1 \input texinfo @c -*-texinfo-*-
2 @setfilename ../../info/tramp
4 @settitle TRAMP User Manual
7 @c This is *so* much nicer :)
10 @c In the Tramp CVS, the version number is auto-frobbed from
11 @c configure.ac, so you should edit that file and run
12 @c "autoconf && ./configure" to change the version number.
14 @c Additionally, flags are set with respect to the Emacs flavor; and
15 @c depending whether Tramp is packaged into (X)Emacs, or standalone.
17 @include trampver.texi
19 @c Macro for formatting a filename according to the respective syntax.
20 @c xxx and yyy are auxiliary macros in order to omit leading and
21 @c trailing whitespace. Not very elegant, but I don't know it better.
27 @macro yyy {one, two}@c
35 @macro trampfn {method, user, host, localname}@c
36 @value{prefix}@yyy{\method\,@value{postfixhop}}@yyy{\user\,@@}\host\@value{postfix}\localname\@c
40 Copyright @copyright{} 1999-2011 Free Software Foundation, Inc.
43 Permission is granted to copy, distribute and/or modify this document
44 under the terms of the GNU Free Documentation License, Version 1.3 or
45 any later version published by the Free Software Foundation; with no
46 Invariant Sections, with the Front-Cover texts being ``A GNU Manual'',
47 and with the Back-Cover Texts as in (a) below. A copy of the license
48 is included in the section entitled ``GNU Free Documentation License''.
50 (a) The FSF's Back-Cover Text is: ``You have the freedom to
51 copy and modify this GNU manual. Buying copies from the FSF
52 supports it in developing GNU and promoting software freedom.''
56 @c Entries for @command{install-info} to use
57 @dircategory @value{emacsname} network features
59 * TRAMP: (tramp). Transparent Remote Access, Multiple Protocol
60 @value{emacsname} remote file access via rsh and rcp.
64 @title @value{tramp} version @value{trampver} User Manual
65 @author by Daniel Pittman
66 @author based on documentation by Kai Gro@ss{}johann
74 @node Top, Overview, (dir), (dir)
75 @top @value{tramp} version @value{trampver} User Manual
77 This file documents @value{tramp} version @value{trampver}, a remote file
78 editing package for @value{emacsname}.
80 @value{tramp} stands for `Transparent Remote (file) Access, Multiple
81 Protocol'. This package provides remote file editing, similar to
82 @value{ftppackagename}.
84 The difference is that @value{ftppackagename} uses FTP to transfer
85 files between the local and the remote host, whereas @value{tramp} uses a
86 combination of @command{rsh} and @command{rcp} or other work-alike
87 programs, such as @command{ssh}/@command{scp}.
89 You can find the latest version of this document on the web at
90 @uref{http://www.gnu.org/software/tramp/}.
92 @c Pointer to the other Emacs flavor is necessary only in case of
93 @c standalone installation.
95 The manual has been generated for @value{emacsname}.
97 If you want to read the info pages for @value{emacsothername}, you
98 should read in @ref{Installation} how to create them.
101 If you're using the other Emacs flavor, you should read the
102 @uref{@value{emacsotherfilename}, @value{emacsothername}} pages.
107 The latest release of @value{tramp} is available for
108 @uref{ftp://ftp.gnu.org/gnu/tramp/, download}, or you may see
109 @ref{Obtaining Tramp} for more details, including the CVS server
112 @value{tramp} also has a @uref{http://savannah.gnu.org/projects/tramp/,
113 Savannah Project Page}.
116 There is a mailing list for @value{tramp}, available at
117 @email{tramp-devel@@gnu.org}, and archived at
118 @uref{http://lists.gnu.org/archive/html/tramp-devel/, the
119 @value{tramp} Mail Archive}.
121 Older archives are located at
122 @uref{http://sourceforge.net/mailarchive/forum.php?forum=tramp-devel,
123 SourceForge Mail Archive} and
124 @uref{http://www.mail-archive.com/emacs-rcp@@ls6.cs.uni-dortmund.de/,
126 @c in HTML output, there's no new paragraph.
135 * Overview:: What @value{tramp} can and cannot do.
139 * Obtaining Tramp:: How to obtain @value{tramp}.
140 * History:: History of @value{tramp}.
141 @ifset installchapter
142 * Installation:: Installing @value{tramp} with your @value{emacsname}.
144 * Configuration:: Configuring @value{tramp} for use.
145 * Usage:: An overview of the operation of @value{tramp}.
146 * Bug Reports:: Reporting Bugs and Problems.
147 * Frequently Asked Questions:: Questions and answers from the mailing list.
148 * Function Index:: @value{tramp} functions.
149 * Variable Index:: User options and variables.
150 * Concept Index:: An item for each concept.
154 * Files directories and localnames:: How file names, directories and localnames are mangled and managed.
155 * Traces and Profiles:: How to Customize Traces.
156 * Issues:: Debatable Issues and What Was Decided.
158 * GNU Free Documentation License:: The license for this documentation.
161 --- The Detailed Node Listing ---
163 @ifset installchapter
164 Installing @value{tramp} with your @value{emacsname}
166 * Installation parameters:: Parameters in order to control installation.
167 * Load paths:: How to plug-in @value{tramp} into your environment.
171 Configuring @value{tramp} for use
173 * Connection types:: Types of connections made to remote machines.
174 * Inline methods:: Inline methods.
175 * External methods:: External methods.
177 * GVFS based methods:: GVFS based external methods.
180 * Gateway methods:: Gateway methods.
182 * Default Method:: Selecting a default method.
183 * Default User:: Selecting a default user.
184 * Default Host:: Selecting a default host.
185 * Multi-hops:: Connecting to a remote host using multiple hops.
186 * Customizing Methods:: Using Non-Standard Methods.
187 * Customizing Completion:: Selecting config files for user/host name completion.
188 * Password handling:: Reusing passwords for several connections.
189 * Connection caching:: Reusing connection related information.
190 * Remote Programs:: How @value{tramp} finds and uses programs on the remote machine.
191 * Remote shell setup:: Remote shell setup hints.
192 * Windows setup hints:: Issues with Cygwin ssh.
193 * Auto-save and Backup:: Auto-save and Backup.
197 * Filename Syntax:: @value{tramp} filename conventions.
198 * Alternative Syntax:: URL-like filename syntax.
199 * Filename completion:: Filename completion.
200 * Remote processes:: Integration with other @value{emacsname} packages.
201 * Cleanup remote connections:: Cleanup remote connections.
203 How file names, directories and localnames are mangled and managed
205 * Localname deconstruction:: Breaking a localname into its components.
207 * External packages:: Integration with external Lisp packages.
214 @chapter An overview of @value{tramp}
217 After the installation of @value{tramp} into your @value{emacsname}, you
218 will be able to access files on remote machines as though they were
219 local. Access to the remote file system for editing files, version
220 control, and @code{dired} are transparently enabled.
222 Your access to the remote machine can be with the @command{rsh},
223 @command{rlogin}, @command{telnet} programs or with any similar
224 connection method. This connection must pass @acronym{ASCII}
225 successfully to be usable but need not be 8-bit clean.
227 The package provides support for @command{ssh} connections out of the
228 box, one of the more common uses of the package. This allows
229 relatively secure access to machines, especially if @command{ftp}
232 Under Windows, @value{tramp} is integrated with the PuTTY package,
233 using the @command{plink} program.
235 The majority of activity carried out by @value{tramp} requires only that
236 the remote login is possible and is carried out at the terminal. In
237 order to access remote files @value{tramp} needs to transfer their content
238 to the local machine temporarily.
240 @value{tramp} can transfer files between the machines in a variety of ways.
241 The details are easy to select, depending on your needs and the
242 machines in question.
244 The fastest transfer methods for large files rely on a remote file
245 transfer package such as @command{rcp}, @command{scp}, @command{rsync}
246 or (under Windows) @command{pscp}.
248 If the remote copy methods are not suitable for you, @value{tramp} also
249 supports the use of encoded transfers directly through the shell.
250 This requires that the @command{mimencode} or @command{uuencode} tools
251 are available on the remote machine. These methods are generally
252 faster for small files.
254 @value{tramp} is still under active development and any problems you encounter,
255 trivial or major, should be reported to the @value{tramp} developers.
259 @subsubheading Behind the scenes
260 @cindex behind the scenes
261 @cindex details of operation
264 This section tries to explain what goes on behind the scenes when you
265 access a remote file through @value{tramp}.
267 Suppose you type @kbd{C-x C-f} and enter part of an @value{tramp} file name,
268 then hit @kbd{@key{TAB}} for completion. Suppose further that this is
269 the first time that @value{tramp} is invoked for the host in question. Here's
274 @value{tramp} discovers that it needs a connection to the host. So it
275 invokes @samp{telnet @var{host}} or @samp{rsh @var{host} -l
276 @var{user}} or a similar tool to connect to the remote host.
277 Communication with this process happens through an
278 @value{emacsname} buffer, that is, the output from the remote end
282 The remote host may prompt for a login name (for @command{telnet}).
283 The login name is given in the file name, so @value{tramp} sends the
284 login name and a newline.
287 The remote host may prompt for a password or pass phrase (for
288 @command{rsh} or for @command{telnet} after sending the login name).
289 @value{tramp} displays the prompt in the minibuffer, asking you for the
290 password or pass phrase.
292 You enter the password or pass phrase. @value{tramp} sends it to the remote
293 host, followed by a newline.
296 @value{tramp} now waits for the shell prompt or for a message that the login
299 If @value{tramp} sees neither of them after a certain period of time
300 (a minute, say), then it issues an error message saying that it
301 couldn't find the remote shell prompt and shows you what the remote
304 If @value{tramp} sees a @samp{login failed} message, it tells you so,
305 aborts the login attempt and allows you to try again.
308 Suppose that the login was successful and @value{tramp} sees the shell prompt
309 from the remote host. Now @value{tramp} invokes @command{/bin/sh} because
310 Bourne shells and C shells have different command
311 syntaxes.@footnote{Invoking @command{/bin/sh} will fail if your login
312 shell doesn't recognize @samp{exec /bin/sh} as a valid command.
313 Maybe you use the Scheme shell @command{scsh}@dots{}}
315 After the Bourne shell has come up, @value{tramp} sends a few commands to
316 ensure a good working environment. It turns off echoing, it sets the
317 shell prompt, and a few other things.
320 Now the remote shell is up and it good working order. Remember, what
321 was supposed to happen is that @value{tramp} tries to find out what files exist
322 on the remote host so that it can do filename completion.
324 So, @value{tramp} basically issues @command{cd} and @command{ls} commands and
325 also sometimes @command{echo} with globbing. Another command that is
326 often used is @command{test} to find out whether a file is writable or a
327 directory or the like. The output of each command is parsed for the
331 Suppose you are finished with filename completion, have entered @kbd{C-x
332 C-f}, a full file name and hit @kbd{@key{RET}}. Now comes the time to
333 transfer the file contents from the remote host to the local host so
334 that you can edit them.
336 See above for an explanation of how @value{tramp} transfers the file contents.
338 For inline transfers, @value{tramp} issues a command like @samp{mimencode -b
339 /path/to/remote/file}, waits until the output has accumulated in the
340 buffer that's used for communication, then decodes that output to
341 produce the file contents.
343 For external transfers, @value{tramp} issues a command like the
346 rcp user@@host:/path/to/remote/file /tmp/tramp.4711
348 It then reads the local temporary file @file{/tmp/tramp.4711} into a
349 buffer and deletes the temporary file.
352 You now edit the buffer contents, blithely unaware of what has happened
353 behind the scenes. (Unless you have read this section, that is.) When
354 you are finished, you type @kbd{C-x C-s} to save the buffer.
357 Again, @value{tramp} transfers the file contents to the remote host
358 either inline or external. This is the reverse of what happens when
362 I hope this has provided you with a basic overview of what happens
363 behind the scenes when you open a file with @value{tramp}.
367 @node Obtaining Tramp
368 @chapter Obtaining Tramp.
369 @cindex obtaining Tramp
371 @value{tramp} is freely available on the Internet and the latest
372 release may be downloaded from
373 @uref{ftp://ftp.gnu.org/gnu/tramp/}. This release includes the full
374 documentation and code for @value{tramp}, suitable for installation.
375 But GNU Emacs (22 or later) includes @value{tramp} already, and there
376 is a @value{tramp} package for XEmacs, as well. So maybe it is easier
377 to just use those. But if you want the bleeding edge, read
380 For the especially brave, @value{tramp} is available from CVS. The CVS
381 version is the latest version of the code and may contain incomplete
382 features or new issues. Use these versions at your own risk.
384 Instructions for obtaining the latest development version of @value{tramp}
385 from CVS can be found by going to the Savannah project page at the
386 following URL and then clicking on the CVS link in the navigation bar
390 @uref{http://savannah.gnu.org/projects/tramp/}
393 Or follow the example session below:
396 ] @strong{cd ~/@value{emacsdir}}
397 ] @strong{export CVS_RSH="ssh"}
398 ] @strong{cvs -z3 -d:pserver:anonymous@@cvs.savannah.gnu.org:/sources/tramp co tramp}
402 You should now have a directory @file{~/@value{emacsdir}/tramp}
403 containing the latest version of @value{tramp}. You can fetch the latest
404 updates from the repository by issuing the command:
407 ] @strong{cd ~/@value{emacsdir}/tramp}
408 ] @strong{export CVS_RSH="ssh"}
409 ] @strong{cvs update -d}
413 Once you've got updated files from the CVS repository, you need to run
414 @command{autoconf} in order to get an up-to-date @file{configure}
418 ] @strong{cd ~/@value{emacsdir}/tramp}
424 @chapter History of @value{tramp}
426 @cindex development history
428 Development was started end of November 1998. The package was called
429 @file{rssh.el}, back then. It only provided one method to access a
430 file, using @command{ssh} to log in to a remote host and using
431 @command{scp} to transfer the file contents. After a while, the name
432 was changed to @file{rcp.el}, and now it's @value{tramp}. Along the way,
433 many more methods for getting a remote shell and for transferring the
434 file contents were added. Support for VC was added.
436 After that, there were added the multi-hop methods in April 2000 and
437 the unification of @value{tramp} and Ange-FTP filenames in July 2002.
438 In July 2004, multi-hop methods have been replaced by proxy hosts.
439 Running commands on remote hosts was introduced in December 2005.
441 Support of gateways exists since April 2007.
444 GVFS integration started in February 2009.
447 In December 2001, @value{tramp} has been added to the XEmacs package
448 repository. Being part of the GNU Emacs repository happened in June
449 2002, the first release including @value{tramp} was GNU Emacs 22.1.
451 @value{tramp} is also a GNU/Linux Debian package since February 2001.
454 @c Installation chapter is necessary only in case of standalone
455 @c installation. Text taken from trampinst.texi.
456 @ifset installchapter
457 @include trampinst.texi
461 @chapter Configuring @value{tramp} for use
462 @cindex configuration
464 @cindex default configuration
465 @value{tramp} is (normally) fully functional when it is initially
466 installed. It is initially configured to use the @command{scp}
467 program to connect to the remote host. So in the easiest case, you
468 just type @kbd{C-x C-f} and then enter the filename
469 @file{@trampfn{, user, machine, /path/to.file}}.
471 On some hosts, there are problems with opening a connection. These are
472 related to the behavior of the remote shell. See @xref{Remote shell
473 setup}, for details on this.
475 If you do not wish to use these commands to connect to the remote
476 host, you should change the default connection and transfer method
477 that @value{tramp} uses. There are several different methods that @value{tramp}
478 can use to connect to remote machines and transfer files
479 (@pxref{Connection types}).
481 If you don't know which method is right for you, see @xref{Default
486 * Connection types:: Types of connections made to remote machines.
487 * Inline methods:: Inline methods.
488 * External methods:: External methods.
490 * GVFS based methods:: GVFS based external methods.
493 * Gateway methods:: Gateway methods.
495 * Default Method:: Selecting a default method.
496 Here we also try to help those who
497 don't have the foggiest which method
499 * Default User:: Selecting a default user.
500 * Default Host:: Selecting a default host.
501 * Multi-hops:: Connecting to a remote host using multiple hops.
502 * Customizing Methods:: Using Non-Standard Methods.
503 * Customizing Completion:: Selecting config files for user/host name completion.
504 * Password handling:: Reusing passwords for several connections.
505 * Connection caching:: Reusing connection related information.
506 * Remote Programs:: How @value{tramp} finds and uses programs on the remote machine.
507 * Remote shell setup:: Remote shell setup hints.
508 * Windows setup hints:: Issues with Cygwin ssh.
509 * Auto-save and Backup:: Auto-save and Backup.
513 @node Connection types
514 @section Types of connections made to remote machines.
515 @cindex connection types, overview
517 There are two basic types of transfer methods, each with its own
518 advantages and limitations. Both types of connection make use of a
519 remote shell access program such as @command{rsh}, @command{ssh} or
520 @command{telnet} to connect to the remote machine.
522 This connection is used to perform many of the operations that @value{tramp}
523 requires to make the remote file system transparently accessible from
524 the local machine. It is only when visiting files that the methods
527 @cindex inline methods
528 @cindex external methods
529 @cindex methods, inline
530 @cindex methods, external
531 Loading or saving a remote file requires that the content of the file
532 be transfered between the two machines. The content of the file can
533 be transfered using one of two methods: the @dfn{inline method} over
534 the same connection used to log in to the remote machine, or the
535 @dfn{external method} through another connection using a remote copy
536 program such as @command{rcp}, @command{scp} or @command{rsync}.
538 The performance of the external methods is generally better than that
539 of the inline methods, at least for large files. This is caused by
540 the need to encode and decode the data when transferring inline.
542 The one exception to this rule are the @command{scp} based transfer
543 methods. While these methods do see better performance when actually
544 transferring files, the overhead of the cryptographic negotiation at
545 startup may drown out the improvement in file transfer times.
547 External methods should be configured such a way that they don't
548 require a password (with @command{ssh-agent}, or such alike). Modern
549 @command{scp} implementations offer options to reuse existing
550 @command{ssh} connections, see method @command{scpc}. If it isn't
551 possible, you should consider @ref{Password handling}, otherwise you
552 will be prompted for a password every copy action.
556 @section Inline methods
557 @cindex inline methods
558 @cindex methods, inline
560 The inline methods in @value{tramp} are quite powerful and can work in
561 situations where you cannot use an external transfer program to connect.
562 Inline methods are the only methods that work when connecting to the
563 remote machine via telnet. (There are also strange inline methods which
564 allow you to transfer files between @emph{user identities} rather than
567 These methods depend on the existence of a suitable encoding and
568 decoding command on remote machine. Locally, @value{tramp} may be able to
569 use features of @value{emacsname} to decode and encode the files or
570 it may require access to external commands to perform that task.
574 @cindex base-64 encoding
575 @value{tramp} checks the availability and usability of commands like
576 @command{mimencode} (part of the @command{metamail} package) or
577 @command{uuencode} on the remote host. The first reliable command
578 will be used. The search path can be customized, see @ref{Remote
581 If both commands aren't available on the remote host, @value{tramp}
582 transfers a small piece of Perl code to the remote host, and tries to
583 apply it for encoding and decoding.
585 The variable @var{tramp-inline-compress-start-size} controls, whether
586 a file shall be compressed before encoding. This could increase
587 transfer speed for large text files.
595 Connect to the remote host with @command{rsh}. Due to the unsecure
596 connection it is recommended for very local host topology only.
598 On operating systems which provide the command @command{remsh} instead
599 of @command{rsh}, you can use the method @option{remsh}. This is true
600 for HP-UX or Cray UNICOS, for example.
607 Connect to the remote host with @command{ssh}. This is identical to
608 the previous option except that the @command{ssh} package is used,
609 making the connection more secure.
611 There are also two variants, @option{ssh1} and @option{ssh2}, that
612 call @samp{ssh -1} and @samp{ssh -2}, respectively. This way, you can
613 explicitly select whether you want to use the SSH protocol version 1
614 or 2 to connect to the remote host. (You can also specify in
615 @file{~/.ssh/config}, the SSH configuration file, which protocol
616 should be used, and use the regular @option{ssh} method.)
618 All the methods based on @command{ssh} have an additional feature: you
619 can specify a host name which looks like @file{host#42} (the real host
620 name, then a hash sign, then a port number). This means to connect to
621 the given host but to also pass @code{-p 42} as arguments to the
622 @command{ssh} command.
625 @item @option{telnet}
626 @cindex method telnet
627 @cindex telnet method
629 Connect to the remote host with @command{telnet}. This is as unsecure
630 as the @option{rsh} method.
637 This method does not connect to a remote host at all, rather it uses
638 the @command{su} program to allow you to edit files as another user.
639 That means, the specified host name in the file name must be either
640 @samp{localhost} or the host name as returned by the function
641 @command{(system-name)}. For an exception of this rule see
649 This is similar to the @option{su} method, but it uses @command{sudo}
650 rather than @command{su} to become a different user.
652 Note that @command{sudo} must be configured to allow you to start a
653 shell as the user. It would be nice if it was sufficient if
654 @command{ls} and @command{mimencode} were allowed, but that is not
655 easy to implement, so I haven't got around to it, yet.
662 As you would expect, this is similar to @option{ssh}, only a little
663 different. Whereas @option{ssh} opens a normal interactive shell on
664 the remote host, this option uses @samp{ssh -t -t @var{host} -l
665 @var{user} /bin/sh} to open a connection. This is useful for users
666 where the normal login shell is set up to ask them a number of
667 questions when logging in. This procedure avoids these questions, and
668 just gives @value{tramp} a more-or-less `standard' login shell to work
671 Note that this procedure does not eliminate questions asked by
672 @command{ssh} itself. For example, @command{ssh} might ask ``Are you
673 sure you want to continue connecting?'' if the host key of the remote
674 host is not known. @value{tramp} does not know how to deal with such a
675 question (yet), therefore you will need to make sure that you can log
676 in without such questions.
678 This is also useful for Windows users where @command{ssh}, when
679 invoked from an @value{emacsname} buffer, tells them that it is not
680 allocating a pseudo tty. When this happens, the login shell is wont
681 to not print any shell prompt, which confuses @value{tramp} mightily.
683 This supports the @samp{-p} argument.
686 @item @option{krlogin}
687 @cindex method krlogin
688 @cindex krlogin method
689 @cindex Kerberos (with krlogin method)
691 This method is also similar to @option{ssh}. It only uses the
692 @command{krlogin -x} command to log in to the remote host.
698 @cindex Kerberos (with ksu method)
700 This is another method from the Kerberos suite. It behaves like @option{su}.
707 This method is mostly interesting for Windows users using the PuTTY
708 implementation of SSH. It uses @samp{plink -ssh} to log in to the
711 This supports the @samp{-P} argument.
713 Additionally, the methods @option{plink1} and @option{plink2} are
714 provided, which call @samp{plink -1 -ssh} or @samp{plink -2 -ssh} in
715 order to use SSH protocol version 1 or 2 explicitly.
717 CCC: Do we have to connect to the remote host once from the command
718 line to accept the SSH key? Maybe this can be made automatic?
720 CCC: Say something about the first shell command failing. This might
721 be due to a wrong setting of @code{tramp-rsh-end-of-line}.
724 @item @option{plinkx}
725 @cindex method plinkx
726 @cindex plinkx method
728 Another method using PuTTY on Windows. Instead of host names, it
729 expects PuTTY session names, calling @samp{plink -load @var{session}
730 -t"}. User names are relevant only in case the corresponding session
731 hasn't defined a user name. Different port numbers must be defined in
737 @node External methods
738 @section External methods
739 @cindex methods, external
740 @cindex external methods
742 The external methods operate through multiple channels, using the
743 remote shell connection for many actions while delegating file
744 transfers to an external transfer utility.
746 This saves the overhead of encoding and decoding that multiplexing the
747 transfer through the one connection has with the inline methods.
749 Since external methods need their own overhead opening a new channel,
750 all files which are smaller than @var{tramp-copy-size-limit} are still
751 transferred with the corresponding inline method. It should provide a
752 fair trade-off between both approaches.
755 @item @option{rcp} --- @command{rsh} and @command{rcp}
758 @cindex rcp (with rcp method)
759 @cindex rsh (with rcp method)
761 This method uses the @command{rsh} and @command{rcp} commands to connect
762 to the remote machine and transfer files. This is probably the fastest
763 connection method available.
765 The alternative method @option{remcp} uses the @command{remsh} and
766 @command{rcp} commands. It should be applied on machines where
767 @command{remsh} is used instead of @command{rsh}.
770 @item @option{scp} --- @command{ssh} and @command{scp}
773 @cindex scp (with scp method)
774 @cindex ssh (with scp method)
776 Using @command{ssh} to connect to the remote host and @command{scp} to
777 transfer files between the machines is the best method for securely
778 connecting to a remote machine and accessing files.
780 The performance of this option is also quite good. It may be slower than
781 the inline methods when you often open and close small files however.
782 The cost of the cryptographic handshake at the start of an @command{scp}
783 session can begin to absorb the advantage that the lack of encoding and
786 There are also two variants, @option{scp1} and @option{scp2}, that
787 call @samp{ssh -1} and @samp{ssh -2}, respectively. This way, you can
788 explicitly select whether you want to use the SSH protocol version 1
789 or 2 to connect to the remote host. (You can also specify in
790 @file{~/.ssh/config}, the SSH configuration file, which protocol
791 should be used, and use the regular @option{scp} method.)
793 All the @command{ssh} based methods support the @samp{-p} feature
794 where you can specify a port number to connect to in the host name.
795 For example, the host name @file{host#42} tells @value{tramp} to
796 specify @samp{-p 42} in the argument list for @command{ssh}, and to
797 specify @samp{-P 42} in the argument list for @command{scp}.
800 @item @option{sftp} --- @command{ssh} and @command{sftp}
803 @cindex sftp (with sftp method)
804 @cindex ssh (with sftp method)
806 That is mostly the same method as @option{scp}, but using
807 @command{sftp} as transfer command. So the same remarks are valid.
809 This command does not work like @value{ftppackagename}, where
810 @command{ftp} is called interactively, and all commands are send from
811 within this session. Instead of, @command{ssh} is used for login.
813 This method supports the @samp{-p} argument.
816 @item @option{rsync} --- @command{ssh} and @command{rsync}
819 @cindex rsync (with rsync method)
820 @cindex ssh (with rsync method)
822 Using the @command{ssh} command to connect securely to the remote
823 machine and the @command{rsync} command to transfer files is almost
824 identical to the @option{scp} method.
826 While @command{rsync} performs much better than @command{scp} when
827 transferring files that exist on both hosts, this advantage is lost if
828 the file exists only on one side of the connection. A file can exists
829 on both the remote and local host, when you copy a file from/to a
830 remote host. When you just open a file from the remote host (or write
831 a file there), a temporary file on the local side is kept as long as
832 the corresponding buffer, visiting this file, is alive.
834 This method supports the @samp{-p} argument.
837 @item @option{scpx} --- @command{ssh} and @command{scp}
840 @cindex scp (with scpx method)
841 @cindex ssh (with scpx method)
843 As you would expect, this is similar to @option{scp}, only a little
844 different. Whereas @option{scp} opens a normal interactive shell on
845 the remote host, this option uses @samp{ssh -t -t @var{host} -l
846 @var{user} /bin/sh} to open a connection. This is useful for users
847 where the normal login shell is set up to ask them a number of
848 questions when logging in. This procedure avoids these questions, and
849 just gives @value{tramp} a more-or-less `standard' login shell to work
852 This is also useful for Windows users where @command{ssh}, when
853 invoked from an @value{emacsname} buffer, tells them that it is not
854 allocating a pseudo tty. When this happens, the login shell is wont
855 to not print any shell prompt, which confuses @value{tramp} mightily.
857 This method supports the @samp{-p} argument.
860 @item @option{scpc} --- @command{ssh} and @command{scp}
863 @cindex scp (with scpc method)
864 @cindex ssh (with scpc method)
866 Newer versions of @option{ssh} (for example OpenSSH 4) offer an option
867 @option{ControlMaster}. This allows @option{scp} to reuse an existing
868 @option{ssh} channel, which increases performance.
870 Before you use this method, you shall check whether your @option{ssh}
871 implementation does support this option. Try from the command line
874 ssh localhost -o ControlMaster=yes
877 This method supports the @samp{-p} argument.
880 @item @option{rsyncc} --- @command{ssh} and @command{rsync}
881 @cindex method rsyncc
882 @cindex rsyncc method
883 @cindex rsync (with rsyncc method)
884 @cindex ssh (with rsyncc method)
886 Like the @option{scpc} method, @option{rsyncc} improves the underlying
887 @command{ssh} connection by the option @option{ControlMaster}. This
888 allows @command{rsync} to reuse an existing @command{ssh} channel,
889 which increases performance.
891 This method supports the @samp{-p} argument.
894 @item @option{pscp} --- @command{plink} and @command{pscp}
897 @cindex pscp (with pscp method)
898 @cindex plink (with pscp method)
899 @cindex PuTTY (with pscp method)
901 This method is similar to @option{scp}, but it uses the
902 @command{plink} command to connect to the remote host, and it uses
903 @command{pscp} for transferring the files. These programs are part
904 of PuTTY, an SSH implementation for Windows.
906 This method supports the @samp{-P} argument.
909 @item @option{psftp} --- @command{plink} and @command{psftp}
912 @cindex psftp (with psftp method)
913 @cindex plink (with psftp method)
914 @cindex PuTTY (with psftp method)
916 As you would expect, this method is similar to @option{sftp}, but it
917 uses the @command{plink} command to connect to the remote host, and it
918 uses @command{psftp} for transferring the files. These programs are
919 part of PuTTY, an SSH implementation for Windows.
921 This method supports the @samp{-P} argument.
924 @item @option{fcp} --- @command{fsh} and @command{fcp}
927 @cindex fsh (with fcp method)
928 @cindex fcp (with fcp method)
930 This method is similar to @option{scp}, but it uses the @command{fsh}
931 command to connect to the remote host, and it uses @command{fcp} for
932 transferring the files. @command{fsh/fcp} are a front-end for
933 @command{ssh} which allow for reusing the same @command{ssh} session
934 for submitting several commands. This avoids the startup overhead of
935 @command{scp} (which has to establish a secure connection whenever it
936 is called). Note, however, that you can also use one of the inline
937 methods to achieve a similar effect.
939 This method uses the command @samp{fsh @var{host} -l @var{user}
940 /bin/sh -i} to establish the connection, it does not work to just say
941 @command{fsh @var{host} -l @var{user}}.
946 There is no inline method using @command{fsh} as the multiplexing
947 provided by the program is not very useful in our context. @value{tramp}
948 opens just one connection to the remote host and then keeps it open,
956 This is not a native @value{tramp} method. Instead, it forwards all
957 requests to @value{ftppackagename}.
959 This works only for unified filenames, see @ref{Issues}.
963 @item @option{smb} --- @command{smbclient}
967 This is another not natural @value{tramp} method. It uses the
968 @command{smbclient} command on different Unices in order to connect to
969 an SMB server. An SMB server might be a Samba (or CIFS) server on
970 another UNIX host or, more interesting, a host running MS Windows. So
971 far, it is tested against MS Windows NT, MS Windows 2000, and MS
974 The first directory in the localname must be a share name on the remote
975 host. Remember that the @code{$} character, in which default shares
976 usually end, must be written @code{$$} due to environment variable
977 substitution in file names. If no share name is given (i.e. remote
978 directory @code{/}), all available shares are listed.
980 Since authorization is done on share level, you will always be
981 prompted for a password if you access another share on the same host.
982 This can be suppressed by @ref{Password handling}.
984 For authorization, MS Windows uses both a user name and a domain name.
985 Because of this, the @value{tramp} syntax has been extended: you can
986 specify a user name which looks like @code{user%domain} (the real user
987 name, then a percent sign, then the domain name). So, to connect to
988 the machine @code{melancholia} as user @code{daniel} of the domain
989 @code{BIZARRE}, and edit @file{.emacs} in the home directory (share
990 @code{daniel$}) I would specify the filename @file{@trampfn{smb,
991 daniel%BIZARRE, melancholia, /daniel$$/.emacs}}.
993 Depending on the Windows domain configuration, a Windows user might be
994 considered as domain user per default. In order to connect as local
995 user, the WINS name of that machine must be given as domain name.
996 Usually, it is the machine name in capital letters. In the example
997 above, the local user @code{daniel} would be specified as
998 @file{@trampfn{smb, daniel%MELANCHOLIA, melancholia, /daniel$$/.emacs}}.
1000 The domain name as well as the user name are optional. If no user
1001 name is specified at all, the anonymous user (without password
1002 prompting) is assumed. This is different from all other @value{tramp}
1003 methods, where in such a case the local user name is taken.
1005 The @option{smb} method supports the @samp{-p} argument.
1007 @strong{Please note:} If @value{emacsname} runs locally under MS
1008 Windows, this method isn't available. Instead, you can use UNC
1009 file names like @file{//melancholia/daniel$$/.emacs}. The only
1010 disadvantage is that there's no possibility to specify another user
1016 @node GVFS based methods
1017 @section GVFS based external methods
1018 @cindex methods, gvfs
1019 @cindex gvfs based methods
1022 The connection methods described in this section are based on GVFS
1023 @uref{http://en.wikipedia.org/wiki/GVFS}. Via GVFS, the remote
1024 filesystem is mounted locally through FUSE. @value{tramp} uses
1025 this local mounted directory internally.
1027 The communication with GVFS is implemented via D-Bus messages.
1028 Therefore, your @value{emacsname} must have D-Bus integration,
1029 @pxref{Top, , D-Bus, dbus}.
1038 This method provides access to WebDAV files and directories. There
1039 exists also the external method @option{davs}, which uses SSL
1040 encryption for the access.
1042 Both methods support the port number specification as discussed above.
1049 OBEX is an FTP-like access protocol for simple devices, like cell
1050 phones. For the time being, @value{tramp} only supports OBEX over Bluetooth.
1053 @item @option{synce}
1054 @cindex method synce
1055 @cindex synce method
1057 The @option{synce} method allows communication with Windows Mobile
1058 devices. Beside GVFS for mounting remote files and directories via
1059 FUSE, it also needs the SYNCE-GVFS plugin.
1062 @defopt tramp-gvfs-methods
1063 This customer option, a list, defines the external methods which
1064 shall be used with GVFS. Per default, these are @option{dav},
1065 @option{davs}, @option{obex} and @option{synce}. Other possible
1066 values are @option{ftp}, @option{sftp} and @option{smb}.
1072 @node Gateway methods
1073 @section Gateway methods
1074 @cindex methods, gateway
1075 @cindex gateway methods
1077 Gateway methods are not methods to access a remote host directly.
1078 These methods are intended to pass firewalls or proxy servers.
1079 Therefore, they can be used for proxy host declarations
1080 (@pxref{Multi-hops}) only.
1082 A gateway method must always come along with a method which supports
1083 port setting. This is because @value{tramp} targets the accompanied
1084 method to @file{localhost#random_port}, from where the firewall or
1085 proxy server is accessed.
1087 Gateway methods support user name and password declarations. These
1088 are used to authenticate towards the corresponding firewall or proxy
1089 server. They can be passed only if your friendly administrator has
1090 granted your access.
1093 @item @option{tunnel}
1094 @cindex method tunnel
1095 @cindex tunnel method
1097 This method implements an HTTP tunnel via the @command{CONNECT}
1098 command (see RFC 2616, 2817). Any HTTP 1.1 compliant (proxy) server
1099 shall support this command.
1101 As authentication method, only @option{Basic Authentication} (see RFC
1102 2617) is implemented so far. If no port number is given in the
1103 declaration, port @option{8080} is used for the proxy server.
1106 @item @option{socks}
1107 @cindex method socks
1108 @cindex socks method
1110 The @command{socks} method provides access to SOCKSv5 servers (see
1111 RFC 1928). @option{Username/Password Authentication} according to RFC
1114 The default port number of the socks server is @option{1080}, if not
1115 specified otherwise.
1121 @node Default Method
1122 @section Selecting a default method
1123 @cindex default method
1125 @vindex tramp-default-method
1126 When you select an appropriate transfer method for your typical usage
1127 you should set the variable @code{tramp-default-method} to reflect that
1128 choice. This variable controls which method will be used when a method
1129 is not specified in the @value{tramp} file name. For example:
1132 (setq tramp-default-method "ssh")
1135 @vindex tramp-default-method-alist
1136 You can also specify different methods for certain user/host
1137 combinations, via the variable @code{tramp-default-method-alist}. For
1138 example, the following two lines specify to use the @option{ssh}
1139 method for all user names matching @samp{john} and the @option{rsync}
1140 method for all host names matching @samp{lily}. The third line
1141 specifies to use the @option{su} method for the user @samp{root} on
1142 the machine @samp{localhost}.
1145 (add-to-list 'tramp-default-method-alist '("" "john" "ssh"))
1146 (add-to-list 'tramp-default-method-alist '("lily" "" "rsync"))
1147 (add-to-list 'tramp-default-method-alist
1148 '("\\`localhost\\'" "\\`root\\'" "su"))
1152 See the documentation for the variable
1153 @code{tramp-default-method-alist} for more details.
1155 External methods are normally preferable to inline methods, giving
1158 @xref{Inline methods}.
1159 @xref{External methods}.
1161 Another consideration with the selection of transfer methods is the
1162 environment you will use them in and, especially when used over the
1163 Internet, the security implications of your preferred method.
1165 The @option{rsh} and @option{telnet} methods send your password as
1166 plain text as you log in to the remote machine, as well as
1167 transferring the files in such a way that the content can easily be
1168 read from other machines.
1170 If you need to connect to remote systems that are accessible from the
1171 Internet, you should give serious thought to using @option{ssh} based
1172 methods to connect. These provide a much higher level of security,
1173 making it a non-trivial exercise for someone to obtain your password
1174 or read the content of the files you are editing.
1177 @subsection Which method is the right one for me?
1178 @cindex choosing the right method
1180 Given all of the above, you are probably thinking that this is all fine
1181 and good, but it's not helping you to choose a method! Right you are.
1182 As a developer, we don't want to boss our users around but give them
1183 maximum freedom instead. However, the reality is that some users would
1184 like to have some guidance, so here I'll try to give you this guidance
1185 without bossing you around. You tell me whether it works @dots{}
1187 My suggestion is to use an inline method. For large files, external
1188 methods might be more efficient, but I guess that most people will
1189 want to edit mostly small files. And if you access large text files,
1190 compression (driven by @var{tramp-inline-compress-start-size}) shall
1191 still result in good performance.
1193 I guess that these days, most people can access a remote machine by
1194 using @command{ssh}. So I suggest that you use the @option{ssh}
1195 method. So, type @kbd{C-x C-f @trampfn{ssh, root, otherhost,
1196 /etc/motd} @key{RET}} to edit the @file{/etc/motd} file on the other
1199 If you can't use @option{ssh} to log in to the remote host, then
1200 select a method that uses a program that works. For instance, Windows
1201 users might like the @option{plink} method which uses the PuTTY
1202 implementation of @command{ssh}. Or you use Kerberos and thus like
1205 For the special case of editing files on the local host as another
1206 user, see the @option{su} or @option{sudo} methods. They offer
1207 shortened syntax for the @samp{root} account, like
1208 @file{@trampfn{su, , , /etc/motd}}.
1210 People who edit large files may want to consider @option{scpc} instead
1211 of @option{ssh}, or @option{pscp} instead of @option{plink}. These
1212 external methods are faster than inline methods for large files.
1213 Note, however, that external methods suffer from some limitations.
1214 Please try first whether you really get a noticeable speed advantage
1215 from using an external method! Maybe even for large files, inline
1216 methods are fast enough.
1220 @section Selecting a default user
1221 @cindex default user
1223 The user part of a @value{tramp} file name can be omitted. Usually,
1224 it is replaced by the user name you are logged in. Often, this is not
1225 what you want. A typical use of @value{tramp} might be to edit some
1226 files with root permissions on the local host. This case, you should
1227 set the variable @code{tramp-default-user} to reflect that choice.
1231 (setq tramp-default-user "root")
1234 @code{tramp-default-user} is regarded as obsolete, and will be removed
1237 @vindex tramp-default-user-alist
1238 You can also specify different users for certain method/host
1239 combinations, via the variable @code{tramp-default-user-alist}. For
1240 example, if you always have to use the user @samp{john} in the domain
1241 @samp{somewhere.else}, you can specify the following:
1244 (add-to-list 'tramp-default-user-alist
1245 '("ssh" ".*\\.somewhere\\.else\\'" "john"))
1249 See the documentation for the variable
1250 @code{tramp-default-user-alist} for more details.
1252 One trap to fall in must be known. If @value{tramp} finds a default
1253 user, this user will be passed always to the connection command as
1254 parameter (for example @samp{ssh here.somewhere.else -l john}. If you
1255 have specified another user for your command in its configuration
1256 files, @value{tramp} cannot know it, and the remote access will fail.
1257 If you have specified in the given example in @file{~/.ssh/config} the
1261 Host here.somewhere.else
1266 than you must discard selecting a default user by @value{tramp}. This
1267 will be done by setting it to @code{nil} (or @samp{lily}, likewise):
1270 (add-to-list 'tramp-default-user-alist
1271 '("ssh" "\\`here\\.somewhere\\.else\\'" nil))
1274 The last entry in @code{tramp-default-user-alist} could be your
1275 default user you'll apply predominantly. You shall @emph{append} it
1276 to that list at the end:
1279 (add-to-list 'tramp-default-user-alist '(nil nil "jonas") t)
1284 @section Selecting a default host
1285 @cindex default host
1287 @vindex tramp-default-host
1288 Finally, it is even possible to omit the host name part of a
1289 @value{tramp} file name. This case, the value of the variable
1290 @code{tramp-default-host} is used. Per default, it is initialized
1291 with the host name your local @value{emacsname} is running.
1293 If you, for example, use @value{tramp} mainly to contact the host
1294 @samp{target} as user @samp{john}, you can specify:
1297 (setq tramp-default-user "john"
1298 tramp-default-host "target")
1301 Then the simple file name @samp{@trampfn{ssh, , ,}} will connect you
1302 to John's home directory on target.
1304 Note, however, that the most simplification @samp{/::} won't work,
1305 because @samp{/:} is the prefix for quoted file names.
1310 @section Connecting to a remote host using multiple hops
1314 Sometimes, the methods described before are not sufficient. Sometimes,
1315 it is not possible to connect to a remote host using a simple command.
1316 For example, if you are in a secured network, you might have to log in
1317 to a `bastion host' first before you can connect to the outside world.
1318 Of course, the target host may also require a bastion host.
1320 @vindex tramp-default-proxies-alist
1321 In order to specify such multiple hops, it is possible to define a proxy
1322 host to pass through, via the variable
1323 @code{tramp-default-proxies-alist}. This variable keeps a list of
1324 triples (@var{host} @var{user} @var{proxy}).
1326 The first matching item specifies the proxy host to be passed for a
1327 file name located on a remote target matching @var{user}@@@var{host}.
1328 @var{host} and @var{user} are regular expressions or @code{nil}, which
1329 is interpreted as a regular expression which always matches.
1331 @var{proxy} must be a Tramp filename which localname part is ignored.
1332 Method and user name on @var{proxy} are optional, which is interpreted
1333 with the default values.
1335 The method must be an inline or gateway method (@pxref{Inline
1336 methods}, @pxref{Gateway methods}).
1339 The method must be an inline method (@pxref{Inline methods}).
1341 If @var{proxy} is @code{nil}, no additional hop is required reaching
1342 @var{user}@@@var{host}.
1344 If you, for example, must pass the host @samp{bastion.your.domain} as
1345 user @samp{bird} for any remote host which is not located in your local
1349 (add-to-list 'tramp-default-proxies-alist
1350 '("\\." nil "@trampfn{ssh, bird, bastion.your.domain,}"))
1351 (add-to-list 'tramp-default-proxies-alist
1352 '("\\.your\\.domain\\'" nil nil))
1355 Please note the order of the code. @code{add-to-list} adds elements at the
1356 beginning of a list. Therefore, most relevant rules must be added last.
1358 Proxy hosts can be cascaded. If there is another host called
1359 @samp{jump.your.domain}, which is the only one in your local domain who
1360 is allowed connecting @samp{bastion.your.domain}, you can add another
1364 (add-to-list 'tramp-default-proxies-alist
1365 '("\\`bastion\\.your\\.domain\\'"
1367 "@trampfn{ssh, , jump.your.domain,}"))
1370 @var{proxy} can contain the patterns @code{%h} or @code{%u}. These
1371 patterns are replaced by the strings matching @var{host} or
1372 @var{user}, respectively.
1374 If you, for example, wants to work as @samp{root} on hosts in the
1375 domain @samp{your.domain}, but login as @samp{root} is disabled for
1376 non-local access, you might add the following rule:
1379 (add-to-list 'tramp-default-proxies-alist
1380 '("\\.your\\.domain\\'" "\\`root\\'" "@trampfn{ssh, , %h,}"))
1383 Opening @file{@trampfn{sudo, , randomhost.your.domain,}} would connect
1384 first @samp{randomhost.your.domain} via @code{ssh} under your account
1385 name, and perform @code{sudo -u root} on that host afterwards. It is
1386 important to know that the given method is applied on the host which
1387 has been reached so far. @code{sudo -u root}, applied on your local
1388 host, wouldn't be useful here.
1390 @var{host}, @var{user} and @var{proxy} can also be Lisp forms. These
1391 forms are evaluated, and must return a string, or @code{nil}. The
1392 previous example could be generalized then: For all hosts except my
1393 local one connect via @code{ssh} first, and apply @code{sudo -u root}
1397 (add-to-list 'tramp-default-proxies-alist
1398 '(nil "\\`root\\'" "@trampfn{ssh, , %h,}"))
1399 (add-to-list 'tramp-default-proxies-alist
1400 '((regexp-quote (system-name)) nil nil))
1403 This is the recommended configuration to work as @samp{root} on remote
1407 Finally, @code{tramp-default-proxies-alist} can be used to pass
1408 firewalls or proxy servers. Imagine your local network has a host
1409 @samp{proxy.your.domain} which is used on port 3128 as HTTP proxy to
1410 the outer world. Your friendly administrator has granted you access
1411 under your user name to @samp{host.other.domain} on that proxy
1412 server.@footnote{HTTP tunnels are intended for secure SSL/TLS
1413 communication. Therefore, many proxy server restrict the tunnels to
1414 related target ports. You might need to run your ssh server on your
1415 target host @samp{host.other.domain} on such a port, like 443 (https).
1416 See @uref{http://savannah.gnu.org/maintenance/CvsFromBehindFirewall}
1417 for discussion of ethical issues.} You would need to add the
1421 (add-to-list 'tramp-default-proxies-alist
1422 '("\\`host\\.other\\.domain\\'" nil
1423 "@trampfn{tunnel, , proxy.your.domain#3128,}"))
1426 Gateway methods can be declared as first hop only in a multiple hop
1431 @node Customizing Methods
1432 @section Using Non-Standard Methods
1433 @cindex customizing methods
1434 @cindex using non-standard methods
1435 @cindex create your own methods
1437 There is a variable @code{tramp-methods} which you can change if the
1438 predefined methods don't seem right.
1440 For the time being, I'll refer you to the Lisp documentation of that
1441 variable, accessible with @kbd{C-h v tramp-methods @key{RET}}.
1444 @node Customizing Completion
1445 @section Selecting config files for user/host name completion
1446 @cindex customizing completion
1447 @cindex selecting config files
1448 @vindex tramp-completion-function-alist
1450 The variable @code{tramp-completion-function-alist} is intended to
1451 customize which files are taken into account for user and host name
1452 completion (@pxref{Filename completion}). For every method, it keeps
1453 a set of configuration files, accompanied by a Lisp function able to
1454 parse that file. Entries in @code{tramp-completion-function-alist}
1455 have the form (@var{method} @var{pair1} @var{pair2} ...).
1457 Each @var{pair} is composed of (@var{function} @var{file}).
1458 @var{function} is responsible to extract user names and host names
1459 from @var{file} for completion. There are two functions which access
1462 @defun tramp-get-completion-function method
1463 This function returns the list of completion functions for @var{method}.
1467 (tramp-get-completion-function "rsh")
1469 @result{} ((tramp-parse-rhosts "/etc/hosts.equiv")
1470 (tramp-parse-rhosts "~/.rhosts"))
1474 @defun tramp-set-completion-function method function-list
1475 This function sets @var{function-list} as list of completion functions
1480 (tramp-set-completion-function "ssh"
1481 '((tramp-parse-sconfig "/etc/ssh_config")
1482 (tramp-parse-sconfig "~/.ssh/config")))
1484 @result{} ((tramp-parse-sconfig "/etc/ssh_config")
1485 (tramp-parse-sconfig "~/.ssh/config"))
1489 The following predefined functions parsing configuration files exist:
1492 @item @code{tramp-parse-rhosts}
1493 @findex tramp-parse-rhosts
1495 This function parses files which are syntactical equivalent to
1496 @file{~/.rhosts}. It returns both host names and user names, if
1499 @item @code{tramp-parse-shosts}
1500 @findex tramp-parse-shosts
1502 This function parses files which are syntactical equivalent to
1503 @file{~/.ssh/known_hosts}. Since there are no user names specified
1504 in such files, it can return host names only.
1506 @item @code{tramp-parse-sconfig}
1507 @findex tramp-parse-shosts
1509 This function returns the host nicknames defined by @code{Host} entries
1510 in @file{~/.ssh/config} style files.
1512 @item @code{tramp-parse-shostkeys}
1513 @findex tramp-parse-shostkeys
1515 SSH2 parsing of directories @file{/etc/ssh2/hostkeys/*} and
1516 @file{~/ssh2/hostkeys/*}. Hosts are coded in file names
1517 @file{hostkey_@var{portnumber}_@var{host-name}.pub}. User names
1518 are always @code{nil}.
1520 @item @code{tramp-parse-sknownhosts}
1521 @findex tramp-parse-shostkeys
1523 Another SSH2 style parsing of directories like
1524 @file{/etc/ssh2/knownhosts/*} and @file{~/ssh2/knownhosts/*}. This
1525 case, hosts names are coded in file names
1526 @file{@var{host-name}.@var{algorithm}.pub}. User names are always @code{nil}.
1528 @item @code{tramp-parse-hosts}
1529 @findex tramp-parse-hosts
1531 A function dedicated to @file{/etc/hosts} style files. It returns
1534 @item @code{tramp-parse-passwd}
1535 @findex tramp-parse-passwd
1537 A function which parses @file{/etc/passwd} like files. Obviously, it
1538 can return user names only.
1540 @item @code{tramp-parse-netrc}
1541 @findex tramp-parse-netrc
1543 Finally, a function which parses @file{~/.netrc} like files.
1546 If you want to keep your own data in a file, with your own structure,
1547 you might provide such a function as well. This function must meet
1548 the following conventions:
1550 @defun my-tramp-parse file
1551 @var{file} must be either a file name on your host, or @code{nil}.
1552 The function must return a list of (@var{user} @var{host}), which are
1553 taken as candidates for user and host name completion.
1557 (my-tramp-parse "~/.my-tramp-hosts")
1559 @result{} ((nil "toto") ("daniel" "melancholia"))
1564 @node Password handling
1565 @section Reusing passwords for several connections.
1568 Sometimes it is necessary to connect to the same remote host several
1569 times. Reentering passwords again and again would be annoying, when
1570 the chosen method does not support access without password prompt
1571 through own configuration.
1573 The best recommendation is to use the method's own mechanism for
1574 password handling. Consider @command{ssh-agent} for @option{ssh}-like
1575 methods, or @command{pageant} for @option{plink}-like methods.
1577 However, if you cannot apply such native password handling,
1578 @value{tramp} offers altenatives.
1581 @anchor{Using an authentication file}
1582 @subsection Using an authentication file
1584 @vindex auth-sources
1585 The package @file{auth-source.el}, originally developed in No Gnus,
1586 offers the possibility to read passwords from a file, like FTP does it
1587 from @file{~/.netrc}. The default authentication file is
1588 @file{~/.authinfo.gpg}, this can be changed via the variable
1589 @code{auth-sources}.
1592 A typical entry in the authentication file would be
1595 machine melancholia port scp login daniel password geheim
1598 The port can be any @value{tramp} method (@pxref{Inline methods},
1599 @pxref{External methods}), to match only this method. When you omit
1600 the port, you match all @value{tramp} methods.
1602 @anchor{Caching passwords}
1603 @subsection Caching passwords
1605 If there is no authentication file, @value{tramp} caches the passwords
1606 entered by you. They will be reused next time if a connection needs
1607 them for the same user name and host name, independently of the
1610 @vindex password-cache-expiry
1611 Passwords are not saved permanently, that means the password caching
1612 is limited to the lifetime of your @value{emacsname} session. You
1613 can influence the lifetime of password caching by customizing the
1614 variable @code{password-cache-expiry}. The value is the number of
1615 seconds how long passwords are cached. Setting it to @code{nil}
1616 disables the expiration.
1618 @vindex password-cache
1619 If you don't like this feature for security reasons, password caching
1620 can be disabled totally by customizing the variable
1621 @code{password-cache} (setting it to @code{nil}).
1623 Implementation Note: password caching is based on the package
1624 @file{password-cache.el}. For the time being, it is activated only
1625 when this package is seen in the @code{load-path} while loading
1627 @ifset installchapter
1628 If you don't use No Gnus, you can take @file{password.el} from the
1629 @value{tramp} @file{contrib} directory, see @ref{Installation
1634 @node Connection caching
1635 @section Reusing connection related information.
1638 @vindex tramp-persistency-file-name
1639 In order to reduce initial connection time, @value{tramp} stores
1640 connection related information persistently. The variable
1641 @code{tramp-persistency-file-name} keeps the file name where these
1642 information are written. Its default value is
1644 @file{~/.emacs.d/tramp}.
1647 @file{~/.xemacs/tramp}.
1649 It is recommended to choose a local file name.
1651 @value{tramp} reads this file during startup, and writes it when
1652 exiting @value{emacsname}. You can simply remove this file if
1653 @value{tramp} shall be urged to recompute these information next
1654 @value{emacsname} startup time.
1656 Using such persistent information can be disabled by setting
1657 @code{tramp-persistency-file-name} to @code{nil}.
1659 Once consequence of reusing connection related information is that
1660 @var{tramp} needs to distinguish hosts. If you, for example, run a
1661 local @code{sshd} on port 3001, which tunnels @command{ssh} to another
1662 host, you could access both @file{@trampfn{ssh, , localhost,}} and
1663 @file{@trampfn{ssh, , localhost#3001,}}. @var{tramp} would use the
1664 same host related information (like paths, Perl variants, etc) for
1665 both connections, although the information is valid only for one of
1668 In order to avoid trouble, you must use another host name for one of
1669 the connections, like introducing a @option{Host} section in
1670 @file{~/.ssh/config} (@pxref{Frequently Asked Questions}) or applying
1671 multiple hops (@pxref{Multi-hops}).
1673 When @value{tramp} detects a changed operating system version on a
1674 remote host (via the command @command{uname -sr}), it flushes all
1675 connection related information for this host, and opens the
1679 @node Remote Programs
1680 @section How @value{tramp} finds and uses programs on the remote machine.
1682 @value{tramp} depends on a number of programs on the remote host in order to
1683 function, including @command{ls}, @command{test}, @command{find} and
1686 In addition to these required tools, there are various tools that may be
1687 required based on the connection method. See @ref{Inline methods} and
1688 @ref{External methods} for details on these.
1690 Certain other tools, such as @command{perl} (or @command{perl5}) and
1691 @command{grep} will be used if they can be found. When they are
1692 available, they are used to improve the performance and accuracy of
1695 @vindex tramp-remote-path
1696 @vindex tramp-default-remote-path
1697 @vindex tramp-own-remote-path
1698 @defopt tramp-remote-path
1699 When @value{tramp} connects to the remote machine, it searches for the
1700 programs that it can use. The variable @code{tramp-remote-path}
1701 controls the directories searched on the remote machine.
1703 By default, this is set to a reasonable set of defaults for most
1704 machines. The symbol @code{tramp-default-remote-path} is a place
1705 holder, it is replaced by the list of directories received via the
1706 command @command{getconf PATH} on your remote machine. For example,
1707 on GNU Debian this is @file{/bin:/usr/bin}, whereas on Solaris this is
1708 @file{/usr/xpg4/bin:/usr/ccs/bin:/usr/bin:/opt/SUNWspro/bin}. It is
1709 recommended to apply this symbol on top of @code{tramp-remote-path}.
1711 It is possible, however, that your local (or remote ;) system
1712 administrator has put the tools you want in some obscure local
1715 In this case, you can still use them with @value{tramp}. You simply
1716 need to add code to your @file{.emacs} to add the directory to the
1717 remote path. This will then be searched by @value{tramp} when you
1718 connect and the software found.
1720 To add a directory to the remote search path, you could use code such
1724 @i{;; We load @value{tramp} to define the variable.}
1726 @i{;; We have @command{perl} in "/usr/local/perl/bin"}
1727 (add-to-list 'tramp-remote-path "/usr/local/perl/bin")
1730 Another possibility is to reuse the path settings of your remote
1731 account when you log in. Usually, these settings are overwritten,
1732 because they might not be useful for @value{tramp}. The place holder
1733 @code{tramp-own-remote-path} preserves these settings. You can
1737 (add-to-list 'tramp-remote-path 'tramp-own-remote-path)
1741 @value{tramp} caches several information, like the Perl binary
1742 location. The changed remote search path wouldn't affect these
1743 settings. In order to force @value{tramp} to recompute these values,
1744 you must exit @value{emacsname}, remove your persistency file
1745 (@pxref{Connection caching}), and restart @value{emacsname}.
1748 @node Remote shell setup
1749 @section Remote shell setup hints
1750 @cindex remote shell setup
1751 @cindex @file{.profile} file
1752 @cindex @file{.login} file
1753 @cindex shell init files
1755 As explained in the @ref{Overview} section, @value{tramp} connects to the
1756 remote host and talks to the shell it finds there. Of course, when you
1757 log in, the shell executes its init files. Suppose your init file
1758 requires you to enter the birth date of your mother; clearly @value{tramp}
1759 does not know this and hence fails to log you in to that host.
1761 There are different possible strategies for pursuing this problem. One
1762 strategy is to enable @value{tramp} to deal with all possible situations.
1763 This is a losing battle, since it is not possible to deal with
1764 @emph{all} situations. The other strategy is to require you to set up
1765 the remote host such that it behaves like @value{tramp} expects. This might
1766 be inconvenient because you have to invest a lot of effort into shell
1767 setup before you can begin to use @value{tramp}.
1769 The package, therefore, pursues a combined approach. It tries to
1770 figure out some of the more common setups, and only requires you to
1771 avoid really exotic stuff. For example, it looks through a list of
1772 directories to find some programs on the remote host. And also, it
1773 knows that it is not obvious how to check whether a file exists, and
1774 therefore it tries different possibilities. (On some hosts and
1775 shells, the command @command{test -e} does the trick, on some hosts
1776 the shell builtin doesn't work but the program @command{/usr/bin/test
1777 -e} or @command{/bin/test -e} works. And on still other hosts,
1778 @command{ls -d} is the right way to do this.)
1780 Below you find a discussion of a few things that @value{tramp} does not deal
1781 with, and that you therefore have to set up correctly.
1784 @item @var{shell-prompt-pattern}
1785 @vindex shell-prompt-pattern
1787 After logging in to the remote host, @value{tramp} has to wait for the remote
1788 shell startup to finish before it can send commands to the remote
1789 shell. The strategy here is to wait for the shell prompt. In order to
1790 recognize the shell prompt, the variable @code{shell-prompt-pattern} has
1791 to be set correctly to recognize the shell prompt on the remote host.
1793 Note that @value{tramp} requires the match for @code{shell-prompt-pattern}
1794 to be at the end of the buffer. Many people have something like the
1795 following as the value for the variable: @code{"^[^>$][>$] *"}. Now
1796 suppose your shell prompt is @code{a <b> c $ }. In this case,
1797 @value{tramp} recognizes the @code{>} character as the end of the prompt,
1798 but it is not at the end of the buffer.
1800 @item @var{tramp-shell-prompt-pattern}
1801 @vindex tramp-shell-prompt-pattern
1803 This regular expression is used by @value{tramp} in the same way as
1804 @code{shell-prompt-pattern}, to match prompts from the remote shell.
1805 This second variable exists because the prompt from the remote shell
1806 might be different from the prompt from a local shell --- after all,
1807 the whole point of @value{tramp} is to log in to remote hosts as a
1808 different user. The default value of
1809 @code{tramp-shell-prompt-pattern} is the same as the default value of
1810 @code{shell-prompt-pattern}, which is reported to work well in many
1813 @item @var{tramp-password-prompt-regexp}
1814 @vindex tramp-password-prompt-regexp
1815 @vindex tramp-wrong-passwd-regexp
1817 During login, @value{tramp} might be forced to enter a password or a
1818 passphrase. The difference between both is that a password is
1819 requested from the shell on the remote host, while a passphrase is
1820 needed for accessing local authentication information, like your ssh
1823 @var{tramp-password-prompt-regexp} handles the detection of such
1824 requests for English environments. When you use another localization
1825 of your (local or remote) host, you might need to adapt this. Example:
1829 tramp-password-prompt-regexp
1833 '("passphrase" "Passphrase"
1835 "password" "Password"
1837 "passwort" "Passwort"
1839 "mot de passe" "Mot de passe") t)
1843 In parallel, it might also be necessary to adapt
1844 @var{tramp-wrong-passwd-regexp}.
1846 @item @command{tset} and other questions
1847 @cindex Unix command tset
1848 @cindex tset Unix command
1850 Some people invoke the @command{tset} program from their shell startup
1851 scripts which asks the user about the terminal type of the shell.
1852 Maybe some shells ask other questions when they are started.
1853 @value{tramp} does not know how to answer these questions. There are
1854 two approaches for dealing with this problem. One approach is to take
1855 care that the shell does not ask any questions when invoked from
1856 @value{tramp}. You can do this by checking the @code{TERM}
1857 environment variable, it will be set to @code{dumb} when connecting.
1859 @vindex tramp-terminal-type
1860 The variable @code{tramp-terminal-type} can be used to change this value
1863 @vindex tramp-actions-before-shell
1864 The other approach is to teach @value{tramp} about these questions. See
1865 the variable @code{tramp-actions-before-shell}. Example:
1868 (defconst my-tramp-prompt-regexp
1869 (concat (regexp-opt '("Enter the birth date of your mother:") t)
1871 "Regular expression matching my login prompt question.")
1873 (defun my-tramp-action (proc vec)
1874 "Enter \"19000101\" in order to give a correct answer."
1875 (save-window-excursion
1876 (with-current-buffer (tramp-get-connection-buffer vec)
1877 (tramp-message vec 6 "\n%s" (buffer-string))
1878 (tramp-send-string vec "19000101"))))
1880 (add-to-list 'tramp-actions-before-shell
1881 '(my-tramp-prompt-regexp my-tramp-action))
1885 @item Environment variables named like users in @file{.profile}
1887 If you have a user named frumple and set the variable @code{FRUMPLE} in
1888 your shell environment, then this might cause trouble. Maybe rename
1889 the variable to @code{FRUMPLE_DIR} or the like.
1891 This weird effect was actually reported by a @value{tramp} user!
1894 @item Non-Bourne commands in @file{.profile}
1896 After logging in to the remote host, @value{tramp} issues the command
1897 @command{exec /bin/sh}. (Actually, the command is slightly
1898 different.) When @command{/bin/sh} is executed, it reads some init
1899 files, such as @file{~/.shrc} or @file{~/.profile}.
1901 Now, some people have a login shell which is not @code{/bin/sh} but a
1902 Bourne-ish shell such as bash or ksh. Some of these people might put
1903 their shell setup into the files @file{~/.shrc} or @file{~/.profile}.
1904 This way, it is possible for non-Bourne constructs to end up in those
1905 files. Then, @command{exec /bin/sh} might cause the Bourne shell to
1906 barf on those constructs.
1908 As an example, imagine somebody putting @command{export FOO=bar} into
1909 the file @file{~/.profile}. The standard Bourne shell does not
1910 understand this syntax and will emit a syntax error when it reaches
1913 Another example is the tilde (@code{~}) character, say when adding
1914 @file{~/bin} to @code{PATH}. Many Bourne shells will not expand this
1915 character, and since there is usually no directory whose name consists
1916 of the single character tilde, strange things will happen.
1918 What can you do about this?
1920 Well, one possibility is to make sure that everything in
1921 @file{~/.shrc} and @file{~/.profile} on all remote hosts is
1922 Bourne-compatible. In the above example, instead of @command{export
1923 FOO=bar}, you might use @command{FOO=bar; export FOO} instead.
1925 The other possibility is to put your non-Bourne shell setup into some
1926 other files. For example, bash reads the file @file{~/.bash_profile}
1927 instead of @file{~/.profile}, if the former exists. So bash
1928 aficionados just rename their @file{~/.profile} to
1929 @file{~/.bash_profile} on all remote hosts, and Bob's your uncle.
1931 The @value{tramp} developers would like to circumvent this problem, so
1932 if you have an idea about it, please tell us. However, we are afraid
1933 it is not that simple: before saying @command{exec /bin/sh},
1934 @value{tramp} does not know which kind of shell it might be talking
1935 to. It could be a Bourne-ish shell like ksh or bash, or it could be a
1936 csh derivative like tcsh, or it could be zsh, or even rc. If the
1937 shell is Bourne-ish already, then it might be prudent to omit the
1938 @command{exec /bin/sh} step. But how to find out if the shell is
1942 @item Interactive shell prompt
1944 @value{tramp} redefines the shell prompt in order to parse the shell's
1945 output robustly. When calling an interactive shell by @kbd{M-x
1946 shell}, this doesn't look nice.
1948 You can redefine the shell prompt by checking the environment variable
1949 @code{INSIDE_EMACS}, which is set by @value{tramp}, in your startup
1950 script @file{~/.emacs_SHELLNAME}. @code{SHELLNAME} might be the string
1951 @code{bash} or similar, in case of doubt you could set it the
1952 environment variable @code{ESHELL} in your @file{.emacs}:
1955 (setenv "ESHELL" "bash")
1958 Your file @file{~/.emacs_SHELLNAME} could contain code like
1961 # Reset the prompt for remote Tramp shells.
1962 if [ "$@{INSIDE_EMACS/*tramp*/tramp@}" == "tramp" ] ; then
1969 @xref{Interactive Shell, , , @value{emacsdir}}.
1976 @node Auto-save and Backup
1977 @section Auto-save and Backup configuration
1981 @vindex backup-directory-alist
1984 @vindex bkup-backup-directory-info
1987 Normally, @value{emacsname} writes backup files to the same directory
1988 as the original files, but this behavior can be changed via the
1991 @code{backup-directory-alist}.
1994 @code{bkup-backup-directory-info}.
1996 In connection with @value{tramp}, this can have unexpected side
1997 effects. Suppose that you specify that all backups should go to the
1998 directory @file{~/.emacs.d/backups/}, and then you edit the file
1999 @file{@trampfn{su, root, localhost, /etc/secretfile}}. The effect is
2000 that the backup file will be owned by you and not by root, thus
2001 possibly enabling others to see it even if they were not intended to
2006 @code{backup-directory-alist}
2009 @code{bkup-backup-directory-info}
2011 is @code{nil} (the default), such problems do not occur.
2013 Therefore, it is useful to set special values for @value{tramp}
2014 files. For example, the following statement effectively `turns off'
2017 @code{backup-directory-alist}
2020 @code{bkup-backup-directory-info}
2022 for @value{tramp} files:
2026 (add-to-list 'backup-directory-alist
2027 (cons tramp-file-name-regexp nil))
2032 (require 'backup-dir)
2033 (add-to-list 'bkup-backup-directory-info
2034 (list tramp-file-name-regexp ""))
2039 It is also possible to disable backups depending on the used method.
2040 The following code disables backups for the @option{su} and
2041 @option{sudo} methods:
2044 (setq backup-enable-predicate
2046 (and (normal-backup-enable-predicate name)
2048 (let ((method (file-remote-p name 'method)))
2049 (when (stringp method)
2050 (member method '("su" "sudo"))))))))
2055 Another possibility is to use the @value{tramp} variable
2057 @code{tramp-backup-directory-alist}.
2060 @code{tramp-bkup-backup-directory-info}.
2062 This variable has the same meaning like
2064 @code{backup-directory-alist}.
2067 @code{bkup-backup-directory-info}.
2069 If a @value{tramp} file is backed up, and DIRECTORY is an absolute
2070 local file name, DIRECTORY is prepended with the @value{tramp} file
2071 name prefix of the file to be backed up.
2078 (add-to-list 'backup-directory-alist
2079 (cons "." "~/.emacs.d/backups/"))
2080 (setq tramp-backup-directory-alist backup-directory-alist)
2085 (require 'backup-dir)
2086 (add-to-list 'bkup-backup-directory-info
2087 (list "." "~/.emacs.d/backups/" 'full-path))
2088 (setq tramp-bkup-backup-directory-info bkup-backup-directory-info)
2093 The backup file name of @file{@trampfn{su, root, localhost,
2094 /etc/secretfile}} would be
2096 @file{@trampfn{su, root, localhost,
2097 ~/.emacs.d/backups/!su:root@@localhost:!etc!secretfile~}}
2100 @file{@trampfn{su, root, localhost,
2101 ~/.emacs.d/backups/![su!root@@localhost]!etc!secretfile~}}
2104 The same problem can happen with auto-saving files.
2106 The variable @code{auto-save-file-name-transforms} keeps information,
2107 on which directory an auto-saved file should go. By default, it is
2108 initialized for @value{tramp} files to the local temporary directory.
2110 On some versions of @value{emacsname}, namely the version built for
2111 Debian GNU/Linux, the variable @code{auto-save-file-name-transforms}
2112 contains the directory where @value{emacsname} was built. A
2113 workaround is to manually set the variable to a sane value.
2115 If auto-saved files should go into the same directory as the original
2116 files, @code{auto-save-file-name-transforms} should be set to @code{nil}.
2118 Another possibility is to set the variable
2119 @code{tramp-auto-save-directory} to a proper value.
2122 For this purpose you can set the variable @code{auto-save-directory}
2127 @node Windows setup hints
2128 @section Issues with Cygwin ssh
2129 @cindex Cygwin, issues
2131 This section needs a lot of work! Please help.
2133 @cindex method sshx with Cygwin
2134 @cindex sshx method with Cygwin
2135 The recent Cygwin installation of @command{ssh} works only with a
2136 Cygwinized @value{emacsname}. You can check it by typing @kbd{M-x
2137 eshell}, and starting @kbd{ssh test.machine}. The problem is evident
2138 if you see a message like this:
2141 Pseudo-terminal will not be allocated because stdin is not a terminal.
2144 Older @command{ssh} versions of Cygwin are told to cooperate with
2145 @value{tramp} selecting @option{sshx} as the connection method. You
2146 can find information about setting up Cygwin in their FAQ at
2147 @uref{http://cygwin.com/faq/}.
2149 @cindex method scpx with Cygwin
2150 @cindex scpx method with Cygwin
2151 If you wish to use the @option{scpx} connection method, then you might
2152 have the problem that @value{emacsname} calls @command{scp} with a
2153 Windows filename such as @code{c:/foo}. The Cygwin version of
2154 @command{scp} does not know about Windows filenames and interprets
2155 this as a remote filename on the host @code{c}.
2157 One possible workaround is to write a wrapper script for @option{scp}
2158 which converts the Windows filename to a Cygwinized filename.
2160 @cindex Cygwin and ssh-agent
2161 @cindex SSH_AUTH_SOCK and @value{emacsname} on Windows
2162 If you want to use either @option{ssh} based method on Windows, then
2163 you might encounter problems with @command{ssh-agent}. Using this
2164 program, you can avoid typing the pass-phrase every time you log in.
2165 However, if you start @value{emacsname} from a desktop shortcut, then
2166 the environment variable @code{SSH_AUTH_SOCK} is not set and so
2167 @value{emacsname} and thus @value{tramp} and thus @command{ssh} and
2168 @command{scp} started from @value{tramp} cannot communicate with
2169 @command{ssh-agent}. It works better to start @value{emacsname} from
2172 If anyone knows how to start @command{ssh-agent} under Windows in such a
2173 way that desktop shortcuts can profit, please holler. I don't really
2174 know anything at all about Windows@dots{}
2178 @chapter Using @value{tramp}
2179 @cindex using @value{tramp}
2181 Once you have installed @value{tramp} it will operate fairly
2182 transparently. You will be able to access files on any remote machine
2183 that you can log in to as though they were local.
2185 Files are specified to @value{tramp} using a formalized syntax specifying the
2186 details of the system to connect to. This is similar to the syntax used
2187 by the @value{ftppackagename} package.
2190 Something that might happen which surprises you is that
2191 @value{emacsname} remembers all your keystrokes, so if you see a
2192 password prompt from @value{emacsname}, say, and hit @kbd{@key{RET}}
2193 twice instead of once, then the second keystroke will be processed by
2194 @value{emacsname} after @value{tramp} has done its thing. Why, this
2195 type-ahead is normal behavior, you say. Right you are, but be aware
2196 that opening a remote file might take quite a while, maybe half a
2197 minute when a connection needs to be opened. Maybe after half a
2198 minute you have already forgotten that you hit that key!
2201 * Filename Syntax:: @value{tramp} filename conventions.
2202 * Alternative Syntax:: URL-like filename syntax.
2203 * Filename completion:: Filename completion.
2204 * Remote processes:: Integration with other @value{emacsname} packages.
2205 * Cleanup remote connections:: Cleanup remote connections.
2209 @node Filename Syntax
2210 @section @value{tramp} filename conventions
2211 @cindex filename syntax
2212 @cindex filename examples
2214 To access the file @var{localname} on the remote machine @var{machine}
2215 you would specify the filename @file{@trampfn{, , machine,
2216 localname}}. This will connect to @var{machine} and transfer the file
2217 using the default method. @xref{Default Method}.
2219 Some examples of @value{tramp} filenames are shown below.
2222 @item @trampfn{, , melancholia, .emacs}
2223 Edit the file @file{.emacs} in your home directory on the machine
2226 @item @trampfn{, , melancholia.danann.net, .emacs}
2227 This edits the same file, using the fully qualified domain name of
2230 @item @trampfn{, , melancholia, ~/.emacs}
2231 This also edits the same file --- the @file{~} is expanded to your
2232 home directory on the remote machine, just like it is locally.
2234 @item @trampfn{, , melancholia, ~daniel/.emacs}
2235 This edits the file @file{.emacs} in the home directory of the user
2236 @code{daniel} on the machine @code{melancholia}. The @file{~<user>}
2237 construct is expanded to the home directory of that user on the remote
2240 @item @trampfn{, , melancholia, /etc/squid.conf}
2241 This edits the file @file{/etc/squid.conf} on the machine
2246 @var{machine} can also be an IPv4 or IPv6 address, like in
2247 @file{@trampfn{, , 127.0.0.1, .emacs}} or @file{@trampfn{, ,
2248 @value{ipv6prefix}::1@value{ipv6postfix}, .emacs}}.
2250 For syntactical reasons, IPv6 addresses must be embedded in square
2251 brackets @file{@value{ipv6prefix}} and @file{@value{ipv6postfix}}.
2254 Unless you specify a different name to use, @value{tramp} will use the
2255 current local user name as the remote user name to log in with. If you
2256 need to log in as a different user, you can specify the user name as
2257 part of the filename.
2259 To log in to the remote machine as a specific user, you use the syntax
2260 @file{@trampfn{, user, machine, path/to.file}}. That means that
2261 connecting to @code{melancholia} as @code{daniel} and editing
2262 @file{.emacs} in your home directory you would specify
2263 @file{@trampfn{, daniel, melancholia, .emacs}}.
2265 It is also possible to specify other file transfer methods
2266 (@pxref{Inline methods}, @pxref{External methods}) as part of the
2269 This is done by putting the method before the user and host name, as
2270 in @file{@value{prefix}@var{method}@value{postfixhop}} (Note the
2274 This is done by replacing the initial @file{@value{prefix}} with
2275 @file{@value{prefix}<method>@value{postfixhop}}. (Note the trailing
2278 The user, machine and file specification remain the same.
2280 So, to connect to the machine @code{melancholia} as @code{daniel},
2281 using the @option{ssh} method to transfer files, and edit
2282 @file{.emacs} in my home directory I would specify the filename
2283 @file{@trampfn{ssh, daniel, melancholia, .emacs}}.
2285 Finally, for some methods it is possible to specify a different port
2286 number than the default one, given by the method. This is specified
2287 by adding @file{#<port>} to the host name, like in @file{@trampfn{ssh,
2288 daniel, melancholia#42, .emacs}}.
2291 @node Alternative Syntax
2292 @section URL-like filename syntax
2293 @cindex filename syntax
2294 @cindex filename examples
2296 Additionally to the syntax described in the previous chapter, it is
2297 possible to use a URL-like syntax for @value{tramp}. This can be
2298 switched on by customizing the variable @code{tramp-syntax}. Please
2299 note that this feature is experimental for the time being.
2301 The variable @code{tramp-syntax} must be set before requiring @value{tramp}:
2304 (setq tramp-syntax 'url)
2308 Then, a @value{tramp} filename would look like this:
2309 @file{/@var{method}://@var{user}@@@var{machine}:@var{port}/@var{path/to.file}}.
2310 @file{/@var{method}://} is mandatory, all other parts are optional.
2311 @file{:@var{port}} is useful for methods only who support this.
2313 The last example from the previous section would look like this:
2314 @file{/ssh://daniel@@melancholia/.emacs}.
2316 For the time being, @code{tramp-syntax} can have the following values:
2320 @item @code{ftp} -- That is the default syntax
2321 @item @code{url} -- URL-like syntax
2324 @item @code{sep} -- That is the default syntax
2325 @item @code{url} -- URL-like syntax
2326 @item @code{ftp} -- EFS-like syntax
2331 @node Filename completion
2332 @section Filename completion
2333 @cindex filename completion
2335 Filename completion works with @value{tramp} for completion of method
2336 names, of user names and of machine names as well as for completion of
2337 file names on remote machines.
2339 In order to enable this, partial completion must be activated in your
2342 @xref{Completion Options, , , @value{emacsdir}}.
2346 If you, for example, type @kbd{C-x C-f @value{prefix}t
2347 @key{TAB}}, @value{tramp} might give you as result the choice for
2350 @multitable {@trampfn{telnet, , melancholia.danann.net,}} {@trampfn{telnet, , 192.168.0.1,}}
2352 @item @value{prefixhop}telnet@value{postfixhop} @tab tmp/
2353 @item @value{prefixhop}toto@value{postfix} @tab
2356 @item @value{prefixhop}telnet@value{postfixhop} @tab @value{prefixhop}toto@value{postfix}
2361 @samp{@value{prefixhop}telnet@value{postfixhop}}
2362 is a possible completion for the respective method,
2364 @samp{tmp/} stands for the directory @file{/tmp} on your local
2367 and @samp{@value{prefixhop}toto@value{postfix}}
2368 might be a host @value{tramp} has detected in your @file{~/.ssh/known_hosts}
2369 file (given you're using default method @option{ssh}).
2371 If you go on to type @kbd{e @key{TAB}}, the minibuffer is completed to
2372 @samp{@value{prefix}telnet@value{postfixhop}}.
2373 Next @kbd{@key{TAB}} brings you all machine names @value{tramp} detects in
2374 your @file{/etc/hosts} file, let's say
2377 @multitable {@trampfn{telnet, , melancholia.danann.net,}} {@trampfn{telnet, , 192.168.0.1,}}
2378 @item @trampfn{telnet, , 127.0.0.1,} @tab @trampfn{telnet, , 192.168.0.1,}
2379 @item @trampfn{telnet, , @value{ipv6prefix}::1@value{ipv6postfix},} @tab @trampfn{telnet, , localhost,}
2380 @item @trampfn{telnet, , melancholia.danann.net,} @tab @trampfn{telnet, , melancholia,}
2384 Now you can choose the desired machine, and you can continue to
2385 complete file names on that machine.
2387 If the configuration files (@pxref{Customizing Completion}), which
2388 @value{tramp} uses for analysis of completion, offer user names, those user
2389 names will be taken into account as well.
2391 Remote machines which have been visited in the past and kept
2392 persistently (@pxref{Connection caching}) will be offered too.
2394 Once the remote machine identification is completed, it comes to
2395 filename completion on the remote host. This works pretty much like
2396 for files on the local host, with the exception that minibuffer
2397 killing via a double-slash works only on the filename part, except
2398 that filename part starts with @file{//}.
2400 A triple-slash stands for the default behavior.
2403 @xref{Minibuffer File, , , @value{emacsdir}}.
2411 @kbd{C-x C-f @trampfn{telnet, , melancholia, /usr/local/bin//etc} @key{TAB}}
2412 @print{} @trampfn{telnet, , melancholia, /etc}
2414 @kbd{C-x C-f @trampfn{telnet, , melancholia, //etc} @key{TAB}}
2417 @kbd{C-x C-f @trampfn{telnet, , melancholia, /usr/local/bin///etc} @key{TAB}}
2422 @kbd{C-x C-f @trampfn{telnet, , melancholia, /usr/local/bin//}}
2423 @print{} @trampfn{telnet, , melancholia, /}
2425 @kbd{C-x C-f @trampfn{telnet, , melancholia, //}}
2430 A remote directory might have changed its contents out of
2431 @value{emacsname} control, for example by creation or deletion of
2432 files by other processes. Therefore, during filename completion, the
2433 remote directory contents are reread regularly in order to detect such
2434 changes, which would be invisible otherwise (@pxref{Connection caching}).
2436 @defopt tramp-completion-reread-directory-timeout
2437 This variable defines the number of seconds since last remote command
2438 before rereading a directory contents. A value of 0 would require an
2439 immediate reread during filename completion, @code{nil} means to use
2440 always cached values for the directory contents.
2444 @node Remote processes
2445 @section Integration with other @value{emacsname} packages.
2449 @value{tramp} supports running processes on a remote host. This
2450 allows to exploit @value{emacsname} packages without modification for
2451 remote file names. It does not work for the @option{ftp} and
2452 @option{smb} methods. Association of a pty, as specified in
2453 @code{start-file-process}, is not supported.
2455 @code{process-file} and @code{start-file-process} work on the remote
2456 host when the variable @code{default-directory} is remote:
2459 (let ((default-directory "/ssh:remote.host:"))
2460 (start-file-process "grep" (get-buffer-create "*grep*")
2461 "/bin/sh" "-c" "grep -e tramp *"))
2465 If the remote host is mounted via GVFS (see @ref{GVFS based methods}),
2466 the remote filesystem is mounted locally. Therefore, there are no
2467 remote processes; all processes run still locally on your machine with
2468 an adapted @code{default-directory}. This section does not apply for
2469 such connection methods.
2472 Remote processes are started when a corresponding command is executed
2473 from a buffer belonging to a remote file or directory. Up to now, the
2474 packages @file{compile.el} (commands like @code{compile} and
2475 @code{grep}) and @file{gud.el} (@code{gdb} or @code{perldb}) have been
2476 integrated. Integration of further packages is planned, any help for
2479 When your program is not found in the default search path
2480 @value{tramp} sets on the remote machine, you should either use an
2481 absolute path, or extend @code{tramp-remote-path} (see @ref{Remote
2485 (add-to-list 'tramp-remote-path "~/bin")
2486 (add-to-list 'tramp-remote-path "/appli/pub/bin")
2489 The environment for your program can be adapted by customizing
2490 @code{tramp-remote-process-environment}. This variable is a list of
2491 strings. It is structured like @code{process-environment}. Each
2492 element is a string of the form ENVVARNAME=VALUE. An entry
2493 ENVVARNAME= disables the corresponding environment variable, which
2494 might have been set in your init file like @file{~/.profile}.
2497 Adding an entry can be performed via @code{add-to-list}:
2500 (add-to-list 'tramp-remote-process-environment "JAVA_HOME=/opt/java")
2503 Changing or removing an existing entry is not encouraged. The default
2504 values are chosen for proper @value{tramp} work. Nevertheless, if for
2505 example a paranoid system administrator disallows changing the
2506 @code{HISTORY} environment variable, you can customize
2507 @code{tramp-remote-process-environment}, or you can apply the
2508 following code in your @file{.emacs}:
2511 (let ((process-environment tramp-remote-process-environment))
2512 (setenv "HISTORY" nil)
2513 (setq tramp-remote-process-environment process-environment))
2516 If you use other @value{emacsname} packages which do not run
2517 out-of-the-box on a remote host, please let us know. We will try to
2518 integrate them as well. @xref{Bug Reports}.
2521 @subsection Running remote programs that create local X11 windows
2523 If you want to run a remote program, which shall connect the X11
2524 server you are using with your local host, you can set the
2525 @code{DISPLAY} environment variable on the remote host:
2528 (add-to-list 'tramp-remote-process-environment
2529 (format "DISPLAY=%s" (getenv "DISPLAY")))
2533 @code{(getenv "DISPLAY")} shall return a string containing a host
2534 name, which can be interpreted on the remote host; otherwise you might
2535 use a fixed host name. Strings like @code{:0} cannot be used properly
2538 Another trick might be that you put @code{ForwardX11 yes} or
2539 @code{ForwardX11Trusted yes} to your @file{~/.ssh/config} file for
2543 @subsection Running shell-command on a remote host
2544 @cindex shell-command
2546 @code{shell-command} allows to execute commands in a shell, either
2547 synchronously, either asynchronously. This works also on remote
2551 @kbd{C-x C-f @trampfn{sudo, , , } @key{RET}}
2552 @kbd{M-! tail -f /var/log/syslog.log & @key{RET}}
2555 You will see the buffer @file{*Async Shell Command*}, containing the
2556 continuous output of the @command{tail} command.
2559 @subsection Running eshell on a remote host
2562 @value{tramp} is integrated into @file{eshell.el}. That is, you can
2563 open an interactive shell on your remote host, and run commands there.
2564 After you have started @code{eshell}, you could perform commands like
2568 @b{~ $} cd @trampfn{sudo, , , /etc} @key{RET}
2569 @b{@trampfn{sudo, root, host, /etc} $} hostname @key{RET}
2571 @b{@trampfn{sudo, root, host, /etc} $} id @key{RET}
2572 uid=0(root) gid=0(root) groups=0(root)
2573 @b{@trampfn{sudo, root, host, /etc} $} find-file shadow @key{RET}
2575 @b{@trampfn{sudo, root, host, /etc} $}
2579 Since @value{emacsname} 23.2, @code{eshell} has also an own
2580 implementation of the @code{su} and @code{sudo} commands. Both
2581 commands change the default directory of the @file{*eshell*} buffer to
2582 the value related to the user the command has switched to. This works
2583 even on remote hosts, adding silently a corresponding entry to the
2584 variable @code{tramp-default-proxies-alist} (@pxref{Multi-hops}):
2587 @b{~ $} cd @trampfn{ssh, user, remotehost, /etc} @key{RET}
2588 @b{@trampfn{ssh, user, remotehost, /etc} $} find-file shadow @key{RET}
2589 File is not readable: @trampfn{ssh, user, remotehost, /etc/shadow}
2590 @b{@trampfn{ssh, user, remotehost, /etc} $} sudo find-file shadow @key{RET}
2593 @b{@trampfn{ssh, user, remotehost, /etc} $} su - @key{RET}
2594 @b{@trampfn{su, root, remotehost, /root} $} id @key{RET}
2595 uid=0(root) gid=0(root) groups=0(root)
2596 @b{@trampfn{su, root, remotehost, /root} $}
2601 @anchor{Running a debugger on a remote host}
2602 @subsection Running a debugger on a remote host
2607 @file{gud.el} offers an unified interface to several symbolic
2611 (@ref{Debuggers, , , @value{emacsdir}}).
2614 With @value{tramp}, it is possible to debug programs on
2615 remote hosts. You can call @code{gdb} with a remote file name:
2618 @kbd{M-x gdb @key{RET}}
2619 @b{Run gdb (like this):} gdb --annotate=3 @trampfn{ssh, , host, ~/myprog} @key{RET}
2622 The file name can also be relative to a remote default directory.
2623 Given you are in a buffer that belongs to the remote directory
2624 @trampfn{ssh, , host, /home/user}, you could call
2627 @kbd{M-x perldb @key{RET}}
2628 @b{Run perldb (like this):} perl -d myprog.pl @key{RET}
2631 It is not possible to use just the absolute local part of a remote
2632 file name as program to debug, like @kbd{perl -d
2633 /home/user/myprog.pl}, though.
2635 Arguments of the program to be debugged are taken literally. That
2636 means, file names as arguments must be given as ordinary relative or
2637 absolute file names, without any remote specification.
2640 @node Cleanup remote connections
2641 @section Cleanup remote connections.
2644 Sometimes it is useful to cleanup remote connections. The following
2645 commands support this.
2647 @deffn Command tramp-cleanup-connection vec
2648 This command flushes all connection related objects. @option{vec} is
2649 the internal representation of a remote connection. Called
2650 interactively, the command offers all active remote connections in the
2651 minibuffer as remote file name prefix like @file{@trampfn{method,
2652 user, host, }}. The cleanup includes password cache (@pxref{Password
2653 handling}), file cache, connection cache (@pxref{Connection caching}),
2657 @deffn Command tramp-cleanup-all-connections
2658 This command flushes objects for all active remote connections. The
2659 same objects are removed as in @code{tramp-cleanup-connection}.
2662 @deffn Command tramp-cleanup-all-buffers
2663 Like in @code{tramp-cleanup-all-connections}, all remote connections
2664 are cleaned up. Additionally all buffers, which are related to a
2665 remote connection, are killed.
2670 @chapter Reporting Bugs and Problems
2673 Bugs and problems with @value{tramp} are actively worked on by the
2674 development team. Feature requests and suggestions are also more than
2677 The @value{tramp} mailing list is a great place to get information on
2678 working with @value{tramp}, solving problems and general discussion
2679 and advice on topics relating to the package. It is moderated so
2680 non-subscribers can post but messages will be delayed, possibly up to
2681 48 hours (or longer in case of holidays), until the moderator approves
2684 The mailing list is at @email{tramp-devel@@gnu.org}. Messages sent to
2685 this address go to all the subscribers. This is @emph{not} the address
2686 to send subscription requests to.
2688 Subscribing to the list is performed via
2689 @uref{http://lists.gnu.org/mailman/listinfo/tramp-devel/,
2690 the @value{tramp} Mail Subscription Page}.
2693 To report a bug in @value{tramp}, you should execute @kbd{M-x
2694 tramp-bug}. This will automatically generate a buffer with the details
2695 of your system and @value{tramp} version.
2697 When submitting a bug report, please try to describe in excruciating
2698 detail the steps required to reproduce the problem, the setup of the
2699 remote machine and any special conditions that exist. You should also
2700 check that your problem is not described already in @xref{Frequently
2703 If you can identify a minimal test case that reproduces the problem,
2704 include that with your bug report. This will make it much easier for
2705 the development team to analyze and correct the problem.
2707 Before reporting the bug, you should set the verbosity level to 6
2708 (@pxref{Traces and Profiles, Traces}) in the @file{~/.emacs} file and
2709 repeat the bug. Then, include the contents of the @file{*tramp/foo*}
2710 and @file{*debug tramp/foo*} buffers in your bug report. A verbosity
2711 level greater than 6 will produce a very huge debug buffer, which is
2712 mostly not necessary for the analysis.
2714 Please be aware that, with a verbosity level of 6 or greater, the
2715 contents of files and directories will be included in the debug
2716 buffer. Passwords you've typed will never be included there.
2719 @node Frequently Asked Questions
2720 @chapter Frequently Asked Questions
2721 @cindex frequently asked questions
2726 Where can I get the latest @value{tramp}?
2728 @value{tramp} is available under the URL below.
2731 @uref{ftp://ftp.gnu.org/gnu/tramp/}
2734 There is also a Savannah project page.
2737 @uref{http://savannah.gnu.org/projects/tramp/}
2741 Which systems does it work on?
2743 The package has been used successfully on GNU Emacs 22, GNU Emacs 23,
2744 XEmacs 21 (starting with 21.4), and SXEmacs 22.
2746 The package was intended to work on Unix, and it really expects a
2747 Unix-like system on the remote end (except the @option{smb} method),
2748 but some people seemed to have some success getting it to work on MS
2749 Windows XP/Vista/7 @value{emacsname}.
2753 How could I speed up @value{tramp}?
2755 In the backstage, @value{tramp} needs a lot of operations on the
2756 remote host. The time for transferring data from and to the remote
2757 host as well as the time needed to perform the operations there count.
2758 In order to speed up @value{tramp}, one could either try to avoid some
2759 of the operations, or one could try to improve their performance.
2761 Use an external method, like @option{scpc}.
2763 Use caching. This is already enabled by default. Information about
2764 the remote host as well as the remote files are cached for reuse. The
2765 information about remote hosts is kept in the file specified in
2766 @code{tramp-persistency-file-name}. Keep this file. If you are
2767 confident that files on remote hosts are not changed out of
2768 @value{emacsname}' control, set @code{remote-file-name-inhibit-cache}
2771 Disable version control. If you access remote files which are not
2772 under version control, a lot of check operations can be avoided by
2773 disabling VC. This can be achieved by
2776 (setq vc-ignore-dir-regexp
2777 (format "\\(%s\\)\\|\\(%s\\)"
2778 vc-ignore-dir-regexp
2779 tramp-file-name-regexp))
2782 Disable excessive traces. The default trace level of @value{tramp},
2783 defined in the variable @code{tramp-verbose}, is 3. You should
2784 increase this level only temporarily, hunting bugs.
2788 @value{tramp} does not connect to the remote host
2790 When @value{tramp} does not connect to the remote host, there are three
2791 reasons heading the bug mailing list:
2796 Unknown characters in the prompt
2798 @value{tramp} needs to recognize the prompt on the remote machine
2799 after execution any command. This is not possible when the prompt
2800 contains unknown characters like escape sequences for coloring. This
2801 should be avoided on the remote side. @xref{Remote shell setup}. for
2802 setting the regular expression detecting the prompt.
2804 You can check your settings after an unsuccessful connection by
2805 switching to the @value{tramp} connection buffer @file{*tramp/foo*},
2806 setting the cursor at the top of the buffer, and applying the expression
2809 @kbd{M-: (re-search-forward (concat tramp-shell-prompt-pattern "$"))}
2812 If it fails, or the cursor is not moved at the end of the buffer, your
2813 prompt is not recognized correctly.
2815 A special problem is the zsh, which uses left-hand side and right-hand
2816 side prompts in parallel. Therefore, it is necessary to disable the
2817 zsh line editor on the remote host. You shall add to @file{~/.zshrc}
2818 the following command:
2821 [ $TERM = "dumb" ] && unsetopt zle && PS1='$ '
2824 Furthermore it has been reported, that @value{tramp} (like sshfs,
2825 incidentally) doesn't work with WinSSHD due to strange prompt settings.
2828 Echoed characters after login
2830 When the remote machine opens an echoing shell, there might be control
2831 characters in the welcome message. @value{tramp} tries to suppress
2832 such echoes via the @code{stty -echo} command, but sometimes this
2833 command is not reached, because the echoed output has confused
2834 @value{tramp} already. In such situations it might be helpful to use
2835 the @option{sshx} or @option{scpx} methods, which allocate a pseudo tty.
2836 @xref{Inline methods}.
2839 @value{tramp} doesn't transfer strings with more than 500 characters
2842 On some few systems, the implementation of @code{process-send-string}
2843 seems to be broken for longer strings. It is reported for HP-UX,
2844 FreeBSD and Tru64 Unix, for example. This case, you should customize
2845 the variable @code{tramp-chunksize} to 500. For a description how to
2846 determine whether this is necessary see the documentation of
2847 @code{tramp-chunksize}.
2849 Additionally, it will be useful to set @code{file-precious-flag} to
2850 @code{t} for @value{tramp} files. Then the file contents will be
2851 written into a temporary file first, which is checked for correct
2854 @pxref{Saving Buffers, , , elisp}
2861 (when (file-remote-p default-directory)
2862 (set (make-local-variable 'file-precious-flag) t))))
2869 @value{tramp} does not recognize hung @command{ssh} sessions
2871 When your network connection is down, @command{ssh} sessions might
2872 hang. @value{tramp} cannot detect it safely, because it still sees a
2873 running @command{ssh} process. Timeouts cannot be used as well,
2874 because it cannot be predicted how long a remote command will last,
2875 for example when copying very large files.
2877 Therefore, you must configure the @command{ssh} process to die
2878 in such a case. The following entry in @file{~/.ssh/config} would do
2883 ServerAliveInterval 5
2888 File name completion does not work with @value{tramp}
2890 When you log in to the remote machine, do you see the output of
2891 @command{ls} in color? If so, this may be the cause of your problems.
2893 @command{ls} outputs @acronym{ANSI} escape sequences that your terminal
2894 emulator interprets to set the colors. These escape sequences will
2895 confuse @value{tramp} however.
2897 In your @file{.bashrc}, @file{.profile} or equivalent on the remote
2898 machine you probably have an alias configured that adds the option
2899 @option{--color=yes} or @option{--color=auto}.
2901 You should remove that alias and ensure that a new login @emph{does not}
2902 display the output of @command{ls} in color. If you still cannot use
2903 filename completion, report a bug to the @value{tramp} developers.
2907 File name completion does not work in large directories
2909 @value{tramp} uses globbing for some operations. (Globbing means to use the
2910 shell to expand wildcards such as `*.c'.) This might create long
2911 command lines, especially in directories with many files. Some shells
2912 choke on long command lines, or don't cope well with the globbing
2915 If you have a large directory on the remote end, you may wish to execute
2916 a command like @samp{ls -d * ..?* > /dev/null} and see if it hangs.
2917 Note that you must first start the right shell, which might be
2918 @command{/bin/sh}, @command{ksh} or @command{bash}, depending on which
2919 of those supports tilde expansion.
2923 How can I get notified when @value{tramp} file transfers are complete?
2925 The following snippet can be put in your @file{~/.emacs} file. It
2926 makes @value{emacsname} beep after reading from or writing to the
2930 (defadvice tramp-handle-write-region
2931 (after tramp-write-beep-advice activate)
2932 "Make tramp beep after writing a file."
2936 (defadvice tramp-handle-do-copy-or-rename-file
2937 (after tramp-copy-beep-advice activate)
2938 "Make tramp beep after copying a file."
2942 (defadvice tramp-handle-insert-file-contents
2943 (after tramp-insert-beep-advice activate)
2944 "Make tramp beep after inserting a file."
2952 I'ld like to get a Visual Warning when working in a sudo:ed context
2954 When you are working with @samp{root} privileges, it might be useful
2955 to get an indication in the buffer's modeline. The following code,
2956 tested with @value{emacsname} 22.1, does the job. You should put it
2957 into your @file{~/.emacs}:
2960 (defun my-mode-line-function ()
2961 (when (string-match "^/su\\(do\\)?:" default-directory)
2962 (setq mode-line-format
2963 (format-mode-line mode-line-format 'font-lock-warning-face))))
2965 (add-hook 'find-file-hooks 'my-mode-line-function)
2966 (add-hook 'dired-mode-hook 'my-mode-line-function)
2973 I'ld like to see a host indication in the mode line when I'm remote
2975 The following code has been tested with @value{emacsname} 22.1. You
2976 should put it into your @file{~/.emacs}:
2979 (defconst my-mode-line-buffer-identification
2983 (if (file-remote-p default-directory)
2984 (tramp-file-name-host
2985 (tramp-dissect-file-name default-directory))
2987 (if (string-match "^[^0-9][^.]*\\(\\..*\\)" host-name)
2988 (substring host-name 0 (match-beginning 1))
2993 mode-line-buffer-identification
2994 my-mode-line-buffer-identification)
3000 mode-line-buffer-identification
3001 my-mode-line-buffer-identification)))
3004 Since @value{emacsname} 23.1, the mode line contains an indication if
3005 @code{default-directory} for the current buffer is on a remote host.
3006 The corresponding tooltip includes the name of that host. If you
3007 still want the host name as part of the mode line, you can use the
3008 example above, but the @code{:eval} clause can be simplified:
3013 (or (file-remote-p default-directory 'host)
3015 (if (string-match "^[^0-9][^.]*\\(\\..*\\)" host-name)
3016 (substring host-name 0 (match-beginning 1))
3024 My remote host does not understand default directory listing options
3026 @value{emacsname} computes the @command{dired} options depending on
3027 the local host you are working. If your @command{ls} command on the
3028 remote host does not understand those options, you can change them
3033 'dired-before-readin-hook
3035 (when (file-remote-p default-directory)
3036 (setq dired-actual-switches "-al"))))
3042 There's this @file{~/.sh_history} file on the remote host which keeps
3043 growing and growing. What's that?
3045 Sometimes, @value{tramp} starts @command{ksh} on the remote host for
3046 tilde expansion. Maybe @command{ksh} saves the history by default.
3047 @value{tramp} tries to turn off saving the history, but maybe you have
3048 to help. For example, you could put this in your @file{.kshrc}:
3051 if [ -f $HOME/.sh_history ] ; then
3052 /bin/rm $HOME/.sh_history
3054 if [ "$@{HISTFILE-unset@}" != "unset" ] ; then
3057 if [ "$@{HISTSIZE-unset@}" != "unset" ] ; then
3063 @item There are longish file names to type. How to shorten this?
3065 Let's say you need regularly access to @file{@trampfn{ssh, news,
3066 news.my.domain, /opt/news/etc}}, which is boring to type again and
3067 again. The following approaches can be mixed:
3071 @item Use default values for method and user name:
3073 You can define default methods and user names for hosts,
3074 (@pxref{Default Method}, @pxref{Default User}):
3077 (setq tramp-default-method "ssh"
3078 tramp-default-user "news")
3081 The file name left to type would be
3082 @kbd{C-x C-f @trampfn{, , news.my.domain, /opt/news/etc}}.
3084 Note that there are some useful settings already. Accessing your
3085 local host as @samp{root} user, is possible just by @kbd{C-x C-f
3088 @item Use configuration possibilities of your method:
3090 Several connection methods (i.e. the programs used) offer powerful
3091 configuration possibilities (@pxref{Customizing Completion}). In the
3092 given case, this could be @file{~/.ssh/config}:
3096 HostName news.my.domain
3100 The file name left to type would be @kbd{C-x C-f @trampfn{ssh, , xy,
3101 /opt/news/etc}}. Depending on files in your directories, it is even
3102 possible to complete the host name with @kbd{C-x C-f
3103 @value{prefix}ssh@value{postfixhop}x @key{TAB}}.
3105 @item Use environment variables:
3107 File names typed in the minibuffer can be expanded by environment
3108 variables. You can set them outside @value{emacsname}, or even with
3112 (setenv "xy" "@trampfn{ssh, news, news.my.domain, /opt/news/etc/}")
3115 Then you need simply to type @kbd{C-x C-f $xy @key{RET}}, and here you
3116 are. The disadvantage is that you cannot edit the file name, because
3117 environment variables are not expanded during editing in the
3120 @item Define own keys:
3122 You can define your own key sequences in @value{emacsname}, which can
3123 be used instead of @kbd{C-x C-f}:
3127 [(control x) (control y)]
3133 "@trampfn{ssh, news, news.my.domain, /opt/news/etc/}"))))
3136 Simply typing @kbd{C-x C-y} would initialize the minibuffer for
3137 editing with your beloved file name.
3139 See also @uref{http://www.emacswiki.org/cgi-bin/wiki/TrampMode, the
3140 Emacs Wiki} for a more comprehensive example.
3142 @item Define own abbreviation (1):
3144 It is possible to define an own abbreviation list for expanding file
3149 'directory-abbrev-alist
3150 '("^/xy" . "@trampfn{ssh, news, news.my.domain, /opt/news/etc/}"))
3153 This shortens the file openening command to @kbd{C-x C-f /xy
3154 @key{RET}}. The disadvantage is, again, that you cannot edit the file
3155 name, because the expansion happens after entering the file name only.
3157 @item Define own abbreviation (2):
3159 The @code{abbrev-mode} gives more flexibility for editing the
3163 (define-abbrev-table 'my-tramp-abbrev-table
3164 '(("xy" "@trampfn{ssh, news, news.my.domain, /opt/news/etc/}")))
3167 'minibuffer-setup-hook
3170 (setq local-abbrev-table my-tramp-abbrev-table)))
3172 (defadvice minibuffer-complete
3173 (before my-minibuffer-complete activate)
3176 ;; If you use partial-completion-mode
3177 (defadvice PC-do-completion
3178 (before my-PC-do-completion activate)
3182 After entering @kbd{C-x C-f xy @key{TAB}}, the minibuffer is
3183 expanded, and you can continue editing.
3185 @item Use bookmarks:
3187 Bookmarks can be used to visit Tramp files or directories.
3189 @pxref{Bookmarks, , , @value{emacsdir}}
3192 When you have opened @file{@trampfn{ssh, news, news.my.domain,
3193 /opt/news/etc/}}, you should save the bookmark via
3195 @kbd{@key{menu-bar} @key{edit} @key{bookmarks} @key{set}}.
3198 @kbd{@key{menu-bar} @key{view} @key{bookmarks} @key{set}}.
3201 Later on, you can always navigate to that bookmark via
3203 @kbd{@key{menu-bar} @key{edit} @key{bookmarks} @key{jump}}.
3206 @kbd{@key{menu-bar} @key{view} @key{bookmarks} @key{jump}}.
3209 @item Use recent files:
3217 remembers visited places.
3220 @pxref{File Conveniences, , , @value{emacsdir}}
3223 @pxref{recent-files, , , edit-utils}
3227 You could keep remote file names in the recent list without checking
3228 their readability through a remote access:
3235 (recent-files-initialize)
3239 (when (file-remote-p (buffer-file-name))
3240 (recent-files-make-permanent)))
3245 The list of files opened recently is reachable via
3247 @kbd{@key{menu-bar} @key{file} @key{Open Recent}}.
3250 @kbd{@key{menu-bar} @key{Recent Files}}.
3254 @item Use filecache:
3256 @file{filecache} remembers visited places. Add the directory into
3260 (eval-after-load "filecache"
3261 '(file-cache-add-directory
3262 "@trampfn{ssh, news, news.my.domain, /opt/news/etc/}"))
3265 Whenever you want to load a file, you can enter @kbd{C-x C-f
3266 C-@key{TAB}} in the minibuffer. The completion is done for the given
3273 @file{bbdb} has a built-in feature for @value{ftppackagename} files,
3274 which works also for @value{tramp}.
3276 @pxref{bbdb-ftp, Storing FTP sites in the BBDB, , bbdb}
3279 You need to load @file{bbdb}:
3286 Then you can create a BBDB entry via @kbd{M-x bbdb-create-ftp-site}.
3287 Because BBDB is not prepared for @value{tramp} syntax, you must
3288 specify a method together with the user name when needed. Example:
3291 @kbd{M-x bbdb-create-ftp-site @key{RET}}
3292 @b{Ftp Site:} news.my.domain @key{RET}
3293 @b{Ftp Directory:} /opt/news/etc/ @key{RET}
3294 @b{Ftp Username:} ssh@value{postfixhop}news @key{RET}
3295 @b{Company:} @key{RET}
3296 @b{Additional Comments:} @key{RET}
3299 When you have opened your BBDB buffer, you can access such an entry by
3300 pressing the key @key{F}.
3305 I would like to thank all @value{tramp} users who have contributed to
3306 the different recipes!
3311 How can I use @value{tramp} to connect to a remote @value{emacsname}
3314 You can configure Emacs Client doing this.
3316 @xref{Emacs Server, , , @value{emacsdir}}.
3319 On the remote host, you start the Emacs Server:
3323 (setq server-host (system-name)
3328 Make sure that the result of @code{(system-name)} can be resolved on
3329 your local host; otherwise you might use a hard coded IP address.
3331 The resulting file @file{~/.emacs.d/server/server} must be copied to
3332 your local host, at the same location. You can call then the Emacs
3333 Client from the command line:
3336 emacsclient @trampfn{ssh, user, host, /file/to/edit}
3339 @code{user} and @code{host} shall be related to your local host.
3341 If you want to use Emacs Client also as editor for other programs, you
3342 could write a script @file{emacsclient.sh}:
3346 emacsclient @trampfn{ssh, $(whoami), $(hostname --fqdn), $1}
3349 Then you must set the environment variable @code{EDITOR} pointing to
3353 export EDITOR=/path/to/emacsclient.sh
3359 How can I disable @value{tramp}?
3361 Shame on you, why did you read until now?
3367 If you just want to have @value{ftppackagename} as default remote
3368 files access package, you should apply the following code:
3371 (setq tramp-default-method "ftp")
3378 @value{tramp} (and @value{ftppackagename}),
3383 you must set @code{tramp-mode} to @code{nil}:
3386 (setq tramp-mode nil)
3390 Unloading @value{tramp} can be achieved by applying @kbd{M-x
3391 tramp-unload-tramp}.
3393 This resets also the @value{ftppackagename} plugins.
3399 @c For the developer
3400 @node Files directories and localnames
3401 @chapter How file names, directories and localnames are mangled and managed.
3404 * Localname deconstruction:: Breaking a localname into its components.
3406 * External packages:: Integration with external Lisp packages.
3411 @node Localname deconstruction
3412 @section Breaking a localname into its components.
3414 @value{tramp} file names are somewhat different, obviously, to ordinary file
3415 names. As such, the lisp functions @code{file-name-directory} and
3416 @code{file-name-nondirectory} are overridden within the @value{tramp}
3419 Their replacements are reasonably simplistic in their approach. They
3420 dissect the filename, call the original handler on the localname and
3421 then rebuild the @value{tramp} file name with the result.
3423 This allows the platform specific hacks in the original handlers to take
3424 effect while preserving the @value{tramp} file name information.
3428 @node External packages
3429 @section Integration with external Lisp packages.
3430 @subsection Filename completion.
3432 While reading filenames in the minibuffer, @value{tramp} must decide
3433 whether it completes possible incomplete filenames, or not. Imagine
3434 there is the following situation: You have typed @kbd{C-x C-f
3435 @value{prefix}ssh@value{postfixhop} @key{TAB}}. @value{tramp} cannot
3436 know, whether @option{ssh} is a method or a host name. It checks
3437 therefore the last input character you have typed. If this is
3438 @key{TAB}, @key{SPACE} or @kbd{?}, @value{tramp} assumes that you are
3439 still in filename completion, and it does not connect to the possible
3440 remote host @option{ssh}.
3442 @vindex tramp-completion-mode
3443 External packages, which use other characters for completing filenames
3444 in the minibuffer, must signal this to @value{tramp}. For this case,
3445 the variable @code{tramp-completion-mode} can be bound temporarily to
3446 a non-@code{nil} value.
3449 (let ((tramp-completion-mode t))
3454 @subsection File attributes cache.
3456 When @value{tramp} runs remote processes, files on the remote host
3457 could change their attributes. Consequently, @value{tramp} must flush
3458 its complete cache keeping attributes for all files of the remote host
3461 This is a performance degradation, because the lost file attributes
3462 must be recomputed when needed again. In cases the caller of
3463 @code{process-file} knows that there are no file attribute changes, it
3464 shall let-bind the variable @code{process-file-side-effects} to
3465 @code{nil}. @value{tramp} wouldn't flush the file attributes cache then.
3468 (let (process-file-side-effects)
3472 For asynchronous processes, @value{tramp} flushes the file attributes
3473 cache via a process sentinel. If the caller of
3474 @code{start-file-process} knows that there are no file attribute
3475 changes, it shall set the process sentinel to @code{nil}. In case the
3476 caller defines an own process sentinel, @value{tramp}'s process
3477 sentinel is overwritten. The caller can still flush the file
3478 attributes cache in its process sentinel with this code:
3481 (unless (memq (process-status proc) '(run open))
3482 (dired-uncache remote-directory))
3485 @code{remote-directory} shall be the root directory, where file
3486 attribute changes can happen during the process lifetime.
3487 @value{tramp} traverses all subdirectories, starting at this
3488 directory. Often, it is sufficient to use @code{default-directory} of
3489 the process buffer as root directory.
3493 @node Traces and Profiles
3494 @chapter How to Customize Traces
3496 All @value{tramp} messages are raised with a verbosity level. The
3497 verbosity level can be any number between 0 and 10. Only messages with
3498 a verbosity level less than or equal to @code{tramp-verbose} are
3501 The verbosity levels are
3503 @w{ 0} silent (no @value{tramp} messages at all)
3504 @*@indent @w{ 1} errors
3505 @*@indent @w{ 2} warnings
3506 @*@indent @w{ 3} connection to remote hosts (default verbosity)
3507 @*@indent @w{ 4} activities
3508 @*@indent @w{ 5} internal
3509 @*@indent @w{ 6} sent and received strings
3510 @*@indent @w{ 7} file caching
3511 @*@indent @w{ 8} connection properties
3512 @*@indent @w{ 9} test commands
3513 @*@indent @w{10} traces (huge)
3515 When @code{tramp-verbose} is greater than or equal to 4, the messages
3516 are also written into a @value{tramp} debug buffer. This debug buffer
3517 is useful for analysing problems; sending a @value{tramp} bug report
3518 should be done with @code{tramp-verbose} set to a verbosity level of at
3519 least 6 (@pxref{Bug Reports}).
3521 The debug buffer is in
3523 @ref{Outline Mode, , , @value{emacsdir}}.
3528 That means, you can change the level of messages to be viewed. If you
3529 want, for example, see only messages up to verbosity level 5, you must
3530 enter @kbd{C-u 6 C-c C-q}.
3532 Other keys for navigating are described in
3533 @ref{Outline Visibility, , , @value{emacsdir}}.
3536 @value{tramp} errors are handled internally in order to raise the
3537 verbosity level 1 messages. When you want to get a Lisp backtrace in
3538 case of an error, you need to set both
3541 (setq debug-on-error t
3545 Sometimes, it might be even necessary to step through @value{tramp}
3546 function call traces. Such traces are enabled by the following code:
3551 (dolist (elt (all-completions "tramp-" obarray 'functionp))
3552 (trace-function-background (intern elt)))
3553 (untrace-function 'tramp-read-passwd)
3554 (untrace-function 'tramp-gw-basic-authentication)
3557 The function call traces are inserted in the buffer
3558 @file{*trace-output*}. @code{tramp-read-passwd} and
3559 @code{tramp-gw-basic-authentication} shall be disabled when the
3560 function call traces are added to @value{tramp}, because both
3561 functions return password strings, which should not be distributed.
3565 @chapter Debatable Issues and What Was Decided
3568 @item The uuencode method does not always work.
3570 Due to the design of @value{tramp}, the encoding and decoding programs
3571 need to read from stdin and write to stdout. On some systems,
3572 @command{uudecode -o -} will read stdin and write the decoded file to
3573 stdout, on other systems @command{uudecode -p} does the same thing.
3574 But some systems have uudecode implementations which cannot do this at
3575 all---it is not possible to call these uudecode implementations with
3576 suitable parameters so that they write to stdout.
3578 Of course, this could be circumvented: the @code{begin foo 644} line
3579 could be rewritten to put in some temporary file name, then
3580 @command{uudecode} could be called, then the temp file could be
3581 printed and deleted.
3583 But I have decided that this is too fragile to reliably work, so on some
3584 systems you'll have to do without the uuencode methods.
3586 @item The @value{tramp} filename syntax differs between GNU Emacs and XEmacs.
3588 The GNU Emacs maintainers wish to use a unified filename syntax for
3589 Ange-FTP and @value{tramp} so that users don't have to learn a new
3590 syntax. It is sufficient to learn some extensions to the old syntax.
3592 For the XEmacs maintainers, the problems caused from using a unified
3593 filename syntax are greater than the gains. The XEmacs package system
3594 uses EFS for downloading new packages. So, obviously, EFS has to be
3595 installed from the start. If the filenames were unified, @value{tramp}
3596 would have to be installed from the start, too.
3599 @strong{Note:} If you'd like to use a similar syntax like
3600 @value{ftppackagename}, you need the following settings in your init
3604 (setq tramp-unified-filenames t)
3608 The autoload of the @value{emacsname} @value{tramp} package must be
3609 disabled. This can be achieved by setting file permissions @code{000}
3610 to the files @file{.../xemacs-packages/lisp/tramp/auto-autoloads.el*}.
3612 In case of unified filenames, all @value{emacsname} download sites are
3613 added to @code{tramp-default-method-alist} with default method
3614 @option{ftp} @xref{Default Method}. These settings shouldn't be
3615 touched for proper working of the @value{emacsname} package system.
3617 The syntax for unified filenames is described in the @value{tramp} manual
3618 for @value{emacsothername}.
3622 @node GNU Free Documentation License
3623 @appendix GNU Free Documentation License
3624 @include doclicense.texi
3626 @node Function Index
3627 @unnumbered Function Index
3630 @node Variable Index
3631 @unnumbered Variable Index
3635 @unnumbered Concept Index
3642 @c * Say something about the .login and .profile files of the remote
3644 @c * Explain how tramp.el works in principle: open a shell on a remote
3645 @c host and then send commands to it.
3646 @c * Use `filename' resp. `file name' consistently.
3647 @c * Use `host' resp. `machine' consistently.
3648 @c * Consistent small or capitalized words especially in menues.