1 \input texinfo @c -*-texinfo-*-
2 @setfilename ../../info/tramp
4 @settitle TRAMP User Manual
7 @c This is *so* much nicer :)
10 @c In the Tramp CVS, the version number is auto-frobbed from
11 @c configure.ac, so you should edit that file and run
12 @c "autoconf && ./configure" to change the version number.
14 @c Additionally, flags are set with respect to the Emacs flavor; and
15 @c depending whether Tramp is packaged into (X)Emacs, or standalone.
17 @include trampver.texi
19 @c Macro for formatting a filename according to the repective syntax.
20 @c xxx and yyy are auxiliary macros in order to omit leading and
21 @c trailing whitespace. Not very elegant, but I don't know it better.
27 @macro yyy {one, two}@c
35 @macro trampfn {method, user, host, localname}@c
36 @value{prefix}@yyy{\method\,@value{postfixhop}}@yyy{\user\,@@}\host\@value{postfix}\localname\@c
40 Copyright @copyright{} 1999, 2000, 2001, 2002, 2003, 2004, 2005,
41 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
44 Permission is granted to copy, distribute and/or modify this document
45 under the terms of the GNU Free Documentation License, Version 1.3 or
46 any later version published by the Free Software Foundation; with no
47 Invariant Sections, with the Front-Cover texts being ``A GNU Manual'',
48 and with the Back-Cover Texts as in (a) below. A copy of the license
49 is included in the section entitled ``GNU Free Documentation License''.
51 (a) The FSF's Back-Cover Text is: ``You have the freedom to
52 copy and modify this GNU manual. Buying copies from the FSF
53 supports it in developing GNU and promoting software freedom.''
57 @c Entries for @command{install-info} to use
58 @dircategory @value{emacsname}
60 * TRAMP: (tramp). Transparent Remote Access, Multiple Protocol
61 @value{emacsname} remote file access via rsh and rcp.
65 @title @value{tramp} version @value{trampver} User Manual
66 @author by Daniel Pittman
67 @author based on documentation by Kai Gro@ss{}johann
75 @node Top, Overview, (dir), (dir)
76 @top @value{tramp} version @value{trampver} User Manual
78 This file documents @value{tramp} version @value{trampver}, a remote file
79 editing package for @value{emacsname}.
81 @value{tramp} stands for `Transparent Remote (file) Access, Multiple
82 Protocol'. This package provides remote file editing, similar to
83 @value{ftppackagename}.
85 The difference is that @value{ftppackagename} uses FTP to transfer
86 files between the local and the remote host, whereas @value{tramp} uses a
87 combination of @command{rsh} and @command{rcp} or other work-alike
88 programs, such as @command{ssh}/@command{scp}.
90 You can find the latest version of this document on the web at
91 @uref{http://www.gnu.org/software/tramp/}.
93 @c Pointer to the other Emacs flavor is necessary only in case of
94 @c standalone installation.
96 The manual has been generated for @value{emacsname}.
98 If you want to read the info pages for @value{emacsothername}, you
99 should read in @ref{Installation} how to create them.
102 If you're using the other Emacs flavor, you should read the
103 @uref{@value{emacsotherfilename}, @value{emacsothername}} pages.
109 This manual is also available as a @uref{@value{japanesemanual},
110 Japanese translation}.
113 The latest release of @value{tramp} is available for
114 @uref{ftp://ftp.gnu.org/gnu/tramp/, download}, or you may see
115 @ref{Obtaining Tramp} for more details, including the CVS server
118 @value{tramp} also has a @uref{http://savannah.gnu.org/projects/tramp/,
119 Savannah Project Page}.
122 There is a mailing list for @value{tramp}, available at
123 @email{tramp-devel@@gnu.org}, and archived at
124 @uref{http://lists.gnu.org/archive/html/tramp-devel/, the
125 @value{tramp} Mail Archive}.
127 Older archives are located at
128 @uref{http://sourceforge.net/mailarchive/forum.php?forum=tramp-devel,
129 SourceForge Mail Archive} and
130 @uref{http://www.mail-archive.com/emacs-rcp@@ls6.cs.uni-dortmund.de/,
132 @c in HTML output, there's no new paragraph.
141 * Overview:: What @value{tramp} can and cannot do.
145 * Obtaining Tramp:: How to obtain @value{tramp}.
146 * History:: History of @value{tramp}.
147 @ifset installchapter
148 * Installation:: Installing @value{tramp} with your @value{emacsname}.
150 * Configuration:: Configuring @value{tramp} for use.
151 * Usage:: An overview of the operation of @value{tramp}.
152 * Bug Reports:: Reporting Bugs and Problems.
153 * Frequently Asked Questions:: Questions and answers from the mailing list.
154 * Function Index:: @value{tramp} functions.
155 * Variable Index:: User options and variables.
156 * Concept Index:: An item for each concept.
160 * Files directories and localnames:: How file names, directories and localnames are mangled and managed.
161 * Traces and Profiles:: How to Customize Traces.
162 * Issues:: Debatable Issues and What Was Decided.
164 * GNU Free Documentation License:: The license for this documentation.
167 --- The Detailed Node Listing ---
169 @ifset installchapter
170 Installing @value{tramp} with your @value{emacsname}
172 * Installation parameters:: Parameters in order to control installation.
173 * Load paths:: How to plug-in @value{tramp} into your environment.
174 * Japanese manual:: Japanese manual.
178 Configuring @value{tramp} for use
180 * Connection types:: Types of connections made to remote machines.
181 * Inline methods:: Inline methods.
182 * External methods:: External methods.
184 * GVFS based methods:: GVFS based external methods.
187 * Gateway methods:: Gateway methods.
189 * Default Method:: Selecting a default method.
190 * Default User:: Selecting a default user.
191 * Default Host:: Selecting a default host.
192 * Multi-hops:: Connecting to a remote host using multiple hops.
193 * Customizing Methods:: Using Non-Standard Methods.
194 * Customizing Completion:: Selecting config files for user/host name completion.
195 * Password handling:: Reusing passwords for several connections.
196 * Connection caching:: Reusing connection related information.
197 * Remote Programs:: How @value{tramp} finds and uses programs on the remote machine.
198 * Remote shell setup:: Remote shell setup hints.
199 * Windows setup hints:: Issues with Cygwin ssh.
200 * Auto-save and Backup:: Auto-save and Backup.
204 * Filename Syntax:: @value{tramp} filename conventions.
205 * Alternative Syntax:: URL-like filename syntax.
206 * Filename completion:: Filename completion.
207 * Remote processes:: Integration with other @value{emacsname} packages.
208 * Cleanup remote connections:: Cleanup remote connections.
210 How file names, directories and localnames are mangled and managed
212 * Localname deconstruction:: Breaking a localname into its components.
214 * External packages:: Integration with external Lisp packages.
221 @chapter An overview of @value{tramp}
224 After the installation of @value{tramp} into your @value{emacsname}, you
225 will be able to access files on remote machines as though they were
226 local. Access to the remote file system for editing files, version
227 control, and @code{dired} are transparently enabled.
229 Your access to the remote machine can be with the @command{rsh},
230 @command{rlogin}, @command{telnet} programs or with any similar
231 connection method. This connection must pass @acronym{ASCII}
232 successfully to be usable but need not be 8-bit clean.
234 The package provides support for @command{ssh} connections out of the
235 box, one of the more common uses of the package. This allows
236 relatively secure access to machines, especially if @command{ftp}
239 Under Windows, @value{tramp} is integrated with the PuTTY package,
240 using the @command{plink} program.
242 The majority of activity carried out by @value{tramp} requires only that
243 the remote login is possible and is carried out at the terminal. In
244 order to access remote files @value{tramp} needs to transfer their content
245 to the local machine temporarily.
247 @value{tramp} can transfer files between the machines in a variety of ways.
248 The details are easy to select, depending on your needs and the
249 machines in question.
251 The fastest transfer methods for large files rely on a remote file
252 transfer package such as @command{rcp}, @command{scp}, @command{rsync}
253 or (under Windows) @command{pscp}.
255 If the remote copy methods are not suitable for you, @value{tramp} also
256 supports the use of encoded transfers directly through the shell.
257 This requires that the @command{mimencode} or @command{uuencode} tools
258 are available on the remote machine. These methods are generally
259 faster for small files.
261 @value{tramp} is still under active development and any problems you encounter,
262 trivial or major, should be reported to the @value{tramp} developers.
266 @subsubheading Behind the scenes
267 @cindex behind the scenes
268 @cindex details of operation
271 This section tries to explain what goes on behind the scenes when you
272 access a remote file through @value{tramp}.
274 Suppose you type @kbd{C-x C-f} and enter part of an @value{tramp} file name,
275 then hit @kbd{@key{TAB}} for completion. Suppose further that this is
276 the first time that @value{tramp} is invoked for the host in question. Here's
281 @value{tramp} discovers that it needs a connection to the host. So it
282 invokes @samp{telnet @var{host}} or @samp{rsh @var{host} -l
283 @var{user}} or a similar tool to connect to the remote host.
284 Communication with this process happens through an
285 @value{emacsname} buffer, that is, the output from the remote end
289 The remote host may prompt for a login name (for @command{telnet}).
290 The login name is given in the file name, so @value{tramp} sends the
291 login name and a newline.
294 The remote host may prompt for a password or pass phrase (for
295 @command{rsh} or for @command{telnet} after sending the login name).
296 @value{tramp} displays the prompt in the minibuffer, asking you for the
297 password or pass phrase.
299 You enter the password or pass phrase. @value{tramp} sends it to the remote
300 host, followed by a newline.
303 @value{tramp} now waits for the shell prompt or for a message that the login
306 If @value{tramp} sees neither of them after a certain period of time
307 (a minute, say), then it issues an error message saying that it
308 couldn't find the remote shell prompt and shows you what the remote
311 If @value{tramp} sees a @samp{login failed} message, it tells you so,
312 aborts the login attempt and allows you to try again.
315 Suppose that the login was successful and @value{tramp} sees the shell prompt
316 from the remote host. Now @value{tramp} invokes @command{/bin/sh} because
317 Bourne shells and C shells have different command
318 syntaxes.@footnote{Invoking @command{/bin/sh} will fail if your login
319 shell doesn't recognize @samp{exec /bin/sh} as a valid command.
320 Maybe you use the Scheme shell @command{scsh}@dots{}}
322 After the Bourne shell has come up, @value{tramp} sends a few commands to
323 ensure a good working environment. It turns off echoing, it sets the
324 shell prompt, and a few other things.
327 Now the remote shell is up and it good working order. Remember, what
328 was supposed to happen is that @value{tramp} tries to find out what files exist
329 on the remote host so that it can do filename completion.
331 So, @value{tramp} basically issues @command{cd} and @command{ls} commands and
332 also sometimes @command{echo} with globbing. Another command that is
333 often used is @command{test} to find out whether a file is writable or a
334 directory or the like. The output of each command is parsed for the
338 Suppose you are finished with filename completion, have entered @kbd{C-x
339 C-f}, a full file name and hit @kbd{@key{RET}}. Now comes the time to
340 transfer the file contents from the remote host to the local host so
341 that you can edit them.
343 See above for an explanation of how @value{tramp} transfers the file contents.
345 For inline transfers, @value{tramp} issues a command like @samp{mimencode -b
346 /path/to/remote/file}, waits until the output has accumulated in the
347 buffer that's used for communication, then decodes that output to
348 produce the file contents.
350 For external transfers, @value{tramp} issues a command like the
353 rcp user@@host:/path/to/remote/file /tmp/tramp.4711
355 It then reads the local temporary file @file{/tmp/tramp.4711} into a
356 buffer and deletes the temporary file.
359 You now edit the buffer contents, blithely unaware of what has happened
360 behind the scenes. (Unless you have read this section, that is.) When
361 you are finished, you type @kbd{C-x C-s} to save the buffer.
364 Again, @value{tramp} transfers the file contents to the remote host
365 either inline or external. This is the reverse of what happens when
369 I hope this has provided you with a basic overview of what happens
370 behind the scenes when you open a file with @value{tramp}.
374 @node Obtaining Tramp
375 @chapter Obtaining Tramp.
376 @cindex obtaining Tramp
378 @value{tramp} is freely available on the Internet and the latest
379 release may be downloaded from
380 @uref{ftp://ftp.gnu.org/gnu/tramp/}. This release includes the full
381 documentation and code for @value{tramp}, suitable for installation.
382 But GNU Emacs (22 or later) includes @value{tramp} already, and there
383 is a @value{tramp} package for XEmacs, as well. So maybe it is easier
384 to just use those. But if you want the bleeding edge, read
387 For the especially brave, @value{tramp} is available from CVS. The CVS
388 version is the latest version of the code and may contain incomplete
389 features or new issues. Use these versions at your own risk.
391 Instructions for obtaining the latest development version of @value{tramp}
392 from CVS can be found by going to the Savannah project page at the
393 following URL and then clicking on the CVS link in the navigation bar
397 @uref{http://savannah.gnu.org/projects/tramp/}
400 Or follow the example session below:
403 ] @strong{cd ~/@value{emacsdir}}
404 ] @strong{export CVS_RSH="ssh"}
405 ] @strong{cvs -z3 -d:pserver:anonymous@@cvs.savannah.gnu.org:/sources/tramp co tramp}
409 You should now have a directory @file{~/@value{emacsdir}/tramp}
410 containing the latest version of @value{tramp}. You can fetch the latest
411 updates from the repository by issuing the command:
414 ] @strong{cd ~/@value{emacsdir}/tramp}
415 ] @strong{export CVS_RSH="ssh"}
416 ] @strong{cvs update -d}
420 Once you've got updated files from the CVS repository, you need to run
421 @command{autoconf} in order to get an up-to-date @file{configure}
425 ] @strong{cd ~/@value{emacsdir}/tramp}
431 @chapter History of @value{tramp}
433 @cindex development history
435 Development was started end of November 1998. The package was called
436 @file{rssh.el}, back then. It only provided one method to access a
437 file, using @command{ssh} to log in to a remote host and using
438 @command{scp} to transfer the file contents. After a while, the name
439 was changed to @file{rcp.el}, and now it's @value{tramp}. Along the way,
440 many more methods for getting a remote shell and for transferring the
441 file contents were added. Support for VC was added.
443 After that, there were added the multi-hop methods in April 2000 and
444 the unification of @value{tramp} and Ange-FTP filenames in July 2002.
445 In July 2004, multi-hop methods have been replaced by proxy hosts.
446 Running commands on remote hosts was introduced in December 2005.
448 Support of gateways exists since April 2007.
451 GVFS integration started in February 2009.
454 Storing files into IMAP mailboxes has been added in September 2009.
457 In December 2001, @value{tramp} has been added to the XEmacs package
458 repository. Being part of the GNU Emacs repository happened in June
459 2002, the first release including @value{tramp} was GNU Emacs 22.1.
461 @value{tramp} is also a GNU/Linux Debian package since February 2001.
464 @c Installation chapter is necessary only in case of standalone
465 @c installation. Text taken from trampinst.texi.
466 @ifset installchapter
467 @include trampinst.texi
471 @chapter Configuring @value{tramp} for use
472 @cindex configuration
474 @cindex default configuration
475 @value{tramp} is (normally) fully functional when it is initially
476 installed. It is initially configured to use the @command{scp}
477 program to connect to the remote host. So in the easiest case, you
478 just type @kbd{C-x C-f} and then enter the filename
479 @file{@trampfn{, user, machine, /path/to.file}}.
481 On some hosts, there are problems with opening a connection. These are
482 related to the behavior of the remote shell. See @xref{Remote shell
483 setup}, for details on this.
485 If you do not wish to use these commands to connect to the remote
486 host, you should change the default connection and transfer method
487 that @value{tramp} uses. There are several different methods that @value{tramp}
488 can use to connect to remote machines and transfer files
489 (@pxref{Connection types}).
491 If you don't know which method is right for you, see @xref{Default
496 * Connection types:: Types of connections made to remote machines.
497 * Inline methods:: Inline methods.
498 * External methods:: External methods.
500 * GVFS based methods:: GVFS based external methods.
503 * Gateway methods:: Gateway methods.
505 * Default Method:: Selecting a default method.
506 Here we also try to help those who
507 don't have the foggiest which method
509 * Default User:: Selecting a default user.
510 * Default Host:: Selecting a default host.
511 * Multi-hops:: Connecting to a remote host using multiple hops.
512 * Customizing Methods:: Using Non-Standard Methods.
513 * Customizing Completion:: Selecting config files for user/host name completion.
514 * Password handling:: Reusing passwords for several connections.
515 * Connection caching:: Reusing connection related information.
516 * Remote Programs:: How @value{tramp} finds and uses programs on the remote machine.
517 * Remote shell setup:: Remote shell setup hints.
518 * Windows setup hints:: Issues with Cygwin ssh.
519 * Auto-save and Backup:: Auto-save and Backup.
523 @node Connection types
524 @section Types of connections made to remote machines.
525 @cindex connection types, overview
527 There are two basic types of transfer methods, each with its own
528 advantages and limitations. Both types of connection make use of a
529 remote shell access program such as @command{rsh}, @command{ssh} or
530 @command{telnet} to connect to the remote machine.
532 This connection is used to perform many of the operations that @value{tramp}
533 requires to make the remote file system transparently accessible from
534 the local machine. It is only when visiting files that the methods
537 @cindex inline methods
538 @cindex external methods
539 @cindex methods, inline
540 @cindex methods, external
541 Loading or saving a remote file requires that the content of the file
542 be transfered between the two machines. The content of the file can
543 be transfered using one of two methods: the @dfn{inline method} over
544 the same connection used to log in to the remote machine, or the
545 @dfn{external method} through another connection using a remote copy
546 program such as @command{rcp}, @command{scp} or @command{rsync}.
548 The performance of the external methods is generally better than that
549 of the inline methods, at least for large files. This is caused by
550 the need to encode and decode the data when transferring inline.
552 The one exception to this rule are the @command{scp} based transfer
553 methods. While these methods do see better performance when actually
554 transferring files, the overhead of the cryptographic negotiation at
555 startup may drown out the improvement in file transfer times.
557 External methods should be configured such a way that they don't
558 require a password (with @command{ssh-agent}, or such alike). Modern
559 @command{scp} implementations offer options to reuse existing
560 @command{ssh} connections, see method @command{scpc}. If it isn't
561 possible, you should consider @ref{Password handling}, otherwise you
562 will be prompted for a password every copy action.
566 @section Inline methods
567 @cindex inline methods
568 @cindex methods, inline
570 The inline methods in @value{tramp} are quite powerful and can work in
571 situations where you cannot use an external transfer program to connect.
572 Inline methods are the only methods that work when connecting to the
573 remote machine via telnet. (There are also strange inline methods which
574 allow you to transfer files between @emph{user identities} rather than
577 These methods depend on the existence of a suitable encoding and
578 decoding command on remote machine. Locally, @value{tramp} may be able to
579 use features of @value{emacsname} to decode and encode the files or
580 it may require access to external commands to perform that task.
584 @cindex base-64 encoding
585 @value{tramp} checks the availability and usability of commands like
586 @command{mimencode} (part of the @command{metamail} package) or
587 @command{uuencode} on the remote host. The first reliable command
588 will be used. The search path can be customized, see @ref{Remote
591 If both commands aren't available on the remote host, @value{tramp}
592 transfers a small piece of Perl code to the remote host, and tries to
593 apply it for encoding and decoding.
595 The variable @var{tramp-inline-compress-start-size} controls, whether
596 a file shall be compressed before encoding. This could increase
597 transfer speed for large text files.
605 Connect to the remote host with @command{rsh}. Due to the unsecure
606 connection it is recommended for very local host topology only.
608 On operating systems which provide the command @command{remsh} instead
609 of @command{rsh}, you can use the method @option{remsh}. This is true
610 for HP-UX or Cray UNICOS, for example.
617 Connect to the remote host with @command{ssh}. This is identical to
618 the previous option except that the @command{ssh} package is used,
619 making the connection more secure.
621 There are also two variants, @option{ssh1} and @option{ssh2}, that
622 call @samp{ssh -1} and @samp{ssh -2}, respectively. This way, you can
623 explicitly select whether you want to use the SSH protocol version 1
624 or 2 to connect to the remote host. (You can also specify in
625 @file{~/.ssh/config}, the SSH configuration file, which protocol
626 should be used, and use the regular @option{ssh} method.)
628 Two other variants, @option{ssh1_old} and @option{ssh2_old}, use the
629 @command{ssh1} and @command{ssh2} commands explicitly. If you don't
630 know what these are, you do not need these options.
632 All the methods based on @command{ssh} have an additional feature: you
633 can specify a host name which looks like @file{host#42} (the real host
634 name, then a hash sign, then a port number). This means to connect to
635 the given host but to also pass @code{-p 42} as arguments to the
636 @command{ssh} command.
639 @item @option{telnet}
640 @cindex method telnet
641 @cindex telnet method
643 Connect to the remote host with @command{telnet}. This is as unsecure
644 as the @option{rsh} method.
651 This method does not connect to a remote host at all, rather it uses
652 the @command{su} program to allow you to edit files as another user.
653 That means, the specified host name in the file name must be either
654 @samp{localhost} or the host name as returned by the function
655 @command{(system-name)}. For an exception of this rule see
663 This is similar to the @option{su} method, but it uses @command{sudo}
664 rather than @command{su} to become a different user.
666 Note that @command{sudo} must be configured to allow you to start a
667 shell as the user. It would be nice if it was sufficient if
668 @command{ls} and @command{mimencode} were allowed, but that is not
669 easy to implement, so I haven't got around to it, yet.
676 As you would expect, this is similar to @option{ssh}, only a little
677 different. Whereas @option{ssh} opens a normal interactive shell on
678 the remote host, this option uses @samp{ssh -t -t @var{host} -l
679 @var{user} /bin/sh} to open a connection. This is useful for users
680 where the normal login shell is set up to ask them a number of
681 questions when logging in. This procedure avoids these questions, and
682 just gives @value{tramp} a more-or-less `standard' login shell to work
685 Note that this procedure does not eliminate questions asked by
686 @command{ssh} itself. For example, @command{ssh} might ask ``Are you
687 sure you want to continue connecting?'' if the host key of the remote
688 host is not known. @value{tramp} does not know how to deal with such a
689 question (yet), therefore you will need to make sure that you can log
690 in without such questions.
692 This is also useful for Windows users where @command{ssh}, when
693 invoked from an @value{emacsname} buffer, tells them that it is not
694 allocating a pseudo tty. When this happens, the login shell is wont
695 to not print any shell prompt, which confuses @value{tramp} mightily.
696 For reasons unknown, some Windows ports for @command{ssh} require the
697 doubled @samp{-t} option.
699 This supports the @samp{-p} argument.
702 @item @option{krlogin}
703 @cindex method krlogin
704 @cindex krlogin method
705 @cindex Kerberos (with krlogin method)
707 This method is also similar to @option{ssh}. It only uses the
708 @command{krlogin -x} command to log in to the remote host.
715 This method is mostly interesting for Windows users using the PuTTY
716 implementation of SSH. It uses @samp{plink -ssh} to log in to the
719 This supports the @samp{-P} argument.
721 Additionally, the methods @option{plink1} and @option{plink2} are
722 provided, which call @samp{plink -1 -ssh} or @samp{plink -2 -ssh} in
723 order to use SSH protocol version 1 or 2 explicitly.
725 CCC: Do we have to connect to the remote host once from the command
726 line to accept the SSH key? Maybe this can be made automatic?
728 CCC: Say something about the first shell command failing. This might
729 be due to a wrong setting of @code{tramp-rsh-end-of-line}.
732 @item @option{plinkx}
733 @cindex method plinkx
734 @cindex plinkx method
736 Another method using PuTTY on Windows. Instead of host names, it
737 expects PuTTY session names, calling @samp{plink -load @var{session}
738 -t"}. User names are relevant only in case the corresponding session
739 hasn't defined a user name. Different port numbers must be defined in
747 This is an experimental implementation of the fish protocol, known from
748 the GNU Midnight Commander or the KDE Konqueror. @value{tramp} expects
749 the fish server implementation from the KDE kioslave. That means, the
750 file @file{~/.fishsrv.pl} is expected to reside on the remote host.
752 The implementation lacks good performance. The code is offered anyway,
753 maybe somebody can improve the performance.
758 @node External methods
759 @section External methods
760 @cindex methods, external
761 @cindex external methods
763 The external methods operate through multiple channels, using the
764 remote shell connection for many actions while delegating file
765 transfers to an external transfer utility.
767 This saves the overhead of encoding and decoding that multiplexing the
768 transfer through the one connection has with the inline methods.
770 Since external methods need their own overhead opening a new channel,
771 all files which are smaller than @var{tramp-copy-size-limit} are still
772 transferred with the corresponding inline method. It should provide a
773 fair trade-off between both approaches.
776 @item @option{rcp} --- @command{rsh} and @command{rcp}
779 @cindex rcp (with rcp method)
780 @cindex rsh (with rcp method)
782 This method uses the @command{rsh} and @command{rcp} commands to connect
783 to the remote machine and transfer files. This is probably the fastest
784 connection method available.
786 The alternative method @option{remcp} uses the @command{remsh} and
787 @command{rcp} commands. It should be applied on machines where
788 @command{remsh} is used instead of @command{rsh}.
791 @item @option{scp} --- @command{ssh} and @command{scp}
794 @cindex scp (with scp method)
795 @cindex ssh (with scp method)
797 Using @command{ssh} to connect to the remote host and @command{scp} to
798 transfer files between the machines is the best method for securely
799 connecting to a remote machine and accessing files.
801 The performance of this option is also quite good. It may be slower than
802 the inline methods when you often open and close small files however.
803 The cost of the cryptographic handshake at the start of an @command{scp}
804 session can begin to absorb the advantage that the lack of encoding and
807 There are also two variants, @option{scp1} and @option{scp2}, that
808 call @samp{ssh -1} and @samp{ssh -2}, respectively. This way, you can
809 explicitly select whether you want to use the SSH protocol version 1
810 or 2 to connect to the remote host. (You can also specify in
811 @file{~/.ssh/config}, the SSH configuration file, which protocol
812 should be used, and use the regular @option{scp} method.)
814 Two other variants, @option{scp1_old} and @option{scp2_old}, use the
815 @command{ssh1} and @command{ssh2} commands explicitly. If you don't
816 know what these are, you do not need these options.
818 All the @command{ssh} based methods support the @samp{-p} feature
819 where you can specify a port number to connect to in the host name.
820 For example, the host name @file{host#42} tells @value{tramp} to
821 specify @samp{-p 42} in the argument list for @command{ssh}, and to
822 specify @samp{-P 42} in the argument list for @command{scp}.
825 @item @option{sftp} --- @command{ssh} and @command{sftp}
828 @cindex sftp (with sftp method)
829 @cindex ssh (with sftp method)
831 That is mostly the same method as @option{scp}, but using
832 @command{sftp} as transfer command. So the same remarks are valid.
834 This command does not work like @value{ftppackagename}, where
835 @command{ftp} is called interactively, and all commands are send from
836 within this session. Instead of, @command{ssh} is used for login.
838 This method supports the @samp{-p} argument.
841 @item @option{rsync} --- @command{ssh} and @command{rsync}
844 @cindex rsync (with rsync method)
845 @cindex ssh (with rsync method)
847 Using the @command{ssh} command to connect securely to the remote
848 machine and the @command{rsync} command to transfer files is almost
849 identical to the @option{scp} method.
851 While @command{rsync} performs much better than @command{scp} when
852 transferring files that exist on both hosts, this advantage is lost if
853 the file exists only on one side of the connection. A file can exists
854 on both the remote and local host, when you copy a file from/to a
855 remote host. When you just open a file from the remote host (or write
856 a file there), a temporary file on the local side is kept as long as
857 the corresponding buffer, visiting this file, is alive.
859 This method supports the @samp{-p} argument.
862 @item @option{scpx} --- @command{ssh} and @command{scp}
865 @cindex scp (with scpx method)
866 @cindex ssh (with scpx method)
868 As you would expect, this is similar to @option{scp}, only a little
869 different. Whereas @option{scp} opens a normal interactive shell on
870 the remote host, this option uses @samp{ssh -t -t @var{host} -l
871 @var{user} /bin/sh} to open a connection. This is useful for users
872 where the normal login shell is set up to ask them a number of
873 questions when logging in. This procedure avoids these questions, and
874 just gives @value{tramp} a more-or-less `standard' login shell to work
877 This is also useful for Windows users where @command{ssh}, when
878 invoked from an @value{emacsname} buffer, tells them that it is not
879 allocating a pseudo tty. When this happens, the login shell is wont
880 to not print any shell prompt, which confuses @value{tramp} mightily.
882 This method supports the @samp{-p} argument.
885 @item @option{scpc} --- @command{ssh} and @command{scp}
888 @cindex scp (with scpc method)
889 @cindex ssh (with scpc method)
891 Newer versions of @option{ssh} (for example OpenSSH 4) offer an option
892 @option{ControlMaster}. This allows @option{scp} to reuse an existing
893 @option{ssh} channel, which increases performance.
895 Before you use this method, you shall check whether your @option{ssh}
896 implementation does support this option. Try from the command line
899 ssh localhost -o ControlMaster=yes
902 This method supports the @samp{-p} argument.
905 @item @option{rsyncc} --- @command{ssh} and @command{rsync}
906 @cindex method rsyncc
907 @cindex rsyncc method
908 @cindex rsync (with rsyncc method)
909 @cindex ssh (with rsyncc method)
911 Like the @option{scpc} method, @option{rsyncc} improves the underlying
912 @command{ssh} connection by the option @option{ControlMaster}. This
913 allows @command{rsync} to reuse an existing @command{ssh} channel,
914 which increases performance.
916 This method supports the @samp{-p} argument.
919 @item @option{pscp} --- @command{plink} and @command{pscp}
922 @cindex pscp (with pscp method)
923 @cindex plink (with pscp method)
924 @cindex PuTTY (with pscp method)
926 This method is similar to @option{scp}, but it uses the
927 @command{plink} command to connect to the remote host, and it uses
928 @command{pscp} for transferring the files. These programs are part
929 of PuTTY, an SSH implementation for Windows.
931 This method supports the @samp{-P} argument.
934 @item @option{psftp} --- @command{plink} and @command{psftp}
937 @cindex psftp (with psftp method)
938 @cindex plink (with psftp method)
939 @cindex PuTTY (with psftp method)
941 As you would expect, this method is similar to @option{sftp}, but it
942 uses the @command{plink} command to connect to the remote host, and it
943 uses @command{psftp} for transferring the files. These programs are
944 part of PuTTY, an SSH implementation for Windows.
946 This method supports the @samp{-P} argument.
949 @item @option{fcp} --- @command{fsh} and @command{fcp}
952 @cindex fsh (with fcp method)
953 @cindex fcp (with fcp method)
955 This method is similar to @option{scp}, but it uses the @command{fsh}
956 command to connect to the remote host, and it uses @command{fcp} for
957 transferring the files. @command{fsh/fcp} are a front-end for
958 @command{ssh} which allow for reusing the same @command{ssh} session
959 for submitting several commands. This avoids the startup overhead of
960 @command{scp} (which has to establish a secure connection whenever it
961 is called). Note, however, that you can also use one of the inline
962 methods to achieve a similar effect.
964 This method uses the command @samp{fsh @var{host} -l @var{user}
965 /bin/sh -i} to establish the connection, it does not work to just say
966 @command{fsh @var{host} -l @var{user}}.
971 There is no inline method using @command{fsh} as the multiplexing
972 provided by the program is not very useful in our context. @value{tramp}
973 opens just one connection to the remote host and then keeps it open,
981 This is not a native @value{tramp} method. Instead of, it forwards all
982 requests to @value{ftppackagename}.
984 This works only for unified filenames, see @ref{Issues}.
988 @item @option{smb} --- @command{smbclient}
992 This is another not natural @value{tramp} method. It uses the
993 @command{smbclient} command on different Unices in order to connect to
994 an SMB server. An SMB server might be a Samba (or CIFS) server on
995 another UNIX host or, more interesting, a host running MS Windows. So
996 far, it is tested towards MS Windows NT, MS Windows 2000, and MS
999 The first directory in the localname must be a share name on the remote
1000 host. Remember, that the @code{$} character in which default shares
1001 usually end, must be written @code{$$} due to environment variable
1002 substitution in file names. If no share name is given (i.e. remote
1003 directory @code{/}), all available shares are listed.
1005 Since authorization is done on share level, you will be prompted
1006 always for a password if you access another share on the same host.
1007 This can be suppressed by @ref{Password handling}.
1009 MS Windows uses for authorization both a user name and a domain name.
1010 Because of this, the @value{tramp} syntax has been extended: you can
1011 specify a user name which looks like @code{user%domain} (the real user
1012 name, then a percent sign, then the domain name). So, to connect to
1013 the machine @code{melancholia} as user @code{daniel} of the domain
1014 @code{BIZARRE}, and edit @file{.emacs} in the home directory (share
1015 @code{daniel$}) I would specify the filename @file{@trampfn{smb,
1016 daniel%BIZARRE, melancholia, /daniel$$/.emacs}}.
1018 Depending on the Windows domain configuration, a Windows user might be
1019 considered as domain user per default. In order to connect as local
1020 user, the WINS name of that machine must be given as domain name.
1021 Usually, it is the machine name in capital letters. In the example
1022 above, the local user @code{daniel} would be specified as
1023 @file{@trampfn{smb, daniel%MELANCHOLIA, melancholia, /daniel$$/.emacs}}.
1025 The domain name as well as the user name are optional. If no user
1026 name is specified at all, the anonymous user (without password
1027 prompting) is assumed. This is different from all other @value{tramp}
1028 methods, where in such a case the local user name is taken.
1030 The @option{smb} method supports the @samp{-p} argument.
1032 @strong{Please note:} If @value{emacsname} runs locally under MS
1033 Windows, this method isn't available. Instead of, you can use UNC
1034 file names like @file{//melancholia/daniel$$/.emacs}. The only
1035 disadvantage is that there's no possibility to specify another user
1042 @cindex method imaps
1044 @cindex imaps method
1046 Accessing an IMAP mailbox is intended to save files there as encrypted
1047 message. It could be used in case there are no other remote file
1050 @value{tramp} supports both @option{imap} and @option{imaps} methods.
1051 The latter one accesses the IMAP server over ssl.
1053 Both methods support the port number specification.
1055 Note, that special handling is needed for declaring a passphrase for
1056 encryption / decryption of the messages (@pxref{Using an
1057 authentication file}).
1064 @node GVFS based methods
1065 @section GVFS based external methods
1066 @cindex methods, gvfs
1067 @cindex gvfs based methods
1070 The connection methods described in this section are based on GVFS
1071 @uref{http://en.wikipedia.org/wiki/GVFS}. Via GVFS, the remote
1072 filesystem is mounted locally through FUSE. @value{tramp} uses
1073 internally this local mounted directory.
1075 The communication with GVFS is implemented via D-Bus messages.
1076 Therefore, your @value{emacsname} must have D-Bus integration,
1077 @pxref{Top, , D-Bus, dbus}.
1086 This method provides access to WebDAV files and directories. There
1087 exists also the external method @option{davs}, which uses SSL
1088 encryption for the access.
1090 Both methods support the port number specification as discussed above.
1097 OBEX is an FTP-like access protocol for simple devices, like cell
1098 phones. Until now @value{tramp} supports only OBEX over Bluetooth.
1101 @item @option{synce}
1102 @cindex method synce
1103 @cindex synce method
1105 The @option{synce} method allows communication with Windows Mobile
1106 devices. Beside GVFS for mounting remote files and directories via
1107 FUSE, it needs also the SYNCE-GVFS plugin.
1110 @defopt tramp-gvfs-methods
1111 This customer option, a list, defines the external methods, which
1112 shall be used with GVFS. Per default, these are @option{dav},
1113 @option{davs}, @option{obex} and @option{synce}. Other possible
1114 values are @option{ftp}, @option{sftp} and @option{smb}.
1120 @node Gateway methods
1121 @section Gateway methods
1122 @cindex methods, gateway
1123 @cindex gateway methods
1125 Gateway methods are not methods to access a remote host directly.
1126 These methods are intended to pass firewalls or proxy servers.
1127 Therefore, they can be used for proxy host declarations
1128 (@pxref{Multi-hops}) only.
1130 A gateway method must come always along with a method who supports
1131 port setting. This is because @value{tramp} targets the accompanied
1132 method to @file{localhost#random_port}, from where the firewall or
1133 proxy server is accessed to.
1135 Gateway methods support user name and password declarations. These
1136 are used to authenticate towards the corresponding firewall or proxy
1137 server. They can be passed only if your friendly administrator has
1138 granted your access.
1141 @item @option{tunnel}
1142 @cindex method tunnel
1143 @cindex tunnel method
1145 This method implements an HTTP tunnel via the @command{CONNECT}
1146 command (see RFC 2616, 2817). Any HTTP 1.1 compliant (proxy) server
1147 shall support this command.
1149 As authentication method, only @option{Basic Authentication} (see RFC
1150 2617) is implemented so far. If no port number is given in the
1151 declaration, port @option{8080} is used for the proxy server.
1154 @item @option{socks}
1155 @cindex method socks
1156 @cindex socks method
1158 The @command{socks} method provides access to SOCKSv5 servers (see
1159 RFC 1928). @option{Username/Password Authentication} according to RFC
1162 The default port number of the socks server is @option{1080}, if not
1163 specified otherwise.
1169 @node Default Method
1170 @section Selecting a default method
1171 @cindex default method
1173 @vindex tramp-default-method
1174 When you select an appropriate transfer method for your typical usage
1175 you should set the variable @code{tramp-default-method} to reflect that
1176 choice. This variable controls which method will be used when a method
1177 is not specified in the @value{tramp} file name. For example:
1180 (setq tramp-default-method "ssh")
1183 @vindex tramp-default-method-alist
1184 You can also specify different methods for certain user/host
1185 combinations, via the variable @code{tramp-default-method-alist}. For
1186 example, the following two lines specify to use the @option{ssh}
1187 method for all user names matching @samp{john} and the @option{rsync}
1188 method for all host names matching @samp{lily}. The third line
1189 specifies to use the @option{su} method for the user @samp{root} on
1190 the machine @samp{localhost}.
1193 (add-to-list 'tramp-default-method-alist '("" "john" "ssh"))
1194 (add-to-list 'tramp-default-method-alist '("lily" "" "rsync"))
1195 (add-to-list 'tramp-default-method-alist
1196 '("\\`localhost\\'" "\\`root\\'" "su"))
1200 See the documentation for the variable
1201 @code{tramp-default-method-alist} for more details.
1203 External methods are normally preferable to inline methods, giving
1206 @xref{Inline methods}.
1207 @xref{External methods}.
1209 Another consideration with the selection of transfer methods is the
1210 environment you will use them in and, especially when used over the
1211 Internet, the security implications of your preferred method.
1213 The @option{rsh} and @option{telnet} methods send your password as
1214 plain text as you log in to the remote machine, as well as
1215 transferring the files in such a way that the content can easily be
1216 read from other machines.
1218 If you need to connect to remote systems that are accessible from the
1219 Internet, you should give serious thought to using @option{ssh} based
1220 methods to connect. These provide a much higher level of security,
1221 making it a non-trivial exercise for someone to obtain your password
1222 or read the content of the files you are editing.
1225 @subsection Which method is the right one for me?
1226 @cindex choosing the right method
1228 Given all of the above, you are probably thinking that this is all fine
1229 and good, but it's not helping you to choose a method! Right you are.
1230 As a developer, we don't want to boss our users around but give them
1231 maximum freedom instead. However, the reality is that some users would
1232 like to have some guidance, so here I'll try to give you this guidance
1233 without bossing you around. You tell me whether it works @dots{}
1235 My suggestion is to use an inline method. For large files, external
1236 methods might be more efficient, but I guess that most people will
1237 want to edit mostly small files. And if you access large text files,
1238 compression (driven by @var{tramp-inline-compress-start-size}) shall
1239 still result in good performance.
1241 I guess that these days, most people can access a remote machine by
1242 using @command{ssh}. So I suggest that you use the @option{ssh}
1243 method. So, type @kbd{C-x C-f @trampfn{ssh, root, otherhost,
1244 /etc/motd} @key{RET}} to edit the @file{/etc/motd} file on the other
1247 If you can't use @option{ssh} to log in to the remote host, then
1248 select a method that uses a program that works. For instance, Windows
1249 users might like the @option{plink} method which uses the PuTTY
1250 implementation of @command{ssh}. Or you use Kerberos and thus like
1253 For the special case of editing files on the local host as another
1254 user, see the @option{su} or @option{sudo} methods. They offer
1255 shortened syntax for the @samp{root} account, like
1256 @file{@trampfn{su, , , /etc/motd}}.
1258 People who edit large files may want to consider @option{scpc} instead
1259 of @option{ssh}, or @option{pscp} instead of @option{plink}. These
1260 external methods are faster than inline methods for large files.
1261 Note, however, that external methods suffer from some limitations.
1262 Please try first whether you really get a noticeable speed advantage
1263 from using an external method! Maybe even for large files, inline
1264 methods are fast enough.
1268 @section Selecting a default user
1269 @cindex default user
1271 The user part of a @value{tramp} file name can be omitted. Usually,
1272 it is replaced by the user name you are logged in. Often, this is not
1273 what you want. A typical use of @value{tramp} might be to edit some
1274 files with root permissions on the local host. This case, you should
1275 set the variable @code{tramp-default-user} to reflect that choice.
1279 (setq tramp-default-user "root")
1282 @code{tramp-default-user} is regarded as obsolete, and will be removed
1285 @vindex tramp-default-user-alist
1286 You can also specify different users for certain method/host
1287 combinations, via the variable @code{tramp-default-user-alist}. For
1288 example, if you always have to use the user @samp{john} in the domain
1289 @samp{somewhere.else}, you can specify the following:
1292 (add-to-list 'tramp-default-user-alist
1293 '("ssh" ".*\\.somewhere\\.else\\'" "john"))
1297 See the documentation for the variable
1298 @code{tramp-default-user-alist} for more details.
1300 One trap to fall in must be known. If @value{tramp} finds a default
1301 user, this user will be passed always to the connection command as
1302 parameter (for example @samp{ssh here.somewhere.else -l john}. If you
1303 have specified another user for your command in its configuration
1304 files, @value{tramp} cannot know it, and the remote access will fail.
1305 If you have specified in the given example in @file{~/.ssh/config} the
1309 Host here.somewhere.else
1314 than you must discard selecting a default user by @value{tramp}. This
1315 will be done by setting it to @code{nil} (or @samp{lily}, likewise):
1318 (add-to-list 'tramp-default-user-alist
1319 '("ssh" "\\`here\\.somewhere\\.else\\'" nil))
1322 The last entry in @code{tramp-default-user-alist} could be your
1323 default user you'll apply predominantly. You shall @emph{append} it
1324 to that list at the end:
1327 (add-to-list 'tramp-default-user-alist '(nil nil "jonas") t)
1332 @section Selecting a default host
1333 @cindex default host
1335 @vindex tramp-default-host
1336 Finally, it is even possible to omit the host name part of a
1337 @value{tramp} file name. This case, the value of the variable
1338 @code{tramp-default-host} is used. Per default, it is initialized
1339 with the host name your local @value{emacsname} is running.
1341 If you, for example, use @value{tramp} mainly to contact the host
1342 @samp{target} as user @samp{john}, you can specify:
1345 (setq tramp-default-user "john"
1346 tramp-default-host "target")
1349 Then the simple file name @samp{@trampfn{ssh, , ,}} will connect you
1350 to John's home directory on target.
1352 Note, however, that the most simplification @samp{/::} won't work,
1353 because @samp{/:} is the prefix for quoted file names.
1358 @section Connecting to a remote host using multiple hops
1362 Sometimes, the methods described before are not sufficient. Sometimes,
1363 it is not possible to connect to a remote host using a simple command.
1364 For example, if you are in a secured network, you might have to log in
1365 to a `bastion host' first before you can connect to the outside world.
1366 Of course, the target host may also require a bastion host.
1368 @vindex tramp-default-proxies-alist
1369 In order to specify such multiple hops, it is possible to define a proxy
1370 host to pass through, via the variable
1371 @code{tramp-default-proxies-alist}. This variable keeps a list of
1372 triples (@var{host} @var{user} @var{proxy}).
1374 The first matching item specifies the proxy host to be passed for a
1375 file name located on a remote target matching @var{user}@@@var{host}.
1376 @var{host} and @var{user} are regular expressions or @code{nil}, which
1377 is interpreted as a regular expression which always matches.
1379 @var{proxy} must be a Tramp filename which localname part is ignored.
1380 Method and user name on @var{proxy} are optional, which is interpreted
1381 with the default values.
1383 The method must be an inline or gateway method (@pxref{Inline
1384 methods}, @pxref{Gateway methods}).
1387 The method must be an inline method (@pxref{Inline methods}).
1389 If @var{proxy} is @code{nil}, no additional hop is required reaching
1390 @var{user}@@@var{host}.
1392 If you, for example, must pass the host @samp{bastion.your.domain} as
1393 user @samp{bird} for any remote host which is not located in your local
1397 (add-to-list 'tramp-default-proxies-alist
1398 '("\\." nil "@trampfn{ssh, bird, bastion.your.domain,}"))
1399 (add-to-list 'tramp-default-proxies-alist
1400 '("\\.your\\.domain\\'" nil nil))
1403 Please note the order of the code. @code{add-to-list} adds elements at the
1404 beginning of a list. Therefore, most relevant rules must be added last.
1406 Proxy hosts can be cascaded. If there is another host called
1407 @samp{jump.your.domain}, which is the only one in your local domain who
1408 is allowed connecting @samp{bastion.your.domain}, you can add another
1412 (add-to-list 'tramp-default-proxies-alist
1413 '("\\`bastion\\.your\\.domain\\'"
1415 "@trampfn{ssh, , jump.your.domain,}"))
1418 @var{proxy} can contain the patterns @code{%h} or @code{%u}. These
1419 patterns are replaced by the strings matching @var{host} or
1420 @var{user}, respectively.
1422 If you, for example, wants to work as @samp{root} on hosts in the
1423 domain @samp{your.domain}, but login as @samp{root} is disabled for
1424 non-local access, you might add the following rule:
1427 (add-to-list 'tramp-default-proxies-alist
1428 '("\\.your\\.domain\\'" "\\`root\\'" "@trampfn{ssh, , %h,}"))
1431 Opening @file{@trampfn{sudo, , randomhost.your.domain,}} would connect
1432 first @samp{randomhost.your.domain} via @code{ssh} under your account
1433 name, and perform @code{sudo -u root} on that host afterwards. It is
1434 important to know that the given method is applied on the host which
1435 has been reached so far. @code{sudo -u root}, applied on your local
1436 host, wouldn't be useful here.
1438 @var{host}, @var{user} and @var{proxy} can also be Lisp forms. These
1439 forms are evaluated, and must return a string, or @code{nil}. The
1440 previous example could be generalized then: For all hosts except my
1441 local one connect via @code{ssh} first, and apply @code{sudo -u root}
1445 (add-to-list 'tramp-default-proxies-alist
1446 '(nil "\\`root\\'" "@trampfn{ssh, , %h,}"))
1447 (add-to-list 'tramp-default-proxies-alist
1448 '((regexp-quote (system-name)) nil nil))
1451 This is the recommended configuration to work as @samp{root} on remote
1455 Finally, @code{tramp-default-proxies-alist} can be used to pass
1456 firewalls or proxy servers. Imagine your local network has a host
1457 @samp{proxy.your.domain} which is used on port 3128 as HTTP proxy to
1458 the outer world. Your friendly administrator has granted you access
1459 under your user name to @samp{host.other.domain} on that proxy
1460 server.@footnote{HTTP tunnels are intended for secure SSL/TLS
1461 communication. Therefore, many proxy server restrict the tunnels to
1462 related target ports. You might need to run your ssh server on your
1463 target host @samp{host.other.domain} on such a port, like 443 (https).
1464 See @uref{http://savannah.gnu.org/maintenance/CvsFromBehindFirewall}
1465 for discussion of ethical issues.} You would need to add the
1469 (add-to-list 'tramp-default-proxies-alist
1470 '("\\`host\\.other\\.domain\\'" nil
1471 "@trampfn{tunnel, , proxy.your.domain#3128,}"))
1474 Gateway methods can be declared as first hop only in a multiple hop
1479 @node Customizing Methods
1480 @section Using Non-Standard Methods
1481 @cindex customizing methods
1482 @cindex using non-standard methods
1483 @cindex create your own methods
1485 There is a variable @code{tramp-methods} which you can change if the
1486 predefined methods don't seem right.
1488 For the time being, I'll refer you to the Lisp documentation of that
1489 variable, accessible with @kbd{C-h v tramp-methods @key{RET}}.
1492 @node Customizing Completion
1493 @section Selecting config files for user/host name completion
1494 @cindex customizing completion
1495 @cindex selecting config files
1496 @vindex tramp-completion-function-alist
1498 The variable @code{tramp-completion-function-alist} is intended to
1499 customize which files are taken into account for user and host name
1500 completion (@pxref{Filename completion}). For every method, it keeps
1501 a set of configuration files, accompanied by a Lisp function able to
1502 parse that file. Entries in @code{tramp-completion-function-alist}
1503 have the form (@var{method} @var{pair1} @var{pair2} ...).
1505 Each @var{pair} is composed of (@var{function} @var{file}).
1506 @var{function} is responsible to extract user names and host names
1507 from @var{file} for completion. There are two functions which access
1510 @defun tramp-get-completion-function method
1511 This function returns the list of completion functions for @var{method}.
1515 (tramp-get-completion-function "rsh")
1517 @result{} ((tramp-parse-rhosts "/etc/hosts.equiv")
1518 (tramp-parse-rhosts "~/.rhosts"))
1522 @defun tramp-set-completion-function method function-list
1523 This function sets @var{function-list} as list of completion functions
1528 (tramp-set-completion-function "ssh"
1529 '((tramp-parse-sconfig "/etc/ssh_config")
1530 (tramp-parse-sconfig "~/.ssh/config")))
1532 @result{} ((tramp-parse-sconfig "/etc/ssh_config")
1533 (tramp-parse-sconfig "~/.ssh/config"))
1537 The following predefined functions parsing configuration files exist:
1540 @item @code{tramp-parse-rhosts}
1541 @findex tramp-parse-rhosts
1543 This function parses files which are syntactical equivalent to
1544 @file{~/.rhosts}. It returns both host names and user names, if
1547 @item @code{tramp-parse-shosts}
1548 @findex tramp-parse-shosts
1550 This function parses files which are syntactical equivalent to
1551 @file{~/.ssh/known_hosts}. Since there are no user names specified
1552 in such files, it can return host names only.
1554 @item @code{tramp-parse-sconfig}
1555 @findex tramp-parse-shosts
1557 This function returns the host nicknames defined by @code{Host} entries
1558 in @file{~/.ssh/config} style files.
1560 @item @code{tramp-parse-shostkeys}
1561 @findex tramp-parse-shostkeys
1563 SSH2 parsing of directories @file{/etc/ssh2/hostkeys/*} and
1564 @file{~/ssh2/hostkeys/*}. Hosts are coded in file names
1565 @file{hostkey_@var{portnumber}_@var{host-name}.pub}. User names
1566 are always @code{nil}.
1568 @item @code{tramp-parse-sknownhosts}
1569 @findex tramp-parse-shostkeys
1571 Another SSH2 style parsing of directories like
1572 @file{/etc/ssh2/knownhosts/*} and @file{~/ssh2/knownhosts/*}. This
1573 case, hosts names are coded in file names
1574 @file{@var{host-name}.@var{algorithm}.pub}. User names are always @code{nil}.
1576 @item @code{tramp-parse-hosts}
1577 @findex tramp-parse-hosts
1579 A function dedicated to @file{/etc/hosts} style files. It returns
1582 @item @code{tramp-parse-passwd}
1583 @findex tramp-parse-passwd
1585 A function which parses @file{/etc/passwd} like files. Obviously, it
1586 can return user names only.
1588 @item @code{tramp-parse-netrc}
1589 @findex tramp-parse-netrc
1591 Finally, a function which parses @file{~/.netrc} like files.
1594 If you want to keep your own data in a file, with your own structure,
1595 you might provide such a function as well. This function must meet
1596 the following conventions:
1598 @defun my-tramp-parse file
1599 @var{file} must be either a file name on your host, or @code{nil}.
1600 The function must return a list of (@var{user} @var{host}), which are
1601 taken as candidates for user and host name completion.
1605 (my-tramp-parse "~/.my-tramp-hosts")
1607 @result{} ((nil "toto") ("daniel" "melancholia"))
1612 @node Password handling
1613 @section Reusing passwords for several connections.
1616 Sometimes it is necessary to connect to the same remote host several
1617 times. Reentering passwords again and again would be annoying, when
1618 the chosen method does not support access without password prompt
1619 through own configuration.
1621 The best recommendation is to use the method's own mechanism for
1622 password handling. Consider @command{ssh-agent} for @option{ssh}-like
1623 methods, or @command{pageant} for @option{plink}-like methods.
1625 However, if you cannot apply such native password handling,
1626 @value{tramp} offers altenatives.
1629 @anchor{Using an authentication file}
1630 @subsection Using an authentication file
1632 @vindex auth-sources
1633 The package @file{auth-source.el}, originally developed in No Gnus,
1634 offers the possibility to read passwords from a file, like FTP does it
1635 from @file{~/.netrc}. The default authentication file is
1636 @file{~/.authinfo.gpg}, this can be changed via the variable
1637 @code{auth-sources}.
1640 A typical entry in the authentication file would be
1643 machine melancholia port scp login daniel password geheim
1646 The port can be any @value{tramp} method (@pxref{Inline methods},
1647 @pxref{External methods}), to match only this method. When you omit
1648 the port, you match all @value{tramp} methods.
1651 A special case are @option{imap}-like methods. Authentication with
1652 the IMAP server is performed via @file{imap.el}, there is no special
1653 need from @value{tramp} point of view. An additional passphrase, used
1654 for symmetric encryption and decryption of the stored messages, should
1655 be given with the special port indication @option{tramp-imap}:
1658 machine melancholia port tramp-imap login daniel password ultrageheim
1662 @anchor{Caching passwords}
1663 @subsection Caching passwords
1665 If there is no authentication file, @value{tramp} caches the passwords
1666 entered by you. They will be reused next time if a connection needs
1667 them for the same user name and host name, independently of the
1670 @vindex password-cache-expiry
1671 Passwords are not saved permanently, that means the password caching
1672 is limited to the lifetime of your @value{emacsname} session. You
1673 can influence the lifetime of password caching by customizing the
1674 variable @code{password-cache-expiry}. The value is the number of
1675 seconds how long passwords are cached. Setting it to @code{nil}
1676 disables the expiration.
1678 @vindex password-cache
1679 If you don't like this feature for security reasons, password caching
1680 can be disabled totally by customizing the variable
1681 @code{password-cache} (setting it to @code{nil}).
1683 Implementation Note: password caching is based on the package
1684 @file{password-cache.el}. For the time being, it is activated only
1685 when this package is seen in the @code{load-path} while loading
1687 @ifset installchapter
1688 If you don't use No Gnus, you can take @file{password.el} from the
1689 @value{tramp} @file{contrib} directory, see @ref{Installation
1694 @node Connection caching
1695 @section Reusing connection related information.
1698 @vindex tramp-persistency-file-name
1699 In order to reduce initial connection time, @value{tramp} stores
1700 connection related information persistently. The variable
1701 @code{tramp-persistency-file-name} keeps the file name where these
1702 information are written. Its default value is
1704 @file{~/.emacs.d/tramp}.
1707 @file{~/.xemacs/tramp}.
1709 It is recommended to choose a local file name.
1711 @value{tramp} reads this file during startup, and writes it when
1712 exiting @value{emacsname}. You can simply remove this file if
1713 @value{tramp} shall be urged to recompute these information next
1714 @value{emacsname} startup time.
1716 Using such persistent information can be disabled by setting
1717 @code{tramp-persistency-file-name} to @code{nil}.
1719 Once consequence of reusing connection related information is that
1720 @var{tramp} needs to distinguish hosts. If you, for example, run a
1721 local @code{sshd} on port 3001, which tunnels @command{ssh} to another
1722 host, you could access both @file{@trampfn{ssh, , localhost,}} and
1723 @file{@trampfn{ssh, , localhost#3001,}}. @var{tramp} would use the
1724 same host related information (like paths, Perl variants, etc) for
1725 both connections, although the information is valid only for one of
1728 In order to avoid trouble, you must use another host name for one of
1729 the connections, like introducing a @option{Host} section in
1730 @file{~/.ssh/config} (@pxref{Frequently Asked Questions}) or applying
1731 multiple hops (@pxref{Multi-hops}).
1733 When @value{tramp} detects a changed operating system version on a
1734 remote host (via the command @command{uname -sr}), it flushes all
1735 connection related information for this host, and opens the
1739 @node Remote Programs
1740 @section How @value{tramp} finds and uses programs on the remote machine.
1742 @value{tramp} depends on a number of programs on the remote host in order to
1743 function, including @command{ls}, @command{test}, @command{find} and
1746 In addition to these required tools, there are various tools that may be
1747 required based on the connection method. See @ref{Inline methods} and
1748 @ref{External methods} for details on these.
1750 Certain other tools, such as @command{perl} (or @command{perl5}) and
1751 @command{grep} will be used if they can be found. When they are
1752 available, they are used to improve the performance and accuracy of
1755 @vindex tramp-remote-path
1756 @vindex tramp-default-remote-path
1757 @vindex tramp-own-remote-path
1758 @defopt tramp-remote-path
1759 When @value{tramp} connects to the remote machine, it searches for the
1760 programs that it can use. The variable @code{tramp-remote-path}
1761 controls the directories searched on the remote machine.
1763 By default, this is set to a reasonable set of defaults for most
1764 machines. The symbol @code{tramp-default-remote-path} is a place
1765 holder, it is replaced by the list of directories received via the
1766 command @command{getconf PATH} on your remote machine. For example,
1767 on GNU Debian this is @file{/bin:/usr/bin}, whereas on Solaris this is
1768 @file{/usr/xpg4/bin:/usr/ccs/bin:/usr/bin:/opt/SUNWspro/bin}. It is
1769 recommended to apply this symbol on top of @code{tramp-remote-path}.
1771 It is possible, however, that your local (or remote ;) system
1772 administrator has put the tools you want in some obscure local
1775 In this case, you can still use them with @value{tramp}. You simply
1776 need to add code to your @file{.emacs} to add the directory to the
1777 remote path. This will then be searched by @value{tramp} when you
1778 connect and the software found.
1780 To add a directory to the remote search path, you could use code such
1784 @i{;; We load @value{tramp} to define the variable.}
1786 @i{;; We have @command{perl} in "/usr/local/perl/bin"}
1787 (add-to-list 'tramp-remote-path "/usr/local/perl/bin")
1790 Another possibility is to reuse the path settings of your remote
1791 account, when you log in. Usually, these settings are overwritten,
1792 because they might not be useful for @value{tramp}. The place holder
1793 @code{tramp-own-remote-path} preserves these settings. You can
1797 (add-to-list 'tramp-remote-path 'tramp-own-remote-path)
1801 @value{tramp} caches several information, like the Perl binary
1802 location. The changed remote search path wouldn't affect these
1803 settings. In order to force @value{tramp} to recompute these values,
1804 you must exit @value{emacsname}, remove your persistency file
1805 (@pxref{Connection caching}), and restart @value{emacsname}.
1808 @node Remote shell setup
1809 @section Remote shell setup hints
1810 @cindex remote shell setup
1811 @cindex @file{.profile} file
1812 @cindex @file{.login} file
1813 @cindex shell init files
1815 As explained in the @ref{Overview} section, @value{tramp} connects to the
1816 remote host and talks to the shell it finds there. Of course, when you
1817 log in, the shell executes its init files. Suppose your init file
1818 requires you to enter the birth date of your mother; clearly @value{tramp}
1819 does not know this and hence fails to log you in to that host.
1821 There are different possible strategies for pursuing this problem. One
1822 strategy is to enable @value{tramp} to deal with all possible situations.
1823 This is a losing battle, since it is not possible to deal with
1824 @emph{all} situations. The other strategy is to require you to set up
1825 the remote host such that it behaves like @value{tramp} expects. This might
1826 be inconvenient because you have to invest a lot of effort into shell
1827 setup before you can begin to use @value{tramp}.
1829 The package, therefore, pursues a combined approach. It tries to
1830 figure out some of the more common setups, and only requires you to
1831 avoid really exotic stuff. For example, it looks through a list of
1832 directories to find some programs on the remote host. And also, it
1833 knows that it is not obvious how to check whether a file exists, and
1834 therefore it tries different possibilities. (On some hosts and
1835 shells, the command @command{test -e} does the trick, on some hosts
1836 the shell builtin doesn't work but the program @command{/usr/bin/test
1837 -e} or @command{/bin/test -e} works. And on still other hosts,
1838 @command{ls -d} is the right way to do this.)
1840 Below you find a discussion of a few things that @value{tramp} does not deal
1841 with, and that you therefore have to set up correctly.
1844 @item @var{shell-prompt-pattern}
1845 @vindex shell-prompt-pattern
1847 After logging in to the remote host, @value{tramp} has to wait for the remote
1848 shell startup to finish before it can send commands to the remote
1849 shell. The strategy here is to wait for the shell prompt. In order to
1850 recognize the shell prompt, the variable @code{shell-prompt-pattern} has
1851 to be set correctly to recognize the shell prompt on the remote host.
1853 Note that @value{tramp} requires the match for @code{shell-prompt-pattern}
1854 to be at the end of the buffer. Many people have something like the
1855 following as the value for the variable: @code{"^[^>$][>$] *"}. Now
1856 suppose your shell prompt is @code{a <b> c $ }. In this case,
1857 @value{tramp} recognizes the @code{>} character as the end of the prompt,
1858 but it is not at the end of the buffer.
1860 @item @var{tramp-shell-prompt-pattern}
1861 @vindex tramp-shell-prompt-pattern
1863 This regular expression is used by @value{tramp} in the same way as
1864 @code{shell-prompt-pattern}, to match prompts from the remote shell.
1865 This second variable exists because the prompt from the remote shell
1866 might be different from the prompt from a local shell --- after all,
1867 the whole point of @value{tramp} is to log in to remote hosts as a
1868 different user. The default value of
1869 @code{tramp-shell-prompt-pattern} is the same as the default value of
1870 @code{shell-prompt-pattern}, which is reported to work well in many
1873 @item @var{tramp-password-prompt-regexp}
1874 @vindex tramp-password-prompt-regexp
1875 @vindex tramp-wrong-passwd-regexp
1877 During login, @value{tramp} might be forced to enter a password or a
1878 passphrase. The difference between both is that a password is
1879 requested from the shell on the remote host, while a passphrase is
1880 needed for accessing local authentication information, like your ssh
1883 @var{tramp-password-prompt-regexp} handles the detection of such
1884 requests for English environments. When you use another localization
1885 of your (local or remote) host, you might need to adapt this. Example:
1889 tramp-password-prompt-regexp
1893 '("passphrase" "Passphrase"
1895 "password" "Password"
1897 "passwort" "Passwort"
1899 "mot de passe" "Mot de passe") t)
1903 In parallel, it might also be necessary to adapt
1904 @var{tramp-wrong-passwd-regexp}.
1906 @item @command{tset} and other questions
1907 @cindex Unix command tset
1908 @cindex tset Unix command
1910 Some people invoke the @command{tset} program from their shell startup
1911 scripts which asks the user about the terminal type of the shell.
1912 Maybe some shells ask other questions when they are started.
1913 @value{tramp} does not know how to answer these questions. There are
1914 two approaches for dealing with this problem. One approach is to take
1915 care that the shell does not ask any questions when invoked from
1916 @value{tramp}. You can do this by checking the @code{TERM}
1917 environment variable, it will be set to @code{dumb} when connecting.
1919 @vindex tramp-terminal-type
1920 The variable @code{tramp-terminal-type} can be used to change this value
1923 @vindex tramp-actions-before-shell
1924 The other approach is to teach @value{tramp} about these questions. See
1925 the variable @code{tramp-actions-before-shell}. Example:
1928 (defconst my-tramp-prompt-regexp
1929 (concat (regexp-opt '("Enter the birth date of your mother:") t)
1931 "Regular expression matching my login prompt question.")
1933 (defun my-tramp-action (proc vec)
1934 "Enter \"19000101\" in order to give a correct answer."
1935 (save-window-excursion
1936 (with-current-buffer (tramp-get-connection-buffer vec)
1937 (tramp-message vec 6 "\n%s" (buffer-string))
1938 (tramp-send-string vec "19000101"))))
1940 (add-to-list 'tramp-actions-before-shell
1941 '(my-tramp-prompt-regexp my-tramp-action))
1945 @item Environment variables named like users in @file{.profile}
1947 If you have a user named frumple and set the variable @code{FRUMPLE} in
1948 your shell environment, then this might cause trouble. Maybe rename
1949 the variable to @code{FRUMPLE_DIR} or the like.
1951 This weird effect was actually reported by a @value{tramp} user!
1954 @item Non-Bourne commands in @file{.profile}
1956 After logging in to the remote host, @value{tramp} issues the command
1957 @command{exec /bin/sh}. (Actually, the command is slightly
1958 different.) When @command{/bin/sh} is executed, it reads some init
1959 files, such as @file{~/.shrc} or @file{~/.profile}.
1961 Now, some people have a login shell which is not @code{/bin/sh} but a
1962 Bourne-ish shell such as bash or ksh. Some of these people might put
1963 their shell setup into the files @file{~/.shrc} or @file{~/.profile}.
1964 This way, it is possible for non-Bourne constructs to end up in those
1965 files. Then, @command{exec /bin/sh} might cause the Bourne shell to
1966 barf on those constructs.
1968 As an example, imagine somebody putting @command{export FOO=bar} into
1969 the file @file{~/.profile}. The standard Bourne shell does not
1970 understand this syntax and will emit a syntax error when it reaches
1973 Another example is the tilde (@code{~}) character, say when adding
1974 @file{~/bin} to @code{$PATH}. Many Bourne shells will not expand this
1975 character, and since there is usually no directory whose name consists
1976 of the single character tilde, strange things will happen.
1978 What can you do about this?
1980 Well, one possibility is to make sure that everything in
1981 @file{~/.shrc} and @file{~/.profile} on all remote hosts is
1982 Bourne-compatible. In the above example, instead of @command{export
1983 FOO=bar}, you might use @command{FOO=bar; export FOO} instead.
1985 The other possibility is to put your non-Bourne shell setup into some
1986 other files. For example, bash reads the file @file{~/.bash_profile}
1987 instead of @file{~/.profile}, if the former exists. So bash
1988 aficionados just rename their @file{~/.profile} to
1989 @file{~/.bash_profile} on all remote hosts, and Bob's your uncle.
1991 The @value{tramp} developers would like to circumvent this problem, so
1992 if you have an idea about it, please tell us. However, we are afraid
1993 it is not that simple: before saying @command{exec /bin/sh},
1994 @value{tramp} does not know which kind of shell it might be talking
1995 to. It could be a Bourne-ish shell like ksh or bash, or it could be a
1996 csh derivative like tcsh, or it could be zsh, or even rc. If the
1997 shell is Bourne-ish already, then it might be prudent to omit the
1998 @command{exec /bin/sh} step. But how to find out if the shell is
2004 @node Auto-save and Backup
2005 @section Auto-save and Backup configuration
2009 @vindex backup-directory-alist
2012 @vindex bkup-backup-directory-info
2015 Normally, @value{emacsname} writes backup files to the same directory
2016 as the original files, but this behavior can be changed via the
2019 @code{backup-directory-alist}.
2022 @code{bkup-backup-directory-info}.
2024 In connection with @value{tramp}, this can have unexpected side
2025 effects. Suppose that you specify that all backups should go to the
2026 directory @file{~/.emacs.d/backups/}, and then you edit the file
2027 @file{@trampfn{su, root, localhost, /etc/secretfile}}. The effect is
2028 that the backup file will be owned by you and not by root, thus
2029 possibly enabling others to see it even if they were not intended to
2034 @code{backup-directory-alist}
2037 @code{bkup-backup-directory-info}
2039 is @code{nil} (the default), such problems do not occur.
2041 Therefore, it is useful to set special values for @value{tramp}
2042 files. For example, the following statement effectively `turns off'
2045 @code{backup-directory-alist}
2048 @code{bkup-backup-directory-info}
2050 for @value{tramp} files:
2054 (add-to-list 'backup-directory-alist
2055 (cons tramp-file-name-regexp nil))
2060 (require 'backup-dir)
2061 (add-to-list 'bkup-backup-directory-info
2062 (list tramp-file-name-regexp ""))
2067 It is also possible to disable backups depending on the used method.
2068 The following code disables backups for the @option{su} and
2069 @option{sudo} methods:
2072 (setq backup-enable-predicate
2074 (and (normal-backup-enable-predicate name)
2076 (let ((method (file-remote-p name 'method)))
2077 (when (stringp method)
2078 (member method '("su" "sudo"))))))))
2083 Another possibility is to use the @value{tramp} variable
2085 @code{tramp-backup-directory-alist}.
2088 @code{tramp-bkup-backup-directory-info}.
2090 This variable has the same meaning like
2092 @code{backup-directory-alist}.
2095 @code{bkup-backup-directory-info}.
2097 If a @value{tramp} file is backed up, and DIRECTORY is an absolute
2098 local file name, DIRECTORY is prepended with the @value{tramp} file
2099 name prefix of the file to be backed up.
2106 (add-to-list 'backup-directory-alist
2107 (cons "." "~/.emacs.d/backups/"))
2108 (setq tramp-backup-directory-alist backup-directory-alist)
2113 (require 'backup-dir)
2114 (add-to-list 'bkup-backup-directory-info
2115 (list "." "~/.emacs.d/backups/" 'full-path))
2116 (setq tramp-bkup-backup-directory-info bkup-backup-directory-info)
2121 The backup file name of @file{@trampfn{su, root, localhost,
2122 /etc/secretfile}} would be
2124 @file{@trampfn{su, root, localhost,
2125 ~/.emacs.d/backups/!su:root@@localhost:!etc!secretfile~}}
2128 @file{@trampfn{su, root, localhost,
2129 ~/.emacs.d/backups/![su!root@@localhost]!etc!secretfile~}}
2132 The same problem can happen with auto-saving files.
2134 The variable @code{auto-save-file-name-transforms} keeps information,
2135 on which directory an auto-saved file should go. By default, it is
2136 initialized for @value{tramp} files to the local temporary directory.
2138 On some versions of @value{emacsname}, namely the version built for
2139 Debian GNU/Linux, the variable @code{auto-save-file-name-transforms}
2140 contains the directory where @value{emacsname} was built. A
2141 workaround is to manually set the variable to a sane value.
2143 If auto-saved files should go into the same directory as the original
2144 files, @code{auto-save-file-name-transforms} should be set to @code{nil}.
2146 Another possibility is to set the variable
2147 @code{tramp-auto-save-directory} to a proper value.
2150 For this purpose you can set the variable @code{auto-save-directory}
2155 @node Windows setup hints
2156 @section Issues with Cygwin ssh
2157 @cindex Cygwin, issues
2159 This section needs a lot of work! Please help.
2161 @cindex method sshx with Cygwin
2162 @cindex sshx method with Cygwin
2163 The recent Cygwin installation of @command{ssh} works only with a
2164 Cygwinized @value{emacsname}. You can check it by typing @kbd{M-x
2165 eshell}, and starting @kbd{ssh test.machine}. The problem is evident
2166 if you see a message like this:
2169 Pseudo-terminal will not be allocated because stdin is not a terminal.
2172 Older @command{ssh} versions of Cygwin are told to cooperate with
2173 @value{tramp} selecting @option{sshx} as the connection method. You
2174 can find information about setting up Cygwin in their FAQ at
2175 @uref{http://cygwin.com/faq/}.
2177 @cindex method scpx with Cygwin
2178 @cindex scpx method with Cygwin
2179 If you wish to use the @option{scpx} connection method, then you might
2180 have the problem that @value{emacsname} calls @command{scp} with a
2181 Windows filename such as @code{c:/foo}. The Cygwin version of
2182 @command{scp} does not know about Windows filenames and interprets
2183 this as a remote filename on the host @code{c}.
2185 One possible workaround is to write a wrapper script for @option{scp}
2186 which converts the Windows filename to a Cygwinized filename.
2188 @cindex Cygwin and ssh-agent
2189 @cindex SSH_AUTH_SOCK and @value{emacsname} on Windows
2190 If you want to use either @option{ssh} based method on Windows, then
2191 you might encounter problems with @command{ssh-agent}. Using this
2192 program, you can avoid typing the pass-phrase every time you log in.
2193 However, if you start @value{emacsname} from a desktop shortcut, then
2194 the environment variable @code{SSH_AUTH_SOCK} is not set and so
2195 @value{emacsname} and thus @value{tramp} and thus @command{ssh} and
2196 @command{scp} started from @value{tramp} cannot communicate with
2197 @command{ssh-agent}. It works better to start @value{emacsname} from
2200 If anyone knows how to start @command{ssh-agent} under Windows in such a
2201 way that desktop shortcuts can profit, please holler. I don't really
2202 know anything at all about Windows@dots{}
2206 @chapter Using @value{tramp}
2207 @cindex using @value{tramp}
2209 Once you have installed @value{tramp} it will operate fairly
2210 transparently. You will be able to access files on any remote machine
2211 that you can log in to as though they were local.
2213 Files are specified to @value{tramp} using a formalized syntax specifying the
2214 details of the system to connect to. This is similar to the syntax used
2215 by the @value{ftppackagename} package.
2218 Something that might happen which surprises you is that
2219 @value{emacsname} remembers all your keystrokes, so if you see a
2220 password prompt from @value{emacsname}, say, and hit @kbd{@key{RET}}
2221 twice instead of once, then the second keystroke will be processed by
2222 @value{emacsname} after @value{tramp} has done its thing. Why, this
2223 type-ahead is normal behavior, you say. Right you are, but be aware
2224 that opening a remote file might take quite a while, maybe half a
2225 minute when a connection needs to be opened. Maybe after half a
2226 minute you have already forgotten that you hit that key!
2229 * Filename Syntax:: @value{tramp} filename conventions.
2230 * Alternative Syntax:: URL-like filename syntax.
2231 * Filename completion:: Filename completion.
2232 * Remote processes:: Integration with other @value{emacsname} packages.
2233 * Cleanup remote connections:: Cleanup remote connections.
2237 @node Filename Syntax
2238 @section @value{tramp} filename conventions
2239 @cindex filename syntax
2240 @cindex filename examples
2242 To access the file @var{localname} on the remote machine @var{machine}
2243 you would specify the filename @file{@trampfn{, , machine,
2244 localname}}. This will connect to @var{machine} and transfer the file
2245 using the default method. @xref{Default Method}.
2247 Some examples of @value{tramp} filenames are shown below.
2250 @item @trampfn{, , melancholia, .emacs}
2251 Edit the file @file{.emacs} in your home directory on the machine
2254 @item @trampfn{, , melancholia.danann.net, .emacs}
2255 This edits the same file, using the fully qualified domain name of
2258 @item @trampfn{, , melancholia, ~/.emacs}
2259 This also edits the same file --- the @file{~} is expanded to your
2260 home directory on the remote machine, just like it is locally.
2262 @item @trampfn{, , melancholia, ~daniel/.emacs}
2263 This edits the file @file{.emacs} in the home directory of the user
2264 @code{daniel} on the machine @code{melancholia}. The @file{~<user>}
2265 construct is expanded to the home directory of that user on the remote
2268 @item @trampfn{, , melancholia, /etc/squid.conf}
2269 This edits the file @file{/etc/squid.conf} on the machine
2274 @var{machine} can also be an IPv4 or IPv6 address, like in
2275 @file{@trampfn{, , 127.0.0.1, .emacs}} or @file{@trampfn{, ,
2276 @value{ipv6prefix}::1@value{ipv6postfix}, .emacs}}.
2278 For syntactical reasons, IPv6 addresses must be embedded in square
2279 brackets @file{@value{ipv6prefix}} and @file{@value{ipv6postfix}}.
2282 Unless you specify a different name to use, @value{tramp} will use the
2283 current local user name as the remote user name to log in with. If you
2284 need to log in as a different user, you can specify the user name as
2285 part of the filename.
2287 To log in to the remote machine as a specific user, you use the syntax
2288 @file{@trampfn{, user, machine, path/to.file}}. That means that
2289 connecting to @code{melancholia} as @code{daniel} and editing
2290 @file{.emacs} in your home directory you would specify
2291 @file{@trampfn{, daniel, melancholia, .emacs}}.
2293 It is also possible to specify other file transfer methods
2294 (@pxref{Inline methods}, @pxref{External methods}) as part of the
2297 This is done by putting the method before the user and host name, as
2298 in @file{@value{prefix}@var{method}@value{postfixhop}} (Note the
2302 This is done by replacing the initial @file{@value{prefix}} with
2303 @file{@value{prefix}<method>@value{postfixhop}}. (Note the trailing
2306 The user, machine and file specification remain the same.
2308 So, to connect to the machine @code{melancholia} as @code{daniel},
2309 using the @option{ssh} method to transfer files, and edit
2310 @file{.emacs} in my home directory I would specify the filename
2311 @file{@trampfn{ssh, daniel, melancholia, .emacs}}.
2313 Finally, for some methods it is possible to specify a different port
2314 number than the default one, given by the method. This is specified
2315 by adding @file{#<port>} to the host name, like in @file{@trampfn{ssh,
2316 daniel, melancholia#42, .emacs}}.
2319 @node Alternative Syntax
2320 @section URL-like filename syntax
2321 @cindex filename syntax
2322 @cindex filename examples
2324 Additionally to the syntax described in the previous chapter, it is
2325 possible to use a URL-like syntax for @value{tramp}. This can be
2326 switched on by customizing the variable @code{tramp-syntax}. Please
2327 note that this feature is experimental for the time being.
2329 The variable @code{tramp-syntax} must be set before requiring @value{tramp}:
2332 (setq tramp-syntax 'url)
2336 Then, a @value{tramp} filename would look like this:
2337 @file{/@var{method}://@var{user}@@@var{machine}:@var{port}/@var{path/to.file}}.
2338 @file{/@var{method}://} is mandatory, all other parts are optional.
2339 @file{:@var{port}} is useful for methods only who support this.
2341 The last example from the previous section would look like this:
2342 @file{/ssh://daniel@@melancholia/.emacs}.
2344 For the time being, @code{tramp-syntax} can have the following values:
2348 @item @code{ftp} -- That is the default syntax
2349 @item @code{url} -- URL-like syntax
2352 @item @code{sep} -- That is the default syntax
2353 @item @code{url} -- URL-like syntax
2354 @item @code{ftp} -- EFS-like syntax
2359 @node Filename completion
2360 @section Filename completion
2361 @cindex filename completion
2363 Filename completion works with @value{tramp} for completion of method
2364 names, of user names and of machine names as well as for completion of
2365 file names on remote machines.
2367 In order to enable this, partial completion must be activated in your
2370 @xref{Completion Options, , , @value{emacsdir}}.
2374 If you, for example, type @kbd{C-x C-f @value{prefix}t
2375 @key{TAB}}, @value{tramp} might give you as result the choice for
2378 @multitable {@trampfn{telnet, , melancholia.danann.net,}} {@trampfn{telnet, , 192.168.0.1,}}
2380 @item @value{prefixhop}telnet@value{postfixhop} @tab tmp/
2381 @item @value{prefixhop}toto@value{postfix} @tab
2384 @item @value{prefixhop}telnet@value{postfixhop} @tab @value{prefixhop}toto@value{postfix}
2389 @samp{@value{prefixhop}telnet@value{postfixhop}}
2390 is a possible completion for the respective method,
2392 @samp{tmp/} stands for the directory @file{/tmp} on your local
2395 and @samp{@value{prefixhop}toto@value{postfix}}
2396 might be a host @value{tramp} has detected in your @file{~/.ssh/known_hosts}
2397 file (given you're using default method @option{ssh}).
2399 If you go on to type @kbd{e @key{TAB}}, the minibuffer is completed to
2400 @samp{@value{prefix}telnet@value{postfixhop}}.
2401 Next @kbd{@key{TAB}} brings you all machine names @value{tramp} detects in
2402 your @file{/etc/hosts} file, let's say
2405 @multitable {@trampfn{telnet, , melancholia.danann.net,}} {@trampfn{telnet, , 192.168.0.1,}}
2406 @item @trampfn{telnet, , 127.0.0.1,} @tab @trampfn{telnet, , 192.168.0.1,}
2407 @item @trampfn{telnet, , @value{ipv6prefix}::1@value{ipv6postfix},} @tab @trampfn{telnet, , localhost,}
2408 @item @trampfn{telnet, , melancholia.danann.net,} @tab @trampfn{telnet, , melancholia,}
2412 Now you can choose the desired machine, and you can continue to
2413 complete file names on that machine.
2415 If the configuration files (@pxref{Customizing Completion}), which
2416 @value{tramp} uses for analysis of completion, offer user names, those user
2417 names will be taken into account as well.
2419 Remote machines, which have been visited in the past and kept
2420 persistently (@pxref{Connection caching}), will be offered too.
2422 Once the remote machine identification is completed, it comes to
2423 filename completion on the remote host. This works pretty much like
2424 for files on the local host, with the exception that minibuffer
2425 killing via a double-slash works only on the filename part, except
2426 that filename part starts with @file{//}.
2428 A triple-slash stands for the default behavior.
2431 @xref{Minibuffer File, , , @value{emacsdir}}.
2439 @kbd{C-x C-f @trampfn{telnet, , melancholia, /usr/local/bin//etc} @key{TAB}}
2440 @print{} @trampfn{telnet, , melancholia, /etc}
2442 @kbd{C-x C-f @trampfn{telnet, , melancholia, //etc} @key{TAB}}
2445 @kbd{C-x C-f @trampfn{telnet, , melancholia, /usr/local/bin///etc} @key{TAB}}
2450 @kbd{C-x C-f @trampfn{telnet, , melancholia, /usr/local/bin//}}
2451 @print{} @trampfn{telnet, , melancholia, /}
2453 @kbd{C-x C-f @trampfn{telnet, , melancholia, //}}
2458 A remote directory might have changed its contents out of
2459 @value{emacsname} control, for example by creation or deletion of
2460 files by other processes. Therefore, during filename completion the
2461 remote directory contents is reread regularly in order to detect such
2462 changes, which would be invisible otherwise (@pxref{Connection caching}).
2464 @defopt tramp-completion-reread-directory-timeout
2465 This variable defines the number of seconds since last remote command
2466 before rereading a directory contents. A value of 0 would require an
2467 immediate reread during filename completion, @code{nil} means to use
2468 always cached values for the directory contents.
2472 @node Remote processes
2473 @section Integration with other @value{emacsname} packages.
2477 @value{tramp} supports running processes on a remote host. This
2478 allows to exploit @value{emacsname} packages without modification for
2479 remote file names. It does not work for the @option{ftp} and
2480 @option{smb} methods. Association of a pty, as specified in
2481 @code{start-file-process}, is not supported.
2484 If the remote host is mounted via GVFS (see @ref{GVFS based methods}),
2485 the remote filesystem is mounted locally. Therefore, there are no
2486 remote processes; all processes run still locally on your machine with
2487 an adapted @code{default-directory}. This section does not apply for
2488 such connection methods.
2491 Remote processes are started when a corresponding command is executed
2492 from a buffer belonging to a remote file or directory. Up to now, the
2493 packages @file{compile.el} (commands like @code{compile} and
2494 @code{grep}) and @file{gud.el} (@code{gdb} or @code{perldb}) have been
2495 integrated. Integration of further packages is planned, any help for
2498 When your program is not found in the default search path
2499 @value{tramp} sets on the remote machine, you should either use an
2500 absolute path, or extend @code{tramp-remote-path} (see @ref{Remote
2504 (add-to-list 'tramp-remote-path "~/bin")
2505 (add-to-list 'tramp-remote-path "/appli/pub/bin")
2508 The environment for your program can be adapted by customizing
2509 @code{tramp-remote-process-environment}. This variable is a list of
2510 strings. It is structured like @code{process-environment}. Each
2511 element is a string of the form ENVVARNAME=VALUE. An entry
2512 ENVVARNAME= disables the corresponding environment variable, which
2513 might have been set in your init file like @file{~/.profile}.
2516 Adding an entry can be performed via @code{add-to-list}:
2519 (add-to-list 'tramp-remote-process-environment "JAVA_HOME=/opt/java")
2522 Changing or removing an existing entry is not encouraged. The default
2523 values are chosen for proper @value{tramp} work. Nevertheless, if for
2524 example a paranoid system administrator disallows changing the
2525 @var{$HISTORY} environment variable, you can customize
2526 @code{tramp-remote-process-environment}, or you can apply the
2527 following code in your @file{.emacs}:
2530 (let ((process-environment tramp-remote-process-environment))
2531 (setenv "HISTORY" nil)
2532 (setq tramp-remote-process-environment process-environment))
2535 If you use other @value{emacsname} packages which do not run
2536 out-of-the-box on a remote host, please let us know. We will try to
2537 integrate them as well. @xref{Bug Reports}.
2540 @subsection Running remote programs that create local X11 windows
2542 If you want to run a remote program, which shall connect the X11
2543 server you are using with your local host, you can set the
2544 @var{$DISPLAY} environment variable on the remote host:
2547 (add-to-list 'tramp-remote-process-environment
2548 (format "DISPLAY=%s" (getenv "DISPLAY")))
2552 @code{(getenv "DISPLAY")} shall return a string containing a host
2553 name, which can be interpreted on the remote host; otherwise you might
2554 use a fixed host name. Strings like @code{:0} cannot be used properly
2557 Another trick might be that you put @code{ForwardX11 yes} or
2558 @code{ForwardX11Trusted yes} to your @file{~/.ssh/config} file for
2562 @subsection Running shell-command on a remote host
2563 @cindex shell-command
2565 @code{shell-command} allows to execute commands in a shell, either
2566 synchronously, either asynchronously. This works also on remote
2570 @kbd{C-x C-f @trampfn{sudo, , , } @key{RET}}
2571 @kbd{M-! tail -f /var/log/syslog.log & @key{RET}}
2574 You will see the buffer @file{*Async Shell Command*}, containing the
2575 continuous output of the @command{tail} command.
2578 @subsection Running eshell on a remote host
2581 @value{tramp} is integrated into @file{eshell.el}. That is, you can
2582 open an interactive shell on your remote host, and run commands there.
2583 After you have started @code{eshell}, you could perform commands like
2587 @b{~ $} cd @trampfn{sudo, , , /etc} @key{RET}
2588 @b{@trampfn{sudo, root, host, /etc} $} hostname @key{RET}
2590 @b{@trampfn{sudo, root, host, /etc} $} id @key{RET}
2591 uid=0(root) gid=0(root) groups=0(root)
2592 @b{@trampfn{sudo, root, host, /etc} $} find-file shadow @key{RET}
2594 @b{@trampfn{sudo, root, host, /etc} $}
2598 Since @value{emacsname} 23.2, @code{eshell} has also an own
2599 implementation of the @code{su} and @code{sudo} commands. Both
2600 commands change the default directory of the @file{*eshell*} buffer to
2601 the value related to the user the command has switched to. This works
2602 even on remote hosts, adding silently a corresponding entry to the
2603 variable @code{tramp-default-proxies-alist} (@pxref{Multi-hops}):
2606 @b{~ $} cd @trampfn{ssh, user, remotehost, /etc} @key{RET}
2607 @b{@trampfn{ssh, user, remotehost, /etc} $} find-file shadow @key{RET}
2608 File is not readable: @trampfn{ssh, user, remotehost, /etc/shadow}
2609 @b{@trampfn{ssh, user, remotehost, /etc} $} sudo find-file shadow @key{RET}
2612 @b{@trampfn{ssh, user, remotehost, /etc} $} su - @key{RET}
2613 @b{@trampfn{su, root, remotehost, /root} $} id @key{RET}
2614 uid=0(root) gid=0(root) groups=0(root)
2615 @b{@trampfn{su, root, remotehost, /root} $}
2620 @anchor{Running a debugger on a remote host}
2621 @subsection Running a debugger on a remote host
2626 @file{gud.el} offers an unified interface to several symbolic
2630 (@ref{Debuggers, , , @value{emacsdir}}).
2633 With @value{tramp}, it is possible to debug programs on
2634 remote hosts. You can call @code{gdb} with a remote file name:
2637 @kbd{M-x gdb @key{RET}}
2638 @b{Run gdb (like this):} gdb --annotate=3 @trampfn{ssh, , host, ~/myprog} @key{RET}
2641 The file name can also be relative to a remote default directory.
2642 Given you are in a buffer that belongs to the remote directory
2643 @trampfn{ssh, , host, /home/user}, you could call
2646 @kbd{M-x perldb @key{RET}}
2647 @b{Run perldb (like this):} perl -d myprog.pl @key{RET}
2650 It is not possible to use just the absolute local part of a remote
2651 file name as program to debug, like @kbd{perl -d
2652 /home/user/myprog.pl}, though.
2654 Arguments of the program to be debugged are taken literally. That
2655 means, file names as arguments must be given as ordinary relative or
2656 absolute file names, without any remote specification.
2659 @node Cleanup remote connections
2660 @section Cleanup remote connections.
2663 Sometimes it is useful to cleanup remote connections. The following
2664 commands support this.
2666 @deffn Command tramp-cleanup-connection vec
2667 This command flushes all connection related objects. @option{vec} is
2668 the internal representation of a remote connection. Called
2669 interactively, the command offers all active remote connections in the
2670 minibuffer as remote file name prefix like @file{@trampfn{method,
2671 user, host, }}. The cleanup includes password cache (@pxref{Password
2672 handling}), file cache, connection cache (@pxref{Connection caching}),
2676 @deffn Command tramp-cleanup-all-connections
2677 This command flushes objects for all active remote connections. The
2678 same objects are removed as in @code{tramp-cleanup-connection}.
2681 @deffn Command tramp-cleanup-all-buffers
2682 Like in @code{tramp-cleanup-all-connections}, all remote connections
2683 are cleaned up. Additionally all buffers, which are related to a
2684 remote connection, are killed.
2689 @chapter Reporting Bugs and Problems
2692 Bugs and problems with @value{tramp} are actively worked on by the
2693 development team. Feature requests and suggestions are also more than
2696 The @value{tramp} mailing list is a great place to get information on
2697 working with @value{tramp}, solving problems and general discussion
2698 and advice on topics relating to the package. It is moderated so
2699 non-subscribers can post but messages will be delayed, possibly up to
2700 48 hours (or longer in case of holidays), until the moderator approves
2703 The mailing list is at @email{tramp-devel@@gnu.org}. Messages sent to
2704 this address go to all the subscribers. This is @emph{not} the address
2705 to send subscription requests to.
2707 Subscribing to the list is performed via
2708 @uref{http://lists.gnu.org/mailman/listinfo/tramp-devel/,
2709 the @value{tramp} Mail Subscription Page}.
2712 To report a bug in @value{tramp}, you should execute @kbd{M-x
2713 tramp-bug}. This will automatically generate a buffer with the details
2714 of your system and @value{tramp} version.
2716 When submitting a bug report, please try to describe in excruciating
2717 detail the steps required to reproduce the problem, the setup of the
2718 remote machine and any special conditions that exist. You should also
2719 check that your problem is not described already in @xref{Frequently
2722 If you can identify a minimal test case that reproduces the problem,
2723 include that with your bug report. This will make it much easier for
2724 the development team to analyze and correct the problem.
2726 Before reporting the bug, you should set the verbosity level to 6
2727 (@pxref{Traces and Profiles, Traces}) in the @file{~/.emacs} file and
2728 repeat the bug. Then, include the contents of the @file{*tramp/foo*}
2729 and @file{*debug tramp/foo*} buffers in your bug report. A verbosity
2730 level greater than 6 will produce a very huge debug buffer, which is
2731 mostly not necessary for the analysis.
2733 Please be aware that, with a verbosity level of 6 or greater, the
2734 contents of files and directories will be included in the debug
2735 buffer. Passwords you've typed will never be included there.
2738 @node Frequently Asked Questions
2739 @chapter Frequently Asked Questions
2740 @cindex frequently asked questions
2745 Where can I get the latest @value{tramp}?
2747 @value{tramp} is available under the URL below.
2750 @uref{ftp://ftp.gnu.org/gnu/tramp/}
2753 There is also a Savannah project page.
2756 @uref{http://savannah.gnu.org/projects/tramp/}
2760 Which systems does it work on?
2762 The package has been used successfully on GNU Emacs 22, GNU Emacs 23,
2763 XEmacs 21 (starting with 21.4), and SXEmacs 22.
2765 The package was intended to work on Unix, and it really expects a
2766 Unix-like system on the remote end (except the @option{smb} and
2767 @option{imap} methods), but some people seemed to have some success
2768 getting it to work on MS Windows XP/Vista/7 @value{emacsname}.
2772 How could I speed up @value{tramp}?
2774 In the backstage, @value{tramp} needs a lot of operations on the
2775 remote host. The time for transferring data from and to the remote
2776 host as well as the time needed to perform the operations there count.
2777 In order to speed up @value{tramp}, one could either try to avoid some
2778 of the operations, or one could try to improve their performance.
2780 Use an external method, like @option{scpc}.
2782 Use caching. This is already enabled by default. Information about
2783 the remote host as well as the remote files are cached for reuse. The
2784 information about remote hosts is kept in the file specified in
2785 @code{tramp-persistency-file-name}. Keep this file.
2787 Disable version control. If you access remote files which are not
2788 under version control, a lot of check operations can be avoided by
2789 disabling VC. This can be achieved by
2792 (setq vc-ignore-dir-regexp
2793 (format "\\(%s\\)\\|\\(%s\\)"
2794 vc-ignore-dir-regexp
2795 tramp-file-name-regexp))
2798 Disable excessive traces. The default trace level of @value{tramp},
2799 defined in the variable @code{tramp-verbose}, is 3. You should
2800 increase this level only temporarily, hunting bugs.
2804 @value{tramp} does not connect to the remote host
2806 When @value{tramp} does not connect to the remote host, there are two
2807 reasons heading the bug mailing list:
2812 Unknown characters in the prompt
2814 @value{tramp} needs to recognize the prompt on the remote machine
2815 after execution any command. This is not possible, when the prompt
2816 contains unknown characters like escape sequences for coloring. This
2817 should be avoided on the remote side. @xref{Remote shell setup}. for
2818 setting the regular expression detecting the prompt.
2820 You can check your settings after an unsuccessful connection by
2821 switching to the @value{tramp} connection buffer @file{*tramp/foo*},
2822 setting the cursor at the top of the buffer, and applying the expression
2825 @kbd{M-: (re-search-forward (concat tramp-shell-prompt-pattern "$"))}
2828 If it fails, or the cursor is not moved at the end of the buffer, your
2829 prompt is not recognized correctly.
2831 A special problem is the zsh, which uses left-hand side and right-hand
2832 side prompts in parallel. Therefore, it is necessary to disable the
2833 zsh line editor on the remote host. You shall add to @file{~/.zshrc}
2834 the following command:
2837 [ $TERM = "dumb" ] && unsetopt zle && PS1='$ '
2841 @value{tramp} doesn't transfer strings with more than 500 characters
2844 On some few systems, the implementation of @code{process-send-string}
2845 seems to be broken for longer strings. It is reported for HP-UX,
2846 FreeBSD and Tru64 Unix, for example. This case, you should customize
2847 the variable @code{tramp-chunksize} to 500. For a description how to
2848 determine whether this is necessary see the documentation of
2849 @code{tramp-chunksize}.
2851 Additionally, it will be useful to set @code{file-precious-flag} to
2852 @code{t} for @value{tramp} files. Then the file contents will be
2853 written into a temporary file first, which is checked for correct
2856 @pxref{Saving Buffers, , , elisp}
2863 (when (file-remote-p default-directory)
2864 (set (make-local-variable 'file-precious-flag) t))))
2871 @value{tramp} does not recognize hung @command{ssh} sessions
2873 When your network connection is down, @command{ssh} sessions might
2874 hang. @value{tramp} cannot detect it safely, because it still sees a
2875 running @command{ssh} process. Timeouts cannot be used as well,
2876 because it cannot be predicted, how long a remote command will last,
2877 for example when copying very large files.
2879 Therefore, you must configure the @command{ssh} process to die
2880 in such a case. The following entry in @file{~/.ssh/config} would do
2885 ServerAliveInterval 5
2890 File name completion does not work with @value{tramp}
2892 When you log in to the remote machine, do you see the output of
2893 @command{ls} in color? If so, this may be the cause of your problems.
2895 @command{ls} outputs @acronym{ANSI} escape sequences that your terminal
2896 emulator interprets to set the colors. These escape sequences will
2897 confuse @value{tramp} however.
2899 In your @file{.bashrc}, @file{.profile} or equivalent on the remote
2900 machine you probably have an alias configured that adds the option
2901 @option{--color=yes} or @option{--color=auto}.
2903 You should remove that alias and ensure that a new login @emph{does not}
2904 display the output of @command{ls} in color. If you still cannot use
2905 filename completion, report a bug to the @value{tramp} developers.
2909 File name completion does not work in large directories
2911 @value{tramp} uses globbing for some operations. (Globbing means to use the
2912 shell to expand wildcards such as `*.c'.) This might create long
2913 command lines, especially in directories with many files. Some shells
2914 choke on long command lines, or don't cope well with the globbing
2917 If you have a large directory on the remote end, you may wish to execute
2918 a command like @samp{ls -d * ..?* > /dev/null} and see if it hangs.
2919 Note that you must first start the right shell, which might be
2920 @command{/bin/sh}, @command{ksh} or @command{bash}, depending on which
2921 of those supports tilde expansion.
2925 How can I get notified when @value{tramp} file transfers are complete?
2927 The following snippet can be put in your @file{~/.emacs} file. It
2928 makes @value{emacsname} beep after reading from or writing to the
2932 (defadvice tramp-handle-write-region
2933 (after tramp-write-beep-advice activate)
2934 "Make tramp beep after writing a file."
2938 (defadvice tramp-handle-do-copy-or-rename-file
2939 (after tramp-copy-beep-advice activate)
2940 "Make tramp beep after copying a file."
2944 (defadvice tramp-handle-insert-file-contents
2945 (after tramp-insert-beep-advice activate)
2946 "Make tramp beep after inserting a file."
2954 I'ld like to get a Visual Warning when working in a sudo:ed context
2956 When you are working with @samp{root} privileges, it might be useful
2957 to get an indication in the buffer's modeline. The following code,
2958 tested with @value{emacsname} 22.1, does the job. You should put it
2959 into your @file{~/.emacs}:
2962 (defun my-mode-line-function ()
2963 (when (string-match "^/su\\(do\\)?:" default-directory)
2964 (setq mode-line-format
2965 (format-mode-line mode-line-format 'font-lock-warning-face))))
2967 (add-hook 'find-file-hooks 'my-mode-line-function)
2968 (add-hook 'dired-mode-hook 'my-mode-line-function)
2975 I'ld like to see a host indication in the mode line when I'm remote
2977 The following code has been tested with @value{emacsname} 22.1. You
2978 should put it into your @file{~/.emacs}:
2981 (defconst my-mode-line-buffer-identification
2985 (if (file-remote-p default-directory)
2986 (tramp-file-name-host
2987 (tramp-dissect-file-name default-directory))
2989 (if (string-match "^[^0-9][^.]*\\(\\..*\\)" host-name)
2990 (substring host-name 0 (match-beginning 1))
2995 mode-line-buffer-identification
2996 my-mode-line-buffer-identification)
3002 mode-line-buffer-identification
3003 my-mode-line-buffer-identification)))
3006 Since @value{emacsname} 23.1, the mode line contains an indication if
3007 @code{default-directory} for the current buffer is on a remote host.
3008 The corresponding tooltip includes the name of that host. If you
3009 still want the host name as part of the mode line, you can use the
3010 example above, but the @code{:eval} clause can be simplified:
3015 (or (file-remote-p default-directory 'host)
3017 (if (string-match "^[^0-9][^.]*\\(\\..*\\)" host-name)
3018 (substring host-name 0 (match-beginning 1))
3026 My remote host does not understand default directory listing options
3028 @value{emacsname} computes the @command{dired} options depending on
3029 the local host you are working. If your @command{ls} command on the
3030 remote host does not understand those options, you can change them
3035 'dired-before-readin-hook
3037 (when (file-remote-p default-directory)
3038 (setq dired-actual-switches "-al"))))
3044 There's this @file{~/.sh_history} file on the remote host which keeps
3045 growing and growing. What's that?
3047 Sometimes, @value{tramp} starts @command{ksh} on the remote host for
3048 tilde expansion. Maybe @command{ksh} saves the history by default.
3049 @value{tramp} tries to turn off saving the history, but maybe you have
3050 to help. For example, you could put this in your @file{.kshrc}:
3053 if [ -f $HOME/.sh_history ] ; then
3054 /bin/rm $HOME/.sh_history
3056 if [ "$@{HISTFILE-unset@}" != "unset" ] ; then
3059 if [ "$@{HISTSIZE-unset@}" != "unset" ] ; then
3065 @item There are longish file names to type. How to shorten this?
3067 Let's say you need regularly access to @file{@trampfn{ssh, news,
3068 news.my.domain, /opt/news/etc}}, which is boring to type again and
3069 again. The following approaches can be mixed:
3073 @item Use default values for method and user name:
3075 You can define default methods and user names for hosts,
3076 (@pxref{Default Method}, @pxref{Default User}):
3079 (setq tramp-default-method "ssh"
3080 tramp-default-user "news")
3083 The file name left to type would be
3084 @kbd{C-x C-f @trampfn{, , news.my.domain, /opt/news/etc}}.
3086 Note, that there are some useful settings already. Accessing your
3087 local host as @samp{root} user, is possible just by @kbd{C-x C-f
3090 @item Use configuration possibilities of your method:
3092 Several connection methods (i.e. the programs used) offer powerful
3093 configuration possibilities (@pxref{Customizing Completion}). In the
3094 given case, this could be @file{~/.ssh/config}:
3098 HostName news.my.domain
3102 The file name left to type would be @kbd{C-x C-f @trampfn{ssh, , xy,
3103 /opt/news/etc}}. Depending on files in your directories, it is even
3104 possible to complete the host name with @kbd{C-x C-f
3105 @value{prefix}ssh@value{postfixhop}x @key{TAB}}.
3107 @item Use environment variables:
3109 File names typed in the minibuffer can be expanded by environment
3110 variables. You can set them outside @value{emacsname}, or even with
3114 (setenv "xy" "@trampfn{ssh, news, news.my.domain, /opt/news/etc/}")
3117 Then you need simply to type @kbd{C-x C-f $xy @key{RET}}, and here you
3118 are. The disadvantage is, that you cannot edit the file name, because
3119 environment variables are not expanded during editing in the
3122 @item Define own keys:
3124 You can define your own key sequences in @value{emacsname}, which can
3125 be used instead of @kbd{C-x C-f}:
3129 [(control x) (control y)]
3135 "@trampfn{ssh, news, news.my.domain, /opt/news/etc/}"))))
3138 Simply typing @kbd{C-x C-y} would initialize the minibuffer for
3139 editing with your beloved file name.
3141 See also @uref{http://www.emacswiki.org/cgi-bin/wiki/TrampMode, the
3142 Emacs Wiki} for a more comprehensive example.
3144 @item Define own abbreviation (1):
3146 It is possible to define an own abbreviation list for expanding file
3151 'directory-abbrev-alist
3152 '("^/xy" . "@trampfn{ssh, news, news.my.domain, /opt/news/etc/}"))
3155 This shortens the file openening command to @kbd{C-x C-f /xy
3156 @key{RET}}. The disadvantage is, again, that you cannot edit the file
3157 name, because the expansion happens after entering the file name only.
3159 @item Define own abbreviation (2):
3161 The @code{abbrev-mode} gives more flexibility for editing the
3165 (define-abbrev-table 'my-tramp-abbrev-table
3166 '(("xy" "@trampfn{ssh, news, news.my.domain, /opt/news/etc/}")))
3169 'minibuffer-setup-hook
3172 (setq local-abbrev-table my-tramp-abbrev-table)))
3174 (defadvice minibuffer-complete
3175 (before my-minibuffer-complete activate)
3178 ;; If you use partial-completion-mode
3179 (defadvice PC-do-completion
3180 (before my-PC-do-completion activate)
3184 After entering @kbd{C-x C-f xy @key{TAB}}, the minibuffer is
3185 expanded, and you can continue editing.
3187 @item Use bookmarks:
3189 Bookmarks can be used to visit Tramp files or directories.
3191 @pxref{Bookmarks, , , @value{emacsdir}}
3194 When you have opened @file{@trampfn{ssh, news, news.my.domain,
3195 /opt/news/etc/}}, you should save the bookmark via
3197 @kbd{@key{menu-bar} @key{edit} @key{bookmarks} @key{set}}.
3200 @kbd{@key{menu-bar} @key{view} @key{bookmarks} @key{set}}.
3203 Later on, you can always navigate to that bookmark via
3205 @kbd{@key{menu-bar} @key{edit} @key{bookmarks} @key{jump}}.
3208 @kbd{@key{menu-bar} @key{view} @key{bookmarks} @key{jump}}.
3211 @item Use recent files:
3219 remembers visited places.
3222 @pxref{File Conveniences, , , @value{emacsdir}}
3225 @pxref{recent-files, , , edit-utils}
3229 You could keep remote file names in the recent list without checking
3230 their readability through a remote access:
3237 (recent-files-initialize)
3241 (when (file-remote-p (buffer-file-name))
3242 (recent-files-make-permanent)))
3247 The list of files opened recently is reachable via
3249 @kbd{@key{menu-bar} @key{file} @key{Open Recent}}.
3252 @kbd{@key{menu-bar} @key{Recent Files}}.
3256 @item Use filecache:
3258 @file{filecache} remembers visited places. Add the directory into
3262 (eval-after-load "filecache"
3263 '(file-cache-add-directory
3264 "@trampfn{ssh, news, news.my.domain, /opt/news/etc/}"))
3267 Whenever you want to load a file, you can enter @kbd{C-x C-f
3268 C-@key{TAB}} in the minibuffer. The completion is done for the given
3275 @file{bbdb} has a built-in feature for @value{ftppackagename} files,
3276 which works also for @value{tramp}.
3278 @pxref{bbdb-ftp, Storing FTP sites in the BBDB, , bbdb}
3281 You need to load @file{bbdb}:
3288 Then you can create a BBDB entry via @kbd{M-x bbdb-create-ftp-site}.
3289 Because BBDB is not prepared for @value{tramp} syntax, you must
3290 specify a method together with the user name, when needed. Example:
3293 @kbd{M-x bbdb-create-ftp-site @key{RET}}
3294 @b{Ftp Site:} news.my.domain @key{RET}
3295 @b{Ftp Directory:} /opt/news/etc/ @key{RET}
3296 @b{Ftp Username:} ssh@value{postfixhop}news @key{RET}
3297 @b{Company:} @key{RET}
3298 @b{Additional Comments:} @key{RET}
3301 When you have opened your BBDB buffer, you can access such an entry by
3302 pressing the key @key{F}.
3307 I would like to thank all @value{tramp} users, who have contributed to
3308 the different recipes!
3313 How can I use @value{tramp} to connect to a remote @value{emacsname}
3316 You can configure Emacs Client doing this.
3318 @xref{Emacs Server, , , @value{emacsdir}}.
3321 On the remote host, you start the Emacs Server:
3325 (setq server-host (system-name)
3330 Make sure, that the result of @code{(system-name)} can be resolved on
3331 your local host; otherwise you might use a hard coded IP address.
3333 The resulting file @file{~/.emacs.d/server/server} must be copied to
3334 your local host, at the same location. You can call then the Emacs
3335 Client from the command line:
3338 emacsclient @trampfn{ssh, user, host, /file/to/edit}
3341 @code{user} and @code{host} shall be related to your local host.
3343 If you want to use Emacs Client also as editor for other programs, you
3344 could write a script @file{emacsclient.sh}:
3348 emacsclient @trampfn{ssh, $(whoami), $(hostname --fqdn), $1}
3351 Then you must set the environment variable @code{EDITOR} pointing to
3355 export EDITOR=/path/to/emacsclient.sh
3361 How can I disable @value{tramp}?
3363 Shame on you, why did you read until now?
3369 If you just want to have @value{ftppackagename} as default remote
3370 files access package, you should apply the following code:
3373 (setq tramp-default-method "ftp")
3380 @value{tramp} (and @value{ftppackagename}),
3385 you must set @code{tramp-mode} to @code{nil}:
3388 (setq tramp-mode nil)
3392 Unloading @value{tramp} can be achieved by applying @kbd{M-x
3393 tramp-unload-tramp}.
3395 This resets also the @value{ftppackagename} plugins.
3401 @c For the developer
3402 @node Files directories and localnames
3403 @chapter How file names, directories and localnames are mangled and managed.
3406 * Localname deconstruction:: Breaking a localname into its components.
3408 * External packages:: Integration with external Lisp packages.
3413 @node Localname deconstruction
3414 @section Breaking a localname into its components.
3416 @value{tramp} file names are somewhat different, obviously, to ordinary file
3417 names. As such, the lisp functions @code{file-name-directory} and
3418 @code{file-name-nondirectory} are overridden within the @value{tramp}
3421 Their replacements are reasonably simplistic in their approach. They
3422 dissect the filename, call the original handler on the localname and
3423 then rebuild the @value{tramp} file name with the result.
3425 This allows the platform specific hacks in the original handlers to take
3426 effect while preserving the @value{tramp} file name information.
3430 @node External packages
3431 @section Integration with external Lisp packages.
3432 @subsection Filename completion.
3434 While reading filenames in the minibuffer, @value{tramp} must decide
3435 whether it completes possible incomplete filenames, or not. Imagine
3436 there is the following situation: You have typed @kbd{C-x C-f
3437 @value{prefix}ssh@value{postfixhop} @key{TAB}}. @value{tramp} cannot
3438 know, whether @option{ssh} is a method or a host name. It checks
3439 therefore the last input character you have typed. If this is
3440 @key{TAB}, @key{SPACE} or @kbd{?}, @value{tramp} assumes that you are
3441 still in filename completion, and it does not connect to the possible
3442 remote host @option{ssh}.
3444 @vindex tramp-completion-mode
3445 External packages, which use other characters for completing filenames
3446 in the minibuffer, must signal this to @value{tramp}. For this case,
3447 the variable @code{tramp-completion-mode} can be bound temporarily to
3448 a non-@code{nil} value.
3451 (let ((tramp-completion-mode t))
3456 @subsection File attributes cache.
3458 When @value{tramp} runs remote processes, files on the remote host
3459 could change their attributes. Consequently, @value{tramp} must flush
3460 its complete cache keeping attributes for all files of the remote host
3463 This is a performance degradation, because the lost file attributes
3464 must be recomputed, when needed again. In cases the caller of
3465 @code{process-file} knows that there are file attribute changes, it
3466 shall let-bind the variable @code{process-file-side-effects} to
3467 @code{nil}. @value{tramp} wouldn't flush the file attributes cache then.
3470 (let (process-file-side-effects)
3476 @node Traces and Profiles
3477 @chapter How to Customize Traces
3479 All @value{tramp} messages are raised with a verbosity level. The
3480 verbosity level can be any number between 0 and 10. Only messages with
3481 a verbosity level less than or equal to @code{tramp-verbose} are
3484 The verbosity levels are
3486 @w{ 0} silent (no @value{tramp} messages at all)
3487 @*@indent @w{ 1} errors
3488 @*@indent @w{ 2} warnings
3489 @*@indent @w{ 3} connection to remote hosts (default verbosity)
3490 @*@indent @w{ 4} activities
3491 @*@indent @w{ 5} internal
3492 @*@indent @w{ 6} sent and received strings
3493 @*@indent @w{ 7} file caching
3494 @*@indent @w{ 8} connection properties
3495 @*@indent @w{10} traces (huge)
3497 When @code{tramp-verbose} is greater than or equal to 4, the messages
3498 are also written into a @value{tramp} debug buffer. This debug buffer
3499 is useful for analysing problems; sending a @value{tramp} bug report
3500 should be done with @code{tramp-verbose} set to a verbosity level of at
3501 least 6 (@pxref{Bug Reports}).
3503 The debug buffer is in
3505 @ref{Outline Mode, , , @value{emacsdir}}.
3510 That means, you can change the level of messages to be viewed. If you
3511 want, for example, see only messages up to verbosity level 5, you must
3512 enter @kbd{C-u 6 C-c C-q}.
3514 Other keys for navigating are described in
3515 @ref{Outline Visibility, , , @value{emacsdir}}.
3518 @value{tramp} errors are handled internally in order to raise the
3519 verbosity level 1 messages. When you want to get a Lisp backtrace in
3520 case of an error, you need to set both
3523 (setq debug-on-error t
3527 Sometimes, it might be even necessary to step through @value{tramp}
3528 function call traces. Such traces are enabled by the following code:
3533 (dolist (elt (all-completions "tramp-" obarray 'functionp))
3534 (trace-function-background (intern elt)))
3535 (untrace-function 'tramp-read-passwd)
3536 (untrace-function 'tramp-gw-basic-authentication)
3539 The function call traces are inserted in the buffer
3540 @file{*trace-output*}. @code{tramp-read-passwd} and
3541 @code{tramp-gw-basic-authentication} shall be disabled when the
3542 function call traces are added to @value{tramp}, because both
3543 functions return password strings, which should not be distributed.
3547 @chapter Debatable Issues and What Was Decided
3550 @item The uuencode method does not always work.
3552 Due to the design of @value{tramp}, the encoding and decoding programs
3553 need to read from stdin and write to stdout. On some systems,
3554 @command{uudecode -o -} will read stdin and write the decoded file to
3555 stdout, on other systems @command{uudecode -p} does the same thing.
3556 But some systems have uudecode implementations which cannot do this at
3557 all---it is not possible to call these uudecode implementations with
3558 suitable parameters so that they write to stdout.
3560 Of course, this could be circumvented: the @code{begin foo 644} line
3561 could be rewritten to put in some temporary file name, then
3562 @command{uudecode} could be called, then the temp file could be
3563 printed and deleted.
3565 But I have decided that this is too fragile to reliably work, so on some
3566 systems you'll have to do without the uuencode methods.
3568 @item The @value{tramp} filename syntax differs between GNU Emacs and XEmacs.
3570 The GNU Emacs maintainers wish to use a unified filename syntax for
3571 Ange-FTP and @value{tramp} so that users don't have to learn a new
3572 syntax. It is sufficient to learn some extensions to the old syntax.
3574 For the XEmacs maintainers, the problems caused from using a unified
3575 filename syntax are greater than the gains. The XEmacs package system
3576 uses EFS for downloading new packages. So, obviously, EFS has to be
3577 installed from the start. If the filenames were unified, @value{tramp}
3578 would have to be installed from the start, too.
3581 @strong{Note:} If you'd like to use a similar syntax like
3582 @value{ftppackagename}, you need the following settings in your init
3586 (setq tramp-unified-filenames t)
3590 The autoload of the @value{emacsname} @value{tramp} package must be
3591 disabled. This can be achieved by setting file permissions @code{000}
3592 to the files @file{.../xemacs-packages/lisp/tramp/auto-autoloads.el*}.
3594 In case of unified filenames, all @value{emacsname} download sites are
3595 added to @code{tramp-default-method-alist} with default method
3596 @option{ftp} @xref{Default Method}. These settings shouldn't be
3597 touched for proper working of the @value{emacsname} package system.
3599 The syntax for unified filenames is described in the @value{tramp} manual
3600 for @value{emacsothername}.
3604 @node GNU Free Documentation License
3605 @appendix GNU Free Documentation License
3606 @include doclicense.texi
3608 @node Function Index
3609 @unnumbered Function Index
3612 @node Variable Index
3613 @unnumbered Variable Index
3617 @unnumbered Concept Index
3624 @c * Say something about the .login and .profile files of the remote
3626 @c * Explain how tramp.el works in principle: open a shell on a remote
3627 @c host and then send commands to it.
3628 @c * Use `filename' resp. `file name' consistently.
3629 @c * Use `host' resp. `machine' consistently.
3630 @c * Consistent small or capitalized words especially in menues.
3633 arch-tag: f96dd66e-6dd3-4c92-8d77-9c56205ba808