as though they were
250 local. Access to the remote file system for editing files, version
251 control, and @code{dired} are transparently enabled.
253 Your access to the remote machine can be with the @command{rsh},
254 @command{rlogin}, @command{telnet} programs or with any similar
255 connection method. This connection must pass @acronym{ASCII}
256 successfully to be usable but need not be 8-bit clean.
258 The package provides support for @command{ssh} connections out of the
259 box, one of the more common uses of the package. This allows
260 relatively secure access to machines, especially if @command{ftp}
263 Under Windows, @value{tramp} is integrated with the PuTTY package,
264 using the @command{plink} program.
266 The majority of activity carried out by @value{tramp} requires only that
267 the remote login is possible and is carried out at the terminal. In
268 order to access remote files @value{tramp} needs to transfer their content
269 to the local machine temporarily.
271 @value{tramp} can transfer files between the machines in a variety of ways.
272 The details are easy to select, depending on your needs and the
273 machines in question.
275 The fastest transfer methods for large files rely on a remote file
276 transfer package such as @command{rcp}, @command{scp}, @command{rsync}
277 or (under Windows) @command{pscp}.
279 If the remote copy methods are not suitable for you, @value{tramp} also
280 supports the use of encoded transfers directly through the shell.
281 This requires that the @command{mimencode} or @command{uuencode} tools
282 are available on the remote machine. These methods are generally
283 faster for small files.
285 @value{tramp} is still under active development and any problems you encounter,
286 trivial or major, should be reported to the @value{tramp} developers.
290 @subsubheading Behind the scenes
291 @cindex behind the scenes
292 @cindex details of operation
295 This section tries to explain what goes on behind the scenes when you
296 access a remote file through @value{tramp}.
298 Suppose you type @kbd{C-x C-f} and enter part of an @value{tramp} file name,
299 then hit @kbd{@key{TAB}} for completion. Suppose further that this is
300 the first time that @value{tramp} is invoked for the host in question. Here's
305 @value{tramp} discovers that it needs a connection to the host. So it
306 invokes @samp{telnet @var{host}} or @samp{rsh @var{host} -l
307 @var{user}} or a similar tool to connect to the remote host.
308 Communication with this process happens through an
309 @value{emacsname} buffer, that is, the output from the remote end
313 The remote host may prompt for a login name (for @command{telnet}).
314 The login name is given in the file name, so @value{tramp} sends the
315 login name and a newline.
318 The remote host may prompt for a password or pass phrase (for
319 @command{rsh} or for @command{telnet} after sending the login name).
320 @value{tramp} displays the prompt in the minibuffer, asking you for the
321 password or pass phrase.
323 You enter the password or pass phrase. @value{tramp} sends it to the remote
324 host, followed by a newline.
327 @value{tramp} now waits for the shell prompt or for a message that the login
330 If @value{tramp} sees neither of them after a certain period of time
331 (a minute, say), then it issues an error message saying that it
332 couldn't find the remote shell prompt and shows you what the remote
335 If @value{tramp} sees a @samp{login failed} message, it tells you so,
336 aborts the login attempt and allows you to try again.
339 Suppose that the login was successful and @value{tramp} sees the shell prompt
340 from the remote host. Now @value{tramp} invokes @command{/bin/sh} because
341 Bourne shells and C shells have different command
342 syntaxes.@footnote{Invoking @command{/bin/sh} will fail if your login
343 shell doesn't recognize @samp{exec /bin/sh} as a valid command.
344 Maybe you use the Scheme shell @command{scsh}@dots{}}
346 After the Bourne shell has come up, @value{tramp} sends a few commands to
347 ensure a good working environment. It turns off echoing, it sets the
348 shell prompt, and a few other things.
351 Now the remote shell is up and it good working order. Remember, what
352 was supposed to happen is that @value{tramp} tries to find out what files exist
353 on the remote host so that it can do filename completion.
355 So, @value{tramp} basically issues @command{cd} and @command{ls} commands and
356 also sometimes @command{echo} with globbing. Another command that is
357 often used is @command{test} to find out whether a file is writable or a
358 directory or the like. The output of each command is parsed for the
362 Suppose you are finished with filename completion, have entered @kbd{C-x
363 C-f}, a full file name and hit @kbd{@key{RET}}. Now comes the time to
364 transfer the file contents from the remote host to the local host so
365 that you can edit them.
367 See above for an explanation of how @value{tramp} transfers the file contents.
369 For inline transfers, @value{tramp} issues a command like @samp{mimencode -b
370 /path/to/remote/file}, waits until the output has accumulated in the
371 buffer that's used for communication, then decodes that output to
372 produce the file contents.
374 For out-of-band transfers, @value{tramp} issues a command like the following:
376 rcp user@@host:/path/to/remote/file /tmp/tramp.4711
378 It then reads the local temporary file @file{/tmp/tramp.4711} into a
379 buffer and deletes the temporary file.
382 You now edit the buffer contents, blithely unaware of what has happened
383 behind the scenes. (Unless you have read this section, that is.) When
384 you are finished, you type @kbd{C-x C-s} to save the buffer.
387 Again, @value{tramp} transfers the file contents to the remote host either
388 inline or out-of-band. This is the reverse of what happens when reading
392 I hope this has provided you with a basic overview of what happens
393 behind the scenes when you open a file with @value{tramp}.
397 @node Obtaining Tramp
398 @chapter Obtaining Tramp.
399 @cindex obtaining Tramp
401 @value{tramp} is freely available on the Internet and the latest
402 release may be downloaded from
403 @uref{ftp://ftp.gnu.org/gnu/tramp/}. This release includes the full
404 documentation and code for @value{tramp}, suitable for installation.
405 But GNU Emacs (22 or later) includes @value{tramp} already, and there
406 is a @value{tramp} package for XEmacs, as well. So maybe it is easier
407 to just use those. But if you want the bleeding edge, read
410 For the especially brave, @value{tramp} is available from CVS. The CVS
411 version is the latest version of the code and may contain incomplete
412 features or new issues. Use these versions at your own risk.
414 Instructions for obtaining the latest development version of @value{tramp}
415 from CVS can be found by going to the Savannah project page at the
416 following URL and then clicking on the CVS link in the navigation bar
420 @uref{http://savannah.gnu.org/projects/tramp/}
423 Or follow the example session below:
426 ] @strong{cd ~/@value{emacsdir}}
427 ] @strong{export CVS_RSH="ssh"}
428 ] @strong{cvs -z3 -d:ext:anoncvs@@savannah.gnu.org:/cvsroot/tramp co tramp}
432 You should now have a directory @file{~/@value{emacsdir}/tramp}
433 containing the latest version of @value{tramp}. You can fetch the latest
434 updates from the repository by issuing the command:
437 ] @strong{cd ~/@value{emacsdir}/tramp}
438 ] @strong{export CVS_RSH="ssh"}
439 ] @strong{cvs update -d}
443 Once you've got updated files from the CVS repository, you need to run
444 @command{autoconf} in order to get an up-to-date @file{configure}
448 ] @strong{cd ~/@value{emacsdir}/tramp}
452 People who have no direct CVS access (maybe because sitting behind a
453 blocking firewall), can try the
454 @uref{http://savannah.gnu.org/cvs-backup/tramp-sources.tar.gz, Nightly
455 CVS Tree Tarball} instead of.
459 @chapter History of @value{tramp}
461 @cindex development history
463 Development was started end of November 1998. The package was called
464 @file{rssh.el}, back then. It only provided one method to access a
465 file, using @command{ssh} to log in to a remote host and using
466 @command{scp} to transfer the file contents. After a while, the name
467 was changed to @file{rcp.el}, and now it's @value{tramp}. Along the way,
468 many more methods for getting a remote shell and for transferring the
469 file contents were added. Support for VC was added.
471 The most recent addition of major features were the multi-hop methods
472 added in April 2000 and the unification of @value{tramp} and Ange-FTP
473 filenames in July 2002. In July 2004, multi-hop methods have been
474 replaced by proxy hosts. Running commands on remote hosts was
475 introduced in December 2005.
477 Support of gateways exists since April 2007.
480 In December 2001, @value{tramp} has been added to the XEmacs package
481 repository. Being part of the GNU Emacs repository happened in June
482 2002, the first release including @value{tramp} was GNU Emacs 22.1.
484 @value{tramp} is also a GNU/Linux Debian package since February 2001.
487 @c Installation chapter is necessary only in case of standalone
488 @c installation. Text taken from trampinst.texi.
489 @ifset installchapter
490 @include trampinst.texi
494 @chapter Configuring @value{tramp} for use
495 @cindex configuration
497 @cindex default configuration
498 @value{tramp} is (normally) fully functional when it is initially
499 installed. It is initially configured to use the @command{scp}
500 program to connect to the remote host. So in the easiest case, you
501 just type @kbd{C-x C-f} and then enter the filename
502 @file{@trampfn{, user, machine, /path/to.file}}.
504 On some hosts, there are problems with opening a connection. These are
505 related to the behavior of the remote shell. See @xref{Remote shell
506 setup}, for details on this.
508 If you do not wish to use these commands to connect to the remote
509 host, you should change the default connection and transfer method
510 that @value{tramp} uses. There are several different methods that @value{tramp}
511 can use to connect to remote machines and transfer files
512 (@pxref{Connection types}).
514 If you don't know which method is right for you, see @xref{Default
519 * Connection types:: Types of connections made to remote machines.
520 * Inline methods:: Inline methods.
521 * External transfer methods:: External transfer methods.
523 * Gateway methods:: Gateway methods.
525 * Default Method:: Selecting a default method.
526 Here we also try to help those who
527 don't have the foggiest which method
529 * Default User:: Selecting a default user.
530 * Default Host:: Selecting a default host.
531 * Multi-hops:: Connecting to a remote host using multiple hops.
532 * Customizing Methods:: Using Non-Standard Methods.
533 * Customizing Completion:: Selecting config files for user/host name completion.
534 * Password caching:: Reusing passwords for several connections.
535 * Connection caching:: Reusing connection related information.
536 * Remote Programs:: How @value{tramp} finds and uses programs on the remote machine.
537 * Remote shell setup:: Remote shell setup hints.
538 * Windows setup hints:: Issues with Cygwin ssh.
539 * Auto-save and Backup:: Auto-save and Backup.
543 @node Connection types
544 @section Types of connections made to remote machines.
545 @cindex connection types, overview
547 There are two basic types of transfer methods, each with its own
548 advantages and limitations. Both types of connection make use of a
549 remote shell access program such as @command{rsh}, @command{ssh} or
550 @command{telnet} to connect to the remote machine.
552 This connection is used to perform many of the operations that @value{tramp}
553 requires to make the remote file system transparently accessible from
554 the local machine. It is only when visiting files that the methods
557 @cindex inline methods
558 @cindex external transfer methods
559 @cindex external methods
560 @cindex out-of-band methods
561 @cindex methods, inline
562 @cindex methods, external transfer
563 @cindex methods, out-of-band
564 Loading or saving a remote file requires that the content of the file
565 be transfered between the two machines. The content of the file can be
566 transfered over the same connection used to log in to the remote
567 machine or the file can be transfered through another connection using
568 a remote copy program such as @command{rcp}, @command{scp} or
569 @command{rsync}. The former are called @dfn{inline methods}, the
570 latter are called @dfn{out-of-band methods} or @dfn{external transfer
571 methods} (@dfn{external methods} for short).
573 The performance of the external transfer methods is generally better
574 than that of the inline methods, at least for large files. This is
575 caused by the need to encode and decode the data when transferring
578 The one exception to this rule are the @command{scp} based transfer
579 methods. While these methods do see better performance when actually
580 transferring files, the overhead of the cryptographic negotiation at
581 startup may drown out the improvement in file transfer times.
583 External transfer methods should be configured such a way that they
584 don't require a password (with @command{ssh-agent}, or such alike).
585 Modern @command{scp} implementations offer options to reuse existing
586 @command{ssh} connections, see method @command{scpc}. If it isn't
587 possible, you should consider @ref{Password caching}, otherwise you
588 will be prompted for a password every copy action.
592 @section Inline methods
593 @cindex inline methods
594 @cindex methods, inline
596 The inline methods in @value{tramp} are quite powerful and can work in
597 situations where you cannot use an external transfer program to connect.
598 Inline methods are the only methods that work when connecting to the
599 remote machine via telnet. (There are also strange inline methods which
600 allow you to transfer files between @emph{user identities} rather than
603 These methods depend on the existence of a suitable encoding and
604 decoding command on remote machine. Locally, @value{tramp} may be able to
605 use features of @value{emacsname} to decode and encode the files or
606 it may require access to external commands to perform that task.
610 @cindex base-64 encoding
611 @value{tramp} checks the availability and usability of commands like
612 @command{mimencode} (part of the @command{metamail} package) or
613 @command{uuencode} on the remote host. The first reliable command
614 will be used. The search path can be customized, see @ref{Remote
617 If both commands aren't available on the remote host, @value{tramp}
618 transfers a small piece of Perl code to the remote host, and tries to
619 apply it for encoding and decoding.
627 Connect to the remote host with @command{rsh}. Due to the unsecure
628 connection it is recommended for very local host topology only.
630 On operating systems which provide the command @command{remsh} instead
631 of @command{rsh}, you can use the method @option{remsh}. This is true
632 for HP-UX or Cray UNICOS, for example.
639 Connect to the remote host with @command{ssh}. This is identical to
640 the previous option except that the @command{ssh} package is used,
641 making the connection more secure.
643 There are also two variants, @option{ssh1} and @option{ssh2}, that
644 call @samp{ssh -1} and @samp{ssh -2}, respectively. This way, you can
645 explicitly select whether you want to use the SSH protocol version 1
646 or 2 to connect to the remote host. (You can also specify in
647 @file{~/.ssh/config}, the SSH configuration file, which protocol
648 should be used, and use the regular @option{ssh} method.)
650 Two other variants, @option{ssh1_old} and @option{ssh2_old}, use the
651 @command{ssh1} and @command{ssh2} commands explicitly. If you don't
652 know what these are, you do not need these options.
654 All the methods based on @command{ssh} have an additional kludgy
655 feature: you can specify a host name which looks like @file{host#42}
656 (the real host name, then a hash sign, then a port number). This
657 means to connect to the given host but to also pass @code{-p 42} as
658 arguments to the @command{ssh} command.
661 @item @option{telnet}
662 @cindex method telnet
663 @cindex telnet method
665 Connect to the remote host with @command{telnet}. This is as unsecure
666 as the @option{rsh} method.
673 This method does not connect to a remote host at all, rather it uses
674 the @command{su} program to allow you to edit files as another user.
675 That means, the specified host name in the file name must be either
676 @samp{localhost} or the host name as returned by the function
677 @command{(system-name)}. For an exception of this rule see
685 This is similar to the @option{su} method, but it uses @command{sudo}
686 rather than @command{su} to become a different user.
688 Note that @command{sudo} must be configured to allow you to start a
689 shell as the user. It would be nice if it was sufficient if
690 @command{ls} and @command{mimencode} were allowed, but that is not
691 easy to implement, so I haven't got around to it, yet.
698 As you would expect, this is similar to @option{ssh}, only a little
699 different. Whereas @option{ssh} opens a normal interactive shell on
700 the remote host, this option uses @samp{ssh -t -t @var{host} -l
701 @var{user} /bin/sh} to open a connection. This is useful for users
702 where the normal login shell is set up to ask them a number of
703 questions when logging in. This procedure avoids these questions, and
704 just gives @value{tramp} a more-or-less `standard' login shell to work
707 Note that this procedure does not eliminate questions asked by
708 @command{ssh} itself. For example, @command{ssh} might ask ``Are you
709 sure you want to continue connecting?'' if the host key of the remote
710 host is not known. @value{tramp} does not know how to deal with such a
711 question (yet), therefore you will need to make sure that you can log
712 in without such questions.
714 This is also useful for Windows users where @command{ssh}, when
715 invoked from an @value{emacsname} buffer, tells them that it is not
716 allocating a pseudo tty. When this happens, the login shell is wont
717 to not print any shell prompt, which confuses @value{tramp} mightily.
718 For reasons unknown, some Windows ports for @command{ssh} require the
719 doubled @samp{-t} option.
721 This supports the @samp{-p} kludge.
724 @item @option{krlogin}
725 @cindex method krlogin
726 @cindex krlogin method
727 @cindex Kerberos (with krlogin method)
729 This method is also similar to @option{ssh}. It only uses the
730 @command{krlogin -x} command to log in to the remote host.
737 This method is mostly interesting for Windows users using the PuTTY
738 implementation of SSH. It uses @samp{plink -ssh} to log in to the
741 This supports the @samp{-P} kludge.
743 Additionally, the methods @option{plink1} and @option{plink2} are
744 provided, which call @samp{plink -1 -ssh} or @samp{plink -2 -ssh} in
745 order to use SSH protocol version 1 or 2 explicitly.
747 CCC: Do we have to connect to the remote host once from the command
748 line to accept the SSH key? Maybe this can be made automatic?
750 CCC: Say something about the first shell command failing. This might
751 be due to a wrong setting of @code{tramp-rsh-end-of-line}.
754 @item @option{plinkx}
755 @cindex method plinkx
756 @cindex plinkx method
758 Another method using PuTTY on Windows. Instead of host names, it
759 expects PuTTY session names, calling @samp{plink -load @var{session}
760 -t"}. User names are relevant only in case the corresponding session
761 hasn't defined a user name. Different port numbers must be defined in
769 This is an experimental implementation of the fish protocol, known from
770 the GNU Midnight Commander or the KDE Konqueror. @value{tramp} expects
771 the fish server implementation from the KDE kioslave. That means, the
772 file @file{~/.fishsrv.pl} is expected to reside on the remote host.
774 The implementation lacks good performance. The code is offered anyway,
775 maybe somebody can improve the performance.
780 @node External transfer methods
781 @section External transfer methods
782 @cindex methods, external transfer
783 @cindex methods, out-of-band
784 @cindex external transfer methods
785 @cindex out-of-band methods
787 The external transfer methods operate through multiple channels, using
788 the remote shell connection for many actions while delegating file
789 transfers to an external transfer utility.
791 This saves the overhead of encoding and decoding that multiplexing the
792 transfer through the one connection has with the inline methods.
794 Since external transfer methods need their own overhead opening a new
795 channel, all files which are smaller than @var{tramp-copy-size-limit}
796 are still transferred with the corresponding inline method. It should
797 provide a fair trade-off between both approaches.
800 @item @option{rcp} --- @command{rsh} and @command{rcp}
803 @cindex rcp (with rcp method)
804 @cindex rsh (with rcp method)
806 This method uses the @command{rsh} and @command{rcp} commands to connect
807 to the remote machine and transfer files. This is probably the fastest
808 connection method available.
810 The alternative method @option{remcp} uses the @command{remsh} and
811 @command{rcp} commands. It should be applied on machines where
812 @command{remsh} is used instead of @command{rsh}.
815 @item @option{scp} --- @command{ssh} and @command{scp}
818 @cindex scp (with scp method)
819 @cindex ssh (with scp method)
821 Using @command{ssh} to connect to the remote host and @command{scp} to
822 transfer files between the machines is the best method for securely
823 connecting to a remote machine and accessing files.
825 The performance of this option is also quite good. It may be slower than
826 the inline methods when you often open and close small files however.
827 The cost of the cryptographic handshake at the start of an @command{scp}
828 session can begin to absorb the advantage that the lack of encoding and
831 There are also two variants, @option{scp1} and @option{scp2}, that
832 call @samp{ssh -1} and @samp{ssh -2}, respectively. This way, you can
833 explicitly select whether you want to use the SSH protocol version 1
834 or 2 to connect to the remote host. (You can also specify in
835 @file{~/.ssh/config}, the SSH configuration file, which protocol
836 should be used, and use the regular @option{scp} method.)
838 Two other variants, @option{scp1_old} and @option{scp2_old}, use the
839 @command{ssh1} and @command{ssh2} commands explicitly. If you don't
840 know what these are, you do not need these options.
842 All the @command{ssh} based methods support the kludgy @samp{-p}
843 feature where you can specify a port number to connect to in the host
844 name. For example, the host name @file{host#42} tells @value{tramp} to
845 specify @samp{-p 42} in the argument list for @command{ssh}, and to
846 specify @samp{-P 42} in the argument list for @command{scp}.
849 @item @option{sftp} --- @command{ssh} and @command{sftp}
852 @cindex sftp (with sftp method)
853 @cindex ssh (with sftp method)
855 That is mostly the same method as @option{scp}, but using
856 @command{sftp} as transfer command. So the same remarks are valid.
858 This command does not work like @value{ftppackagename}, where
859 @command{ftp} is called interactively, and all commands are send from
860 within this session. Instead of, @command{ssh} is used for login.
862 This method supports the @samp{-p} hack.
865 @item @option{rsync} --- @command{ssh} and @command{rsync}
868 @cindex rsync (with rsync method)
869 @cindex ssh (with rsync method)
871 Using the @command{ssh} command to connect securely to the remote
872 machine and the @command{rsync} command to transfer files is almost
873 identical to the @option{scp} method.
875 While @command{rsync} performs much better than @command{scp} when
876 transferring files that exist on both hosts, this advantage is lost if
877 the file exists only on one side of the connection.
879 The @command{rsync} based method may be considerably faster than the
880 @command{rcp} based methods when writing to the remote system. Reading
881 files to the local machine is no faster than with a direct copy.
883 This method supports the @samp{-p} hack.
886 @item @option{scpx} --- @command{ssh} and @command{scp}
889 @cindex scp (with scpx method)
890 @cindex ssh (with scpx method)
892 As you would expect, this is similar to @option{scp}, only a little
893 different. Whereas @option{scp} opens a normal interactive shell on
894 the remote host, this option uses @samp{ssh -t -t @var{host} -l
895 @var{user} /bin/sh} to open a connection. This is useful for users
896 where the normal login shell is set up to ask them a number of
897 questions when logging in. This procedure avoids these questions, and
898 just gives @value{tramp} a more-or-less `standard' login shell to work
901 This is also useful for Windows users where @command{ssh}, when
902 invoked from an @value{emacsname} buffer, tells them that it is not
903 allocating a pseudo tty. When this happens, the login shell is wont
904 to not print any shell prompt, which confuses @value{tramp} mightily.
906 This method supports the @samp{-p} hack.
909 @item @option{scpc} --- @command{ssh} and @command{scp}
912 @cindex scp (with scpx method)
913 @cindex ssh (with scpx method)
915 Newer versions of @option{ssh} (for example OpenSSH 4) offer an option
916 @option{ControlMaster}. This allows @option{scp} to reuse an existing
917 @option{ssh} channel, which increases performance.
919 Before you use this method, you shall check whether your @option{ssh}
920 implementation does support this option. Try from the command line
923 ssh localhost -o ControlMaster=yes
926 This method supports the @samp{-p} hack.
929 @item @option{pscp} --- @command{plink} and @command{pscp}
932 @cindex pscp (with pscp method)
933 @cindex plink (with pscp method)
934 @cindex PuTTY (with pscp method)
936 This method is similar to @option{scp}, but it uses the
937 @command{plink} command to connect to the remote host, and it uses
938 @command{pscp} for transferring the files. These programs are part
939 of PuTTY, an SSH implementation for Windows.
941 This method supports the @samp{-P} hack.
944 @item @option{psftp} --- @command{plink} and @command{psftp}
947 @cindex psftp (with psftp method)
948 @cindex plink (with psftp method)
949 @cindex PuTTY (with psftp method)
951 As you would expect, this method is similar to @option{sftp}, but it
952 uses the @command{plink} command to connect to the remote host, and it
953 uses @command{psftp} for transferring the files. These programs are
954 part of PuTTY, an SSH implementation for Windows.
956 This method supports the @samp{-P} hack.
959 @item @option{fcp} --- @command{fsh} and @command{fcp}
962 @cindex fsh (with fcp method)
963 @cindex fcp (with fcp method)
965 This method is similar to @option{scp}, but it uses the @command{fsh}
966 command to connect to the remote host, and it uses @command{fcp} for
967 transferring the files. @command{fsh/fcp} are a front-end for
968 @command{ssh} which allow for reusing the same @command{ssh} session
969 for submitting several commands. This avoids the startup overhead of
970 @command{scp} (which has to establish a secure connection whenever it
971 is called). Note, however, that you can also use one of the inline
972 methods to achieve a similar effect.
974 This method uses the command @samp{fsh @var{host} -l @var{user}
975 /bin/sh -i} to establish the connection, it does not work to just say
976 @command{fsh @var{host} -l @var{user}}.
981 There is no inline method using @command{fsh} as the multiplexing
982 provided by the program is not very useful in our context. @value{tramp}
983 opens just one connection to the remote host and then keeps it open,
991 This is not a native @value{tramp} method. Instead of, it forwards all
992 requests to @value{ftppackagename}.
994 This works only for unified filenames, see @ref{Issues}.
998 @item @option{smb} --- @command{smbclient}
1002 This is another not natural @value{tramp} method. It uses the
1003 @command{smbclient} command on different Unices in order to connect to
1004 an SMB server. An SMB server might be a Samba (or CIFS) server on
1005 another UNIX host or, more interesting, a host running MS Windows. So
1006 far, it is tested towards MS Windows NT, MS Windows 2000, and MS
1009 The first directory in the localname must be a share name on the remote
1010 host. Remember, that the @code{$} character in which default shares
1011 usually end, must be written @code{$$} due to environment variable
1012 substitution in file names. If no share name is given (i.e. remote
1013 directory @code{/}), all available shares are listed.
1015 Since authorization is done on share level, you will be prompted
1016 always for a password if you access another share on the same host.
1017 This can be suppressed by @ref{Password caching}.
1019 MS Windows uses for authorization both a user name and a domain name.
1020 Because of this, the @value{tramp} syntax has been extended: you can
1021 specify a user name which looks like @code{user%domain} (the real user
1022 name, then a percent sign, then the domain name). So, to connect to
1023 the machine @code{melancholia} as user @code{daniel} of the domain
1024 @code{BIZARRE}, and edit @file{.emacs} in the home directory (share
1025 @code{daniel$}) I would specify the filename @file{@trampfn{smb,
1026 daniel%BIZARRE, melancholia, /daniel$$/.emacs}}.
1028 Depending on the Windows domain configuration, a Windows user might be
1029 considered as domain user per default. In order to connect as local
1030 user, the WINS name of that machine must be given as domain name.
1031 Usually, it is the machine name in capital letters. In the example
1032 above, the local user @code{daniel} would be specified as
1033 @file{@trampfn{smb, daniel%MELANCHOLIA, melancholia, /daniel$$/.emacs}}.
1035 The domain name as well as the user name are optional. If no user
1036 name is specified at all, the anonymous user (without password
1037 prompting) is assumed. This is different from all other @value{tramp}
1038 methods, where in such a case the local user name is taken.
1040 The @option{smb} method supports the @samp{-p} hack.
1042 @strong{Please note:} If @value{emacsname} runs locally under MS
1043 Windows, this method isn't available. Instead of, you can use UNC
1044 file names like @file{//melancholia/daniel$$/.emacs}. The only
1045 disadvantage is that there's no possibility to specify another user
1052 @node Gateway methods
1053 @section Gateway methods
1054 @cindex methods, gateway
1055 @cindex gateway methods
1057 Gateway methods are not methods to access a remote host directly.
1058 These methods are intended to pass firewalls or proxy servers.
1059 Therefore, they can be used for proxy host declarations
1060 (@pxref{Multi-hops}) only.
1062 A gateway method must come always along with a method who supports
1063 port setting (referred to as @samp{-p} kludge). This is because
1064 @value{tramp} targets the accompanied method to
1065 @file{localhost#random_port}, from where the firewall or proxy server
1068 Gateway methods support user name and password declarations. These
1069 are used to authenticate towards the corresponding firewall or proxy
1070 server. They can be passed only if your friendly administrator has
1071 granted your access.
1074 @item @option{tunnel}
1075 @cindex method tunnel
1076 @cindex tunnel method
1078 This method implements an HTTP tunnel via the @command{CONNECT}
1079 command (see RFC 2616, 2817). Any HTTP 1.1 compliant (proxy) server
1080 shall support this command.
1082 As authentication method, only @option{Basic Authentication} (see RFC
1083 2617) is implemented so far. If no port number is given in the
1084 declaration, port @option{8080} is used for the proxy server.
1087 @item @option{socks}
1088 @cindex method socks
1089 @cindex socks method
1091 The @command{socks} method provides access to SOCKSv5 servers (see
1092 RFC 1928). @option{Username/Password Authentication} according to RFC
1095 The default port number of the socks server is @option{1080}, if not
1096 specified otherwise.
1102 @node Default Method
1103 @section Selecting a default method
1104 @cindex default method
1106 @vindex tramp-default-method
1107 When you select an appropriate transfer method for your typical usage
1108 you should set the variable @code{tramp-default-method} to reflect that
1109 choice. This variable controls which method will be used when a method
1110 is not specified in the @value{tramp} file name. For example:
1113 (setq tramp-default-method "ssh")
1116 @vindex tramp-default-method-alist
1117 You can also specify different methods for certain user/host
1118 combinations, via the variable @code{tramp-default-method-alist}. For
1119 example, the following two lines specify to use the @option{ssh}
1120 method for all user names matching @samp{john} and the @option{rsync}
1121 method for all host names matching @samp{lily}. The third line
1122 specifies to use the @option{su} method for the user @samp{root} on
1123 the machine @samp{localhost}.
1126 (add-to-list 'tramp-default-method-alist '("" "john" "ssh"))
1127 (add-to-list 'tramp-default-method-alist '("lily" "" "rsync"))
1128 (add-to-list 'tramp-default-method-alist
1129 '("\\`localhost\\'" "\\`root\\'" "su"))
1133 See the documentation for the variable
1134 @code{tramp-default-method-alist} for more details.
1136 External transfer methods are normally preferable to inline transfer
1137 methods, giving better performance.
1139 @xref{Inline methods}.
1140 @xref{External transfer methods}.
1142 Another consideration with the selection of transfer methods is the
1143 environment you will use them in and, especially when used over the
1144 Internet, the security implications of your preferred method.
1146 The @option{rsh} and @option{telnet} methods send your password as
1147 plain text as you log in to the remote machine, as well as
1148 transferring the files in such a way that the content can easily be
1149 read from other machines.
1151 If you need to connect to remote systems that are accessible from the
1152 Internet, you should give serious thought to using @option{ssh} based
1153 methods to connect. These provide a much higher level of security,
1154 making it a non-trivial exercise for someone to obtain your password
1155 or read the content of the files you are editing.
1158 @subsection Which method is the right one for me?
1159 @cindex choosing the right method
1161 Given all of the above, you are probably thinking that this is all fine
1162 and good, but it's not helping you to choose a method! Right you are.
1163 As a developer, we don't want to boss our users around but give them
1164 maximum freedom instead. However, the reality is that some users would
1165 like to have some guidance, so here I'll try to give you this guidance
1166 without bossing you around. You tell me whether it works @dots{}
1168 My suggestion is to use an inline method. For large files, out-of-band
1169 methods might be more efficient, but I guess that most people will want
1170 to edit mostly small files.
1172 I guess that these days, most people can access a remote machine by
1173 using @command{ssh}. So I suggest that you use the @option{ssh}
1174 method. So, type @kbd{C-x C-f @trampfn{ssh, root, otherhost,
1175 /etc/motd} @key{RET}} to edit the @file{/etc/motd} file on the other
1178 If you can't use @option{ssh} to log in to the remote host, then
1179 select a method that uses a program that works. For instance, Windows
1180 users might like the @option{plink} method which uses the PuTTY
1181 implementation of @command{ssh}. Or you use Kerberos and thus like
1184 For the special case of editing files on the local host as another
1185 user, see the @option{su} or @option{sudo} methods. They offer
1186 shortened syntax for the @samp{root} account, like
1187 @file{@trampfn{su, , , /etc/motd}}.
1189 People who edit large files may want to consider @option{scpc} instead
1190 of @option{ssh}, or @option{pscp} instead of @option{plink}. These
1191 out-of-band methods are faster than inline methods for large files.
1192 Note, however, that out-of-band methods suffer from some limitations.
1193 Please try first whether you really get a noticeable speed advantage
1194 from using an out-of-band method! Maybe even for large files, inline
1195 methods are fast enough.
1199 @section Selecting a default user
1200 @cindex default user
1202 The user part of a @value{tramp} file name can be omitted. Usually,
1203 it is replaced by the user name you are logged in. Often, this is not
1204 what you want. A typical use of @value{tramp} might be to edit some
1205 files with root permissions on the local host. This case, you should
1206 set the variable @code{tramp-default-user} to reflect that choice.
1210 (setq tramp-default-user "root")
1213 @code{tramp-default-user} is regarded as obsolete, and will be removed
1216 @vindex tramp-default-user-alist
1217 You can also specify different users for certain method/host
1218 combinations, via the variable @code{tramp-default-user-alist}. For
1219 example, if you always have to use the user @samp{john} in the domain
1220 @samp{somewhere.else}, you can specify the following:
1223 (add-to-list 'tramp-default-user-alist
1224 '("ssh" ".*\\.somewhere\\.else\\'" "john"))
1228 See the documentation for the variable
1229 @code{tramp-default-user-alist} for more details.
1231 One trap to fall in must be known. If @value{tramp} finds a default
1232 user, this user will be passed always to the connection command as
1233 parameter (for example @samp{ssh here.somewhere.else -l john}. If you
1234 have specified another user for your command in its configuration
1235 files, @value{tramp} cannot know it, and the remote access will fail.
1236 If you have specified in the given example in @file{~/.ssh/config} the
1240 Host here.somewhere.else
1245 than you must discard selecting a default user by @value{tramp}. This
1246 will be done by setting it to @code{nil} (or @samp{lily}, likewise):
1249 (add-to-list 'tramp-default-user-alist
1250 '("ssh" "\\`here\\.somewhere\\.else\\'" nil))
1253 The last entry in @code{tramp-default-user-alist} could be your
1254 default user you'll apply predominantly. You shall @emph{append} it
1255 to that list at the end:
1258 (add-to-list 'tramp-default-user-alist '(nil nil "jonas") t)
1263 @section Selecting a default host
1264 @cindex default host
1266 @vindex tramp-default-host
1267 Finally, it is even possible to omit the host name part of a
1268 @value{tramp} file name. This case, the value of the variable
1269 @code{tramp-default-host} is used. Per default, it is initialized
1270 with the host name your local @value{emacsname} is running.
1272 If you, for example, use @value{tramp} mainly to contact the host
1273 @samp{target} as user @samp{john}, you can specify:
1276 (setq tramp-default-user "john"
1277 tramp-default-host "target")
1280 Then the simple file name @samp{@trampfn{ssh, , ,}} will connect you
1281 to John's home directory on target.
1283 Note, however, that the most simplification @samp{/::} won't work,
1284 because @samp{/:} is the prefix for quoted file names.
1289 @section Connecting to a remote host using multiple hops
1293 Sometimes, the methods described before are not sufficient. Sometimes,
1294 it is not possible to connect to a remote host using a simple command.
1295 For example, if you are in a secured network, you might have to log in
1296 to a `bastion host' first before you can connect to the outside world.
1297 Of course, the target host may also require a bastion host.
1299 @vindex tramp-default-proxies-alist
1300 In order to specify such multiple hops, it is possible to define a proxy
1301 host to pass through, via the variable
1302 @code{tramp-default-proxies-alist}. This variable keeps a list of
1303 triples (@var{host} @var{user} @var{proxy}).
1305 The first matching item specifies the proxy host to be passed for a
1306 file name located on a remote target matching @var{user}@@@var{host}.
1307 @var{host} and @var{user} are regular expressions or @code{nil}, which
1308 is interpreted as a regular expression which always matches.
1310 @var{proxy} must be a Tramp filename which localname part is ignored.
1311 Method and user name on @var{proxy} are optional, which is interpreted
1312 with the default values.
1314 The method must be an inline or gateway method (@pxref{Inline
1315 methods}, @pxref{Gateway methods}).
1318 The method must be an inline method (@pxref{Inline methods}).
1320 If @var{proxy} is @code{nil}, no additional hop is required reaching
1321 @var{user}@@@var{host}.
1323 If you, for example, must pass the host @samp{bastion.your.domain} as
1324 user @samp{bird} for any remote host which is not located in your local
1328 (add-to-list 'tramp-default-proxies-alist
1329 '("\\." nil "@trampfn{ssh, bird, bastion.your.domain,}"))
1330 (add-to-list 'tramp-default-proxies-alist
1331 '("\\.your\\.domain\\'" nil nil))
1334 Please note the order of the code. @code{add-to-list} adds elements at the
1335 beginning of a list. Therefore, most relevant rules must be added last.
1337 Proxy hosts can be cascaded. If there is another host called
1338 @samp{jump.your.domain}, which is the only one in your local domain who
1339 is allowed connecting @samp{bastion.your.domain}, you can add another
1343 (add-to-list 'tramp-default-proxies-alist
1344 '("\\`bastion\\.your\\.domain\\'"
1346 "@trampfn{ssh, , jump.your.domain,}"))
1349 @var{proxy} can contain the patterns @code{%h} or @code{%u}. These
1350 patterns are replaced by the strings matching @var{host} or
1351 @var{user}, respectively.
1353 If you, for example, wants to work as @samp{root} on hosts in the
1354 domain @samp{your.domain}, but login as @samp{root} is disabled for
1355 non-local access, you might add the following rule:
1358 (add-to-list 'tramp-default-proxies-alist
1359 '("\\.your\\.domain\\'" "\\`root\\'" "@trampfn{ssh, , %h,}"))
1362 Opening @file{@trampfn{sudo, , randomhost.your.domain,}} would connect
1363 first @samp{randomhost.your.domain} via @code{ssh} under your account
1364 name, and perform @code{sudo -u root} on that host afterwards. It is
1365 important to know that the given method is applied on the host which
1366 has been reached so far. @code{sudo -u root}, applied on your local
1367 host, wouldn't be useful here.
1369 This is the recommended configuration to work as @samp{root} on remote
1373 Finally, @code{tramp-default-proxies-alist} can be used to pass
1374 firewalls or proxy servers. Imagine your local network has a host
1375 @samp{proxy.your.domain} which is used on port 3128 as HTTP proxy to
1376 the outer world. Your friendly administrator has granted you access
1377 under your user name to @samp{host.other.domain} on that proxy
1378 server.@footnote{HTTP tunnels are intended for secure SSL/TLS
1379 communication. Therefore, many proxy server restrict the tunnels to
1380 related target ports. You might need to run your ssh server on your
1381 target host @samp{host.other.domain} on such a port, like 443 (https).
1382 See @uref{http://savannah.gnu.org/maintenance/CvsFromBehindFirewall}
1383 for discussion of ethical issues.} You would need to add the
1387 (add-to-list 'tramp-default-proxies-alist
1388 '("\\`host\\.other\\.domain\\'" nil
1389 "@trampfn{tunnel, , proxy.your.domain#3128,}"))
1392 Gateway methods can be declared as first hop only in a multiple hop
1397 @node Customizing Methods
1398 @section Using Non-Standard Methods
1399 @cindex customizing methods
1400 @cindex using non-standard methods
1401 @cindex create your own methods
1403 There is a variable @code{tramp-methods} which you can change if the
1404 predefined methods don't seem right.
1406 For the time being, I'll refer you to the Lisp documentation of that
1407 variable, accessible with @kbd{C-h v tramp-methods @key{RET}}.
1410 @node Customizing Completion
1411 @section Selecting config files for user/host name completion
1412 @cindex customizing completion
1413 @cindex selecting config files
1414 @vindex tramp-completion-function-alist
1416 The variable @code{tramp-completion-function-alist} is intended to
1417 customize which files are taken into account for user and host name
1418 completion (@pxref{Filename completion}). For every method, it keeps
1419 a set of configuration files, accompanied by a Lisp function able to
1420 parse that file. Entries in @code{tramp-completion-function-alist}
1421 have the form (@var{method} @var{pair1} @var{pair2} ...).
1423 Each @var{pair} is composed of (@var{function} @var{file}).
1424 @var{function} is responsible to extract user names and host names
1425 from @var{file} for completion. There are two functions which access
1428 @defun tramp-get-completion-function method
1429 This function returns the list of completion functions for @var{method}.
1433 (tramp-get-completion-function "rsh")
1435 @result{} ((tramp-parse-rhosts "/etc/hosts.equiv")
1436 (tramp-parse-rhosts "~/.rhosts"))
1440 @defun tramp-set-completion-function method function-list
1441 This function sets @var{function-list} as list of completion functions
1446 (tramp-set-completion-function "ssh"
1447 '((tramp-parse-sconfig "/etc/ssh_config")
1448 (tramp-parse-sconfig "~/.ssh/config")))
1450 @result{} ((tramp-parse-sconfig "/etc/ssh_config")
1451 (tramp-parse-sconfig "~/.ssh/config"))
1455 The following predefined functions parsing configuration files exist:
1458 @item @code{tramp-parse-rhosts}
1459 @findex tramp-parse-rhosts
1461 This function parses files which are syntactical equivalent to
1462 @file{~/.rhosts}. It returns both host names and user names, if
1465 @item @code{tramp-parse-shosts}
1466 @findex tramp-parse-shosts
1468 This function parses files which are syntactical equivalent to
1469 @file{~/.ssh/known_hosts}. Since there are no user names specified
1470 in such files, it can return host names only.
1472 @item @code{tramp-parse-sconfig}
1473 @findex tramp-parse-shosts
1475 This function returns the host nicknames defined by @code{Host} entries
1476 in @file{~/.ssh/config} style files.
1478 @item @code{tramp-parse-shostkeys}
1479 @findex tramp-parse-shostkeys
1481 SSH2 parsing of directories @file{/etc/ssh2/hostkeys/*} and
1482 @file{~/ssh2/hostkeys/*}. Hosts are coded in file names
1483 @file{hostkey_@var{portnumber}_@var{host-name}.pub}. User names
1484 are always @code{nil}.
1486 @item @code{tramp-parse-sknownhosts}
1487 @findex tramp-parse-shostkeys
1489 Another SSH2 style parsing of directories like
1490 @file{/etc/ssh2/knownhosts/*} and @file{~/ssh2/knownhosts/*}. This
1491 case, hosts names are coded in file names
1492 @file{@var{host-name}.@var{algorithm}.pub}. User names are always @code{nil}.
1494 @item @code{tramp-parse-hosts}
1495 @findex tramp-parse-hosts
1497 A function dedicated to @file{/etc/hosts} style files. It returns
1500 @item @code{tramp-parse-passwd}
1501 @findex tramp-parse-passwd
1503 A function which parses @file{/etc/passwd} like files. Obviously, it
1504 can return user names only.
1506 @item @code{tramp-parse-netrc}
1507 @findex tramp-parse-netrc
1509 Finally, a function which parses @file{~/.netrc} like files.
1512 If you want to keep your own data in a file, with your own structure,
1513 you might provide such a function as well. This function must meet
1514 the following conventions:
1516 @defun my-tramp-parse file
1517 @var{file} must be either a file name on your host, or @code{nil}.
1518 The function must return a list of (@var{user} @var{host}), which are
1519 taken as candidates for user and host name completion.
1523 (my-tramp-parse "~/.my-tramp-hosts")
1525 @result{} ((nil "toto") ("daniel" "melancholia"))
1530 @node Password caching
1531 @section Reusing passwords for several connections.
1534 Sometimes it is necessary to connect to the same remote host several
1535 times. Reentering passwords again and again would be annoying, when
1536 the chosen method does not support access without password prompt
1537 through own configuration.
1539 By default, @value{tramp} caches the passwords entered by you. They will
1540 be reused next time if a connection needs them for the same user name
1541 and host name, independently of the connection method.
1543 @vindex password-cache-expiry
1544 Passwords are not saved permanently, that means the password caching
1545 is limited to the lifetime of your @value{emacsname} session. You
1546 can influence the lifetime of password caching by customizing the
1547 variable @code{password-cache-expiry}. The value is the number of
1548 seconds how long passwords are cached. Setting it to @code{nil}
1549 disables the expiration.
1551 @vindex password-cache
1552 If you don't like this feature for security reasons, password caching
1553 can be disabled totally by customizing the variable
1554 @code{password-cache} (setting it to @code{nil}).
1556 Implementation Note: password caching is based on the package
1557 @file{password.el} in No Gnus. For the time being, it is activated
1558 only when this package is seen in the @code{load-path} while loading
1560 @ifset installchapter
1561 If you don't use No Gnus, you can take @file{password.el} from the
1562 @value{tramp} @file{contrib} directory, see @ref{Installation
1565 It will be activated mandatory once No Gnus has found its way into
1569 @node Connection caching
1570 @section Reusing connection related information.
1573 @vindex tramp-persistency-file-name
1574 In order to reduce initial connection time, @value{tramp} stores
1575 connection related information persistently. The variable
1576 @code{tramp-persistency-file-name} keeps the file name where these
1577 information are written. Its default value is
1579 @file{~/.emacs.d/tramp}.
1582 @file{~/.xemacs/tramp}.
1584 It is recommended to choose a local file name.
1586 @value{tramp} reads this file during startup, and writes it when
1587 exiting @value{emacsname}. You can simply remove this file if
1588 @value{tramp} shall be urged to recompute these information next
1589 @value{emacsname} startup time.
1591 Using such persistent information can be disabled by setting
1592 @code{tramp-persistency-file-name} to @code{nil}.
1594 Once consequence of reusing connection related information is that
1595 @var{tramp} needs to distinguish hosts. If you, for example, run a
1596 local @code{sshd} on port 3001, which tunnels @command{ssh} to another
1597 host, you could access both @file{@trampfn{ssh, , localhost,}} and
1598 @file{@trampfn{ssh, , localhost#3001,}}. @var{tramp} would use the
1599 same host related information (like paths, Perl variants, etc) for
1600 both connections, although the information is valid only for one of
1603 In order to avoid trouble, you must use another host name for one of
1604 the connections, like introducing a @option{Host} section in
1605 @file{~/.ssh/config} (@pxref{Frequently Asked Questions}) or applying
1606 multiple hops (@pxref{Multi-hops}).
1608 When @value{tramp} detects a changed operating system version on a
1609 remote host (via the command @command{uname -sr}), it flushes all
1610 connection related information for this host, quits the execution, and
1611 displays a message like this:
1614 Quit: "Connection reset, because remote host changed from `Linux
1615 2.6.22-13-generic' to `Linux 2.6.22-14-generic'"
1619 You can simply open the remote file again in such a case.
1622 @node Remote Programs
1623 @section How @value{tramp} finds and uses programs on the remote machine.
1625 @value{tramp} depends on a number of programs on the remote host in order to
1626 function, including @command{ls}, @command{test}, @command{find} and
1629 In addition to these required tools, there are various tools that may be
1630 required based on the connection method. See @ref{Inline methods} and
1631 @ref{External transfer methods} for details on these.
1633 Certain other tools, such as @command{perl} (or @command{perl5}) and
1634 @command{grep} will be used if they can be found. When they are
1635 available, they are used to improve the performance and accuracy of
1638 @vindex tramp-remote-path
1639 When @value{tramp} connects to the remote machine, it searches for the
1640 programs that it can use. The variable @code{tramp-remote-path}
1641 controls the directories searched on the remote machine.
1643 By default, this is set to a reasonable set of defaults for most
1644 machines. The symbol @code{tramp-default-remote-path} is a place
1645 holder, it is replaced by the list of directories received via the
1646 command @command{getconf PATH} on your remote machine. For example,
1647 on GNU Debian this is @file{/bin:/usr/bin}, whereas on Solaris this is
1648 @file{/usr/xpg4/bin:/usr/ccs/bin:/usr/bin:/opt/SUNWspro/bin}. It is
1649 recommended to apply this symbol on top of @code{tramp-remote-path}.
1651 It is possible, however, that your local (or remote ;) system
1652 administrator has put the tools you want in some obscure local
1655 In this case, you can still use them with @value{tramp}. You simply
1656 need to add code to your @file{.emacs} to add the directory to the
1657 remote path. This will then be searched by @value{tramp} when you
1658 connect and the software found.
1660 To add a directory to the remote search path, you could use code such
1664 @i{;; We load @value{tramp} to define the variable.}
1666 @i{;; We have @command{perl} in "/usr/local/perl/bin"}
1667 (add-to-list 'tramp-remote-path "/usr/local/perl/bin")
1670 @value{tramp} caches several information, like the Perl binary
1671 location. The changed remote search path wouldn't affect these
1672 settings. In order to force @value{tramp} to recompute these values,
1673 you must exit @value{emacsname}, remove your persistency file
1674 (@pxref{Connection caching}), and restart @value{emacsname}.
1677 @node Remote shell setup
1678 @section Remote shell setup hints
1679 @cindex remote shell setup
1680 @cindex @file{.profile} file
1681 @cindex @file{.login} file
1682 @cindex shell init files
1684 As explained in the @ref{Overview} section, @value{tramp} connects to the
1685 remote host and talks to the shell it finds there. Of course, when you
1686 log in, the shell executes its init files. Suppose your init file
1687 requires you to enter the birth date of your mother; clearly @value{tramp}
1688 does not know this and hence fails to log you in to that host.
1690 There are different possible strategies for pursuing this problem. One
1691 strategy is to enable @value{tramp} to deal with all possible situations.
1692 This is a losing battle, since it is not possible to deal with
1693 @emph{all} situations. The other strategy is to require you to set up
1694 the remote host such that it behaves like @value{tramp} expects. This might
1695 be inconvenient because you have to invest a lot of effort into shell
1696 setup before you can begin to use @value{tramp}.
1698 The package, therefore, pursues a combined approach. It tries to
1699 figure out some of the more common setups, and only requires you to
1700 avoid really exotic stuff. For example, it looks through a list of
1701 directories to find some programs on the remote host. And also, it
1702 knows that it is not obvious how to check whether a file exists, and
1703 therefore it tries different possibilities. (On some hosts and
1704 shells, the command @command{test -e} does the trick, on some hosts
1705 the shell builtin doesn't work but the program @command{/usr/bin/test
1706 -e} or @command{/bin/test -e} works. And on still other hosts,
1707 @command{ls -d} is the right way to do this.)
1709 Below you find a discussion of a few things that @value{tramp} does not deal
1710 with, and that you therefore have to set up correctly.
1713 @item @var{shell-prompt-pattern}
1714 @vindex shell-prompt-pattern
1716 After logging in to the remote host, @value{tramp} has to wait for the remote
1717 shell startup to finish before it can send commands to the remote
1718 shell. The strategy here is to wait for the shell prompt. In order to
1719 recognize the shell prompt, the variable @code{shell-prompt-pattern} has
1720 to be set correctly to recognize the shell prompt on the remote host.
1722 Note that @value{tramp} requires the match for @code{shell-prompt-pattern}
1723 to be at the end of the buffer. Many people have something like the
1724 following as the value for the variable: @code{"^[^>$][>$] *"}. Now
1725 suppose your shell prompt is @code{a <b> c $ }. In this case,
1726 @value{tramp} recognizes the @code{>} character as the end of the prompt,
1727 but it is not at the end of the buffer.
1729 @item @var{tramp-shell-prompt-pattern}
1730 @vindex tramp-shell-prompt-pattern
1732 This regular expression is used by @value{tramp} in the same way as
1733 @code{shell-prompt-pattern}, to match prompts from the remote shell.
1734 This second variable exists because the prompt from the remote shell
1735 might be different from the prompt from a local shell --- after all,
1736 the whole point of @value{tramp} is to log in to remote hosts as a
1737 different user. The default value of
1738 @code{tramp-shell-prompt-pattern} is the same as the default value of
1739 @code{shell-prompt-pattern}, which is reported to work well in many
1742 @item @var{tramp-password-prompt-regexp}
1743 @vindex tramp-password-prompt-regexp
1744 @vindex tramp-wrong-passwd-regexp
1746 During login, @value{tramp} might be forced to enter a password or a
1747 passphrase. The difference between both is that a password is
1748 requested from the shell on the remote host, while a passphrase is
1749 needed for accessing local authentication information, like your ssh
1752 @var{tramp-password-prompt-regexp} handles the detection of such
1753 requests for English environments. When you use another localization
1754 of your (local or remote) host, you might need to adapt this. Example:
1758 tramp-password-prompt-regexp
1762 '("passphrase" "Passphrase"
1764 "password" "Password"
1766 "passwort" "Passwort"
1768 "mot de passe" "Mot de passe") t)
1772 In parallel, it might also be necessary to adapt
1773 @var{tramp-wrong-passwd-regexp}.
1775 @item @command{tset} and other questions
1776 @cindex Unix command tset
1777 @cindex tset Unix command
1779 Some people invoke the @command{tset} program from their shell startup
1780 scripts which asks the user about the terminal type of the shell.
1781 Maybe some shells ask other questions when they are started.
1782 @value{tramp} does not know how to answer these questions. There are
1783 two approaches for dealing with this problem. One approach is to take
1784 care that the shell does not ask any questions when invoked from
1785 @value{tramp}. You can do this by checking the @code{TERM}
1786 environment variable, it will be set to @code{dumb} when connecting.
1788 @vindex tramp-terminal-type
1789 The variable @code{tramp-terminal-type} can be used to change this value
1792 @vindex tramp-actions-before-shell
1793 The other approach is to teach @value{tramp} about these questions. See
1794 the variable @code{tramp-actions-before-shell}. Example:
1797 (defconst my-tramp-prompt-regexp
1798 (concat (regexp-opt '("Enter the birth date of your mother:") t)
1800 "Regular expression matching my login prompt question.")
1802 (defun my-tramp-action (proc vec)
1803 "Enter \"19000101\" in order to give a correct answer."
1804 (save-window-excursion
1805 (with-current-buffer (tramp-get-connection-buffer vec)
1806 (tramp-message vec 6 "\n%s" (buffer-string))
1807 (tramp-send-string vec "19000101"))))
1809 (add-to-list 'tramp-actions-before-shell
1810 '(my-tramp-prompt-regexp my-tramp-action))
1814 @item Environment variables named like users in @file{.profile}
1816 If you have a user named frumple and set the variable @code{FRUMPLE} in
1817 your shell environment, then this might cause trouble. Maybe rename
1818 the variable to @code{FRUMPLE_DIR} or the like.
1820 This weird effect was actually reported by a @value{tramp} user!
1823 @item Non-Bourne commands in @file{.profile}
1825 After logging in to the remote host, @value{tramp} issues the command
1826 @command{exec /bin/sh}. (Actually, the command is slightly
1827 different.) When @command{/bin/sh} is executed, it reads some init
1828 files, such as @file{~/.shrc} or @file{~/.profile}.
1830 Now, some people have a login shell which is not @code{/bin/sh} but a
1831 Bourne-ish shell such as bash or ksh. Some of these people might put
1832 their shell setup into the files @file{~/.shrc} or @file{~/.profile}.
1833 This way, it is possible for non-Bourne constructs to end up in those
1834 files. Then, @command{exec /bin/sh} might cause the Bourne shell to
1835 barf on those constructs.
1837 As an example, imagine somebody putting @command{export FOO=bar} into
1838 the file @file{~/.profile}. The standard Bourne shell does not
1839 understand this syntax and will emit a syntax error when it reaches
1842 Another example is the tilde (@code{~}) character, say when adding
1843 @file{~/bin} to @code{$PATH}. Many Bourne shells will not expand this
1844 character, and since there is usually no directory whose name consists
1845 of the single character tilde, strange things will happen.
1847 What can you do about this?
1849 Well, one possibility is to make sure that everything in
1850 @file{~/.shrc} and @file{~/.profile} on all remote hosts is
1851 Bourne-compatible. In the above example, instead of @command{export
1852 FOO=bar}, you might use @command{FOO=bar; export FOO} instead.
1854 The other possibility is to put your non-Bourne shell setup into some
1855 other files. For example, bash reads the file @file{~/.bash_profile}
1856 instead of @file{~/.profile}, if the former exists. So bash
1857 aficionados just rename their @file{~/.profile} to
1858 @file{~/.bash_profile} on all remote hosts, and Bob's your uncle.
1860 The @value{tramp} developers would like to circumvent this problem, so
1861 if you have an idea about it, please tell us. However, we are afraid
1862 it is not that simple: before saying @command{exec /bin/sh},
1863 @value{tramp} does not know which kind of shell it might be talking
1864 to. It could be a Bourne-ish shell like ksh or bash, or it could be a
1865 csh derivative like tcsh, or it could be zsh, or even rc. If the
1866 shell is Bourne-ish already, then it might be prudent to omit the
1867 @command{exec /bin/sh} step. But how to find out if the shell is
1873 @node Auto-save and Backup
1874 @section Auto-save and Backup configuration
1878 @vindex backup-directory-alist
1881 @vindex bkup-backup-directory-info
1884 Normally, @value{emacsname} writes backup files to the same directory
1885 as the original files, but this behavior can be changed via the
1888 @code{backup-directory-alist}.
1891 @code{bkup-backup-directory-info}.
1893 In connection with @value{tramp}, this can have unexpected side
1894 effects. Suppose that you specify that all backups should go to the
1895 directory @file{~/.emacs.d/backups/}, and then you edit the file
1896 @file{@trampfn{su, root, localhost, /etc/secretfile}}. The effect is
1897 that the backup file will be owned by you and not by root, thus
1898 possibly enabling others to see it even if they were not intended to
1903 @code{backup-directory-alist}
1906 @code{bkup-backup-directory-info}
1908 is @code{nil} (the default), such problems do not occur.
1910 Therefore, it is useful to set special values for @value{tramp}
1911 files. For example, the following statement effectively `turns off'
1914 @code{backup-directory-alist}
1917 @code{bkup-backup-directory-info}
1919 for @value{tramp} files:
1923 (add-to-list 'backup-directory-alist
1924 (cons tramp-file-name-regexp nil))
1929 (require 'backup-dir)
1930 (add-to-list 'bkup-backup-directory-info
1931 (list tramp-file-name-regexp ""))
1935 Another possibility is to use the @value{tramp} variable
1937 @code{tramp-backup-directory-alist}.
1940 @code{tramp-bkup-backup-directory-info}.
1942 This variable has the same meaning like
1944 @code{backup-directory-alist}.
1947 @code{bkup-backup-directory-info}.
1949 If a @value{tramp} file is backed up, and DIRECTORY is an absolute
1950 local file name, DIRECTORY is prepended with the @value{tramp} file
1951 name prefix of the file to be backed up.
1958 (add-to-list 'backup-directory-alist
1959 (cons "." "~/.emacs.d/backups/"))
1960 (setq tramp-backup-directory-alist backup-directory-alist)
1965 (require 'backup-dir)
1966 (add-to-list 'bkup-backup-directory-info
1967 (list "." "~/.emacs.d/backups/" 'full-path))
1968 (setq tramp-bkup-backup-directory-info bkup-backup-directory-info)
1973 The backup file name of @file{@trampfn{su, root, localhost,
1974 /etc/secretfile}} would be
1976 @file{@trampfn{su, root, localhost,
1977 ~/.emacs.d/backups/!su:root@@localhost:!etc!secretfile~}}
1980 @file{@trampfn{su, root, localhost,
1981 ~/.emacs.d/backups/![su!root@@localhost]!etc!secretfile~}}
1984 The same problem can happen with auto-saving files.
1986 Since @value{emacsname} 21, the variable
1987 @code{auto-save-file-name-transforms} keeps information, on which
1988 directory an auto-saved file should go. By default, it is initialized
1989 for @value{tramp} files to the local temporary directory.
1991 On some versions of @value{emacsname}, namely the version built for
1992 Debian GNU/Linux, the variable @code{auto-save-file-name-transforms}
1993 contains the directory where @value{emacsname} was built. A
1994 workaround is to manually set the variable to a sane value.
1996 If auto-saved files should go into the same directory as the original
1997 files, @code{auto-save-file-name-transforms} should be set to @code{nil}.
1999 Another possibility is to set the variable
2000 @code{tramp-auto-save-directory} to a proper value.
2003 For this purpose you can set the variable @code{auto-save-directory}
2008 @node Windows setup hints
2009 @section Issues with Cygwin ssh
2010 @cindex Cygwin, issues
2012 This section needs a lot of work! Please help.
2014 @cindex method sshx with Cygwin
2015 @cindex sshx method with Cygwin
2016 The recent Cygwin installation of @command{ssh} works only with a
2017 Cygwinized @value{emacsname}. You can check it by typing @kbd{M-x
2018 eshell}, and starting @kbd{ssh test.machine}. The problem is evident
2019 if you see a message like this:
2022 Pseudo-terminal will not be allocated because stdin is not a terminal.
2025 Older @command{ssh} versions of Cygwin are told to cooperate with
2026 @value{tramp} selecting @option{sshx} as the connection method. You
2027 can find information about setting up Cygwin in their FAQ at
2028 @uref{http://cygwin.com/faq/}.
2030 @cindex method scpx with Cygwin
2031 @cindex scpx method with Cygwin
2032 If you wish to use the @option{scpx} connection method, then you might
2033 have the problem that @value{emacsname} calls @command{scp} with a
2034 Windows filename such as @code{c:/foo}. The Cygwin version of
2035 @command{scp} does not know about Windows filenames and interprets
2036 this as a remote filename on the host @code{c}.
2038 One possible workaround is to write a wrapper script for @option{scp}
2039 which converts the Windows filename to a Cygwinized filename.
2041 @cindex Cygwin and ssh-agent
2042 @cindex SSH_AUTH_SOCK and @value{emacsname} on Windows
2043 If you want to use either @option{ssh} based method on Windows, then
2044 you might encounter problems with @command{ssh-agent}. Using this
2045 program, you can avoid typing the pass-phrase every time you log in.
2046 However, if you start @value{emacsname} from a desktop shortcut, then
2047 the environment variable @code{SSH_AUTH_SOCK} is not set and so
2048 @value{emacsname} and thus @value{tramp} and thus @command{ssh} and
2049 @command{scp} started from @value{tramp} cannot communicate with
2050 @command{ssh-agent}. It works better to start @value{emacsname} from
2053 If anyone knows how to start @command{ssh-agent} under Windows in such a
2054 way that desktop shortcuts can profit, please holler. I don't really
2055 know anything at all about Windows@dots{}
2059 @chapter Using @value{tramp}
2060 @cindex using @value{tramp}
2062 Once you have installed @value{tramp} it will operate fairly
2063 transparently. You will be able to access files on any remote machine
2064 that you can log in to as though they were local.
2066 Files are specified to @value{tramp} using a formalized syntax specifying the
2067 details of the system to connect to. This is similar to the syntax used
2068 by the @value{ftppackagename} package.
2071 Something that might happen which surprises you is that
2072 @value{emacsname} remembers all your keystrokes, so if you see a
2073 password prompt from @value{emacsname}, say, and hit @kbd{@key{RET}}
2074 twice instead of once, then the second keystroke will be processed by
2075 @value{emacsname} after @value{tramp} has done its thing. Why, this
2076 type-ahead is normal behavior, you say. Right you are, but be aware
2077 that opening a remote file might take quite a while, maybe half a
2078 minute when a connection needs to be opened. Maybe after half a
2079 minute you have already forgotten that you hit that key!
2082 * Filename Syntax:: @value{tramp} filename conventions.
2083 * Alternative Syntax:: URL-like filename syntax.
2084 * Filename completion:: Filename completion.
2085 * Remote processes:: Integration with other @value{emacsname} packages.
2086 * Cleanup remote connections:: Cleanup remote connections.
2090 @node Filename Syntax
2091 @section @value{tramp} filename conventions
2092 @cindex filename syntax
2093 @cindex filename examples
2095 To access the file @var{localname} on the remote machine @var{machine}
2096 you would specify the filename @file{@trampfn{, , machine,
2097 localname}}. This will connect to @var{machine} and transfer the file
2098 using the default method. @xref{Default Method}.
2100 Some examples of @value{tramp} filenames are shown below.
2103 @item @trampfn{, , melancholia, .emacs}
2104 Edit the file @file{.emacs} in your home directory on the machine
2107 @item @trampfn{, , melancholia.danann.net, .emacs}
2108 This edits the same file, using the fully qualified domain name of
2111 @item @trampfn{, , melancholia, ~/.emacs}
2112 This also edits the same file --- the @file{~} is expanded to your
2113 home directory on the remote machine, just like it is locally.
2115 @item @trampfn{, , melancholia, ~daniel/.emacs}
2116 This edits the file @file{.emacs} in the home directory of the user
2117 @code{daniel} on the machine @code{melancholia}. The @file{~<user>}
2118 construct is expanded to the home directory of that user on the remote
2121 @item @trampfn{, , melancholia, /etc/squid.conf}
2122 This edits the file @file{/etc/squid.conf} on the machine
2127 Unless you specify a different name to use, @value{tramp} will use the
2128 current local user name as the remote user name to log in with. If you
2129 need to log in as a different user, you can specify the user name as
2130 part of the filename.
2132 To log in to the remote machine as a specific user, you use the syntax
2133 @file{@trampfn{, user, machine, path/to.file}}. That means that
2134 connecting to @code{melancholia} as @code{daniel} and editing
2135 @file{.emacs} in your home directory you would specify
2136 @file{@trampfn{, daniel, melancholia, .emacs}}.
2138 It is also possible to specify other file transfer methods
2139 (@pxref{Inline methods}, @pxref{External transfer methods}) as part of
2142 This is done by putting the method before the user and host name, as
2143 in @file{@value{prefix}@var{method}@value{postfixhop}} (Note the
2147 This is done by replacing the initial @file{@value{prefix}} with
2148 @file{@value{prefix}<method>@value{postfixhop}}. (Note the trailing
2151 The user, machine and file specification remain the same.
2153 So, to connect to the machine @code{melancholia} as @code{daniel},
2154 using the @option{ssh} method to transfer files, and edit
2155 @file{.emacs} in my home directory I would specify the filename
2156 @file{@trampfn{ssh, daniel, melancholia, .emacs}}.
2159 @node Alternative Syntax
2160 @section URL-like filename syntax
2161 @cindex filename syntax
2162 @cindex filename examples
2164 Additionally to the syntax described in the previous chapter, it is
2165 possible to use a URL-like syntax for @value{tramp}. This can be
2166 switched on by customizing the variable @code{tramp-syntax}. Please
2167 note that this feature is experimental for the time being.
2169 The variable @code{tramp-syntax} must be set before requiring @value{tramp}:
2172 (setq tramp-syntax 'url)
2176 Then, a @value{tramp} filename would look like this:
2177 @file{/@var{method}://@var{user}@@@var{machine}:@var{port}/@var{path/to.file}}.
2178 @file{/@var{method}://} is mandatory, all other parts are optional.
2179 @file{:@var{port}} is useful for methods only who support this.
2181 The last example from the previous section would look like this:
2182 @file{/ssh://daniel@@melancholia/.emacs}.
2184 For the time being, @code{tramp-syntax} can have the following values:
2188 @item @code{ftp} -- That is the default syntax
2189 @item @code{url} -- URL-like syntax
2192 @item @code{sep} -- That is the default syntax
2193 @item @code{url} -- URL-like syntax
2194 @item @code{ftp} -- EFS-like syntax
2199 @node Filename completion
2200 @section Filename completion
2201 @cindex filename completion
2203 Filename completion works with @value{tramp} for completion of method
2204 names, of user names and of machine names as well as for completion of
2205 file names on remote machines.
2207 In order to enable this, Partial Completion mode must be set
2208 on@footnote{If you don't use Partial Completion mode, but want to
2209 keep full completion, load @value{tramp} like this in your
2213 ;; Preserve Tramp's completion features.
2214 (let ((partial-completion-mode t))
2219 @xref{Completion Options, , , @value{emacsdir}}.
2223 If you, for example, type @kbd{C-x C-f @value{prefix}t
2224 @key{TAB}}, @value{tramp} might give you as result the choice for
2228 @value{prefixhop}telnet@value{postfixhop} tmp/
2229 @value{prefixhop}toto@value{postfix}
2232 @value{prefixhop}telnet@value{postfixhop} @value{prefixhop}toto@value{postfix}
2236 @samp{@value{prefixhop}telnet@value{postfixhop}}
2237 is a possible completion for the respective method,
2239 @samp{tmp/} stands for the directory @file{/tmp} on your local
2242 and @samp{@value{prefixhop}toto@value{postfix}}
2243 might be a host @value{tramp} has detected in your @file{~/.ssh/known_hosts}
2244 file (given you're using default method @option{ssh}).
2246 If you go on to type @kbd{e @key{TAB}}, the minibuffer is completed to
2247 @samp{@value{prefix}telnet@value{postfixhop}}.
2248 Next @kbd{@key{TAB}} brings you all machine names @value{tramp} detects in
2249 your @file{/etc/hosts} file, let's say
2252 @trampfn{telnet, , 127.0.0.1,} @trampfn{telnet, , 192.168.0.1,}
2253 @trampfn{telnet, , localhost,} @trampfn{telnet, , melancholia.danann.net,}
2254 @trampfn{telnet, , melancholia,}
2257 Now you can choose the desired machine, and you can continue to
2258 complete file names on that machine.
2260 If the configuration files (@pxref{Customizing Completion}), which
2261 @value{tramp} uses for analysis of completion, offer user names, those user
2262 names will be taken into account as well.
2264 Remote machines, which have been visited in the past and kept
2265 persistently (@pxref{Connection caching}), will be offered too.
2267 Once the remote machine identification is completed, it comes to
2268 filename completion on the remote host. This works pretty much like
2269 for files on the local host, with the exception that minibuffer
2270 killing via a double-slash works only on the filename part, except
2271 that filename part starts with @file{//}.
2273 A triple-slash stands for the default behaviour.
2276 @xref{Minibuffer File, , , @value{emacsdir}}.
2284 @kbd{C-x C-f @trampfn{telnet, , melancholia, /usr/local/bin//etc} @key{TAB}}
2285 @print{} @trampfn{telnet, , melancholia, /etc}
2287 @kbd{C-x C-f @trampfn{telnet, , melancholia, //etc} @key{TAB}}
2290 @kbd{C-x C-f @trampfn{telnet, , melancholia, /usr/local/bin///etc} @key{TAB}}
2295 @kbd{C-x C-f @trampfn{telnet, , melancholia, /usr/local/bin//}}
2296 @print{} @trampfn{telnet, , melancholia, /}
2298 @kbd{C-x C-f @trampfn{telnet, , melancholia, //}}
2303 A remote directory might have changed its contents out of
2304 @value{emacsname} control, for example by creation or deletion of
2305 files by other processes. Therefore, during filename completion the
2306 remote directory contents is reread regularly in order to detect such
2307 changes, which would be invisible otherwise (@pxref{Connection caching}).
2309 @defopt tramp-completion-reread-directory-timeout
2310 This variable defines the number of seconds since last remote command
2311 before rereading a directory contents. A value of 0 would require an
2312 immediate reread during filename completion, @code{nil} means to use
2313 always cached values for the directory contents.
2317 @node Remote processes
2318 @section Integration with other @value{emacsname} packages.
2322 @value{tramp} supports running processes on a remote host. This
2323 allows to exploit @value{emacsname} packages without modification for
2324 remote file names. It does not work for the @option{ftp} and
2325 @option{smb} methods.
2327 Remote processes are started when a corresponding command is executed
2328 from a buffer belonging to a remote file or directory. Up to now, the
2329 packages @file{compile.el} (commands like @code{compile} and
2330 @code{grep}) and @file{gud.el} (@code{gdb} or @code{perldb}) have been
2331 integrated. Integration of further packages is planned, any help for
2334 When your program is not found in the default search path
2335 @value{tramp} sets on the remote machine, you should either use an
2336 absolute path, or extend @code{tramp-remote-path} (see @ref{Remote
2340 (add-to-list 'tramp-remote-path "~/bin")
2341 (add-to-list 'tramp-remote-path "/appli/pub/bin")
2344 The environment for your program can be adapted by customizing
2345 @code{tramp-remote-process-environment}. This variable is a list of
2346 strings. It is structured like @code{process-environment}. Each
2347 element is a string of the form ENVVARNAME=VALUE. An entry
2348 ENVVARNAME= disables the corresponding environment variable, which
2349 might have been set in your init file like @file{~/.profile}.
2352 Adding an entry can be performed via @code{add-to-list}:
2355 (add-to-list 'tramp-remote-process-environment "JAVA_HOME=/opt/java")
2358 Changing or removing an existing entry is not encouraged. The default
2359 values are chosen for proper @value{tramp} work. Nevertheless, if for
2360 example a paranoid system administrator disallows changing the
2361 @var{$HISTORY} environment variable, you can customize
2362 @code{tramp-remote-process-environment}, or you can apply the
2363 following code in your @file{.emacs}:
2366 (let ((process-environment tramp-remote-process-environment))
2367 (setenv "HISTORY" nil)
2368 (setq tramp-remote-process-environment process-environment))
2371 If you use other @value{emacsname} packages which do not run
2372 out-of-the-box on a remote host, please let us know. We will try to
2373 integrate them as well. @xref{Bug Reports}.
2376 @subsection Running shell-command on a remote host
2377 @cindex shell-command
2379 @code{shell-command} allows to execute commands in a shell, either
2380 synchronously, either asynchronously. This works also on remote
2384 @kbd{C-x C-f @trampfn{sudo, , , } @key{RET}}
2385 @kbd{M-! tail -f /var/log/syslog.log & @key{RET}}
2388 You will see the buffer @file{*Async Shell Command*}, containing the
2389 continous output of the @command{tail} command.
2392 @subsection Running eshell on a remote host
2395 @value{tramp} is integrated into @file{eshell.el}. That is, you can
2396 open an interactive shell on your remote host, and run commands there.
2397 After you have started @code{eshell}, you could perform commands like
2401 @b{~ $} cd @trampfn{sudo, , , /etc} @key{RET}
2402 @b{@trampfn{sudo, root, host, /etc} $} hostname @key{RET}
2404 @b{@trampfn{sudo, root, host, /etc} $} id @key{RET}
2405 uid=0(root) gid=0(root) groups=0(root)
2406 @b{@trampfn{sudo, root, host, /etc} $} find-file shadow @key{RET}
2408 @b{@trampfn{sudo, root, host, /etc} $}
2412 @anchor{Running a debugger on a remote host}
2413 @subsection Running a debugger on a remote host
2418 @file{gud.el} offers an unified interface to several symbolic
2422 (@ref{Debuggers, , , @value{emacsdir}}).
2425 With @value{tramp}, it is possible to debug programs on
2426 remote hosts. You can call @code{gdb} with a remote file name:
2429 @kbd{M-x gdb @key{RET}}
2430 @b{Run gdb (like this):} gdb --annotate=3 @trampfn{ssh, , host, ~/myprog} @key{RET}
2433 The file name can also be relative to a remote default directory.
2434 Given you are in a buffer that belongs to the remote directory
2435 @trampfn{ssh, , host, /home/user}, you could call
2438 @kbd{M-x perldb @key{RET}}
2439 @b{Run perldb (like this):} perl -d myprog.pl @key{RET}
2442 It is not possible to use just the absolute local part of a remote
2443 file name as program to debug, like @kbd{perl -d
2444 /home/user/myprog.pl}, though.
2446 Arguments of the program to be debugged are taken literally. That
2447 means, file names as arguments must be given as ordinary relative or
2448 absolute file names, without any remote specification.
2451 @node Cleanup remote connections
2452 @section Cleanup remote connections.
2455 Sometimes it is useful to cleanup remote connections. The following
2456 commands support this.
2458 @deffn Command tramp-cleanup-connection vec
2459 This command flushes all connection related objects. @option{vec} is
2460 the internal representation of a remote connection. Called
2461 interactively, the command offers all active remote connections in the
2462 minibuffer as remote file name prefix like @file{@trampfn{method,
2463 user, host, }}. The cleanup includes password cache (@pxref{Password
2464 caching}), file cache, connection cache (@pxref{Connection caching}),
2468 @deffn Command tramp-cleanup-all-connections
2469 This command flushes objects for all active remote connections. The
2470 same objects are removed as in @code{tramp-cleanup-connection}.
2473 @deffn Command tramp-cleanup-all-buffers
2474 Like in @code{tramp-cleanup-all-connections}, all remote connections
2475 are cleaned up. Additionally all buffers, which are related to a
2476 remote connection, are killed.
2481 @chapter Reporting Bugs and Problems
2484 Bugs and problems with @value{tramp} are actively worked on by the
2485 development team. Feature requests and suggestions are also more than
2488 The @value{tramp} mailing list is a great place to get information on
2489 working with @value{tramp}, solving problems and general discussion
2490 and advice on topics relating to the package. It is moderated so
2491 non-subscribers can post but messages will be delayed, possibly up to
2492 48 hours (or longer in case of holidays), until the moderator approves
2495 The mailing list is at @email{tramp-devel@@gnu.org}. Messages sent to
2496 this address go to all the subscribers. This is @emph{not} the address
2497 to send subscription requests to.
2499 Subscribing to the list is performed via
2500 @uref{http://lists.gnu.org/mailman/listinfo/tramp-devel/,
2501 the @value{tramp} Mail Subscription Page}.
2504 To report a bug in @value{tramp}, you should execute @kbd{M-x
2505 tramp-bug}. This will automatically generate a buffer with the details
2506 of your system and @value{tramp} version.
2508 When submitting a bug report, please try to describe in excruciating
2509 detail the steps required to reproduce the problem, the setup of the
2510 remote machine and any special conditions that exist. You should also
2511 check that your problem is not described already in @xref{Frequently
2514 If you can identify a minimal test case that reproduces the problem,
2515 include that with your bug report. This will make it much easier for
2516 the development team to analyze and correct the problem.
2518 Before reporting the bug, you should set the verbosity level to 6
2519 (@pxref{Traces and Profiles, Traces}) in the @file{~/.emacs} file and
2520 repeat the bug. Then, include the contents of the @file{*tramp/foo*}
2521 and @file{*debug tramp/foo*} buffers in your bug report. A verbosity
2522 level greater than 6 will produce a very huge debug buffer, which is
2523 mostly not necessary for the analysis.
2525 Please be aware that, with a verbosity level of 6 or greater, the
2526 contents of files and directories will be included in the debug
2527 buffer. Passwords you've typed will never be included there.
2530 @node Frequently Asked Questions
2531 @chapter Frequently Asked Questions
2532 @cindex frequently asked questions
2537 Where can I get the latest @value{tramp}?
2539 @value{tramp} is available under the URL below.
2542 @uref{ftp://ftp.gnu.org/gnu/tramp/}
2545 There is also a Savannah project page.
2548 @uref{http://savannah.gnu.org/projects/tramp/}
2552 Which systems does it work on?
2554 The package has been used successfully on GNU Emacs 21, GNU Emacs 22
2555 and XEmacs 21 (starting with 21.4). Gateway methods are supported for
2558 The package was intended to work on Unix, and it really expects a
2559 Unix-like system on the remote end (except the @option{smb} method),
2560 but some people seemed to have some success getting it to work on MS
2561 Windows NT/2000/XP @value{emacsname}.
2563 There is some informations on @value{tramp} on NT at the following URL;
2564 many thanks to Joe Stoy for providing the information:
2565 @uref{ftp://ftp.comlab.ox.ac.uk/tmp/Joe.Stoy/}
2567 @c The link is broken. I've contacted Tom for clarification. Michael.
2569 The above mostly contains patches to old ssh versions; Tom Roche has a
2570 Web page with instructions:
2571 @uref{http://www4.ncsu.edu/~tlroche/plinkTramp.html}
2575 How could I speed up @value{tramp}?
2577 In the backstage, @value{tramp} needs a lot of operations on the
2578 remote host. The time for transferring data from and to the remote
2579 host as well as the time needed to perform the operations there count.
2580 In order to speed up @value{tramp}, one could either try to avoid some
2581 of the operations, or one could try to improve their performance.
2583 Use an external transfer method, like @option{scpc}.
2585 Use caching. This is already enabled by default. Information about
2586 the remote host as well as the remote files are cached for reuse. The
2587 information about remote hosts is kept in the file specified in
2588 @code{tramp-persistency-file-name}. Keep this file.
2590 Disable version control. If you access remote files which are not
2591 under version control, a lot of check operations can be avoided by
2592 disabling VC. This can be achieved by
2595 (setq vc-handled-backends nil)
2598 Disable excessive traces. The default trace level of @value{tramp},
2599 defined in the variable @code{tramp-verbose}, is 3. You should
2600 increase this level only temporarily, hunting bugs.
2604 @value{tramp} does not connect to the remote host
2606 When @value{tramp} does not connect to the remote host, there are two
2607 reasons heading the bug mailing list:
2612 Unknown characters in the prompt
2614 @value{tramp} needs to recognize the prompt on the remote machine
2615 after execution any command. This is not possible, when the prompt
2616 contains unknown characters like escape sequences for coloring. This
2617 should be avoided on the remote side. @xref{Remote shell setup}. for
2618 setting the regular expression detecting the prompt.
2620 You can check your settings after an unsuccessful connection by
2621 switching to the @value{tramp} connection buffer @file{*tramp/foo*},
2622 setting the cursor at the top of the buffer, and applying the expression
2625 @kbd{M-: (re-search-forward (concat tramp-shell-prompt-pattern "$"))}
2628 If it fails, or the cursor is not moved at the end of the buffer, your
2629 prompt is not recognised correctly.
2631 A special problem is the zsh, which uses left-hand side and right-hand
2632 side prompts in parallel. Therefore, it is necessary to disable the
2633 zsh line editor on the remote host. You shall add to @file{~/.zshrc}
2634 the following command:
2637 [ $TERM = "dumb" ] && unsetopt zle && PS1='$ '
2642 @value{tramp} doesn't transfer strings with more than 500 characters
2645 On some few systems, the implementation of @code{process-send-string}
2646 seems to be broken for longer strings. It is reported for HP-UX,
2647 FreeBSD and Tru64 Unix, for example. This case, you should customize
2648 the variable @code{tramp-chunksize} to 500. For a description how to
2649 determine whether this is necessary see the documentation of
2650 @code{tramp-chunksize}.
2652 Additionally, it will be useful to set @code{file-precious-flag} to
2653 @code{t} for @value{tramp} files. Then the file contents will be
2654 written into a temporary file first, which is checked for correct
2657 @pxref{Saving Buffers, , , elisp}
2664 (when (file-remote-p default-directory)
2665 (set (make-local-variable 'file-precious-flag) t))))
2672 File name completion does not work with @value{tramp}
2674 When you log in to the remote machine, do you see the output of
2675 @command{ls} in color? If so, this may be the cause of your problems.
2677 @command{ls} outputs @acronym{ANSI} escape sequences that your terminal
2678 emulator interprets to set the colors. These escape sequences will
2679 confuse @value{tramp} however.
2681 In your @file{.bashrc}, @file{.profile} or equivalent on the remote
2682 machine you probably have an alias configured that adds the option
2683 @option{--color=yes} or @option{--color=auto}.
2685 You should remove that alias and ensure that a new login @emph{does not}
2686 display the output of @command{ls} in color. If you still cannot use
2687 filename completion, report a bug to the @value{tramp} developers.
2691 File name completion does not work in large directories
2693 @value{tramp} uses globbing for some operations. (Globbing means to use the
2694 shell to expand wildcards such as `*.c'.) This might create long
2695 command lines, especially in directories with many files. Some shells
2696 choke on long command lines, or don't cope well with the globbing
2699 If you have a large directory on the remote end, you may wish to execute
2700 a command like @samp{ls -d * ..?* > /dev/null} and see if it hangs.
2701 Note that you must first start the right shell, which might be
2702 @command{/bin/sh}, @command{ksh} or @command{bash}, depending on which
2703 of those supports tilde expansion.
2707 How can I get notified when @value{tramp} file transfers are complete?
2709 The following snippet can be put in your @file{~/.emacs} file. It
2710 makes @value{emacsname} beep after reading from or writing to the
2714 (defadvice tramp-handle-write-region
2715 (after tramp-write-beep-advice activate)
2716 "Make tramp beep after writing a file."
2720 (defadvice tramp-handle-do-copy-or-rename-file
2721 (after tramp-copy-beep-advice activate)
2722 "Make tramp beep after copying a file."
2726 (defadvice tramp-handle-insert-file-contents
2727 (after tramp-insert-beep-advice activate)
2728 "Make tramp beep after inserting a file."
2736 I'ld like to get a Visual Warning when working in a sudo:ed context
2738 When you are working with @samp{root} privileges, it might be useful
2739 to get an indication in the buffer's modeline. The following code,
2740 tested with @value{emacsname} 22.1, does the job. You should put it
2741 into your @file{~/.emacs}:
2744 (defun my-mode-line-function ()
2745 (when (string-match "^/su\\(do\\)?:" default-directory)
2746 (setq mode-line-format
2747 (format-mode-line mode-line-format 'font-lock-warning-face))))
2749 (add-hook 'find-file-hooks 'my-mode-line-function)
2750 (add-hook 'dired-mode-hook 'my-mode-line-function)
2757 I'ld like to see a host indication in the mode line when I'm remote
2759 The following code has been tested with @value{emacsname} 22.1. You
2760 should put it into your @file{~/.emacs}:
2763 (defconst my-mode-line-buffer-identification
2767 (if (file-remote-p default-directory)
2768 (tramp-file-name-host
2769 (tramp-dissect-file-name default-directory))
2771 (if (string-match "^[^0-9][^.]*\\(\\..*\\)" host-name)
2772 (substring host-name 0 (match-beginning 1))
2777 mode-line-buffer-identification
2778 my-mode-line-buffer-identification)
2784 mode-line-buffer-identification
2785 my-mode-line-buffer-identification)))
2788 Since @value{emacsname} 23.1, the mode line contains an indication if
2789 @code{default-directory} for the current buffer is on a remote host.
2790 The corresponding tooltip includes the name of that host. If you
2791 still want the host name as part of the mode line, you can use the
2792 example above, but the @code{:eval} clause can be simplified:
2797 (or (file-remote-p default-directory 'host)
2799 (if (string-match "^[^0-9][^.]*\\(\\..*\\)" host-name)
2800 (substring host-name 0 (match-beginning 1))
2808 My remote host does not understand default directory listing options
2810 @value{emacsname} computes the @command{dired} options depending on
2811 the local host you are working. If your @command{ls} command on the
2812 remote host does not understand those options, you can change them
2817 'dired-before-readin-hook
2819 (when (file-remote-p default-directory)
2820 (setq dired-actual-switches "-al"))))
2826 There's this @file{~/.sh_history} file on the remote host which keeps
2827 growing and growing. What's that?
2829 Sometimes, @value{tramp} starts @command{ksh} on the remote host for
2830 tilde expansion. Maybe @command{ksh} saves the history by default.
2831 @value{tramp} tries to turn off saving the history, but maybe you have
2832 to help. For example, you could put this in your @file{.kshrc}:
2835 if [ -f $HOME/.sh_history ] ; then
2836 /bin/rm $HOME/.sh_history
2838 if [ "$@{HISTFILE-unset@}" != "unset" ] ; then
2841 if [ "$@{HISTSIZE-unset@}" != "unset" ] ; then
2847 @item There are longish file names to type. How to shorten this?
2849 Let's say you need regularly access to @file{@trampfn{ssh, news,
2850 news.my.domain, /opt/news/etc}}, which is boring to type again and
2851 again. The following approaches can be mixed:
2855 @item Use default values for method and user name:
2857 You can define default methods and user names for hosts,
2858 (@pxref{Default Method}, @pxref{Default User}):
2861 (setq tramp-default-method "ssh"
2862 tramp-default-user "news")
2865 The file name left to type would be
2866 @kbd{C-x C-f @trampfn{, , news.my.domain, /opt/news/etc}}.
2868 Note, that there are some useful settings already. Accessing your
2869 local host as @samp{root} user, is possible just by @kbd{C-x C-f
2872 @item Use configuration possibilities of your method:
2874 Several connection methods (i.e. the programs used) offer powerful
2875 configuration possibilities (@pxref{Customizing Completion}). In the
2876 given case, this could be @file{~/.ssh/config}:
2880 HostName news.my.domain
2884 The file name left to type would be @kbd{C-x C-f @trampfn{ssh, , xy,
2885 /opt/news/etc}}. Depending on files in your directories, it is even
2886 possible to complete the host name with @kbd{C-x C-f
2887 @value{prefix}ssh@value{postfixhop}x @key{TAB}}.
2889 @item Use environment variables:
2891 File names typed in the minibuffer can be expanded by environment
2892 variables. You can set them outside @value{emacsname}, or even with
2896 (setenv "xy" "@trampfn{ssh, news, news.my.domain, /opt/news/etc/}")
2899 Then you need simply to type @kbd{C-x C-f $xy @key{RET}}, and here you
2900 are. The disadvantage is, that you cannot edit the file name, because
2901 environment variables are not expanded during editing in the
2904 @item Define own keys:
2906 You can define your own key sequences in @value{emacsname}, which can
2907 be used instead of @kbd{C-x C-f}:
2911 [(control x) (control y)]
2917 "@trampfn{ssh, news, news.my.domain, /opt/news/etc/}"))))
2920 Simply typing @kbd{C-x C-y} would initialize the minibuffer for
2921 editing with your beloved file name.
2923 See also @uref{http://www.emacswiki.org/cgi-bin/wiki/TrampMode, the
2924 Emacs Wiki} for a more comprehensive example.
2926 @item Define own abbreviation (1):
2928 It is possible to define an own abbreviation list for expanding file
2933 'directory-abbrev-alist
2934 '("^/xy" . "@trampfn{ssh, news, news.my.domain, /opt/news/etc/}"))
2937 This shortens the file openening command to @kbd{C-x C-f /xy
2938 @key{RET}}. The disadvantage is, again, that you cannot edit the file
2939 name, because the expansion happens after entering the file name only.
2941 @item Define own abbreviation (2):
2943 The @code{abbrev-mode} gives more flexibility for editing the
2947 (define-abbrev-table 'my-tramp-abbrev-table
2948 '(("xy" "@trampfn{ssh, news, news.my.domain, /opt/news/etc/}")))
2951 'minibuffer-setup-hook
2954 (setq local-abbrev-table my-tramp-abbrev-table)))
2956 (defadvice minibuffer-complete
2957 (before my-minibuffer-complete activate)
2960 ;; If you use partial-completion-mode
2961 (defadvice PC-do-completion
2962 (before my-PC-do-completion activate)
2966 After entering @kbd{C-x C-f xy @key{TAB}}, the minibuffer is
2967 expanded, and you can continue editing.
2969 @item Use bookmarks:
2971 Bookmarks can be used to visit Tramp files or directories.
2973 @pxref{Bookmarks, , , @value{emacsdir}}
2976 When you have opened @file{@trampfn{ssh, news, news.my.domain,
2977 /opt/news/etc/}}, you should save the bookmark via
2979 @kbd{@key{menu-bar} @key{edit} @key{bookmarks} @key{set}}.
2982 @kbd{@key{menu-bar} @key{view} @key{bookmarks} @key{set}}.
2985 Later on, you can always navigate to that bookmark via
2987 @kbd{@key{menu-bar} @key{edit} @key{bookmarks} @key{jump}}.
2990 @kbd{@key{menu-bar} @key{view} @key{bookmarks} @key{jump}}.
2993 @item Use recent files:
3001 remembers visited places.
3004 @pxref{File Conveniences, , , @value{emacsdir}}
3007 @pxref{recent-files, , , edit-utils}
3011 You could keep remote file names in the recent list without checking
3012 their readability through a remote access:
3019 (recent-files-initialize)
3023 (when (file-remote-p (buffer-file-name))
3024 (recent-files-make-permanent)))
3029 The list of files opened recently is reachable via
3031 @kbd{@key{menu-bar} @key{file} @key{Open Recent}}.
3034 @kbd{@key{menu-bar} @key{Recent Files}}.
3038 @item Use filecache:
3040 @file{filecache} remembers visited places. Add the directory into
3044 (eval-after-load "filecache"
3045 '(file-cache-add-directory
3046 "@trampfn{ssh, news, news.my.domain, /opt/news/etc/}"))
3049 Whenever you want to load a file, you can enter @kbd{C-x C-f
3050 C-@key{TAB}} in the minibuffer. The completion is done for the given
3057 @file{bbdb} has a built-in feature for @value{ftppackagename} files,
3058 which works also for @value{tramp}.
3060 @pxref{bbdb-ftp, Storing FTP sites in the BBDB, , bbdb}
3063 You need to load @file{bbdb}:
3070 Then you can create a BBDB entry via @kbd{M-x bbdb-create-ftp-site}.
3071 Because BBDB is not prepared for @value{tramp} syntax, you must
3072 specify a method together with the user name, when needed. Example:
3075 @kbd{M-x bbdb-create-ftp-site @key{RET}}
3076 @b{Ftp Site:} news.my.domain @key{RET}
3077 @b{Ftp Directory:} /opt/news/etc/ @key{RET}
3078 @b{Ftp Username:} ssh@value{postfixhop}news @key{RET}
3079 @b{Company:} @key{RET}
3080 @b{Additional Comments:} @key{RET}
3083 When you have opened your BBDB buffer, you can access such an entry by
3084 pressing the key @key{F}.
3089 I would like to thank all @value{tramp} users, who have contributed to
3090 the different recipes!
3094 How can I disable @value{tramp}?
3096 Shame on you, why did you read until now?
3099 If you just want to have @value{ftppackagename} as default remote
3100 files access package, you should apply the following code:
3103 (setq tramp-default-method "ftp")
3107 Unloading @value{tramp} can be achieved by applying @kbd{M-x
3108 tramp-unload-tramp}.
3110 This resets also the @value{ftppackagename} plugins.
3115 @c For the developer
3116 @node Version Control
3117 @chapter The inner workings of remote version control
3118 @cindex Version Control
3120 Unlike @value{ftppackagename}, @value{tramp} has full shell access to the
3121 remote machine. This makes it possible to provide version control for
3122 files accessed under @value{tramp}.
3124 The actual version control binaries must be installed on the remote
3125 machine, accessible in the directories specified in
3126 @code{tramp-remote-path}.
3128 This transparent integration with the version control systems is one of
3129 the most valuable features provided by @value{tramp}, but it is far from perfect.
3130 Work is ongoing to improve the transparency of the system.
3133 * Version Controlled Files:: Determining if a file is under version control.
3134 * Remote Commands:: Executing the version control commands on the remote machine.
3135 * Changed workfiles:: Detecting if the working file has changed.
3136 * Checking out files:: Bringing the workfile out of the repository.
3137 * Miscellaneous Version Control:: Things related to Version Control that don't fit elsewhere.
3141 @node Version Controlled Files
3142 @section Determining if a file is under version control
3144 The VC package uses the existence of on-disk revision control master
3145 files to determine if a given file is under revision control. These file
3146 tests happen on the remote machine through the standard @value{tramp} mechanisms.
3149 @node Remote Commands
3150 @section Executing the version control commands on the remote machine
3152 There are no hooks provided by VC to allow intercepting of the version
3153 control command execution. The calls occur through the
3154 @code{call-process} mechanism, a function that is somewhat more
3155 efficient than the @code{shell-command} function but that does not
3156 provide hooks for remote execution of commands.
3158 To work around this, the functions @code{vc-do-command} and
3159 @code{vc-simple-command} have been advised to intercept requests for
3160 operations on files accessed via @value{tramp}.
3162 In the case of a remote file, the @code{shell-command} interface is
3163 used, with some wrapper code, to provide the same functionality on the
3164 remote machine as would be seen on the local machine.
3167 @node Changed workfiles
3168 @section Detecting if the working file has changed
3170 As there is currently no way to get access to the mtime of a file on a
3171 remote machine in a portable way, the @code{vc-workfile-unchanged-p}
3172 function is advised to call an @value{tramp} specific function for remote files.
3174 The @code{tramp-vc-workfile-unchanged-p} function uses the functioning VC
3175 diff functionality to determine if any changes have occurred between the
3176 workfile and the version control master.
3178 This requires that a shell command be executed remotely, a process that
3179 is notably heavier-weight than the mtime comparison used for local
3180 files. Unfortunately, unless a portable solution to the issue is found,
3181 this will remain the cost of remote version control.
3184 @node Checking out files
3185 @section Bringing the workfile out of the repository
3187 VC will, by default, check for remote files and refuse to act on them
3188 when checking out files from the repository. To work around this
3189 problem, the function @code{vc-checkout} knows about @value{tramp} files and
3190 allows version control to occur.
3193 @node Miscellaneous Version Control
3194 @section Things related to Version Control that don't fit elsewhere
3196 Minor implementation details, &c.
3199 * Remote File Ownership:: How VC determines who owns a workfile.
3200 * Back-end Versions:: How VC determines what release your RCS is.
3204 @node Remote File Ownership
3205 @subsection How VC determines who owns a workfile
3207 @value{emacsname} provides the @code{user-login-name} function to
3208 return the login name of the current user as well as mapping from
3209 arbitrary user id values back to login names. The VC code uses this
3210 functionality to map from the uid of the owner of a workfile to the
3211 login name in some circumstances.
3213 This will not, for obvious reasons, work if the remote system has a
3214 different set of logins. As such, it is necessary to delegate to the
3215 remote machine the job of determining the login name associated with a
3218 Unfortunately, with the profusion of distributed management systems such
3219 as @code{NIS}, @code{NIS+} and @code{NetInfo}, there is no simple,
3220 reliable and portable method for performing this mapping.
3222 Thankfully, the only place in the VC code that depends on the mapping of
3223 a uid to a login name is the @code{vc-file-owner} function. This returns
3224 the login of the owner of the file as a string.
3226 This function has been advised to use the output of @command{ls} on the
3227 remote machine to determine the login name, delegating the problem of
3228 mapping the uid to the login to the remote system which should know more
3232 @node Back-end Versions
3233 @subsection How VC determines what release your RCS is
3235 VC needs to know what release your revision control binaries you are
3236 running as not all features VC supports are available with older
3237 versions of @command{rcs(1)}, @command{cvs(1)} or @command{sccs(1)}.
3239 The default implementation of VC determines this value the first time it
3240 is needed and then stores the value globally to avoid the overhead of
3241 executing a process and parsing its output each time the information is
3244 Unfortunately, life is not quite so easy when remote version control
3245 comes into the picture. Each remote machine may have a different version
3246 of the version control tools and, while this is painful, we need to
3247 ensure that unavailable features are not used remotely.
3249 To resolve this issue, @value{tramp} currently takes the sledgehammer
3250 approach of making the release values of the revision control tools
3251 local to each @value{tramp} buffer, forcing VC to determine these values
3252 again each time a new file is visited.
3254 This has, quite obviously, some performance implications. Thankfully,
3255 most of the common operations performed by VC do not actually require
3256 that the remote version be known. This makes the problem far less
3259 Eventually these values will be captured by @value{tramp} on a system by
3260 system basis and the results cached to improve performance.
3263 @node Files directories and localnames
3264 @chapter How file names, directories and localnames are mangled and managed.
3267 * Localname deconstruction:: Breaking a localname into its components.
3269 * External packages:: Integration with external Lisp packages.
3274 @node Localname deconstruction
3275 @section Breaking a localname into its components.
3277 @value{tramp} file names are somewhat different, obviously, to ordinary file
3278 names. As such, the lisp functions @code{file-name-directory} and
3279 @code{file-name-nondirectory} are overridden within the @value{tramp}
3282 Their replacements are reasonably simplistic in their approach. They
3283 dissect the filename, call the original handler on the localname and
3284 then rebuild the @value{tramp} file name with the result.
3286 This allows the platform specific hacks in the original handlers to take
3287 effect while preserving the @value{tramp} file name information.
3291 @node External packages
3292 @section Integration with external Lisp packages.
3294 While reading filenames in the minibuffer, @value{tramp} must decide
3295 whether it completes possible incomplete filenames, or not. Imagine
3296 there is the following situation: You have typed @kbd{C-x C-f
3297 @value{prefix}ssh@value{postfixhop} @key{TAB}}. @value{tramp} cannot
3298 know, whether @option{ssh} is a method or a host name. It checks
3299 therefore the last input character you have typed. If this is
3300 @key{TAB}, @key{SPACE} or @kbd{?}, @value{tramp} assumes that you are
3301 still in filename completion, and it does not connect to the possible
3302 remote host @option{ssh}.
3304 @vindex tramp-completion-mode
3305 External packages, which use other characters for completing filenames
3306 in the minibuffer, must signal this to @value{tramp}. For this case,
3307 the variable @code{tramp-completion-mode} can be bound temporarily to
3311 (let ((tramp-completion-mode t))
3317 @node Traces and Profiles
3318 @chapter How to Customize Traces
3320 All @value{tramp} messages are raised with a verbosity level. The
3321 verbosity level can be any number between 0 and 10. Only messages with
3322 a verbosity level less than or equal to @code{tramp-verbose} are
3325 The verbosity levels are
3327 @w{ 0} silent (no @value{tramp} messages at all)
3328 @*@indent @w{ 1} errors
3329 @*@indent @w{ 2} warnings
3330 @*@indent @w{ 3} connection to remote hosts (default verbosity)
3331 @*@indent @w{ 4} activities
3332 @*@indent @w{ 5} internal
3333 @*@indent @w{ 6} sent and received strings
3334 @*@indent @w{ 7} file caching
3335 @*@indent @w{ 8} connection properties
3336 @*@indent @w{10} traces (huge)
3338 When @code{tramp-verbose} is greater than or equal to 4, the messages
3339 are also written into a @value{tramp} debug buffer. This debug buffer
3340 is useful for analysing problems; sending a @value{tramp} bug report
3341 should be done with @code{tramp-verbose} set to a verbosity level of at
3342 least 6 (@pxref{Bug Reports}).
3344 The debug buffer is in
3346 @ref{Outline Mode, , , @value{emacsdir}}.
3351 That means, you can change the level of messages to be viewed. If you
3352 want, for example, see only messages up to verbosity level 5, you must
3353 enter @kbd{C-u 6 C-c C-q}.
3355 Other keys for navigating are described in
3356 @ref{Outline Visibility, , , @value{emacsdir}}.
3359 @value{tramp} errors are handled internally in order to raise the
3360 verbosity level 1 messages. When you want to get a Lisp backtrace in
3361 case of an error, you need to set both
3364 (setq debug-on-error t
3368 Sometimes, it might be even necessary to step through @value{tramp}
3369 function call traces. Such traces are enabled by the following code:
3374 (dolist (elt (all-completions "tramp-" obarray 'functionp))
3375 (trace-function-background (intern elt)))
3376 (untrace-function 'tramp-read-passwd)
3377 (untrace-function 'tramp-gw-basic-authentication)
3380 The function call traces are inserted in the buffer
3381 @file{*trace-output*}. @code{tramp-read-passwd} and
3382 @code{tramp-gw-basic-authentication} shall be disabled when the
3383 function call traces are added to @value{tramp}, because both
3384 functions return password strings, which should not be distributed.
3388 @chapter Debatable Issues and What Was Decided
3391 @item The uuencode method does not always work.
3393 Due to the design of @value{tramp}, the encoding and decoding programs
3394 need to read from stdin and write to stdout. On some systems,
3395 @command{uudecode -o -} will read stdin and write the decoded file to
3396 stdout, on other systems @command{uudecode -p} does the same thing.
3397 But some systems have uudecode implementations which cannot do this at
3398 all---it is not possible to call these uudecode implementations with
3399 suitable parameters so that they write to stdout.
3401 Of course, this could be circumvented: the @code{begin foo 644} line
3402 could be rewritten to put in some temporary file name, then
3403 @command{uudecode} could be called, then the temp file could be
3404 printed and deleted.
3406 But I have decided that this is too fragile to reliably work, so on some
3407 systems you'll have to do without the uuencode methods.
3409 @item The @value{tramp} filename syntax differs between GNU Emacs and XEmacs.
3411 The GNU Emacs maintainers wish to use a unified filename syntax for
3412 Ange-FTP and @value{tramp} so that users don't have to learn a new
3413 syntax. It is sufficient to learn some extensions to the old syntax.
3415 For the XEmacs maintainers, the problems caused from using a unified
3416 filename syntax are greater than the gains. The XEmacs package system
3417 uses EFS for downloading new packages. So, obviously, EFS has to be
3418 installed from the start. If the filenames were unified, @value{tramp}
3419 would have to be installed from the start, too.
3422 @strong{Note:} If you'd like to use a similar syntax like
3423 @value{ftppackagename}, you need the following settings in your init
3427 (setq tramp-unified-filenames t)
3431 The autoload of the @value{emacsname} @value{tramp} package must be
3432 disabled. This can be achieved by setting file permissions @code{000}
3433 to the files @file{.../xemacs-packages/lisp/tramp/auto-autoloads.el*}.
3435 In case of unified filenames, all @value{emacsname} download sites are
3436 added to @code{tramp-default-method-alist} with default method
3437 @option{ftp} @xref{Default Method}. These settings shouldn't be
3438 touched for proper working of the @value{emacsname} package system.
3440 The syntax for unified filenames is described in the @value{tramp} manual
3441 for @value{emacsothername}.
3445 @node GNU Free Documentation License
3446 @appendix GNU Free Documentation License
3447 @include doclicense.texi
3449 @node Function Index
3450 @unnumbered Function Index
3453 @node Variable Index
3454 @unnumbered Variable Index
3458 @unnumbered Concept Index
3462 @c End of tramp.texi - the TRAMP User Manual
3467 @c * Say something about the .login and .profile files of the remote
3469 @c * Explain how tramp.el works in principle: open a shell on a remote
3470 @c host and then send commands to it.
3471 @c * Make terminology "inline" vs "out-of-band" consistent.
3472 @c It seems that "external" is also used instead of "out-of-band".
3475 @c ** Use `filename' resp. `file name' consistently.
3476 @c ** Use `host' resp. `machine' consistently.
3477 @c ** Consistent small or capitalized words especially in menues.
3480 arch-tag: f96dd66e-6dd3-4c92-8d77-9c56205ba808