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1 | \input texinfo @c -*-texinfo-*- |
2 | @c %**start of header | |
6344cbf1 | 3 | @setfilename ../info/tramp |
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4 | @settitle TRAMP User Manual |
5 | @setchapternewpage odd | |
6 | @c %**end of header | |
7 | ||
8 | @c This is *so* much nicer :) | |
9 | @footnotestyle end | |
10 | ||
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11 | @c In the Tramp CVS, the version number is auto-frobbed from |
12 | @c configure.ac, so you should edit that file and run | |
13 | @c "autoconf && ./configure" to change the version number. | |
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14 | |
15 | @c Additionally, flags are set with respect to the Emacs flavor; and | |
16 | @c depending whether Tramp is packaged into (X)Emacs, or standalone. | |
17 | ||
b1a2b924 | 18 | @include trampver.texi |
fb7933a3 | 19 | |
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20 | @c Macro to make formatting of the tramp program name consistent. |
21 | @macro tramp | |
22 | @sc{tramp} | |
23 | @end macro | |
24 | ||
16674e4f | 25 | @c Macros for formatting a filename. |
884b79ec | 26 | @c trampfn is for a full filename, trampfnmhp means method, host, localname |
16674e4f | 27 | @c were given, and so on. |
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28 | @macro trampfn(method, user, host, localname) |
29 | @value{tramp-prefix}@value{method}@value{user}@@@value{host}@value{tramp-postfix}@value{localname} | |
16674e4f | 30 | @end macro |
fb7933a3 | 31 | |
f08d9f0e | 32 | @copying |
18d6d595 | 33 | Copyright @copyright{} 1999, 2000, 2001, 2002, 2003 Free Software |
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34 | Foundation, Inc. |
35 | ||
884b79ec | 36 | @quotation |
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37 | Permission is granted to copy, distribute and/or modify this document |
38 | under the terms of the GNU Free Documentation License, Version 1.1 or | |
39 | any later version published by the Free Software Foundation; with no | |
40 | Invariant Sections, with the Front-Cover texts being ``A GNU | |
41 | Manual'', and with the Back-Cover Texts as in (a) below. A copy of the | |
42 | license is included in the section entitled ``GNU Free Documentation | |
43 | License'' in the Emacs manual. | |
44 | ||
45 | (a) The FSF's Back-Cover Text is: ``You have freedom to copy and modify | |
46 | this GNU Manual, like GNU software. Copies published by the Free | |
47 | Software Foundation raise funds for GNU development.'' | |
48 | ||
49 | This document is part of a collection distributed under the GNU Free | |
50 | Documentation License. If you want to distribute this document | |
51 | separately from the collection, you can do so by adding a copy of the | |
52 | license to the document, as described in section 6 of the license. | |
53 | @end quotation | |
54 | @end copying | |
55 | ||
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56 | @c Entries for @command{install-info} to use |
57 | @dircategory Emacs | |
58 | @direntry | |
59 | * TRAMP: (tramp). Transparent Remote Access, Multiple Protocol | |
60 | Emacs remote file access via rsh and rcp. | |
61 | @end direntry | |
62 | ||
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63 | @tex |
64 | ||
65 | @titlepage | |
16674e4f | 66 | @title @tramp{} version @trampver{} User Manual |
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67 | |
68 | @author by Daniel Pittman | |
69 | @author based on documentation by Kai Gro@ss{}johann | |
f08d9f0e | 70 | |
fb7933a3 | 71 | @page |
f08d9f0e | 72 | @insertcopying |
fb7933a3 | 73 | |
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74 | @end titlepage |
75 | @page | |
76 | ||
77 | @end tex | |
78 | ||
79 | @ifnottex | |
92eeeafc | 80 | @node Top, Overview, (dir), (dir) |
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81 | @top @tramp{} version @trampver{} User Manual |
82 | ||
83 | This file documents @tramp{} version @trampver{}, a remote file | |
84 | editing package for @value{emacs-name}. | |
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85 | |
86 | @tramp{} stands for `Transparent Remote (file) Access, Multiple | |
87 | Protocol'. This package provides remote file editing, similar to | |
16674e4f | 88 | @value{ftp-package-name}. |
fb7933a3 | 89 | |
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90 | The difference is that @value{ftp-package-name} uses FTP to transfer |
91 | files between the local and the remote host, whereas @tramp{} uses a | |
92 | combination of @command{rsh} and @command{rcp} or other work-alike | |
93 | programs, such as @command{ssh}/@command{scp}. | |
fb7933a3 | 94 | |
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95 | You can find the latest version of this document on the web at |
96 | @uref{http://www.freesoftware.fsf.org/tramp/}. | |
97 | ||
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98 | @c Pointer to the other Emacs flavor is necessary only in case of |
99 | @c standalone installation. Text taken from trampinst.texi. | |
100 | @ifset tramp-inst | |
101 | @otherflavor{} | |
102 | @end ifset | |
103 | ||
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104 | @ifhtml |
105 | This manual is also available as a @uref{tramp_ja.html, Japanese | |
106 | translation}. | |
107 | ||
108 | The latest release of @tramp{} is available for | |
109 | @uref{http://savannah.gnu.org/download/tramp/, | |
110 | download}, or you may see @ref{Obtaining @tramp{}} for more details, | |
111 | including the CVS server details. | |
112 | ||
113 | @tramp{} also has a @uref{https://savannah.gnu.org/projects/tramp/, | |
114 | Savannah Project Page}. | |
115 | @end ifhtml | |
116 | ||
117 | There is a mailing list for @tramp{}, available at | |
118 | @email{tramp-devel@@mail.freesoftware.fsf.org}, and archived at | |
119 | @uref{http://www.mail-archive.com/emacs-rcp@@ls6.cs.uni-dortmund.de/} as | |
120 | well as the usual Savannah archives. | |
121 | ||
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122 | @insertcopying |
123 | ||
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124 | @end ifnottex |
125 | ||
126 | @menu | |
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127 | * Overview:: What @tramp{} can and cannot do. |
128 | ||
129 | For the end user: | |
7e190783 | 130 | |
18d6d595 | 131 | * Obtaining @tramp{}:: How to obtain @tramp{}. |
16674e4f | 132 | * History:: History of @tramp{}. |
7e190783 | 133 | @ifset tramp-inst |
16674e4f | 134 | * Installation:: Installing @tramp{} with your @value{emacs-name}. |
7e190783 | 135 | @end ifset |
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136 | * Configuration:: Configuring @tramp{} for use. |
137 | * Usage:: An overview of the operation of @tramp{}. | |
16674e4f | 138 | * Bug Reports:: Reporting Bugs and Problems. |
fb7933a3 | 139 | * Frequently Asked Questions:: Questions and answers from the mailing list. |
41bed43c | 140 | * Concept Index:: An item for each concept |
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141 | |
142 | For the developer: | |
7e190783 | 143 | |
fb7933a3 | 144 | * Version Control:: The inner workings of remote version control. |
884b79ec | 145 | * Files directories and localnames:: How file names, directories and localnames are mangled and managed. |
16674e4f | 146 | * Issues:: Debatable Issues and What Was Decided. |
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147 | |
148 | @detailmenu | |
149 | --- The Detailed Node Listing --- | |
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150 | @c |
151 | @ifset tramp-inst | |
152 | Installing @tramp{} with your @value{emacs-name} | |
153 | ||
154 | * Installation parameters:: Parameters in order to control installation. | |
155 | * Load paths:: How to plug-in @tramp{} into your environment. | |
156 | ||
157 | @end ifset | |
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158 | |
159 | Configuring @tramp{} for use | |
160 | ||
161 | * Connection types:: Types of connections made to remote machines. | |
162 | * Inline methods:: Inline methods. | |
163 | * External transfer methods:: External transfer methods. | |
164 | * Multi-hop Methods:: Connecting to a remote host using multiple hops. | |
165 | * Default Method:: Selecting a default method. | |
166 | * Customizing Methods:: Using Non-Standard Methods. | |
16674e4f | 167 | * Customizing Completion:: Selecting config files for user/host name completion. |
fb7933a3 | 168 | * Remote Programs:: How @tramp{} finds and uses programs on the remote machine. |
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169 | * Remote shell setup:: Remote shell setup hints. |
170 | * Windows setup hints:: Issues with Cygwin ssh. | |
b1a2b924 | 171 | * Auto-save and Backup:: Auto-save and Backup. |
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172 | |
173 | Using @tramp | |
174 | ||
175 | * Filename Syntax:: @tramp{} filename conventions. | |
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176 | * Multi-hop filename syntax:: Multi-hop filename conventions. |
177 | * Filename completion:: Filename completion. | |
178 | * Dired:: Dired. | |
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179 | |
180 | The inner workings of remote version control | |
181 | ||
182 | * Version Controlled Files:: Determining if a file is under version control. | |
183 | * Remote Commands:: Executing the version control commands on the remote machine. | |
184 | * Changed workfiles:: Detecting if the working file has changed. | |
185 | * Checking out files:: Bringing the workfile out of the repository. | |
16674e4f | 186 | * Miscellaneous Version Control:: Things related to Version Control that don't fit elsewhere. |
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187 | |
188 | Things related to Version Control that don't fit elsewhere | |
189 | ||
190 | * Remote File Ownership:: How VC determines who owns a workfile. | |
191 | * Back-end Versions:: How VC determines what release your RCS is. | |
192 | ||
7e190783 | 193 | How file names, directories and localnames are mangled and managed |
fb7933a3 | 194 | |
b1a2b924 | 195 | * Localname deconstruction:: Breaking a localname into its components. |
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196 | |
197 | @end detailmenu | |
198 | @end menu | |
199 | ||
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200 | @node Overview |
201 | @chapter An overview of @tramp | |
92eeeafc | 202 | @cindex overview |
fb7933a3 | 203 | |
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204 | After the installation of @tramp{} into your @value{emacs-name}, you |
205 | will be able to access files on remote machines as though they were | |
206 | local. Access to the remote file system for editing files, version | |
207 | control, and @command{dired} are transparently enabled. | |
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208 | |
209 | Your access to the remote machine can be with the @command{rsh}, | |
210 | @command{rlogin}, @command{telnet} programs or with any similar | |
92eeeafc | 211 | connection method. This connection must pass ASCII successfully to be |
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212 | usable but need not be 8-bit clean. |
213 | ||
214 | The package provides support for @command{ssh} connections out of the | |
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215 | box, one of the more common uses of the package. This allows |
216 | relatively secure access to machines, especially if @command{ftp} | |
217 | access is disabled. | |
fb7933a3 | 218 | |
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219 | The majority of activity carried out by @tramp{} requires only that |
220 | the remote login is possible and is carried out at the terminal. In | |
221 | order to access remote files @tramp{} needs to transfer their content | |
222 | to the local machine temporarily. | |
fb7933a3 | 223 | |
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224 | @tramp{} can transfer files between the machines in a variety of ways. |
225 | The details are easy to select, depending on your needs and the | |
226 | machines in question. | |
fb7933a3 | 227 | |
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228 | The fastest transfer methods (for large files) rely on a remote file |
229 | transfer package such as @command{rcp}, @command{scp} or | |
230 | @command{rsync}. The use of these methods is only possible if the | |
231 | file copy command does not ask for a password for the remote machine. | |
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232 | |
233 | If the remote copy methods are not suitable for you, @tramp{} also | |
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234 | supports the use of encoded transfers directly through the shell. |
235 | This requires that the @command{mimencode} or @command{uuencode} tools | |
236 | are available on the remote machine. These methods are generally | |
237 | faster for small files. | |
fb7933a3 | 238 | |
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239 | Within these limitations, @tramp{} is quite powerful. It is worth |
240 | noting that, as of the time of writing, it is far from a polished | |
241 | end-user product. For a while yet you should expect to run into rough | |
242 | edges and problems with the code now and then. | |
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243 | |
244 | It is finished enough that the developers use it for day to day work but | |
245 | the installation and setup can be a little difficult to master, as can | |
246 | the terminology. | |
247 | ||
248 | @tramp{} is still under active development and any problems you encounter, | |
249 | trivial or major, should be reported to the @tramp{} developers. | |
250 | @xref{Bug Reports}. | |
251 | ||
252 | ||
253 | @subsubheading Behind the scenes | |
92eeeafc | 254 | @cindex behind the scenes |
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255 | @cindex details of operation |
256 | @cindex how it works | |
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257 | |
258 | This section tries to explain what goes on behind the scenes when you | |
259 | access a remote file through @tramp{}. | |
260 | ||
261 | Suppose you type @kbd{C-x C-f} and enter part of an @tramp{} file name, | |
262 | then hit @kbd{@key{TAB}} for completion. Suppose further that this is | |
263 | the first time that @tramp{} is invoked for the host in question. Here's | |
264 | what happens: | |
265 | ||
266 | @itemize | |
267 | @item | |
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268 | @tramp{} discovers that it needs a connection to the host. So it |
269 | invokes @samp{telnet @var{host}} or @samp{rsh @var{host} -l | |
270 | @var{user}} or a similar tool to connect to the remote host. | |
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271 | Communication with this process happens through an |
272 | @value{emacs-name} buffer, that is, the output from the remote end | |
273 | goes into a buffer. | |
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274 | |
275 | @item | |
276 | The remote host may prompt for a login name (for @command{telnet}). The | |
277 | login name is given in the file name, so @tramp{} sends the login name and | |
278 | a newline. | |
279 | ||
280 | @item | |
281 | The remote host may prompt for a password or pass phrase (for | |
282 | @command{rsh} or for @command{telnet} after sending the login name). | |
283 | @tramp{} displays the prompt in the minibuffer, asking you for the | |
284 | password or pass phrase. | |
285 | ||
286 | You enter the password or pass phrase. @tramp{} sends it to the remote | |
287 | host, followed by a newline. | |
288 | ||
289 | @item | |
290 | @tramp{} now waits for the shell prompt or for a message that the login | |
291 | failed. | |
292 | ||
293 | If @tramp{} sees neither of them after a certain period of time (a minute, | |
294 | say), then it issues an error message saying that it couldn't find the | |
295 | remote shell prompt and shows you what the remote host has sent. | |
296 | ||
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297 | If @tramp{} sees a @samp{login failed} message, it tells you so, |
298 | aborts the login attempt and allows you to try again. | |
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299 | |
300 | @item | |
301 | Suppose that the login was successful and @tramp{} sees the shell prompt | |
302 | from the remote host. Now @tramp{} invokes @command{/bin/sh} because | |
303 | Bourne shells and C shells have different command | |
304 | syntaxes.@footnote{Invoking @command{/bin/sh} will fail if your login | |
92eeeafc | 305 | shell doesn't recognize @samp{exec /bin/sh} as a valid command. |
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306 | Maybe you use the Scheme shell @command{scsh}@dots{}} |
307 | ||
308 | After the Bourne shell has come up, @tramp{} sends a few commands to | |
309 | ensure a good working environment. It turns off echoing, it sets the | |
310 | shell prompt, and a few other things. | |
311 | ||
312 | @item | |
313 | Now the remote shell is up and it good working order. Remember, what | |
314 | was supposed to happen is that @tramp{} tries to find out what files exist | |
315 | on the remote host so that it can do filename completion. | |
316 | ||
317 | So, @tramp{} basically issues @command{cd} and @command{ls} commands and | |
318 | also sometimes @command{echo} with globbing. Another command that is | |
319 | often used is @command{test} to find out whether a file is writable or a | |
320 | directory or the like. The output of each command is parsed for the | |
321 | necessary operation. | |
322 | ||
323 | @item | |
324 | Suppose you are finished with filename completion, have entered @kbd{C-x | |
325 | C-f}, a full file name and hit @kbd{@key{RET}}. Now comes the time to | |
326 | transfer the file contents from the remote host to the local host so | |
327 | that you can edit them. | |
328 | ||
329 | See above for an explanation of how @tramp{} transfers the file contents. | |
330 | ||
92eeeafc | 331 | For inline transfers, @tramp{} issues a command like @samp{mimencode -b |
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332 | /path/to/remote/file}, waits until the output has accumulated in the |
333 | buffer that's used for communication, then decodes that output to | |
334 | produce the file contents. | |
335 | ||
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336 | For out-of-band transfers, @tramp{} issues a command like the following: |
337 | @example | |
338 | rcp user@@host:/path/to/remote/file /tmp/tramp.4711 | |
339 | @end example | |
340 | It then reads the local temporary file @file{/tmp/tramp.4711} into a | |
341 | buffer and deletes the temporary file. | |
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342 | |
343 | @item | |
344 | You now edit the buffer contents, blithely unaware of what has happened | |
345 | behind the scenes. (Unless you have read this section, that is.) When | |
346 | you are finished, you type @kbd{C-x C-s} to save the buffer. | |
347 | ||
348 | @item | |
349 | Again, @tramp{} transfers the file contents to the remote host either | |
350 | inline or out-of-band. This is the reverse of what happens when reading | |
351 | the file. | |
352 | ||
353 | @end itemize | |
354 | ||
355 | I hope this has provided you with a basic overview of what happens | |
356 | behind the scenes when you open a file with @tramp{}. | |
357 | ||
358 | ||
359 | @c For the end user | |
360 | @node Obtaining @tramp{} | |
361 | @chapter Obtaining @tramp{}. | |
92eeeafc | 362 | @cindex obtaining Tramp |
fb7933a3 | 363 | |
b1a2b924 KG |
364 | @tramp{} is freely available on the Internet and the latest release |
365 | may be downloaded from | |
366 | @uref{http://savannah.nongnu.org/download/tramp/}. This | |
367 | release includes the full documentation and code for @tramp{}, | |
368 | suitable for installation. But Emacs (21.4 or later) includes | |
369 | @tramp{} already, and there is a @tramp{} package for XEmacs, as well. | |
370 | So maybe it is easier to just use those. But if you want the bleeding | |
92eeeafc | 371 | edge, read on@dots{...} |
fb7933a3 | 372 | |
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373 | For the especially brave, @tramp{} is available from CVS. The CVS |
374 | version is the latest version of the code and may contain incomplete | |
375 | features or new issues. Use these versions at your own risk. | |
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376 | |
377 | Instructions for obtaining the latest development version of @tramp{} | |
16674e4f | 378 | from CVS can be found by going to the Savannah project page at the |
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379 | following URL and then clicking on the CVS link in the navigation bar |
380 | at the top. | |
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381 | |
382 | @noindent | |
383 | @uref{http://savannah.gnu.org/projects/tramp/} | |
384 | ||
385 | @noindent | |
386 | Or follow the example session below: | |
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387 | |
388 | @example | |
16674e4f | 389 | ] @strong{cd ~/@value{emacs-dir}} |
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390 | ] @strong{cvs -d:pserver:anoncvs@@subversions.gnu.org:/cvsroot/tramp login} |
391 | ||
392 | (Logging in to anoncvs@@subversions.gnu.org) | |
393 | CVS password: @strong{(just hit RET here)} | |
394 | @dots{} | |
395 | ||
396 | ] @strong{cvs -z3 -d:pserver:anoncvs@@subversions.gnu.org:/cvsroot/tramp co tramp} | |
397 | @end example | |
398 | ||
16674e4f | 399 | @noindent |
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400 | You should now have a directory @file{~/@value{emacs-dir}/tramp} |
401 | containing the latest version of @tramp{}. You can fetch the latest | |
402 | updates from the repository by issuing the command: | |
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403 | |
404 | @example | |
16674e4f | 405 | ] @strong{cd ~/@value{emacs-dir}/tramp} |
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406 | ] @strong{cvs update -d} |
407 | @end example | |
408 | ||
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409 | @noindent |
410 | Once you've got updated files from the CVS repository, you need to run | |
411 | @command{autoconf} in order to get an up-to-date @file{configure} | |
412 | script: | |
413 | ||
414 | @example | |
415 | ] @strong{cd ~/@value{emacs-dir}/tramp} | |
416 | ] @strong{autoconf} | |
417 | @end example | |
418 | ||
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419 | |
420 | @node History | |
421 | @chapter History of @tramp{} | |
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422 | @cindex history |
423 | @cindex development history | |
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424 | |
425 | Development was started end of November 1998. The package was called | |
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426 | @file{rssh.el}, back then. It only provided one method to access a |
427 | file, using @command{ssh} to log in to a remote host and using | |
428 | @command{scp} to transfer the file contents. After a while, the name | |
429 | was changed to @file{rcp.el}, and now it's @tramp{}. Along the way, | |
430 | many more methods for getting a remote shell and for transferring the | |
431 | file contents were added. Support for VC was added. | |
fb7933a3 | 432 | |
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433 | The most recent addition of major features were the multi-hop methods |
434 | added in April 2000 and the unification of @tramp{} and Ange-FTP | |
435 | filenames in July 2002. | |
fb7933a3 | 436 | |
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437 | @c Installation chapter is necessary only in case of standalone |
438 | @c installation. Text taken from trampinst.texi. | |
439 | @ifset tramp-inst | |
440 | @installationchapter{} | |
16674e4f | 441 | @end ifset |
fb7933a3 | 442 | |
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443 | @node Configuration |
444 | @chapter Configuring @tramp{} for use | |
92eeeafc | 445 | @cindex configuration |
fb7933a3 | 446 | |
92eeeafc | 447 | @cindex default configuration |
fb7933a3 | 448 | @tramp{} is (normally) fully functional when it is initially |
16674e4f | 449 | installed. It is initially configured to use the @command{ssh} program |
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450 | to connect to the remote host and to use base-64 encoding (on the |
451 | remote host, via @command{mimencode}, and on the local host via the | |
452 | built-in support for base-64 encoding in Emacs). | |
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453 | |
454 | On some hosts, there are problems with opening a connection. These are | |
455 | related to the behavior of the remote shell. See @xref{Remote shell | |
456 | setup}, for details on this. | |
457 | ||
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458 | If you do not wish to use these commands to connect to the remote |
459 | host, you should change the default connection and transfer method | |
460 | that @tramp uses. There are several different methods that @tramp{} | |
461 | can use to connect to remote machines and transfer files | |
462 | (@pxref{Connection types}). | |
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463 | |
464 | ||
465 | @menu | |
466 | * Connection types:: Types of connections made to remote machines. | |
467 | * Inline methods:: Inline methods. | |
468 | * External transfer methods:: External transfer methods. | |
469 | * Multi-hop Methods:: Connecting to a remote host using multiple hops. | |
470 | * Default Method:: Selecting a default method. | |
471 | * Customizing Methods:: Using Non-Standard Methods. | |
16674e4f | 472 | * Customizing Completion:: Selecting config files for user/host name completion. |
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473 | * Remote Programs:: How @tramp{} finds and uses programs on the remote machine. |
474 | * Remote shell setup:: Remote shell setup hints. | |
475 | * Windows setup hints:: Issues with Cygwin ssh. | |
b1a2b924 | 476 | * Auto-save and Backup:: Auto-save and Backup. |
fb7933a3 KG |
477 | @end menu |
478 | ||
479 | ||
480 | @node Connection types | |
481 | @section Types of connections made to remote machines. | |
92eeeafc | 482 | @cindex connection types, overview |
fb7933a3 KG |
483 | |
484 | There are two basic types of transfer methods, each with its own | |
92eeeafc | 485 | advantages and limitations. Both types of connection make use of a |
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486 | remote shell access program such as @command{rsh}, @command{ssh} or |
487 | @command{telnet} to connect to the remote machine. | |
488 | ||
489 | This connection is used to perform many of the operations that @tramp | |
490 | requires to make the remote file system transparently accessible from | |
491 | the local machine. It is only when visiting files that the methods | |
492 | differ. | |
493 | ||
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494 | @cindex inline methods |
495 | @cindex external transfer methods | |
496 | @cindex external methods | |
497 | @cindex out-of-band methods | |
498 | @cindex methods, inline | |
499 | @cindex methods, external transfer | |
500 | @cindex methods, out-of-band | |
501 | Loading or saving a remote file requires that the content of the file | |
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502 | be transfered between the two machines. The content of the file can be |
503 | transfered over the same connection used to log in to the remote | |
504 | machine or the file can be transfered through another connection using | |
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505 | a remote copy program such as @command{rcp}, @command{scp} or |
506 | @command{rsync}. The former are called @dfn{inline methods}, the | |
507 | latter are called @dfn{out-of-band methods} or @dfn{external transfer | |
508 | methods} (@dfn{external methods} for short). | |
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509 | |
510 | The performance of the external transfer methods is generally better | |
92eeeafc KG |
511 | than that of the inline methods, at least for large files. This is |
512 | caused by the need to encode and decode the data when transferring | |
513 | inline. | |
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514 | |
515 | The one exception to this rule are the @command{scp} based transfer | |
516 | methods. While these methods do see better performance when actually | |
517 | transferring files, the overhead of the cryptographic negotiation at | |
518 | startup may drown out the improvement in file transfer times. | |
519 | ||
520 | External transfer methods do require that the remote copy command is not | |
521 | interactive --- that is, the command does not prompt you for a password. | |
522 | If you cannot perform remote copies without a password, you will need to | |
523 | use an inline transfer method to work with @tramp{}. | |
524 | ||
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525 | @cindex multi-hop methods |
526 | @cindex methods, multi-hop | |
fb7933a3 KG |
527 | A variant of the inline methods are the @dfn{multi-hop methods}. |
528 | These methods allow you to connect a remote host using a number `hops', | |
529 | each of which connects to a different host. This is useful if you are | |
530 | in a secured network where you need to go through a bastion host to | |
531 | connect to the outside world. | |
532 | ||
533 | ||
534 | @node Inline methods | |
535 | @section Inline methods | |
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536 | @cindex inline methods |
537 | @cindex methods, inline | |
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538 | |
539 | The inline methods in @tramp{} are quite powerful and can work in | |
540 | situations where you cannot use an external transfer program to connect. | |
541 | Inline methods are the only methods that work when connecting to the | |
542 | remote machine via telnet. (There are also strange inline methods which | |
543 | allow you to transfer files between @emph{user identities} rather than | |
544 | hosts, see below.) | |
545 | ||
546 | These methods depend on the existence of a suitable encoding and | |
92eeeafc | 547 | decoding command on remote machine. Locally, @tramp{} may be able to use |
fb7933a3 KG |
548 | features of Emacs to decode and encode the files or it may require |
549 | access to external commands to perform that task. | |
550 | ||
92eeeafc | 551 | @cindex uuencode |
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552 | @cindex mimencode |
553 | @cindex base-64 encoding | |
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554 | @tramp{} checks the availability and usability of commands like |
555 | @command{mimencode} (part of the @command{metamail} package) or | |
556 | @command{uuencode} on the remote host. The first reliable command | |
557 | will be used. The search path can be customized, see @ref{Remote | |
558 | Programs}. | |
fb7933a3 | 559 | |
abc6be8d | 560 | If both commands aren't available on the remote host, @tramp{} |
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561 | transfers a small piece of Perl code to the remote host, and tries to |
562 | apply it for encoding and decoding. | |
fb7933a3 | 563 | |
fb7933a3 | 564 | |
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565 | @table @asis |
566 | @item @option{rsh} | |
567 | @cindex method rsh | |
568 | @cindex rsh method | |
fb7933a3 | 569 | |
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570 | Connect to the remote host with @command{rsh}. Due to the unsecure |
571 | connection it is recommended for very local host topology only. | |
fb7933a3 | 572 | |
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573 | On operating systems which provide the command @command{remsh} instead |
574 | of @command{rsh}, you can use the method @option{remsh}. This is true | |
575 | for HP-UX or Cray UNICOS, for example. | |
576 | ||
fb7933a3 | 577 | |
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578 | @item @option{ssh} |
579 | @cindex method ssh | |
580 | @cindex ssh method | |
fb7933a3 | 581 | |
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582 | Connect to the remote host with @command{ssh}. This is identical to |
583 | the previous option except that the @command{ssh} package is used, | |
584 | making the connection more secure. | |
fb7933a3 | 585 | |
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586 | There are also two variants, @option{ssh1} and @option{ssh2}, that |
587 | call @samp{ssh -1} and @samp{ssh -2}, respectively. This way, you can | |
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588 | explicitly select whether you want to use the SSH protocol version 1 |
589 | or 2 to connect to the remote host. (You can also specify in | |
590 | @file{~/.ssh/config}, the SSH configuration file, which protocol | |
f08d9f0e | 591 | should be used, and use the regular @option{ssh} method.) |
90dc758d | 592 | |
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593 | Two other variants, @option{ssh1_old} and @option{ssh2_old}, use the |
594 | @command{ssh1} and @command{ssh2} commands explicitly. If you don't | |
595 | know what these are, you do not need these options. | |
fb7933a3 | 596 | |
16674e4f | 597 | All the methods based on @command{ssh} have an additional kludgy |
8e3a1104 KG |
598 | feature: you can specify a host name which looks like @file{host#42} |
599 | (the real host name, then a hash sign, then a port number). This | |
600 | means to connect to the given host but to also pass @code{-p 42} as | |
601 | arguments to the @command{ssh} command. | |
602 | ||
fb7933a3 | 603 | |
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604 | @item @option{telnet} |
605 | @cindex method telnet | |
606 | @cindex telnet method | |
fb7933a3 | 607 | |
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608 | Connect to the remote host with @command{telnet}. This is as unsecure |
609 | as the @option{rsh} method. | |
fb7933a3 | 610 | |
fb7933a3 | 611 | |
f08d9f0e | 612 | @item @option{su} |
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613 | @cindex method su |
614 | @cindex su method | |
fb7933a3 | 615 | |
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616 | This method does not connect to a remote host at all, rather it uses |
617 | the @command{su} program to allow you to edit files as another user. | |
fb7933a3 | 618 | |
fb7933a3 | 619 | |
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620 | @item @option{sudo} |
621 | @cindex method sudo | |
622 | @cindex sudo method | |
fb7933a3 | 623 | |
f08d9f0e | 624 | This is similar to the @option{su} method, but it uses @command{sudo} |
fb7933a3 KG |
625 | rather than @command{su} to become a different user. |
626 | ||
627 | Note that @command{sudo} must be configured to allow you to start a | |
628 | shell as the user. It would be nice if it was sufficient if | |
f08d9f0e KG |
629 | @command{ls} and @command{mimencode} were allowed, but that is not |
630 | easy to implement, so I haven't got around to it, yet. | |
fb7933a3 | 631 | |
fb7933a3 | 632 | |
f08d9f0e KG |
633 | @item @option{sshx} |
634 | @cindex method sshx | |
635 | @cindex sshx method | |
636 | @cindex Cygwin (with sshx method) | |
fb7933a3 | 637 | |
f08d9f0e KG |
638 | As you expect, this is similar to @option{ssh}, only a little |
639 | different. Whereas @option{ssh} opens a normal interactive shell on | |
92eeeafc | 640 | the remote host, this option uses @samp{ssh -t -t @var{host} -l |
16674e4f | 641 | @var{user} /bin/sh} to open a connection. This is useful for users |
92eeeafc KG |
642 | where the normal login shell is set up to ask them a number of |
643 | questions when logging in. This procedure avoids these questions, and | |
644 | just gives @tramp{} a more-or-less `standard' login shell to work | |
645 | with. | |
fb7933a3 | 646 | |
83fa16cf KG |
647 | Note that this procedure does not eliminate questions asked by |
648 | @command{ssh} itself. For example, @command{ssh} might ask ``Are you | |
649 | sure you want to continue connecting?'' if the host key of the remote | |
abc6be8d | 650 | host is not known. @tramp{} does not know how to deal with such a |
83fa16cf KG |
651 | question (yet), therefore you will need to make sure that you can log |
652 | in without such questions. | |
653 | ||
fb7933a3 KG |
654 | This is also useful for Windows users where @command{ssh}, when |
655 | invoked from an Emacs buffer, tells them that it is not allocating a | |
656 | pseudo tty. When this happens, the login shell is wont to not print | |
92eeeafc KG |
657 | any shell prompt, which confuses @tramp{} mightily. For reasons |
658 | unknown, some Windows ports for @command{ssh} (maybe the Cygwin one) | |
659 | require the doubled @samp{-t} option. | |
fb7933a3 | 660 | |
92eeeafc | 661 | This supports the @samp{-p} kludge. |
8e3a1104 | 662 | |
fb7933a3 | 663 | |
f08d9f0e KG |
664 | @item @option{krlogin} |
665 | @cindex method krlogin | |
666 | @cindex km krlogin | |
667 | @cindex Kerberos (with krlogin method) | |
fb7933a3 | 668 | |
f08d9f0e | 669 | This method is also similar to @option{ssh}. It only uses the |
fb7933a3 KG |
670 | @command{krlogin -x} command to log in to the remote host. |
671 | ||
672 | ||
f08d9f0e KG |
673 | @item @option{plink} |
674 | @cindex method plink | |
675 | @cindex plink method | |
fb7933a3 KG |
676 | |
677 | This method is mostly interesting for Windows users using the PuTTY | |
92eeeafc | 678 | implementation of SSH. It uses @samp{plink -ssh} to log in to the |
fb7933a3 KG |
679 | remote host. |
680 | ||
41bed43c KG |
681 | Additionally, the method @option{plink1} is provided, which calls |
682 | @samp{plink -1 -ssh} in order to use SSH protocol version 1 | |
683 | explicitely. | |
684 | ||
fb7933a3 KG |
685 | CCC: Do we have to connect to the remote host once from the command |
686 | line to accept the SSH key? Maybe this can be made automatic? | |
687 | ||
abc6be8d KG |
688 | CCC: Does @command{plink} support the @samp{-p} option? @tramp{} will |
689 | support that, anyway. | |
8e3a1104 | 690 | |
92eeeafc | 691 | @end table |
fb7933a3 KG |
692 | |
693 | ||
694 | ||
695 | @node External transfer methods | |
696 | @section External transfer methods | |
92eeeafc KG |
697 | @cindex methods, external transfer |
698 | @cindex methods, out-of-band | |
699 | @cindex external transfer methods | |
700 | @cindex out-of-band methods | |
fb7933a3 KG |
701 | |
702 | The external transfer methods operate through multiple channels, using | |
703 | the remote shell connection for many actions while delegating file | |
704 | transfers to an external transfer utility. | |
705 | ||
706 | This saves the overhead of encoding and decoding that multiplexing the | |
707 | transfer through the one connection has with the inline methods. | |
708 | ||
709 | If you want to use an external transfer method you @emph{must} be able | |
710 | to execute the transfer utility to copy files to and from the remote | |
711 | machine without any interaction. | |
712 | ||
92eeeafc | 713 | @cindex ssh-agent |
fb7933a3 KG |
714 | This means that you will need to use @command{ssh-agent} if you use the |
715 | @command{scp} program for transfers, or maybe your version of | |
716 | @command{scp} accepts a password on the command line.@footnote{PuTTY's | |
717 | @command{pscp} allows you to specify the password on the command line.} | |
718 | If you use @command{rsync} via @command{ssh} then the same rule must | |
719 | apply to that connection. | |
720 | ||
721 | If you cannot get @command{scp} to run without asking for a password but | |
722 | would still like to use @command{ssh} to secure your connection, have a | |
723 | look at the @command{ssh} based inline methods. | |
724 | ||
725 | ||
92eeeafc | 726 | @table @asis |
fb7933a3 | 727 | @item @option{rcp} --- @command{rsh} and @command{rcp} |
92eeeafc KG |
728 | @cindex method rcp |
729 | @cindex rcp method | |
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730 | @cindex rcp (with rcp method) |
731 | @cindex rsh (with rcp method) | |
fb7933a3 KG |
732 | |
733 | This method uses the @command{rsh} and @command{rcp} commands to connect | |
41bed43c | 734 | to the remote machine and transfer files. This is probably the fastest |
fb7933a3 KG |
735 | connection method available. |
736 | ||
41bed43c KG |
737 | The alternative method @option{remcp} uses the @command{remsh} and |
738 | @command{rcp} commands. It should be applied on machines where | |
739 | @command{remsh} is used instead of @command{rsh}. | |
740 | ||
fb7933a3 KG |
741 | |
742 | @item @option{scp} --- @command{ssh} and @command{scp} | |
92eeeafc KG |
743 | @cindex method scp |
744 | @cindex scp method | |
e28e4d20 KG |
745 | @cindex scp (with scp method) |
746 | @cindex ssh (with scp method) | |
fb7933a3 KG |
747 | |
748 | Using @command{ssh} to connect to the remote host and @command{scp} to | |
749 | transfer files between the machines is the best method for securely | |
750 | connecting to a remote machine and accessing files. | |
751 | ||
752 | The performance of this option is also quite good. It may be slower than | |
753 | the inline methods when you often open and close small files however. | |
754 | The cost of the cryptographic handshake at the start of an @command{scp} | |
755 | session can begin to absorb the advantage that the lack of encoding and | |
756 | decoding presents. | |
757 | ||
f08d9f0e KG |
758 | There are also two variants, @option{scp1} and @option{scp2}, that |
759 | call @samp{ssh -1} and @samp{ssh -2}, respectively. This way, you can | |
760 | explicitly select whether you want to use the SSH protocol version 1 | |
761 | or 2 to connect to the remote host. (You can also specify in | |
762 | @file{~/.ssh/config}, the SSH configuration file, which protocol | |
763 | should be used, and use the regular @option{ssh} method.) | |
764 | ||
765 | Two other variants, @option{scp1_old} and @option{scp2_old}, use the | |
766 | @command{ssh1} and @command{ssh2} commands explicitly. If you don't | |
767 | know what these are, you do not need these options. | |
768 | ||
16674e4f | 769 | All the @command{ssh} based methods support the kludgy @samp{-p} |
8e3a1104 | 770 | feature where you can specify a port number to connect to in the host |
abc6be8d | 771 | name. For example, the host name @file{host#42} tells @tramp{} to |
92eeeafc | 772 | specify @samp{-p 42} in the argument list for @command{ssh}. |
8e3a1104 | 773 | |
fb7933a3 KG |
774 | |
775 | @item @option{rsync} --- @command{ssh} and @command{rsync} | |
92eeeafc KG |
776 | @cindex method rsync |
777 | @cindex rsync method | |
e28e4d20 KG |
778 | @cindex rsync (with rsync method) |
779 | @cindex ssh (with rsync method) | |
fb7933a3 KG |
780 | |
781 | Using the @command{ssh} command to connect securely to the remote | |
782 | machine and the @command{rsync} command to transfer files is almost | |
783 | identical to the @option{scp} method. | |
784 | ||
785 | While @command{rsync} performs much better than @command{scp} when | |
786 | transferring files that exist on both hosts, this advantage is lost if | |
787 | the file exists only on one side of the connection. | |
788 | ||
789 | The @command{rsync} based method may be considerably faster than the | |
790 | @command{rcp} based methods when writing to the remote system. Reading | |
abc6be8d | 791 | files to the local machine is no faster than with a direct copy. |
fb7933a3 | 792 | |
92eeeafc | 793 | This method supports the @samp{-p} hack. |
8e3a1104 | 794 | |
fb7933a3 KG |
795 | |
796 | @item @option{scpx} --- @command{ssh} and @command{scp} | |
92eeeafc KG |
797 | @cindex method scpx |
798 | @cindex scpx method | |
e28e4d20 KG |
799 | @cindex scp (with scpx method) |
800 | @cindex ssh (with scpx method) | |
801 | @cindex Cygwin (with scpx method) | |
fb7933a3 KG |
802 | |
803 | As you expect, this is similar to @option{scp}, only a little | |
92eeeafc KG |
804 | different. Whereas @option{scp} opens a normal interactive shell on |
805 | the remote host, this option uses @samp{ssh -t -t @var{host} -l | |
806 | @var{user} /bin/sh} to open a connection. This is useful for users | |
807 | where the normal login shell is set up to ask them a number of | |
808 | questions when logging in. This procedure avoids these questions, and | |
809 | just gives @tramp{} a more-or-less `standard' login shell to work | |
810 | with. | |
fb7933a3 KG |
811 | |
812 | This is also useful for Windows users where @command{ssh}, when | |
813 | invoked from an Emacs buffer, tells them that it is not allocating a | |
814 | pseudo tty. When this happens, the login shell is wont to not print | |
92eeeafc KG |
815 | any shell prompt, which confuses @tramp{} mightily. Maybe this |
816 | applies to the Cygwin port of SSH. | |
fb7933a3 | 817 | |
92eeeafc | 818 | This method supports the @samp{-p} hack. |
8e3a1104 | 819 | |
fb7933a3 KG |
820 | |
821 | @item @option{pscp} --- @command{plink} and @command{pscp} | |
92eeeafc KG |
822 | @cindex method pscp |
823 | @cindex pscp method | |
e28e4d20 KG |
824 | @cindex pscp (with pscp method) |
825 | @cindex plink (with pscp method) | |
826 | @cindex PuTTY (with pscp method) | |
fb7933a3 KG |
827 | |
828 | This method is similar to @option{scp}, but it uses the | |
829 | @command{plink} command to connect to the remote host, and it uses | |
830 | @command{pscp} for transferring the files. These programs are part | |
831 | of PuTTY, an SSH implementation for Windows. | |
832 | ||
92eeeafc | 833 | CCC: Does @command{plink} support the @samp{-p} hack? |
8e3a1104 | 834 | |
fb7933a3 KG |
835 | |
836 | @item @option{fcp} --- @command{fsh} and @command{fcp} | |
92eeeafc KG |
837 | @cindex method fcp |
838 | @cindex fcp method | |
e28e4d20 KG |
839 | @cindex fsh (with fcp method) |
840 | @cindex fcp (with fcp method) | |
fb7933a3 KG |
841 | |
842 | This method is similar to @option{scp}, but it uses the @command{fsh} | |
843 | command to connect to the remote host, and it uses @command{fcp} for | |
844 | transferring the files. @command{fsh/fcp} are a front-end for | |
845 | @command{ssh} which allow for reusing the same @command{ssh} session | |
846 | for submitting several commands. This avoids the startup overhead of | |
847 | @command{scp} (which has to establish a secure connection whenever it | |
848 | is called). Note, however, that you can also use one of the inline | |
849 | methods to achieve a similar effect. | |
850 | ||
92eeeafc KG |
851 | This method uses the command @samp{fsh @var{host} -l @var{user} |
852 | /bin/sh -i} to establish the connection, it does not work to just say | |
853 | @command{fsh @var{host} -l @var{user}}. | |
fb7933a3 | 854 | |
e28e4d20 KG |
855 | @cindex method fsh |
856 | @cindex fsh method | |
92eeeafc KG |
857 | There is no inline method using @command{fsh} as the multiplexing |
858 | provided by the program is not very useful in our context. @tramp{} | |
859 | opens just one connection to the remote host and then keeps it open, | |
860 | anyway. | |
861 | ||
f08d9f0e KG |
862 | |
863 | @ifset emacs | |
864 | @item @option{ftp} | |
865 | @cindex method ftp | |
866 | @cindex ftp method | |
867 | ||
abc6be8d | 868 | This is not a native @tramp{} method. Instead of, it forwards all |
f08d9f0e KG |
869 | requests to @value{ftp-package-name}. |
870 | @end ifset | |
871 | ||
abc6be8d KG |
872 | |
873 | @item @option{smb} --- @command{smbclient} | |
874 | @cindex method smb | |
875 | @cindex smb method | |
876 | ||
877 | This is another not natural @tramp{} method. It uses the | |
878 | @command{smbclient} command on different Unices in order to connect to | |
879 | an SMB server. An SMB server might be a Samba (or CIFS) server on | |
880 | another UNIX host or, more interesting, a host running MS Windows. So | |
881 | far, it is tested towards MS Windows NT, MS Windows 2000, and MS | |
882 | Windows XP. | |
883 | ||
884b79ec | 884 | The first directory in the localname must be a share name on the remote |
abc6be8d KG |
885 | host. Remember, that the @code{$} character in which default shares |
886 | usually end, must be written @code{$$} due to environment variable | |
887 | substitution in file names. If no share name is given (i.e. remote | |
888 | directory @code{/}), all available shares are listed. | |
889 | ||
890 | Since authorization is done on share level, you will be prompted | |
891 | always for a password if you access another share on the same host. | |
892 | Due to security reasons, the password is not cached. | |
893 | ||
894 | MS Windows uses for authorization both a user name and a domain name. | |
895 | Because of this, the @tramp{} syntax has been extended: you can | |
896 | specify a user name which looks like @code{user%domain} (the real user | |
897 | name, then a percent sign, then the domain name). So, to connect to | |
898 | the machine @code{melancholia} as user @code{daniel} of the domain | |
899 | @code{BIZARRE}, and edit @file{.emacs} in the home directory (share | |
900 | @code{daniel$}) I would specify the filename | |
901 | @file{@value{tramp-prefix}smb@value{tramp-postfix-single-hop}daniel%BIZARRE@@melancholia@value{tramp-postfix}/daniel$$/.emacs}. | |
902 | ||
903 | The domain name as well as the user name are optional. If no user | |
904 | name is specified at all, the anonymous user (without password | |
905 | prompting) is assumed. This is different from all other @tramp{} | |
906 | methods, where in such a case the local user name is taken. | |
907 | ||
908 | The @option{smb} method supports the @samp{-p} hack. | |
909 | ||
910 | @strong{Please note:} If Emacs runs locally under MS Windows, this | |
911 | method isn't available. Instead of, you can use UNC file names like | |
912 | @file{//melancholia/daniel$$/.emacs}. The only disadvantage is that | |
41bed43c | 913 | there's no possibility to specify another user name. |
abc6be8d | 914 | |
92eeeafc | 915 | @end table |
fb7933a3 KG |
916 | |
917 | @node Multi-hop Methods | |
918 | @section Connecting to a remote host using multiple hops | |
92eeeafc KG |
919 | @cindex multi-hop methods |
920 | @cindex methods, multi-hop | |
fb7933a3 KG |
921 | |
922 | Sometimes, the methods described before are not sufficient. Sometimes, | |
923 | it is not possible to connect to a remote host using a simple command. | |
924 | For example, if you are in a secured network, you might have to log in | |
925 | to a `bastion host' first before you can connect to the outside world. | |
926 | Of course, the target host may also require a bastion host. The format | |
927 | of multi-hop filenames is slightly different than the format of normal | |
928 | @tramp{} methods. | |
929 | ||
92eeeafc KG |
930 | @cindex method multi |
931 | @cindex multi method | |
884b79ec KG |
932 | A multi-hop file name specifies a method, a number of hops, and a |
933 | localname (path name on the remote system). The method name is always | |
f08d9f0e | 934 | @option{multi}. |
fb7933a3 | 935 | |
f08d9f0e KG |
936 | Each hop consists of a @dfn{hop method} specification, a user name and |
937 | a host name. The hop method can be an inline method only. The | |
938 | following hop methods are (currently) available: | |
fb7933a3 | 939 | |
92eeeafc KG |
940 | @table @option |
941 | @item telnet | |
942 | @cindex hop method telnet | |
943 | @cindex telnet hop method | |
fb7933a3 KG |
944 | |
945 | Uses the well-known @command{telnet} program to connect to the host. | |
946 | Whereas user name and host name are supplied in the file name, the | |
947 | user is queried for the password. | |
948 | ||
92eeeafc KG |
949 | @item rsh |
950 | @cindex hop method rsh | |
951 | @cindex rsh hop method | |
fb7933a3 KG |
952 | |
953 | This uses @command{rsh} to connect to the host. You do not need to | |
954 | enter a password unless @command{rsh} explicitly asks for it. | |
955 | ||
41bed43c KG |
956 | The variant @option{remsh} uses the @command{remsh} command. It |
957 | should be applied on machines where @command{remsh} is used instead of | |
958 | @command{rsh}. | |
959 | ||
92eeeafc KG |
960 | @item ssh |
961 | @cindex hop method ssh | |
962 | @cindex ssh hop method | |
fb7933a3 KG |
963 | |
964 | This uses @command{ssh} to connect to the host. You might have to enter | |
965 | a password or a pass phrase. | |
966 | ||
92eeeafc KG |
967 | @item su |
968 | @cindex hop method su | |
969 | @cindex su hop method | |
fb7933a3 KG |
970 | |
971 | This method does not actually contact a different host, but it allows | |
972 | you to become a different user on the host you're currently on. This | |
973 | might be useful if you want to edit files as root, but the remote host | |
974 | does not allow remote root logins. In this case you can use | |
975 | @option{telnet}, @option{rsh} or @option{ssh} to connect to the | |
976 | remote host as a non-root user, then use an @option{su} hop to become | |
977 | root. But @option{su} need not be the last hop in a sequence, you could | |
978 | also use it somewhere in the middle, if the need arises. | |
979 | ||
f08d9f0e | 980 | Even though you @emph{must} specify both user and host with an |
fb7933a3 KG |
981 | @option{su} hop, the host name is ignored and only the user name is |
982 | used. | |
983 | ||
92eeeafc KG |
984 | @item sudo |
985 | @cindex hop method sudo | |
986 | @cindex sudo hop method | |
fb7933a3 KG |
987 | |
988 | This is similar to the @option{su} hop, except that it uses | |
989 | @command{sudo} rather than @command{su} to become a different user. | |
990 | ||
92eeeafc | 991 | @end table |
fb7933a3 | 992 | |
92eeeafc KG |
993 | Some people might wish to use port forwarding with @command{ssh} or |
994 | maybe they have to use a nonstandard port. This can be accomplished | |
995 | by putting a stanza in @file{~/.ssh/config} for the account which | |
996 | specifies a different port number for a certain host name. But it can | |
f08d9f0e KG |
997 | also be accomplished within @tramp{}, by adding a multi-hop method. |
998 | For example: | |
fb7933a3 KG |
999 | |
1000 | @lisp | |
16674e4f KG |
1001 | (add-to-list |
1002 | 'tramp-multi-connection-function-alist | |
1003 | '("sshf" tramp-multi-connect-rlogin "ssh %h -l %u -p 4400%n")) | |
fb7933a3 KG |
1004 | @end lisp |
1005 | ||
16674e4f | 1006 | Now you can use an @code{sshf} hop which connects to port 4400 instead of |
fb7933a3 KG |
1007 | the standard port. |
1008 | ||
1009 | ||
1010 | @node Default Method | |
1011 | @section Selecting a default method | |
92eeeafc | 1012 | @cindex default method |
fb7933a3 | 1013 | |
92eeeafc | 1014 | @vindex tramp-default-method |
fb7933a3 KG |
1015 | When you select an appropriate transfer method for your typical usage |
1016 | you should set the variable @var{tramp-default-method} to reflect that | |
92eeeafc | 1017 | choice. This variable controls which method will be used when a method |
884b79ec | 1018 | is not specified in the @tramp{} file name. For example: |
fb7933a3 KG |
1019 | |
1020 | @lisp | |
1021 | (setq tramp-default-method "scp") | |
1022 | @end lisp | |
1023 | ||
92eeeafc KG |
1024 | @vindex tramp-default-method-alist |
1025 | You can also specify different methods for certain user/host | |
1026 | combinations, via the variable @var{tramp-default-method-alist}. For | |
f08d9f0e | 1027 | example, the following two lines specify to use the @option{ssh} |
92eeeafc KG |
1028 | method for all user names matching @samp{john} and the @option{rsync} |
1029 | method for all host names matching @samp{lily}. The third line | |
f08d9f0e | 1030 | specifies to use the @option{su} method for the user @samp{root} on |
92eeeafc KG |
1031 | the machine @samp{localhost}. |
1032 | ||
1033 | @lisp | |
f08d9f0e | 1034 | (add-to-list 'tramp-default-method-alist '("" "john" "ssh")) |
92eeeafc KG |
1035 | (add-to-list 'tramp-default-method-alist '("lily" "" "rsync")) |
1036 | (add-to-list 'tramp-default-method-alist | |
f08d9f0e | 1037 | '("\\`localhost\\'" "\\`root\\'" "su")) |
92eeeafc KG |
1038 | @end lisp |
1039 | ||
1040 | @noindent | |
1041 | See the documentation for the variable | |
1042 | @var{tramp-default-method-alist} for more details. | |
1043 | ||
fb7933a3 KG |
1044 | External transfer methods are normally preferable to inline transfer |
1045 | methods, giving better performance. They may not be useful if you use | |
1046 | many remote machines where you cannot log in without a password. | |
1047 | ||
1048 | @xref{Inline methods}. | |
1049 | @xref{External transfer methods}. | |
1050 | @xref{Multi-hop Methods}. | |
1051 | ||
1052 | Another consideration with the selection of transfer methods is the | |
1053 | environment you will use them in and, especially when used over the | |
1054 | Internet, the security implications of your preferred method. | |
1055 | ||
1056 | The @command{rsh} and @command{telnet} methods send your password as | |
1057 | plain text as you log in to the remote machine, as well as transferring | |
1058 | the files in such a way that the content can easily be read from other | |
1059 | machines. | |
1060 | ||
1061 | If you need to connect to remote systems that are accessible from the | |
1062 | Internet, you should give serious thought to using @command{ssh} based | |
1063 | methods to connect. These provide a much higher level of security, | |
1064 | making it a non-trivial exercise for someone to obtain your password or | |
1065 | read the content of the files you are editing. | |
1066 | ||
1067 | @node Customizing Methods | |
1068 | @section Using Non-Standard Methods | |
92eeeafc KG |
1069 | @cindex customizing methods |
1070 | @cindex using non-standard methods | |
1071 | @cindex create your own methods | |
fb7933a3 KG |
1072 | |
1073 | There is a variable @code{tramp-methods} which you can change if the | |
1074 | predefined methods don't seem right. | |
1075 | ||
1076 | For the time being, I'll refer you to the Lisp documentation of that | |
1077 | variable, accessible with @kbd{C-h v tramp-methods @key{RET}}. | |
1078 | ||
1079 | ||
16674e4f KG |
1080 | @node Customizing Completion |
1081 | @section Selecting config files for user/host name completion | |
1082 | @cindex customizing completion | |
1083 | @cindex selecting config files | |
1084 | @vindex tramp-completion-function-alist | |
1085 | ||
1086 | The variable @code{tramp-completion-function-alist} is intended to | |
abc6be8d | 1087 | customize which files are taken into account for user and host name |
16674e4f KG |
1088 | completion (@pxref{Filename completion}). For every method, it keeps |
1089 | a set of configuration files, accompanied by a Lisp function able to | |
1090 | parse that file. Entries in @code{tramp-completion-function-alist} | |
1091 | have the form (@var{method} @var{pair1} @var{pair2} ...). | |
1092 | ||
1093 | Each @var{pair} is composed of (@var{function} @var{file}). | |
1094 | @var{function} is responsible to extract user names and host names | |
1095 | from @var{file} for completion. There are two functions which access | |
1096 | this variable: | |
1097 | ||
1098 | @defun tramp-get-completion-function method | |
1099 | This function returns the list of completion functions for @var{method}. | |
1100 | ||
1101 | Example: | |
1102 | @example | |
1103 | (tramp-get-completion-function "rsh") | |
1104 | ||
1105 | @result{} ((tramp-parse-rhosts "/etc/hosts.equiv") | |
1106 | (tramp-parse-rhosts "~/.rhosts")) | |
1107 | @end example | |
1108 | @end defun | |
1109 | ||
1110 | @defun tramp-set-completion-function method function-list | |
1111 | This function sets @var{function-list} as list of completion functions | |
884b79ec | 1112 | for @var{method}. |
16674e4f KG |
1113 | |
1114 | Example: | |
1115 | @example | |
1116 | (tramp-set-completion-function "ssh" | |
18d6d595 KG |
1117 | '((tramp-parse-sconfig "/etc/ssh_config") |
1118 | (tramp-parse-sconfig "~/.ssh/config"))) | |
16674e4f | 1119 | |
18d6d595 KG |
1120 | @result{} ((tramp-parse-sconfig "/etc/ssh_config") |
1121 | (tramp-parse-sconfig "~/.ssh/config")) | |
16674e4f KG |
1122 | @end example |
1123 | @end defun | |
1124 | ||
18d6d595 | 1125 | The following predefined functions parsing configuration files exist: |
16674e4f KG |
1126 | |
1127 | @table @asis | |
1128 | @item @code{tramp-parse-rhosts} | |
1129 | @findex tramp-parse-rhosts | |
1130 | ||
1131 | This function parses files which are syntactical equivalent to | |
1132 | @file{~/.rhosts}. It returns both host names and user names, if | |
1133 | specified. | |
1134 | ||
1135 | @item @code{tramp-parse-shosts} | |
1136 | @findex tramp-parse-shosts | |
1137 | ||
1138 | This function parses files which are syntactical equivalent to | |
18d6d595 | 1139 | @file{~/.ssh/known_hosts}. Since there are no user names specified |
16674e4f KG |
1140 | in such files, it can return host names only. |
1141 | ||
18d6d595 KG |
1142 | @item @code{tramp-parse-sconfig} |
1143 | @findex tramp-parse-shosts | |
1144 | ||
41bed43c | 1145 | This function returns the host nicknames defined by @code{Host} entries |
18d6d595 KG |
1146 | in @file{~/.ssh/config} style files. |
1147 | ||
16674e4f KG |
1148 | @item @code{tramp-parse-hosts} |
1149 | @findex tramp-parse-hosts | |
1150 | ||
1151 | A function dedicated to @file{/etc/hosts} style files. It returns | |
1152 | host names only. | |
1153 | ||
1154 | @item @code{tramp-parse-passwd} | |
1155 | @findex tramp-parse-passwd | |
1156 | ||
292ffc15 KG |
1157 | A function which parses @file{/etc/passwd} like files. Obviously, it |
1158 | can return user names only. | |
16674e4f | 1159 | |
292ffc15 KG |
1160 | @item @code{tramp-parse-netrc} |
1161 | @findex tramp-parse-netrc | |
1162 | ||
1163 | Finally, a function which parses @file{~/.netrc} like files. | |
1164 | @end table | |
16674e4f KG |
1165 | |
1166 | If you want to keep your own data in a file, with your own structure, | |
1167 | you might provide such a function as well. This function must meet | |
1168 | the following conventions: | |
1169 | ||
1170 | @defun my-tramp-parse file | |
1171 | @var{file} must be either a file name on your host, or @code{nil}. The | |
1172 | function must return a list of (@var{user} @var{host}), which are | |
1173 | taken as candidates for user and host name completion. | |
1174 | ||
1175 | Example: | |
1176 | @example | |
1177 | (my-tramp-parse "~/.my-tramp-hosts") | |
1178 | ||
1179 | @result{} ((nil "toto") ("daniel" "melancholia")) | |
1180 | @end example | |
1181 | @end defun | |
1182 | ||
1183 | ||
fb7933a3 KG |
1184 | @node Remote Programs |
1185 | @section How @tramp{} finds and uses programs on the remote machine. | |
1186 | ||
1187 | @tramp{} depends on a number of programs on the remote host in order to | |
1188 | function, including @command{ls}, @command{test}, @command{find} and | |
1189 | @command{cat}. | |
1190 | ||
1191 | In addition to these required tools, there are various tools that may be | |
1192 | required based on the connection method. See @ref{Inline methods} and | |
1193 | @ref{External transfer methods} for details on these. | |
1194 | ||
1195 | Certain other tools, such as @command{perl} (or @command{perl5}) and | |
1196 | @command{grep} will be used if they can be found. When they are | |
1197 | available, they are used to improve the performance and accuracy of | |
1198 | remote file access. | |
1199 | ||
92eeeafc | 1200 | @vindex tramp-remote-path |
fb7933a3 KG |
1201 | When @tramp{} connects to the remote machine, it searches for the |
1202 | programs that it can use. The variable @var{tramp-remote-path} controls | |
1203 | the directories searched on the remote machine. | |
1204 | ||
1205 | By default, this is set to a reasonable set of defaults for most | |
1206 | machines. It is possible, however, that your local (or remote ;) system | |
1207 | administrator has put the tools you want in some obscure local | |
1208 | directory. | |
1209 | ||
1210 | In this case, you can still use them with @tramp{}. You simply need to | |
1211 | add code to your @file{.emacs} to add the directory to the remote path. | |
1212 | This will then be searched by @tramp{} when you connect and the software | |
1213 | found. | |
1214 | ||
1215 | To add a directory to the remote search path, you could use code such | |
1216 | as: | |
1217 | ||
16674e4f KG |
1218 | @lisp |
1219 | @i{;; We load @tramp{} to define the variable.} | |
1220 | (require 'tramp) | |
1221 | @i{;; We have @command{perl} in "/usr/local/perl/bin"} | |
92eeeafc | 1222 | (add-to-list 'tramp-remote-path "/usr/local/perl/bin") |
16674e4f KG |
1223 | @end lisp |
1224 | ||
fb7933a3 KG |
1225 | |
1226 | @node Remote shell setup | |
1227 | @comment node-name, next, previous, up | |
1228 | @section Remote shell setup hints | |
92eeeafc | 1229 | @cindex remote shell setup |
e28e4d20 KG |
1230 | @cindex @file{.profile} file |
1231 | @cindex @file{.login} file | |
92eeeafc | 1232 | @cindex shell init files |
fb7933a3 KG |
1233 | |
1234 | As explained in the @ref{Overview} section, @tramp{} connects to the | |
1235 | remote host and talks to the shell it finds there. Of course, when you | |
1236 | log in, the shell executes its init files. Suppose your init file | |
16674e4f | 1237 | requires you to enter the birth date of your mother; clearly @tramp{} |
fb7933a3 KG |
1238 | does not know this and hence fails to log you in to that host. |
1239 | ||
1240 | There are different possible strategies for pursuing this problem. One | |
1241 | strategy is to enable @tramp{} to deal with all possible situations. | |
1242 | This is a losing battle, since it is not possible to deal with | |
1243 | @emph{all} situations. The other strategy is to require you to set up | |
1244 | the remote host such that it behaves like @tramp{} expect. This might | |
1245 | be inconvenient because you have to invest a lot of effort into shell | |
1246 | setup before you can begin to use @tramp{}. | |
1247 | ||
1248 | The package, therefore, pursues a combined approach. It tries to figure | |
1249 | out some of the more common setups, and only requires you to avoid | |
1250 | really exotic stuff. For example, it looks through a list of | |
1251 | directories to find some programs on the remote host. And also, it | |
abc6be8d | 1252 | knows that it is not obvious how to check whether a file exists, and |
fb7933a3 KG |
1253 | therefore it tries different possibilities. (On some hosts and shells, |
1254 | the command @code{test -e} does the trick, on some hosts the shell | |
1255 | builtin doesn't work but the program @code{/usr/bin/test -e} or | |
1256 | @code{/bin/test -e} works. And on still other hosts, @code{ls -d} is | |
1257 | the right way to do this.) | |
1258 | ||
1259 | Below you find a discussion of a few things that @tramp{} does not deal | |
1260 | with, and that you therefore have to set up correctly. | |
1261 | ||
92eeeafc KG |
1262 | @table @asis |
1263 | @item @var{shell-prompt-pattern} | |
fb7933a3 | 1264 | @vindex shell-prompt-pattern |
92eeeafc | 1265 | |
fb7933a3 KG |
1266 | After logging in to the remote host, @tramp{} has to wait for the remote |
1267 | shell startup to finish before it can send commands to the remote | |
1268 | shell. The strategy here is to wait for the shell prompt. In order to | |
1269 | recognize the shell prompt, the variable @code{shell-prompt-pattern} has | |
1270 | to be set correctly to recognize the shell prompt on the remote host. | |
1271 | ||
abc6be8d KG |
1272 | Note that @tramp{} requires the match for @code{shell-prompt-pattern} |
1273 | to be at the end of the buffer. Many people have something like the | |
83fa16cf | 1274 | following as the value for the variable: @code{"^[^>$][>$] *"}. Now |
abc6be8d KG |
1275 | suppose your shell prompt is @code{a <b> c $ }. In this case, |
1276 | @tramp{} recognizes the @code{>} character as the end of the prompt, | |
1277 | but it is not at the end of the buffer. | |
83fa16cf | 1278 | |
16674e4f KG |
1279 | @item @var{tramp-shell-prompt-pattern} |
1280 | @vindex tramp-shell-prompt-pattern | |
1281 | ||
1282 | This regular expression is used by @tramp{} in the same way as | |
1283 | @code{shell-prompt-pattern}, to match prompts from the remote shell. | |
1284 | This second variable exists because the prompt from the remote shell | |
1285 | might be different from the prompt from a local shell --- after all, | |
1286 | the whole point of @tramp{} is to log in to remote hosts as a | |
1287 | different user. The default value of | |
1288 | @code{tramp-shell-prompt-pattern} is the same as the default value of | |
1289 | @code{shell-prompt-pattern}, which is reported to work well in many | |
1290 | circumstances. | |
1291 | ||
fb7933a3 | 1292 | @item @code{tset} and other questions |
92eeeafc KG |
1293 | @cindex Unix command tset |
1294 | @cindex tset Unix command | |
fb7933a3 KG |
1295 | |
1296 | Some people invoke the @code{tset} program from their shell startup | |
16674e4f KG |
1297 | scripts which asks the user about the terminal type of the shell. |
1298 | Maybe some shells ask other questions when they are started. @tramp{} | |
1299 | does not know how to answer these questions. There are two approaches | |
1300 | for dealing with this problem. One approach is to take care that the | |
1301 | shell does not ask any questions when invoked from @tramp{}. You can | |
1302 | do this by checking the @code{TERM} environment variable, it will be | |
1303 | set to @code{dumb} when connecting. | |
fb7933a3 KG |
1304 | |
1305 | @vindex tramp-terminal-type | |
1306 | The variable @code{tramp-terminal-type} can be used to change this value | |
16674e4f KG |
1307 | to @code{dumb}. |
1308 | ||
1309 | The other approach is to teach @tramp{} about these questions. See | |
1310 | the variables @code{tramp-actions-before-shell} and | |
1311 | @code{tramp-multi-actions} (for multi-hop connections). | |
fb7933a3 | 1312 | |
6013ce47 KG |
1313 | @item Non-Bourne commands in @file{.profile} |
1314 | ||
1315 | After logging in to the remote host, @tramp{} issues the command | |
1316 | @code{exec /bin/sh}. (Actually, the command is slightly different.) | |
1317 | When @code{/bin/sh} is executed, it reads some init files, such as | |
1318 | @file{~/.shrc} or @file{~/.profile}. | |
1319 | ||
1320 | Now, some people have a login shell which is not @code{/bin/sh} but a | |
1321 | Bourne-ish shell such as bash or ksh. Some of these people might put | |
1322 | their shell setup into the files @code{~/.shrc} or @code{~/.profile}. | |
1323 | This way, it is possible for non-Bourne constructs to end up in those | |
1324 | files. Then, @code{exec /bin/sh} might cause the Bourne shell to barf | |
1325 | on those constructs. | |
1326 | ||
1327 | As an example, imagine somebody putting @code{export FOO=bar} into the | |
1328 | file @file{~/.profile}. The standard Bourne shell does not understand | |
1329 | this syntax and will emit a syntax error when it reaches this line. | |
1330 | ||
1331 | Another example is the tilde (@code{~}) character, say when adding | |
1332 | @file{~/bin} to @code{$PATH}. Many Bourne shells will not expand this | |
1333 | character, and since there is usually no directory whose name consists | |
1334 | of the single character tilde, strange things will happen. | |
1335 | ||
1336 | What can you do about this? | |
1337 | ||
1338 | Well, one possibility is to make sure that everything in @file{~/.shrc} | |
1339 | and @file{~/.profile} on all remote hosts is Bourne-compatible. In the | |
1340 | above example, instead of @code{export FOO=bar}, you might use | |
1341 | @code{FOO=bar; export FOO} instead. | |
1342 | ||
1343 | The other possibility is to put your non-Bourne shell setup into some | |
1344 | other files. For example, bash reads the file @file{~/.bash_profile} | |
1345 | instead of @file{~/.profile}, if the former exists. So bash | |
1346 | aficionados just rename their @file{~/.profile} to | |
1347 | @file{~/.bash_profile} on all remote hosts, and Bob's your uncle. | |
1348 | ||
1349 | The @tramp{} developers would like to circumvent this problem, so if you | |
1350 | have an idea about it, please tell us. However, we are afraid it is not | |
1351 | that simple: before saying @code{exec /bin/sh}, @tramp{} does not know | |
1352 | which kind of shell it might be talking to. It could be a Bourne-ish | |
1353 | shell like ksh or bash, or it could be a csh derivative like tcsh, or | |
1354 | it could be zsh, or even rc. If the shell is Bourne-ish already, then | |
1355 | it might be prudent to omit the @code{exec /bin/sh} step. But how to | |
1356 | find out if the shell is Bourne-ish? | |
1357 | ||
92eeeafc | 1358 | @end table |
fb7933a3 KG |
1359 | |
1360 | ||
b1a2b924 KG |
1361 | @node Auto-save and Backup |
1362 | @section Auto-save and Backup configuration | |
1363 | @cindex auto-save | |
1364 | @cindex backup | |
1365 | @vindex backup-directory-alist | |
1366 | ||
1367 | Explaining auto-save is still to do. | |
1368 | ||
1369 | Normally, Emacs writes backup files to the same directory as the | |
1370 | original files, but this behavior can be changed via the variable | |
1371 | @code{backup-directory-alist}. In connection with @tramp{}, this can | |
1372 | have unexpected side effects. Suppose that you specify that all backups | |
1373 | should go to the directory @file{~/.emacs.d/backups/}, and then you edit | |
1374 | the file @file{/su:root@@localhost:/etc/secretfile}. The effect is that | |
1375 | the backup file will be owned by you and not by root, thus possibly | |
1376 | enabling others to see it even if they were not intended to see it. | |
1377 | ||
1378 | When @code{backup-directory-alist} is nil (the default), such problems | |
1379 | do not occur. | |
1380 | ||
1381 | If you wish to customize the variable, the workaround is to include | |
1382 | special settings for Tramp files. For example, the following statement | |
1383 | effectively `turns off' the effect of @code{backup-directory-alist} for | |
1384 | @tramp{} files: | |
1385 | ||
1386 | @lisp | |
1387 | (require 'tramp) | |
1388 | (add-to-list 'backup-directory-alist | |
1389 | (cons tramp-file-name-regexp nil)) | |
1390 | @end lisp | |
1391 | ||
1392 | ||
fb7933a3 KG |
1393 | @node Windows setup hints |
1394 | @section Issues with Cygwin ssh | |
e28e4d20 | 1395 | @cindex Cygwin, issues |
fb7933a3 KG |
1396 | |
1397 | This section needs a lot of work! Please help. | |
1398 | ||
abc6be8d KG |
1399 | @cindex method sshx with Cygwin |
1400 | @cindex sshx method with Cygwin | |
fb7933a3 KG |
1401 | If you use the Cygwin installation of ssh (you have to explicitly select |
1402 | it in the installer), then it should work out of the box to just select | |
abc6be8d | 1403 | @code{sshx} as the connection method. You can find information about |
fb7933a3 KG |
1404 | setting up Cygwin in their FAQ at @uref{http://cygwin.com/faq/}. |
1405 | ||
abc6be8d KG |
1406 | @cindex method scpx with Cygwin |
1407 | @cindex scpx method with Cygwin | |
1408 | If you wish to use the @code{scpx} connection method, then you might | |
1409 | have the problem that Emacs calls @code{scp} with a Windows filename | |
1410 | such as @code{c:/foo}. The Cygwin version of @code{scp} does not know | |
1411 | about Windows filenames and interprets this as a remote filename on the | |
1412 | host @code{c}. | |
1413 | ||
1414 | One possible workaround is to write a wrapper script for @code{scp} | |
1415 | which converts the Windows filename to a Cygwinized filename. | |
1416 | ||
1417 | I guess that another workaround is to run Emacs under Cygwin, or to run | |
1418 | a Cygwinized Emacs. | |
1419 | ||
1420 | @cindex Cygwin and ssh-agent | |
1421 | @cindex SSH_AUTH_SOCK and Emacs on Windows | |
1422 | If you want to use either @code{ssh} based method on Windows, then you | |
1423 | might encounter problems with @code{ssh-agent}. Using this program, | |
1424 | you can avoid typing the pass-phrase every time you log in (and the | |
1425 | @code{scpx} method more or less requires you to use @code{ssh-agent} | |
1426 | because it does not allow you to type a password or pass-phrase). | |
1427 | However, if you start Emacs from a desktop shortcut, then the | |
1428 | environment variable @code{SSH_AUTH_SOCK} is not set and so Emacs and | |
1429 | thus @tramp{} and thus @code{ssh} and @code{scp} started from @tramp{} | |
1430 | cannot communicate with @code{ssh-agent}. It works better to start | |
1431 | Emacs from the shell. | |
1432 | ||
1433 | If anyone knows how to start @code{ssh-agent} under Windows in such a | |
1434 | way that desktop shortcuts can profit, please holler. I don't really | |
1435 | know anything at all about Windows@dots{} | |
1436 | ||
fb7933a3 KG |
1437 | |
1438 | @node Usage | |
1439 | @chapter Using @tramp | |
92eeeafc | 1440 | @cindex using @tramp |
fb7933a3 KG |
1441 | |
1442 | Once you have installed @tramp{} it will operate fairly transparently. You | |
1443 | will be able to access files on any remote machine that you can log in | |
1444 | to as though they were local. | |
1445 | ||
1446 | Files are specified to @tramp{} using a formalized syntax specifying the | |
92eeeafc | 1447 | details of the system to connect to. This is similar to the syntax used |
16674e4f KG |
1448 | by the @value{ftp-package-name} package. |
1449 | ||
1450 | @cindex type-ahead | |
1451 | Something that might happen which surprises you is that Emacs | |
1452 | remembers all your keystrokes, so if you see a password prompt from | |
1453 | Emacs, say, and hit @kbd{@key{RET}} twice instead of once, then the | |
1454 | second keystroke will be processed by Emacs after @tramp{} has done | |
1455 | its thing. Why, this type-ahead is normal behavior, you say. Right | |
1456 | you are, but be aware that opening a remote file might take quite a | |
1457 | while, maybe half a minute when a connection needs to be opened. | |
1458 | Maybe after half a minute you have already forgotten that you hit that | |
1459 | key! | |
fb7933a3 KG |
1460 | |
1461 | @menu | |
1462 | * Filename Syntax:: @tramp{} filename conventions. | |
16674e4f KG |
1463 | * Multi-hop filename syntax:: Multi-hop filename conventions. |
1464 | * Filename completion:: Filename completion. | |
1465 | * Dired:: Dired. | |
fb7933a3 KG |
1466 | @end menu |
1467 | ||
1468 | ||
1469 | @node Filename Syntax | |
1470 | @section @tramp{} filename conventions | |
92eeeafc KG |
1471 | @cindex filename syntax |
1472 | @cindex filename examples | |
fb7933a3 | 1473 | |
884b79ec | 1474 | To access the file @var{localname} on the remote machine @var{machine} you |
16674e4f | 1475 | would specify the filename |
884b79ec | 1476 | @file{@value{tramp-prefix}@var{machine}@value{tramp-postfix}@var{localname}}. |
16674e4f KG |
1477 | This will connect to @var{machine} and transfer the file using the |
1478 | default method. @xref{Default Method}. | |
fb7933a3 | 1479 | |
16674e4f | 1480 | Some examples of @tramp{} filenames are shown below. |
fb7933a3 KG |
1481 | |
1482 | @table @file | |
16674e4f | 1483 | @item @value{tramp-prefix}melancholia@value{tramp-postfix}.emacs |
fb7933a3 KG |
1484 | Edit the file @file{.emacs} in your home directory on the machine |
1485 | @code{melancholia}. | |
1486 | ||
16674e4f | 1487 | @item @value{tramp-prefix}melancholia.danann.net@value{tramp-postfix}.emacs |
fb7933a3 KG |
1488 | This edits the same file, using the fully qualified domain name of |
1489 | the machine. | |
1490 | ||
16674e4f | 1491 | @item @value{tramp-prefix}melancholia@value{tramp-postfix}~/.emacs |
fb7933a3 KG |
1492 | This also edits the same file --- the @file{~} is expanded to your |
1493 | home directory on the remote machine, just like it is locally. | |
1494 | ||
16674e4f | 1495 | @item @value{tramp-prefix}melancholia@value{tramp-postfix}~daniel/.emacs |
fb7933a3 KG |
1496 | This edits the file @file{.emacs} in the home directory of the user |
1497 | @code{daniel} on the machine @code{melancholia}. The @file{~<user>} | |
1498 | construct is expanded to the home directory of that user on the remote | |
1499 | machine. | |
1500 | ||
16674e4f | 1501 | @item @value{tramp-prefix}melancholia@value{tramp-postfix}/etc/squid.conf |
fb7933a3 KG |
1502 | This edits the file @file{/etc/squid.conf} on the machine |
1503 | @code{melancholia}. | |
1504 | ||
1505 | @end table | |
1506 | ||
16674e4f KG |
1507 | Unless you specify a different name to use, @tramp{} will use the |
1508 | current local user name as the remote user name to log in with. If you | |
1509 | need to log in as a different user, you can specify the user name as | |
1510 | part of the filename. | |
fb7933a3 | 1511 | |
16674e4f KG |
1512 | To log in to the remote machine as a specific user, you use the syntax |
1513 | @file{@value{tramp-prefix}@var{user}@@@var{machine}@value{tramp-postfix}/@var{path/to.file}}. | |
1514 | That means that connecting to @code{melancholia} as @code{daniel} and | |
f37fc5a7 | 1515 | editing @file{.emacs} in your home directory you would specify |
16674e4f | 1516 | @file{@value{tramp-prefix}daniel@@melancholia@value{tramp-postfix}.emacs}. |
fb7933a3 KG |
1517 | |
1518 | It is also possible to specify other file transfer methods | |
16674e4f KG |
1519 | (@pxref{Default Method}) as part of the filename. |
1520 | @ifset emacs | |
1521 | This is done by putting the method before the user and host name, as | |
1522 | in | |
1523 | @file{@value{tramp-prefix}@var{method}@value{tramp-postfix-single-hop}} | |
abc6be8d | 1524 | (Note the trailing colon). |
16674e4f KG |
1525 | @end ifset |
1526 | @ifset xemacs | |
1527 | This is done by replacing the initial | |
1528 | @file{@value{tramp-prefix}} with | |
1529 | @file{@value{tramp-prefix}<method>@value{tramp-postfix-single-hop}}. | |
1530 | (Note the trailing slash!). | |
1531 | @end ifset | |
1532 | The user, machine and file specification remain the same. | |
fb7933a3 | 1533 | |
f37fc5a7 KG |
1534 | So, to connect to the machine @code{melancholia} as @code{daniel}, |
1535 | using the @option{su} method to transfer files, and edit @file{.emacs} | |
1536 | in my home directory I would specify the filename | |
16674e4f | 1537 | @file{@value{tramp-prefix}su@value{tramp-postfix-single-hop}daniel@@melancholia@value{tramp-postfix}.emacs}. |
fb7933a3 KG |
1538 | |
1539 | ||
1540 | @node Multi-hop filename syntax | |
1541 | @section Multi-hop filename conventions | |
92eeeafc KG |
1542 | @cindex filename syntax for multi-hop files |
1543 | @cindex multi-hop filename syntax | |
fb7933a3 KG |
1544 | |
1545 | The syntax of multi-hop file names is necessarily slightly different | |
16674e4f KG |
1546 | than the syntax of other @tramp{} file names. Here's an example |
1547 | multi-hop file name, first in Emacs syntax and then in XEmacs syntax: | |
fb7933a3 | 1548 | |
16674e4f KG |
1549 | @example |
1550 | @value{tramp-prefix}multi@value{tramp-postfix-single-hop}rsh@value{tramp-postfix-multi-hop}out@@gate@value{tramp-postfix-single-hop}telnet@value{tramp-postfix-multi-hop}kai@@real.host@value{tramp-postfix}/path/to.file | |
1551 | @end example | |
fb7933a3 KG |
1552 | |
1553 | This is quite a mouthful. So let's go through it step by step. The | |
16674e4f KG |
1554 | file name consists of three parts. |
1555 | @ifset emacs | |
1556 | The parts are separated by colons | |
1557 | @end ifset | |
1558 | @ifset xemacs | |
1559 | The parts are separated by slashes and square brackets. | |
1560 | @end ifset | |
1561 | The first part is @file{@value{tramp-prefix}multi}, the method | |
1562 | specification. The second part is | |
1563 | @file{rsh@value{tramp-postfix-multi-hop}out@@gate@value{tramp-postfix-single-hop}telnet@value{tramp-postfix-multi-hop}kai@@real.host} | |
1564 | and specifies the hops. The final part is @file{/path/to.file} and | |
1565 | specifies the file name on the remote host. | |
fb7933a3 | 1566 | |
abc6be8d | 1567 | The first part and the final part should be clear. See @ref{Multi-hop |
fb7933a3 KG |
1568 | Methods}, for a list of alternatives for the method specification. |
1569 | ||
16674e4f KG |
1570 | The second part can be subdivided again into components, so-called |
1571 | hops. In the above file name, there are two hops, | |
1572 | @file{rsh@value{tramp-postfix-multi-hop}out@@gate} and | |
1573 | @file{telnet@value{tramp-postfix-multi-hop}kai@@real.host}. | |
fb7933a3 KG |
1574 | |
1575 | Each hop can @emph{again} be subdivided into (three) components, the | |
1576 | @dfn{hop method}, the @dfn{user name} and the @dfn{host name}. The | |
1577 | meaning of the second and third component should be clear, and the hop | |
1578 | method says what program to use to perform that hop. | |
1579 | ||
16674e4f KG |
1580 | The first hop, @file{rsh@value{tramp-postfix-multi-hop}out@@gate}, |
1581 | says to use @command{rsh} to log in as user @code{out} to the host | |
1582 | @code{gate}. Starting at that host, the second hop, | |
1583 | @file{telnet@value{tramp-postfix-multi-hop}kai@@real.host}, says to | |
1584 | use @command{telnet} to log in as user @code{kai} to host | |
1585 | @code{real.host}. | |
1586 | ||
1587 | @xref{Multi-hop Methods}, for a list of possible hop method values. | |
1588 | The variable @code{tramp-multi-connection-function-alist} contains the | |
1589 | list of possible hop methods and information on how to execute them, | |
1590 | should you want to add your own. | |
fb7933a3 | 1591 | |
16674e4f KG |
1592 | |
1593 | @node Filename completion | |
1594 | @section Filename completion | |
1595 | @cindex filename completion | |
1596 | ||
1597 | Filename completion works with @tramp{} for both completing methods, | |
1598 | user names and machine names (except multi hop methods) as well as for | |
1599 | files on remote machines. | |
1600 | ||
1601 | If you, for example, type @kbd{C-x C-f @value{tramp-prefix}t | |
1602 | @key{TAB}}, @tramp{} might give you as result the choice for | |
1603 | ||
1604 | @example | |
1605 | @ifset emacs | |
1606 | @value{tramp-prefix-single-hop}telnet@value{tramp-postfix-single-hop} tmp/ | |
1607 | @value{tramp-prefix-single-hop}toto@value{tramp-postfix} | |
1608 | @end ifset | |
1609 | @ifset xemacs | |
1610 | @value{tramp-prefix-single-hop}telnet@value{tramp-postfix-single-hop} @value{tramp-prefix-single-hop}toto@value{tramp-postfix} | |
1611 | @end ifset | |
1612 | @end example | |
177c0ea7 | 1613 | |
16674e4f KG |
1614 | @samp{@value{tramp-prefix-single-hop}telnet@value{tramp-postfix-single-hop}} |
1615 | is a possible completion for the respective method, | |
1616 | @ifset emacs | |
1617 | @samp{tmp/} stands for the directory @file{/tmp} on your local | |
1618 | machine, | |
1619 | @end ifset | |
1620 | and @samp{@value{tramp-prefix-single-hop}toto@value{tramp-postfix}} | |
1621 | might be a host @tramp has detected in your @file{~/.ssh/known_hosts} | |
1622 | file (given you're using default method @option{ssh}). | |
1623 | ||
1624 | If you go on to type @kbd{e @key{TAB}}, the minibuffer is completed to | |
1625 | @samp{@value{tramp-prefix}telnet@value{tramp-postfix-single-hop}}. | |
1626 | Next @kbd{@key{TAB}} brings you all machine names @tramp{} detects in | |
1627 | your @file{/etc/hosts} file, let's say | |
1628 | ||
1629 | @example | |
1630 | @value{tramp-prefix-single-hop}telnet@value{tramp-postfix-single-hop}127.0.0.1@value{tramp-postfix} @value{tramp-prefix-single-hop}telnet@value{tramp-postfix-single-hop}192.168.0.1@value{tramp-postfix} | |
1631 | @value{tramp-prefix-single-hop}telnet@value{tramp-postfix-single-hop}localhost@value{tramp-postfix} @value{tramp-prefix-single-hop}telnet@value{tramp-postfix-single-hop}melancholia.danann.net@value{tramp-postfix} | |
1632 | @value{tramp-prefix-single-hop}telnet@value{tramp-postfix-single-hop}melancholia@value{tramp-postfix} | |
1633 | @end example | |
1634 | ||
1635 | Now you can choose the desired machine, and you can continue to | |
1636 | complete file names on that machine. | |
1637 | ||
1638 | As filename completion needs to fetch the listing of files from the | |
1639 | remote machine, this feature is sometimes fairly slow. As @tramp{} | |
1640 | does not yet cache the results of directory listing, there is no gain | |
1641 | in performance the second time you complete filenames. | |
1642 | ||
1643 | If the configuration files (@pxref{Customizing Completion}), which | |
1644 | @tramp{} uses for analysis of completion, offer user names, those user | |
1645 | names will be taken into account as well. | |
fb7933a3 KG |
1646 | |
1647 | ||
1648 | @node Dired | |
16674e4f | 1649 | @section Dired |
92eeeafc | 1650 | @cindex dired |
fb7933a3 KG |
1651 | |
1652 | @tramp{} works transparently with dired, enabling you to use this powerful | |
1653 | file management tool to manage files on any machine you have access to | |
1654 | over the Internet. | |
1655 | ||
fb7933a3 | 1656 | If you need to browse a directory tree, Dired is a better choice, at |
92eeeafc | 1657 | present, than filename completion. Dired has its own cache mechanism |
fb7933a3 KG |
1658 | and will only fetch the directory listing once. |
1659 | ||
1660 | ||
1661 | @node Bug Reports | |
1662 | @chapter Reporting Bugs and Problems | |
92eeeafc | 1663 | @cindex bug reports |
fb7933a3 KG |
1664 | |
1665 | Bugs and problems with @tramp{} are actively worked on by the development | |
1666 | team. Feature requests and suggestions are also more than welcome. | |
1667 | ||
1668 | The @tramp{} mailing list is a great place to get information on working | |
1669 | with @tramp{}, solving problems and general discussion and advice on topics | |
1670 | relating to the package. | |
1671 | ||
1672 | The mailing list is at @email{tramp-devel@@mail.freesoftware.fsf.org}. | |
1673 | Messages sent to this address go to all the subscribers. This is | |
1674 | @emph{not} the address to send subscription requests to. | |
1675 | ||
1676 | For help on subscribing to the list, send mail to the administrative | |
1677 | address, @email{tramp-devel-request@@mail.freesoftware.fsf.org}, with the | |
1678 | subject @samp{help}. | |
1679 | ||
1680 | To report a bug in @tramp{}, you should execute @kbd{M-x tramp-bug}. This | |
1681 | will automatically generate a buffer with the details of your system and | |
1682 | @tramp{} version. | |
1683 | ||
1684 | When submitting a bug report, please try to describe in excruciating | |
1685 | detail the steps required to reproduce the problem, the setup of the | |
1686 | remote machine and any special conditions that exist. | |
1687 | ||
1688 | If you can identify a minimal test case that reproduces the problem, | |
1689 | include that with your bug report. This will make it much easier for the | |
1690 | development team to analyze and correct the problem. | |
1691 | ||
1692 | @node Frequently Asked Questions | |
1693 | @chapter Frequently Asked Questions | |
92eeeafc KG |
1694 | @cindex frequently asked questions |
1695 | @cindex FAQ | |
fb7933a3 KG |
1696 | |
1697 | @itemize @bullet | |
92eeeafc KG |
1698 | @item |
1699 | Where can I get the latest @tramp{}? | |
fb7933a3 | 1700 | |
16674e4f | 1701 | @tramp{} is available under the URL below. |
fb7933a3 | 1702 | |
16674e4f | 1703 | @noindent |
b1a2b924 | 1704 | @uref{http://savannah.nongnu.org/download/tramp/} |
16674e4f KG |
1705 | |
1706 | @noindent | |
1707 | There is also a Savannah project page. | |
1708 | ||
1709 | @noindent | |
1710 | @uref{https://savannah.gnu.org/projects/tramp/} | |
fb7933a3 | 1711 | |
92eeeafc KG |
1712 | @item |
1713 | Which systems does it work on? | |
fb7933a3 KG |
1714 | |
1715 | The package has been used successfully on Emacs 20 and Emacs 21, as well | |
1716 | as XEmacs 21. XEmacs 20 is more problematic, see the notes in | |
1717 | @file{tramp.el}. I don't think anybody has really tried it on Emacs 19. | |
1718 | ||
1719 | The package was intended to work on Unix, and it really expects a | |
1720 | Unix-like system on the remote end, but some people seemed to have some | |
1721 | success getting it to work on NT Emacs. | |
1722 | ||
abc6be8d KG |
1723 | There is some informations on @tramp{} on NT at the following URL; |
1724 | many thanks to Joe Stoy for providing the information: | |
fb7933a3 KG |
1725 | @uref{ftp://ftp.comlab.ox.ac.uk/tmp/Joe.Stoy/} |
1726 | ||
1727 | The above mostly contains patches to old ssh versions; Tom Roche has a | |
1728 | Web page with instructions: | |
1729 | @uref{http://www4.ncsu.edu/~tlroche/plinkTramp.html} | |
1730 | ||
1731 | ??? Is the XEmacs info correct? | |
1732 | ||
1733 | ??? Can somebody provide some information for getting it to work on NT | |
1734 | Emacs? I think there was some issue with @command{ssh}? | |
1735 | ||
1736 | ||
92eeeafc | 1737 | @item |
18d6d595 KG |
1738 | I can't stop @value{ftp-package-name} starting with @value{emacs-name} |
1739 | ||
1740 | @ifset emacs | |
1741 | @value{ftp-package-name} is loaded from @tramp{} automatically if you | |
1742 | require a file by the ftp method. Unfortunately, there are some Lisp | |
1743 | packages which make @value{ftp-package-name} file name handlers active. | |
1744 | You can see it applying @kbd{C-h v file-name-handler-alist}: | |
1745 | ||
1746 | @example | |
1747 | file-name-handler-alist's value is | |
1748 | (("^/[^/:]*\\'" . ange-ftp-completion-hook-function) | |
1749 | ("^/[^/:]*[^/:.]:" . ange-ftp-hook-function) | |
1750 | ("^/[^/]*$" . tramp-completion-file-name-handler) | |
1751 | ("\\`/[^/:]+:" . tramp-file-name-handler) | |
1752 | ("\\`/:" . file-name-non-special)) | |
1753 | @end example | |
1754 | ||
1755 | Please try to find out which package is responsible for loading | |
1756 | @value{ftp-package-name}, and raise a bug report. | |
fb7933a3 | 1757 | |
18d6d595 KG |
1758 | A workaround is to require @value{ftp-package-name} before @tramp{} in |
1759 | your @file{~/.emacs}, because @tramp{} cleans up the entries in | |
1760 | @code{file-name-handler-alist}: | |
1761 | ||
1762 | @lisp | |
1763 | ;; @value{ftp-package-name} temporarily required | |
1764 | (require 'ange-ftp) | |
1765 | ;; @tramp{} cleans up @code{file-name-handler-alist} | |
1766 | (require 'tramp) | |
1767 | @end lisp | |
1768 | @end ifset | |
1769 | ||
1770 | @ifset xemacs | |
1771 | Not all the older versions of @tramp{} supported @value{emacs-name} | |
1772 | correctly. The first thing to do is to make sure that you have the | |
1773 | latest version of @tramp{} installed. | |
fb7933a3 KG |
1774 | |
1775 | If you do, please try and find out exactly the conditions required for | |
18d6d595 KG |
1776 | the @value{ftp-package-name} handlers to fire. If you can, putting a |
1777 | breakpoint on @code{efs-ftp-path} and sending in the stack trace along | |
1778 | with your bug report would make it easier for the developers to work out | |
1779 | what is going wrong. | |
1780 | @end ifset | |
fb7933a3 KG |
1781 | |
1782 | ||
92eeeafc KG |
1783 | @item |
1784 | File name completion does not work with @tramp{} | |
fb7933a3 KG |
1785 | |
1786 | When you log in to the remote machine, do you see the output of | |
1787 | @command{ls} in color? If so, this may be the cause of your problems. | |
1788 | ||
1789 | @command{ls} outputs @acronym{ANSI} escape sequences that your terminal | |
18d6d595 | 1790 | emulator interprets to set the colors. These escape sequences will |
fb7933a3 KG |
1791 | confuse @tramp{} however. |
1792 | ||
1793 | In your @file{.bashrc}, @file{.profile} or equivalent on the remote | |
1794 | machine you probably have an alias configured that adds the option | |
1795 | @option{--color=yes} or @option{--color=auto}. | |
1796 | ||
1797 | You should remove that alias and ensure that a new login @emph{does not} | |
18d6d595 | 1798 | display the output of @command{ls} in color. If you still cannot use |
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1799 | filename completion, report a bug to the @tramp{} developers. |
1800 | ||
1801 | ||
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1802 | @item |
1803 | File name completion does not work in large directories | |
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1804 | |
1805 | @tramp{} uses globbing for some operations. (Globbing means to use the | |
1806 | shell to expand wildcards such as `*.c'.) This might create long | |
abc6be8d | 1807 | command lines, especially in directories with many files. Some shells |
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1808 | choke on long command lines, or don't cope well with the globbing |
1809 | itself. | |
1810 | ||
1811 | If you have a large directory on the remote end, you may wish to execute | |
92eeeafc | 1812 | a command like @samp{ls -d * ..?* > /dev/null} and see if it hangs. |
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1813 | Note that you must first start the right shell, which might be |
1814 | @command{/bin/sh}, @command{ksh} or @command{bash}, depending on which | |
1815 | of those supports tilde expansion. | |
1816 | ||
1817 | ||
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1818 | @item |
1819 | What kinds of systems does @tramp{} work on | |
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1820 | |
1821 | @tramp{} really expects the remote system to be a Unix-like system. The | |
1822 | local system should preferably be Unix-like, as well, but @tramp{} might | |
1823 | work on NT with some tweaking. | |
1824 | ||
1825 | ||
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1826 | @item |
1827 | How can I get notified when @tramp{} file transfers are complete? | |
fb7933a3 KG |
1828 | |
1829 | The following snippet can be put in your @file{~/.emacs} file. It makes | |
1830 | Emacs beep after reading from or writing to the remote host. | |
1831 | ||
1832 | @lisp | |
1833 | (defadvice tramp-handle-write-region | |
1834 | (after tramp-write-beep-advice activate) | |
1835 | " make tramp beep after writing a file." | |
1836 | (interactive) | |
1837 | (beep)) | |
1838 | (defadvice tramp-handle-do-copy-or-rename-file | |
1839 | (after tramp-copy-beep-advice activate) | |
1840 | " make tramp beep after copying a file." | |
1841 | (interactive) | |
1842 | (beep)) | |
1843 | (defadvice tramp-handle-insert-file-contents | |
1844 | (after tramp-copy-beep-advice activate) | |
1845 | " make tramp beep after copying a file." | |
1846 | (interactive) | |
1847 | (beep)) | |
1848 | @end lisp | |
1849 | ||
1850 | ||
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1851 | @item |
1852 | There's this @file{~/.sh_history} file on the remote host which keeps | |
1853 | growing and growing. What's that? | |
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1854 | |
1855 | Sometimes, @tramp{} starts @code{ksh} on the remote host for tilde | |
1856 | expansion. Maybe @code{ksh} saves the history by default. @tramp{} | |
1857 | tries to turn off saving the history, but maybe you have to help. For | |
1858 | example, you could put this in your @file{.kshrc}: | |
1859 | ||
1860 | @example | |
1861 | if [ -f $HOME/.sh_history ] ; then | |
1862 | /bin/rm $HOME/.sh_history | |
1863 | fi | |
1864 | if [ "$@{HISTFILE-unset@}" != "unset" ] ; then | |
1865 | unset HISTFILE | |
1866 | fi | |
1867 | if [ "$@{HISTSIZE-unset@}" != "unset" ] ; then | |
1868 | unset HISTSIZE | |
1869 | fi | |
1870 | @end example | |
1871 | ||
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1872 | |
1873 | @item @tramp{} doesn't transfer strings with more than 500 characters | |
1874 | correctly | |
1875 | ||
1876 | On some few systems, the implementation of @code{process-send-string} | |
1877 | seems to be broken for longer strings. This case, you should | |
1878 | customize the variable @code{tramp-chunksize} to 500. For a | |
1879 | description how to determine whether this is necessary see the | |
1880 | documentation of @code{tramp-chunksize}. | |
1881 | ||
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1882 | @end itemize |
1883 | ||
1884 | ||
1885 | @c For the developer | |
1886 | @node Version Control | |
1887 | @chapter The inner workings of remote version control | |
41bed43c | 1888 | @cindex Version Control |
fb7933a3 | 1889 | |
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1890 | Unlike @value{ftp-package-name}, @tramp{} has full shell access to the |
1891 | remote machine. This makes it possible to provide version control for | |
1892 | files accessed under @tramp{}. | |
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1893 | |
1894 | The actual version control binaries must be installed on the remote | |
1895 | machine, accessible in the directories specified in | |
1896 | @var{tramp-remote-path}. | |
1897 | ||
1898 | This transparent integration with the version control systems is one of | |
1899 | the most valuable features provided by @tramp{}, but it is far from perfect. | |
1900 | Work is ongoing to improve the transparency of the system. | |
1901 | ||
1902 | @menu | |
1903 | * Version Controlled Files:: Determining if a file is under version control. | |
1904 | * Remote Commands:: Executing the version control commands on the remote machine. | |
1905 | * Changed workfiles:: Detecting if the working file has changed. | |
1906 | * Checking out files:: Bringing the workfile out of the repository. | |
16674e4f | 1907 | * Miscellaneous Version Control:: Things related to Version Control that don't fit elsewhere. |
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1908 | @end menu |
1909 | ||
1910 | ||
1911 | @node Version Controlled Files | |
1912 | @section Determining if a file is under version control | |
1913 | ||
1914 | The VC package uses the existence of on-disk revision control master | |
1915 | files to determine if a given file is under revision control. These file | |
1916 | tests happen on the remote machine through the standard @tramp{} mechanisms. | |
1917 | ||
1918 | ||
1919 | @node Remote Commands | |
1920 | @section Executing the version control commands on the remote machine | |
1921 | ||
1922 | There are no hooks provided by VC to allow intercepting of the version | |
1923 | control command execution. The calls occur through the | |
1924 | @code{call-process} mechanism, a function that is somewhat more | |
1925 | efficient than the @code{shell-command} function but that does not | |
1926 | provide hooks for remote execution of commands. | |
1927 | ||
1928 | To work around this, the functions @code{vc-do-command} and | |
1929 | @code{vc-simple-command} have been advised to intercept requests for | |
1930 | operations on files accessed via @tramp{}. | |
1931 | ||
1932 | In the case of a remote file, the @code{shell-command} interface is | |
1933 | used, with some wrapper code, to provide the same functionality on the | |
884b79ec | 1934 | remote machine as would be seen on the local machine. |
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1935 | |
1936 | ||
1937 | @node Changed workfiles | |
1938 | @section Detecting if the working file has changed | |
1939 | ||
1940 | As there is currently no way to get access to the mtime of a file on a | |
1941 | remote machine in a portable way, the @code{vc-workfile-unchanged-p} | |
1942 | function is advised to call an @tramp{} specific function for remote files. | |
1943 | ||
1944 | The @code{tramp-vc-workfile-unchanged-p} function uses the functioning VC | |
1945 | diff functionality to determine if any changes have occurred between the | |
1946 | workfile and the version control master. | |
1947 | ||
1948 | This requires that a shell command be executed remotely, a process that | |
1949 | is notably heavier-weight than the mtime comparison used for local | |
1950 | files. Unfortunately, unless a portable solution to the issue is found, | |
1951 | this will remain the cost of remote version control. | |
1952 | ||
1953 | ||
1954 | @node Checking out files | |
1955 | @section Bringing the workfile out of the repository | |
1956 | ||
1957 | VC will, by default, check for remote files and refuse to act on them | |
1958 | when checking out files from the repository. To work around this | |
1959 | problem, the function @code{vc-checkout} knows about @tramp{} files and | |
1960 | allows version control to occur. | |
1961 | ||
1962 | ||
1963 | @node Miscellaneous Version Control | |
1964 | @section Things related to Version Control that don't fit elsewhere | |
1965 | ||
1966 | Minor implementation details, &c. | |
1967 | ||
1968 | @menu | |
1969 | * Remote File Ownership:: How VC determines who owns a workfile. | |
1970 | * Back-end Versions:: How VC determines what release your RCS is. | |
1971 | @end menu | |
1972 | ||
1973 | ||
1974 | @node Remote File Ownership | |
1975 | @subsection How VC determines who owns a workfile | |
1976 | ||
1977 | Emacs provides the @code{user-full-name} function to return the login name | |
1978 | of the current user as well as mapping from arbitrary user id values | |
1979 | back to login names. The VC code uses this functionality to map from the | |
1980 | uid of the owner of a workfile to the login name in some circumstances. | |
1981 | ||
1982 | This will not, for obvious reasons, work if the remote system has a | |
1983 | different set of logins. As such, it is necessary to delegate to the | |
1984 | remote machine the job of determining the login name associated with a | |
1985 | uid. | |
1986 | ||
1987 | Unfortunately, with the profusion of distributed management systems such | |
1988 | as @code{NIS}, @code{NIS+} and @code{NetInfo}, there is no simple, | |
1989 | reliable and portable method for performing this mapping. | |
1990 | ||
1991 | Thankfully, the only place in the VC code that depends on the mapping of | |
1992 | a uid to a login name is the @code{vc-file-owner} function. This returns | |
1993 | the login of the owner of the file as a string. | |
1994 | ||
1995 | This function has been advised to use the output of @command{ls} on the | |
1996 | remote machine to determine the login name, delegating the problem of | |
1997 | mapping the uid to the login to the remote system which should know more | |
1998 | about it than I do. | |
1999 | ||
2000 | ||
2001 | @node Back-end Versions | |
2002 | @subsection How VC determines what release your RCS is | |
2003 | ||
2004 | VC needs to know what release your revision control binaries you are | |
2005 | running as not all features VC supports are available with older | |
2006 | versions of @command{rcs(1)}, @command{cvs(1)} or @command{sccs(1)}. | |
2007 | ||
2008 | The default implementation of VC determines this value the first time it | |
2009 | is needed and then stores the value globally to avoid the overhead of | |
2010 | executing a process and parsing its output each time the information is | |
2011 | needed. | |
2012 | ||
2013 | Unfortunately, life is not quite so easy when remote version control | |
2014 | comes into the picture. Each remote machine may have a different version | |
2015 | of the version control tools and, while this is painful, we need to | |
2016 | ensure that unavailable features are not used remotely. | |
2017 | ||
2018 | To resolve this issue, @tramp{} currently takes the sledgehammer | |
2019 | approach of making the release values of the revision control tools | |
2020 | local to each @tramp{} buffer, forcing VC to determine these values | |
2021 | again each time a new file is visited. | |
2022 | ||
2023 | This has, quite obviously, some performance implications. Thankfully, | |
2024 | most of the common operations performed by VC do not actually require | |
2025 | that the remote version be known. This makes the problem far less | |
2026 | apparent. | |
2027 | ||
2028 | Eventually these values will be captured by @tramp{} on a system by | |
2029 | system basis and the results cached to improve performance. | |
2030 | ||
2031 | ||
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2032 | @node Files directories and localnames |
2033 | @chapter How file names, directories and localnames are mangled and managed. | |
fb7933a3 KG |
2034 | |
2035 | @menu | |
884b79ec | 2036 | * Localname deconstruction:: Breaking a localname into its components. |
fb7933a3 KG |
2037 | @end menu |
2038 | ||
2039 | ||
884b79ec KG |
2040 | @node Localname deconstruction |
2041 | @section Breaking a localname into its components. | |
fb7933a3 | 2042 | |
884b79ec | 2043 | @tramp{} file names are somewhat different, obviously, to ordinary file |
fb7933a3 | 2044 | names. As such, the lisp functions @code{file-name-directory} and |
884b79ec KG |
2045 | @code{file-name-nondirectory} are overridden within the @tramp{} |
2046 | package. | |
fb7933a3 KG |
2047 | |
2048 | Their replacements are reasonably simplistic in their approach. They | |
884b79ec KG |
2049 | dissect the filename, call the original handler on the localname and |
2050 | then rebuild the @tramp{} file name with the result. | |
fb7933a3 KG |
2051 | |
2052 | This allows the platform specific hacks in the original handlers to take | |
884b79ec | 2053 | effect while preserving the @tramp{} file name information. |
fb7933a3 KG |
2054 | |
2055 | ||
2056 | @node Issues | |
2057 | @chapter Debatable Issues and What Was Decided | |
2058 | ||
2059 | @itemize @bullet | |
2060 | @item The uuencode method does not always work. | |
2061 | ||
2062 | Due to the design of @tramp{}, the encoding and decoding programs need to | |
2063 | read from stdin and write to stdout. On some systems, @code{uudecode -o | |
2064 | -} will read stdin and write the decoded file to stdout, on other | |
2065 | systems @code{uudecode -p} does the same thing. But some systems have | |
2066 | uudecode implementations which cannot do this at all---it is not | |
2067 | possible to call these uudecode implementations with suitable parameters | |
2068 | so that they write to stdout. | |
2069 | ||
2070 | Of course, this could be circumvented: the @code{begin foo 644} line | |
2071 | could be rewritten to put in some temporary file name, then | |
2072 | @code{uudecode} could be called, then the temp file could be printed and | |
2073 | deleted. | |
2074 | ||
2075 | But I have decided that this is too fragile to reliably work, so on some | |
2076 | systems you'll have to do without the uuencode methods. | |
2077 | ||
2078 | @item @tramp{} does not work on XEmacs 20. | |
2079 | ||
2080 | This is because it requires the macro @code{with-timeout} which does not | |
2081 | appear to exist in XEmacs 20. I'm somewhat reluctant to add an | |
2082 | emulation macro to @tramp{}, but if somebody who uses XEmacs 20 steps | |
2083 | forward and wishes to implement and test it, please contact me or the | |
2084 | mailing list. | |
2085 | ||
f37fc5a7 KG |
2086 | @item The @tramp{} filename syntax differs between Emacs and XEmacs. |
2087 | ||
2088 | The Emacs maintainers wish to use a unified filename syntax for | |
2089 | Ange-FTP and @tramp{} so that users don't have to learn a new | |
2090 | syntax. It is sufficient to learn some extensions to the old syntax. | |
2091 | ||
2092 | For the XEmacs maintainers, the problems caused from using a unified | |
abc6be8d KG |
2093 | filename syntax are greater than the gains. The XEmacs package system |
2094 | uses EFS for downloading new packages. So, obviously, EFS has to be | |
2095 | installed from the start. If the filenames were unified, @tramp{} | |
f37fc5a7 KG |
2096 | would have to be installed from the start, too. |
2097 | ||
fb7933a3 KG |
2098 | @end itemize |
2099 | ||
41bed43c KG |
2100 | @node Concept Index |
2101 | @comment node-name, next, previous, up | |
2102 | @unnumbered Concept Index | |
2103 | @printindex cp | |
2104 | @contents | |
fb7933a3 KG |
2105 | @c End of tramp.texi - the TRAMP User Manual |
2106 | @bye | |
2107 | ||
2108 | @c TODO | |
2109 | @c | |
2110 | @c * Say something about the .login and .profile files of the remote | |
2111 | @c shells. | |
2112 | @c * Explain how tramp.el works in principle: open a shell on a remote | |
2113 | @c host and then send commands to it. | |
83fa16cf KG |
2114 | @c * Mention that bookmarks are a cool feature to go along with Tramp. |
2115 | @c * Make terminology "inline" vs "out-of-band" consistent. | |
2116 | @c It seems that "external" is also used instead of "out-of-band". | |
fb7933a3 | 2117 | |
16674e4f KG |
2118 | @c * M. Albinus |
2119 | @c ** Use `filename' resp. `file name' consistently. | |
2120 | @c ** Use `host' resp. `machine' consistently. | |
2121 | @c ** Consistent small or capitalized words especially in menues. | |
ab5796a9 MB |
2122 | |
2123 | @ignore | |
2124 | arch-tag: f96dd66e-6dd3-4c92-8d77-9c56205ba808 | |
2125 | @end ignore |