1 @c This is part of the Emacs manual.
2 @c Copyright (C) 1985-1987, 1993-1995, 1997, 2000-2012
3 @c Free Software Foundation, Inc.
4 @c See file emacs.texi for copying conditions.
6 @chapter Miscellaneous Commands
8 This chapter contains several brief topics that do not fit anywhere
9 else: viewing ``document files'', reading Usenet news, running shell
10 commands and shell subprocesses, using a single shared Emacs for
11 utilities that expect to run an editor as a subprocess, printing
12 hardcopy, sorting text, narrowing display to part of the buffer,
13 editing binary files, saving an Emacs session for later resumption,
14 following hyperlinks, browsing images, emulating other editors, and
15 various diversions and amusements.
29 Gnus is an Emacs package primarily designed for reading and posting
30 Usenet news. It can also be used to read and respond to messages from
31 a number of other sources---email, remote directories, digests, and so
32 on. Here we introduce Gnus and describe several basic features.
34 For full details, see @ref{Top, Gnus,, gnus, The Gnus Manual}.
37 For full details on Gnus, type @kbd{C-h i} and then select the Gnus
42 * Buffers of Gnus:: The group, summary, and article buffers.
43 * Gnus Startup:: What you should know about starting Gnus.
44 * Gnus Group Buffer:: A short description of Gnus group commands.
45 * Gnus Summary Buffer:: A short description of Gnus summary commands.
49 @subsection Gnus Buffers
51 Gnus uses several buffers to display information and to receive
52 commands. The three most commonly-used Gnus buffers are the
53 @dfn{group buffer}, the @dfn{summary buffer} and the @dfn{article
56 The @dfn{group buffer} contains a list of article sources (e.g.@:
57 newsgroups and email inboxes), which are collectively referred to as
58 @dfn{groups}. This is the first buffer Gnus displays when it starts
59 up. It normally displays only the groups to which you subscribe and
60 that contain unread articles. From this buffer, you can select a
63 The @dfn{summary buffer} lists the articles in a single group,
64 showing one article per line. By default, it displays each article's
65 author, subject, and line
70 number, but this is customizable; @xref{Summary Buffer Format,,, gnus,
73 The summary buffer is created when you select a group in the group
74 buffer, and is killed when you exit the group.
76 From the summary buffer, you can choose an article to view. The
77 article is displayed in the @dfn{article buffer}. In normal Gnus
78 usage, you view this buffer but do not select it---all useful Gnus
79 commands can be invoked from the summary buffer. But you can select
80 the article buffer, and execute Gnus commands from it, if you wish.
83 @subsection When Gnus Starts Up
86 @cindex @file{.newsrc} file
87 If your system has been set up for reading Usenet news, getting
88 started with Gnus is easy---just type @kbd{M-x gnus}.
90 On starting up, Gnus reads your @dfn{news initialization file}: a
91 file named @file{.newsrc} in your home directory which lists your
92 Usenet newsgroups and subscriptions (this file is not unique to Gnus;
93 it is used by many other newsreader programs). It then tries to
94 contact the system's default news server, which is typically specified
95 by the @env{NNTPSERVER} environment variable.
97 If your system does not have a default news server, or if you wish
98 to use Gnus for reading email, then before invoking @kbd{M-x gnus} you
99 need to tell Gnus where to get news and/or mail. To do this,
100 customize the variables @code{gnus-select-method} and/or
101 @code{gnus-secondary-select-methods}.
103 See the Gnus manual for details.
106 @xref{Finding the News,,, gnus, The Gnus Manual}.
109 Once Gnus has started up, it displays the group buffer. By default,
110 the group buffer shows only a small number of @dfn{subscribed groups}.
111 Groups with other statuses---@dfn{unsubscribed}, @dfn{killed}, or
112 @dfn{zombie}---are hidden. The first time you start Gnus, any group
113 to which you are not subscribed is made into a killed group; any group
114 that subsequently appears on the news server becomes a zombie group.
116 To proceed, you must select a group in the group buffer to open the
117 summary buffer for that group; then, select an article in the summary
118 buffer to view its article buffer in a separate window. The following
119 sections explain how to use the group and summary buffers to do this.
121 To quit Gnus, type @kbd{q} in the group buffer. This automatically
122 records your group statuses in the files @file{.newsrc} and
123 @file{.newsrc.eld}, so that they take effect in subsequent Gnus
126 @node Gnus Group Buffer
127 @subsection Using the Gnus Group Buffer
129 The following commands are available in the Gnus group buffer:
132 @kindex SPC @r{(Gnus Group mode)}
133 @findex gnus-group-read-group
135 Switch to the summary buffer for the group on the current line.
137 @kindex l @r{(Gnus Group mode)}
138 @kindex A s @r{(Gnus Group mode)}
139 @findex gnus-group-list-groups
142 In the group buffer, list only the groups to which you subscribe and
143 which contain unread articles (this is the default listing).
145 @kindex L @r{(Gnus Group mode)}
146 @kindex A u @r{(Gnus Group mode)}
147 @findex gnus-group-list-all-groups
150 List all subscribed and unsubscribed groups, but not killed or zombie
153 @kindex A k @r{(Gnus Group mode)}
154 @findex gnus-group-list-all-groups
158 @kindex A z @r{(Gnus Group mode)}
159 @findex gnus-group-list-all-groups
163 @kindex u @r{(Gnus Group mode)}
164 @findex gnus-group-unsubscribe-current-group
165 @cindex subscribe groups
166 @cindex unsubscribe groups
168 Toggle the subscription status of the group on the current line
169 (i.e.@: turn a subscribed group into an unsubscribed group, or vice
170 versa). Invoking this on a killed or zombie group turns it into an
173 @kindex C-k @r{(Gnus Group mode)}
174 @findex gnus-group-kill-group
176 Kill the group on the current line. Killed groups are not recorded in
177 the @file{.newsrc} file, and they are not shown in the @kbd{l} or
180 @kindex DEL @r{(Gnus Group mode)}
182 Move point to the previous group containing unread articles.
184 @kindex n @r{(Gnus Group mode)}
185 @findex gnus-group-next-unread-group
186 @findex gnus-summary-next-unread-article
188 Move point to the next unread group.
190 @kindex p @r{(Gnus Group mode)}
191 @findex gnus-group-prev-unread-group
192 @findex gnus-summary-prev-unread-article
194 Move point to the previous unread group.
196 @kindex q @r{(Gnus Group mode)}
197 @findex gnus-group-exit
199 Update your Gnus settings, and quit Gnus.
202 @node Gnus Summary Buffer
203 @subsection Using the Gnus Summary Buffer
205 The following commands are available in the Gnus summary buffer:
208 @kindex SPC @r{(Gnus Summary mode)}
209 @findex gnus-group-read-group
211 If there is no article selected, select the article on the current
212 line and display its article buffer. Otherwise, try scrolling the
213 selected article buffer in its window; on reaching the end of the
214 buffer, select the next unread article.
216 Thus, you can read through all articles by repeatedly typing
219 @kindex DEL @r{(Gnus Summary mode)}
220 @findex gnus-summary-prev-page
222 Scroll the text of the article backwards.
224 @kindex n @r{(Gnus Summary mode)}
225 @findex gnus-group-next-unread-group
226 @findex gnus-summary-next-unread-article
228 Select the next unread article.
230 @kindex p @r{(Gnus Summary mode)}
231 @findex gnus-group-prev-unread-group
232 @findex gnus-summary-prev-unread-article
234 Select the previous unread article.
236 @kindex s @r{(Gnus Summary mode)}
237 @findex gnus-summary-isearch-article
239 Do an incremental search on the selected article buffer, as if you
240 switched to the buffer and typed @kbd{C-s} (@pxref{Incremental
243 @kindex M-s @r{(Gnus Summary mode)}
244 @findex gnus-summary-search-article-forward
245 @item M-s @var{regexp} @key{RET}
246 Search forward for articles containing a match for @var{regexp}.
248 @kindex q @r{(Gnus Summary mode)}
250 Exit the summary buffer and return to the group buffer.
254 @section Document Viewing
258 @cindex PostScript file
259 @cindex OpenDocument file
260 @cindex Microsoft Office file
262 @cindex mode, DocView
263 @cindex document viewer (DocView)
264 @findex doc-view-mode
266 DocView mode is a major mode for viewing DVI, PostScript (PS), PDF,
267 OpenDocument, and Microsoft Office documents. It provides features
268 such as slicing, zooming, and searching inside documents. It works by
269 converting the document to a set of images using the @command{gs}
270 (GhostScript) command and other external tools @footnote{@code{gs} is
271 a hard requirement. For DVI files, @code{dvipdf} or @code{dvipdfm} is
272 needed. For OpenDocument and Microsoft Office documents, the
273 @code{unoconv} tool is needed.}, and displaying those images.
275 @findex doc-view-toggle-display
276 @findex doc-view-toggle-display
277 @cindex doc-view-minor-mode
278 When you visit a document file that can be displayed with DocView
279 mode, Emacs automatically uses DocView mode @footnote{The needed
280 external tools for the document type must be available, and Emacs must
281 be running in a graphical frame and have PNG image support. If any of
282 these requirements is not fulfilled, Emacs falls back to another major
283 mode.}. As an exception, when you visit a PostScript file, Emacs
284 switches to PS mode, a major mode for editing PostScript files as
285 text; however, it also enables DocView minor mode, so you can type
286 @kbd{C-c C-c} to view the document with DocView. In either DocView
287 mode or DocView minor mode, repeating @kbd{C-c C-c}
288 (@code{doc-view-toggle-display}) toggles between DocView and the
289 underlying file contents.
291 You can explicitly enable DocView mode with the command @code{M-x
292 doc-view-mode}. You can toggle DocView minor mode with @code{M-x
293 doc-view-minor-mode}.
295 When DocView mode starts, it displays a welcome screen and begins
296 formatting the file, page by page. It displays the first page once
297 that has been formatted.
299 To kill the DocView buffer, type @kbd{k}
300 (@code{doc-view-kill-proc-and-buffer}). To bury it, type @kbd{q}
301 (@code{quit-window}).
304 * Navigation: DocView Navigation. Navigating DocView buffers.
305 * Searching: DocView Searching. Searching inside documents.
306 * Slicing: DocView Slicing. Specifying which part of a page is displayed.
307 * Conversion: DocView Conversion. Influencing and triggering conversion.
310 @node DocView Navigation
311 @subsection DocView Navigation
313 In DocView mode, you can scroll the current page using the usual
314 Emacs movement keys: @kbd{C-p}, @kbd{C-n}, @kbd{C-b}, @kbd{C-f}, and
317 @vindex doc-view-continuous
318 By default, the line-motion keys @kbd{C-p} and @kbd{C-n} stop
319 scrolling at the beginning and end of the current page, respectively.
320 However, if you change the variable @code{doc-view-continuous} to a
321 non-@code{nil} value, then @kbd{C-p} displays the previous page if you
322 are already at the beginning of the current page, and @kbd{C-n}
323 displays the next page if you are at the end of the current page.
325 @findex doc-view-next-page
326 @findex doc-view-previous-page
327 @kindex n @r{(DocView mode)}
328 @kindex p @r{(DocView mode)}
329 @kindex C-x ] @r{(DocView mode)}
330 @kindex C-x [ @r{(DocView mode)}
331 You can also display the next page by typing @kbd{n}, @key{next} or
332 @kbd{C-x ]} (@code{doc-view-next-page}). To display the previous
333 page, type @kbd{p}, @key{prior} or @kbd{C-x [}
334 (@code{doc-view-previous-page}).
336 @findex doc-view-scroll-up-or-next-page
337 @findex doc-view-scroll-down-or-previous-page
338 @kindex SPC @r{(DocView mode)}
339 @kindex DEL @r{(DocView mode)}
340 @key{SPC} (@code{doc-view-scroll-up-or-next-page}) is a convenient
341 way to advance through the document. It scrolls within the current
342 page or advances to the next. @key{DEL} moves backwards in a similar
343 way (@code{doc-view-scroll-down-or-previous-page}).
345 @findex doc-view-first-page
346 @findex doc-view-last-page
347 @findex doc-view-goto-page
348 @kindex M-< @r{(DocView mode)}
349 @kindex M-> @r{(DocView mode)}
350 To go to the first page, type @kbd{M-<}
351 (@code{doc-view-first-page}); to go to the last one, type @kbd{M->}
352 (@code{doc-view-last-page}). To jump to a page by its number, type
353 @kbd{M-g M-g} or @kbd{M-g g} (@code{doc-view-goto-page}).
355 @findex doc-view-enlarge
356 @findex doc-view-shrink
357 @vindex doc-view-resolution
358 @kindex + @r{(DocView mode)}
359 @kindex - @r{(DocView mode)}
360 You can enlarge or shrink the document with @kbd{+}
361 (@code{doc-view-enlarge}) and @kbd{-} (@code{doc-view-shrink}). These
362 commands work by reconverting the document at the new size. To
363 specify the default size for DocView, customize the variable
364 @code{doc-view-resolution}.
366 @node DocView Searching
367 @subsection DocView Searching
369 In DocView mode, you can search the file's text for a regular
370 expression (@pxref{Regexps}). The interface for searching is inspired
371 by @code{isearch} (@pxref{Incremental Search}).
373 @findex doc-view-search
374 @findex doc-view-search-backward
375 @findex doc-view-show-tooltip
376 To begin a search, type @kbd{C-s} (@code{doc-view-search}) or
377 @kbd{C-r} (@code{doc-view-search-backward}). This reads a regular
378 expression using a minibuffer, then echoes the number of matches found
379 within the document. You can move forward and back among the matches
380 by typing @kbd{C-s} and @kbd{C-r}. DocView mode has no way to show
381 the match inside the page image; instead, it displays a tooltip (at
382 the mouse position) listing all matching lines in the current page.
383 To force display of this tooltip, type @kbd{C-t}
384 (@code{doc-view-show-tooltip}).
386 To start a new search, use the search command with a prefix
387 argument; i.e., @kbd{C-u C-s} for a forward search or @kbd{C-u C-r}
388 for a backward search.
390 @node DocView Slicing
391 @subsection DocView Slicing
393 Documents often have wide margins for printing. They are annoying
394 when reading the document on the screen, because they use up screen
395 space and can cause inconvenient scrolling.
397 @findex doc-view-set-slice
398 @findex doc-view-set-slice-using-mouse
399 With DocView you can hide these margins by selecting a @dfn{slice}
400 of pages to display. A slice is a rectangle within the page area;
401 once you specify a slice in DocView, it applies to whichever page you
404 To specify the slice numerically, type @kbd{s s}
405 (@code{doc-view-set-slice}); then enter the top left pixel position
406 and the slice's width and height.
407 @c ??? how does this work?
409 A more convenient graphical way to specify the slice is with @kbd{s
410 m} (@code{doc-view-set-slice-using-mouse}), where you use the mouse to
412 @c ??? How does this work?
414 @findex doc-view-reset-slice
415 To cancel the selected slice, type @kbd{s r}
416 (@code{doc-view-reset-slice}). Then DocView shows the entire page
417 including its entire margins.
419 @node DocView Conversion
420 @subsection DocView Conversion
422 @vindex doc-view-cache-directory
423 @findex doc-view-clear-cache
424 For efficiency, DocView caches the images produced by @command{gs}.
425 The name of this directory is given by the variable
426 @code{doc-view-cache-directory}. You can clear the cache directory by
427 typing @code{M-x doc-view-clear-cache}.
429 @findex doc-view-kill-proc
430 @findex doc-view-kill-proc-and-buffer
431 To force reconversion of the currently viewed document, type @kbd{r}
432 or @kbd{g} (@code{revert-buffer}). To kill the converter process
433 associated with the current buffer, type @kbd{K}
434 (@code{doc-view-kill-proc}). The command @kbd{k}
435 (@code{doc-view-kill-proc-and-buffer}) kills the converter process and
439 @section Running Shell Commands from Emacs
441 @cindex shell commands
443 Emacs has commands for passing single command lines to shell
444 subprocesses, and for running a shell interactively with input and
445 output to an Emacs buffer, and for running a shell in a terminal
449 @item M-! @var{cmd} @key{RET}
450 Run the shell command @var{cmd} and display the output
451 (@code{shell-command}).
452 @item M-| @var{cmd} @key{RET}
453 Run the shell command @var{cmd} with region contents as input;
454 optionally replace the region with the output
455 (@code{shell-command-on-region}).
456 @item M-& @var{cmd} @key{RET}
457 Run the shell command @var{cmd} asynchronously, and display the output
458 (@code{async-shell-command}).
460 Run a subshell with input and output through an Emacs buffer. You can
461 then give commands interactively.
463 Run a subshell with input and output through an Emacs buffer. You can
464 then give commands interactively. Full terminal emulation is
469 Whenever you specify a relative file name for an executable program
470 (either in the @var{cmd} argument to one of the above commands, or in
471 other contexts), Emacs searches for the program in the directories
472 specified by the variable @code{exec-path}. The value of this
473 variable must be a list of directory names; the default value is
474 initialized from the environment variable @env{PATH} when Emacs is
475 started (@pxref{General Variables}).
477 @kbd{M-x eshell} invokes a shell implemented entirely in Emacs. It
478 is documented in its own manual.
480 @xref{Top,Eshell,Eshell, eshell, Eshell: The Emacs Shell}.
483 See the Eshell Info manual, which is distributed with Emacs.
487 * Single Shell:: How to run one shell command and return.
488 * Interactive Shell:: Permanent shell taking input via Emacs.
489 * Shell Mode:: Special Emacs commands used with permanent shell.
490 * Shell Prompts:: Two ways to recognize shell prompts.
491 * History: Shell History. Repeating previous commands in a shell buffer.
492 * Directory Tracking:: Keeping track when the subshell changes directory.
493 * Options: Shell Options. Options for customizing Shell mode.
494 * Terminal emulator:: An Emacs window as a terminal emulator.
495 * Term Mode:: Special Emacs commands used in Term mode.
496 * Remote Host:: Connecting to another computer.
497 * Serial Terminal:: Connecting to a serial port.
501 @subsection Single Shell Commands
504 @findex shell-command
505 @kbd{M-!} (@code{shell-command}) reads a line of text using the
506 minibuffer and executes it as a shell command, in a subshell made just
507 for that command. Standard input for the command comes from the null
508 device. If the shell command produces any output, the output appears
509 either in the echo area (if it is short), or in an Emacs buffer named
510 @file{*Shell Command Output*}, displayed in another window (if the
513 For instance, one way to decompress a file named @file{foo.gz} is to
514 type @kbd{M-! gunzip foo.gz @key{RET}}. That shell command normally
515 creates the file @file{foo} and produces no terminal output.
517 A numeric argument to @code{shell-command}, e.g.@: @kbd{M-1 M-!},
518 causes it to insert terminal output into the current buffer instead of
519 a separate buffer. It puts point before the output, and sets the mark
520 after the output. For instance, @kbd{M-1 M-! gunzip < foo.gz
521 @key{RET}} would insert the uncompressed form of the file
522 @file{foo.gz} into the current buffer.
524 Provided the specified shell command does not end with @samp{&}, it
525 runs @dfn{synchronously}, and you must wait for it to exit before
526 continuing to use Emacs. To stop waiting, type @kbd{C-g} to quit;
527 this sends a @code{SIGINT} signal to terminate the shell command (this
528 is the same signal that @kbd{C-c} normally generates in the shell).
529 Emacs then waits until the command actually terminates. If the shell
530 command doesn't stop (because it ignores the @code{SIGINT} signal),
531 type @kbd{C-g} again; this sends the command a @code{SIGKILL} signal,
532 which is impossible to ignore.
535 @findex async-shell-command
536 A shell command that ends in @samp{&} is executed
537 @dfn{asynchronously}, and you can continue to use Emacs as it runs.
538 You can also type @kbd{M-&} (@code{async-shell-command}) to execute a
539 shell command asynchronously; this is exactly like calling @kbd{M-!}
540 with a trailing @samp{&}, except that you do not need the @samp{&}.
541 The output buffer for asynchronous shell commands is named
542 @samp{*Async Shell Command*}. Emacs inserts the output into this
543 buffer as it comes in, whether or not the buffer is visible in a
547 @findex shell-command-on-region
548 @kbd{M-|} (@code{shell-command-on-region}) is like @kbd{M-!}, but
549 passes the contents of the region as the standard input to the shell
550 command, instead of no input. With a numeric argument, it deletes the
551 old region and replaces it with the output from the shell command.
553 For example, you can use @kbd{M-|} with the @command{gpg} program to
554 see what keys are in the buffer. If the buffer contains a GnuPG key,
555 type @kbd{C-x h M-| gpg @key{RET}} to feed the entire buffer contents
556 to @command{gpg}. This will output the list of keys to the
557 @file{*Shell Command Output*} buffer.
559 @vindex shell-file-name
560 The above commands use the shell specified by the variable
561 @code{shell-file-name}. Its default value is determined by the
562 @env{SHELL} environment variable when Emacs is started. If the file
563 name is relative, Emacs searches the directories listed in
564 @code{exec-path} (@pxref{Shell}).
566 To specify a coding system for @kbd{M-!} or @kbd{M-|}, use the command
567 @kbd{C-x @key{RET} c} immediately beforehand. @xref{Communication Coding}.
569 @vindex shell-command-default-error-buffer
570 By default, error output is intermixed with the regular output in
571 the output buffer. But if you change the value of the variable
572 @code{shell-command-default-error-buffer} to a string, error output is
573 inserted into a buffer of that name.
575 @node Interactive Shell
576 @subsection Interactive Subshell
579 To run a subshell interactively, type @kbd{M-x shell}. This creates
580 (or reuses) a buffer named @file{*shell*}, and runs a shell subprocess
581 with input coming from and output going to that buffer. That is to
582 say, any terminal output from the subshell goes into the buffer,
583 advancing point, and any terminal input for the subshell comes from
584 text in the buffer. To give input to the subshell, go to the end of
585 the buffer and type the input, terminated by @key{RET}.
587 While the subshell is waiting or running a command, you can switch
588 windows or buffers and perform other editing in Emacs. Emacs inserts
589 the output from the subshell into the Shell buffer whenever it has
590 time to process it (e.g.@: while waiting for keyboard input).
592 @cindex @code{comint-highlight-input} face
593 @cindex @code{comint-highlight-prompt} face
594 In the Shell buffer, prompts are displayed with the face
595 @code{comint-highlight-prompt}, and submitted input lines are
596 displayed with the face @code{comint-highlight-input}. This makes it
597 easier to distinguish input lines from the shell output.
600 To make multiple subshells, invoke @kbd{M-x shell} with a prefix
601 argument (e.g. @kbd{C-u M-x shell}). Then the command will read a
602 buffer name, and create (or reuse) a subshell in that buffer. You can
603 also rename the @file{*shell*} buffer using @kbd{M-x rename-uniquely},
604 then create a new @file{*shell*} buffer using plain @kbd{M-x shell}.
605 Subshells in different buffers run independently and in parallel.
607 @vindex explicit-shell-file-name
608 @cindex environment variables for subshells
609 @cindex @env{ESHELL} environment variable
610 @cindex @env{SHELL} environment variable
611 To specify the shell file name used by @kbd{M-x shell}, customize
612 the variable @code{explicit-shell-file-name}. If this is @code{nil}
613 (the default), Emacs uses the environment variable @env{ESHELL} if it
614 exists. Otherwise, it usually uses the variable
615 @code{shell-file-name} (@pxref{Single Shell}); but if the default
616 directory is remote (@pxref{Remote Files}), it prompts you for the
619 Emacs sends the new shell the contents of the file
620 @file{~/.emacs_@var{shellname}} as input, if it exists, where
621 @var{shellname} is the name of the file that the shell was loaded
622 from. For example, if you use bash, the file sent to it is
623 @file{~/.emacs_bash}. If this file is not found, Emacs tries with
624 @file{~/.emacs.d/init_@var{shellname}.sh}.
626 To specify a coding system for the shell, you can use the command
627 @kbd{C-x @key{RET} c} immediately before @kbd{M-x shell}. You can
628 also change the coding system for a running subshell by typing
629 @kbd{C-x @key{RET} p} in the shell buffer. @xref{Communication
632 @cindex @env{INSIDE_EMACS} environment variable
633 @cindex @env{EMACS} environment variable
634 Emacs sets the environment variable @env{INSIDE_EMACS} in the
635 subshell to @samp{@var{version},comint}, where @var{version} is the
636 Emacs version (e.g.@: @samp{24.1}). Programs can check this variable
637 to determine whether they are running inside an Emacs subshell. (It
638 also sets the @env{EMACS} environment variable to @code{t}, if that
639 environment variable is not already defined. However, this
640 environment variable is deprecated; programs that use it should switch
641 to using @env{INSIDE_EMACS} instead.)
644 @subsection Shell Mode
648 The major mode for Shell buffers is Shell mode. Many of its special
649 commands are bound to the @kbd{C-c} prefix, and resemble the usual
650 editing and job control characters present in ordinary shells, except
651 that you must type @kbd{C-c} first. Here is a list of Shell mode
656 @kindex RET @r{(Shell mode)}
657 @findex comint-send-input
658 Send the current line as input to the subshell
659 (@code{comint-send-input}). Any shell prompt at the beginning of the
660 line is omitted (@pxref{Shell Prompts}). If point is at the end of
661 buffer, this is like submitting the command line in an ordinary
662 interactive shell. However, you can also invoke @key{RET} elsewhere
663 in the shell buffer to submit the current line as input.
666 @kindex TAB @r{(Shell mode)}
667 @findex completion-at-point
668 Complete the command name or file name before point in the shell
669 buffer (@code{completion-at-point}). This uses the usual Emacs
670 completion rules (@pxref{Completion}), with the completion
671 alternatives being file names, environment variable names, the shell
672 command history, and history references (@pxref{History References}).
674 @vindex shell-completion-fignore
675 @vindex comint-completion-fignore
676 The variable @code{shell-completion-fignore} specifies a list of file
677 name extensions to ignore in Shell mode completion. The default
678 setting is @code{nil}, but some users prefer @code{("~" "#" "%")} to
679 ignore file names ending in @samp{~}, @samp{#} or @samp{%}. Other
680 related Comint modes use the variable @code{comint-completion-fignore}
684 @kindex M-? @r{(Shell mode)}
685 @findex comint-dynamic-list-filename@dots{}
686 Display temporarily a list of the possible completions of the file
687 name before point (@code{comint-dynamic-list-filename-completions}).
690 @kindex C-d @r{(Shell mode)}
691 @findex comint-delchar-or-maybe-eof
692 Either delete a character or send @acronym{EOF}
693 (@code{comint-delchar-or-maybe-eof}). Typed at the end of the shell
694 buffer, this sends @acronym{EOF} to the subshell. Typed at any other
695 position in the buffer, this deletes a character as usual.
698 @kindex C-c C-a @r{(Shell mode)}
699 @findex comint-bol-or-process-mark
700 Move to the beginning of the line, but after the prompt if any
701 (@code{comint-bol-or-process-mark}). If you repeat this command twice
702 in a row, the second time it moves back to the process mark, which is
703 the beginning of the input that you have not yet sent to the subshell.
704 (Normally that is the same place---the end of the prompt on this
705 line---but after @kbd{C-c @key{SPC}} the process mark may be in a
709 Accumulate multiple lines of input, then send them together. This
710 command inserts a newline before point, but does not send the preceding
711 text as input to the subshell---at least, not yet. Both lines, the one
712 before this newline and the one after, will be sent together (along with
713 the newline that separates them), when you type @key{RET}.
716 @kindex C-c C-u @r{(Shell mode)}
717 @findex comint-kill-input
718 Kill all text pending at end of buffer to be sent as input
719 (@code{comint-kill-input}). If point is not at end of buffer,
720 this only kills the part of this text that precedes point.
723 @kindex C-c C-w @r{(Shell mode)}
724 Kill a word before point (@code{backward-kill-word}).
727 @kindex C-c C-c @r{(Shell mode)}
728 @findex comint-interrupt-subjob
729 Interrupt the shell or its current subjob if any
730 (@code{comint-interrupt-subjob}). This command also kills
731 any shell input pending in the shell buffer and not yet sent.
734 @kindex C-c C-z @r{(Shell mode)}
735 @findex comint-stop-subjob
736 Stop the shell or its current subjob if any (@code{comint-stop-subjob}).
737 This command also kills any shell input pending in the shell buffer and
741 @findex comint-quit-subjob
742 @kindex C-c C-\ @r{(Shell mode)}
743 Send quit signal to the shell or its current subjob if any
744 (@code{comint-quit-subjob}). This command also kills any shell input
745 pending in the shell buffer and not yet sent.
748 @kindex C-c C-o @r{(Shell mode)}
749 @findex comint-delete-output
750 Delete the last batch of output from a shell command
751 (@code{comint-delete-output}). This is useful if a shell command spews
752 out lots of output that just gets in the way.
755 @kindex C-c C-s @r{(Shell mode)}
756 @findex comint-write-output
757 Write the last batch of output from a shell command to a file
758 (@code{comint-write-output}). With a prefix argument, the file is
759 appended to instead. Any prompt at the end of the output is not
764 @kindex C-c C-r @r{(Shell mode)}
765 @kindex C-M-l @r{(Shell mode)}
766 @findex comint-show-output
767 Scroll to display the beginning of the last batch of output at the top
768 of the window; also move the cursor there (@code{comint-show-output}).
771 @kindex C-c C-e @r{(Shell mode)}
772 @findex comint-show-maximum-output
773 Scroll to put the end of the buffer at the bottom of the window
774 (@code{comint-show-maximum-output}).
777 @kindex C-c C-f @r{(Shell mode)}
778 @findex shell-forward-command
779 @vindex shell-command-regexp
780 Move forward across one shell command, but not beyond the current line
781 (@code{shell-forward-command}). The variable @code{shell-command-regexp}
782 specifies how to recognize the end of a command.
785 @kindex C-c C-b @r{(Shell mode)}
786 @findex shell-backward-command
787 Move backward across one shell command, but not beyond the current line
788 (@code{shell-backward-command}).
791 Ask the shell for its working directory, and update the Shell buffer's
792 default directory. @xref{Directory Tracking}.
794 @item M-x send-invisible @key{RET} @var{text} @key{RET}
795 @findex send-invisible
796 Send @var{text} as input to the shell, after reading it without
797 echoing. This is useful when a shell command runs a program that asks
800 Please note that Emacs will not echo passwords by default. If you
801 really want them to be echoed, evaluate the following Lisp
805 (remove-hook 'comint-output-filter-functions
806 'comint-watch-for-password-prompt)
809 @item M-x comint-continue-subjob
810 @findex comint-continue-subjob
811 Continue the shell process. This is useful if you accidentally suspend
812 the shell process.@footnote{You should not suspend the shell process.
813 Suspending a subjob of the shell is a completely different matter---that
814 is normal practice, but you must use the shell to continue the subjob;
815 this command won't do it.}
817 @item M-x comint-strip-ctrl-m
818 @findex comint-strip-ctrl-m
819 Discard all control-M characters from the current group of shell output.
820 The most convenient way to use this command is to make it run
821 automatically when you get output from the subshell. To do that,
822 evaluate this Lisp expression:
825 (add-hook 'comint-output-filter-functions
826 'comint-strip-ctrl-m)
829 @item M-x comint-truncate-buffer
830 @findex comint-truncate-buffer
831 This command truncates the shell buffer to a certain maximum number of
832 lines, specified by the variable @code{comint-buffer-maximum-size}.
833 Here's how to do this automatically each time you get output from the
837 (add-hook 'comint-output-filter-functions
838 'comint-truncate-buffer)
844 Shell mode is a derivative of Comint mode, a general-purpose mode for
845 communicating with interactive subprocesses. Most of the features of
846 Shell mode actually come from Comint mode, as you can see from the
847 command names listed above. The special features of Shell mode include
848 the directory tracking feature, and a few user commands.
850 Other Emacs features that use variants of Comint mode include GUD
851 (@pxref{Debuggers}) and @kbd{M-x run-lisp} (@pxref{External Lisp}).
854 You can use @kbd{M-x comint-run} to execute any program of your choice
855 in a subprocess using unmodified Comint mode---without the
856 specializations of Shell mode.
859 @subsection Shell Prompts
861 @cindex prompt, shell
862 A prompt is text output by a program to show that it is ready to
863 accept new user input. Normally, Comint mode (and thus Shell mode)
864 automatically figures out part of the buffer is a prompt, based on the
865 output of the subprocess. (Specifically, it assumes that any received
866 output line which doesn't end with a newline is a prompt.)
868 Comint mode divides the buffer into two types of @dfn{fields}: input
869 fields (where user input is typed) and output fields (everywhere
870 else). Prompts are part of the output fields. Most Emacs motion
871 commands do not cross field boundaries, unless they move over multiple
872 lines. For instance, when point is in the input field on a shell
873 command line, @kbd{C-a} puts point at the beginning of the input
874 field, after the prompt. Internally, the fields are implemented using
875 the @code{field} text property (@pxref{Text Properties,,, elisp, the
876 Emacs Lisp Reference Manual}).
878 @vindex comint-use-prompt-regexp
879 @vindex shell-prompt-pattern
880 If you change the variable @code{comint-use-prompt-regexp} to a
881 non-@code{nil} value, then Comint mode recognize prompts using a
882 regular expression (@pxref{Regexps}). In Shell mode, the regular
883 expression is specified by the variable @code{shell-prompt-pattern}.
884 The default value of @code{comint-use-prompt-regexp} is @code{nil},
885 because this method for recognizing prompts is unreliable, but you may
886 want to set it to a non-@code{nil} value in unusual circumstances. In
887 that case, Emacs does not divide the Comint buffer into fields, so the
888 general motion commands behave as they normally do in buffers without
889 special text properties. However, you can use the paragraph motion
890 commands to conveniently navigate the buffer (@pxref{Paragraphs}); in
891 Shell mode, Emacs uses @code{shell-prompt-pattern} as paragraph
895 @subsection Shell Command History
897 Shell buffers support three ways of repeating earlier commands. You
898 can use keys like those used for the minibuffer history; these work
899 much as they do in the minibuffer, inserting text from prior commands
900 while point remains always at the end of the buffer. You can move
901 through the buffer to previous inputs in their original place, then
902 resubmit them or copy them to the end. Or you can use a
903 @samp{!}-style history reference.
906 * Ring: Shell Ring. Fetching commands from the history list.
907 * Copy: Shell History Copying. Moving to a command and then copying it.
908 * History References:: Expanding @samp{!}-style history references.
912 @subsubsection Shell History Ring
915 @findex comint-previous-input
916 @kindex M-p @r{(Shell mode)}
919 Fetch the next earlier old shell command.
921 @kindex M-n @r{(Shell mode)}
922 @findex comint-next-input
925 Fetch the next later old shell command.
927 @kindex M-r @r{(Shell mode)}
928 @findex comint-history-isearch-backward-regexp
930 Begin an incremental regexp search of old shell commands.
933 @kindex C-c C-x @r{(Shell mode)}
934 @findex comint-get-next-from-history
935 Fetch the next subsequent command from the history.
938 @kindex C-c . @r{(Shell mode)}
939 @findex comint-input-previous-argument
940 Fetch one argument from an old shell command.
943 @kindex C-c C-l @r{(Shell mode)}
944 @findex comint-dynamic-list-input-ring
945 Display the buffer's history of shell commands in another window
946 (@code{comint-dynamic-list-input-ring}).
949 Shell buffers provide a history of previously entered shell
950 commands. To reuse shell commands from the history, use the editing
951 commands @kbd{M-p}, @kbd{M-n}, @kbd{M-r} and @kbd{M-s}. These work
952 just like the minibuffer history commands (@pxref{Minibuffer
953 History}), except that they operate within the Shell buffer rather
956 @kbd{M-p} fetches an earlier shell command to the end of the shell
957 buffer. Successive use of @kbd{M-p} fetches successively earlier
958 shell commands, each replacing any text that was already present as
959 potential shell input. @kbd{M-n} does likewise except that it finds
960 successively more recent shell commands from the buffer.
961 @kbd{C-@key{UP}} works like @kbd{M-p}, and @kbd{C-@key{DOWN}} like
964 The history search command @kbd{M-r} begins an incremental regular
965 expression search of previous shell commands. After typing @kbd{M-r},
966 start typing the desired string or regular expression; the last
967 matching shell command will be displayed in the current line.
968 Incremental search commands have their usual effects---for instance,
969 @kbd{C-s} and @kbd{C-r} search forward and backward for the next match
970 (@pxref{Incremental Search}). When you find the desired input, type
971 @key{RET} to terminate the search. This puts the input in the command
972 line. Any partial input you were composing before navigating the
973 history list is restored when you go to the beginning or end of the
976 Often it is useful to reexecute several successive shell commands that
977 were previously executed in sequence. To do this, first find and
978 reexecute the first command of the sequence. Then type @kbd{C-c C-x};
979 that will fetch the following command---the one that follows the command
980 you just repeated. Then type @key{RET} to reexecute this command. You
981 can reexecute several successive commands by typing @kbd{C-c C-x
982 @key{RET}} over and over.
984 The command @kbd{C-c .}@: (@code{comint-input-previous-argument})
985 copies an individual argument from a previous command, like @kbd{ESC
986 .} in Bash. The simplest use copies the last argument from the
987 previous shell command. With a prefix argument @var{n}, it copies the
988 @var{n}th argument instead. Repeating @kbd{C-c .} copies from an
989 earlier shell command instead, always using the same value of @var{n}
990 (don't give a prefix argument when you repeat the @kbd{C-c .}
993 These commands get the text of previous shell commands from a special
994 history list, not from the shell buffer itself. Thus, editing the shell
995 buffer, or even killing large parts of it, does not affect the history
996 that these commands access.
998 @vindex shell-input-ring-file-name
999 Some shells store their command histories in files so that you can
1000 refer to commands from previous shell sessions. Emacs reads
1001 the command history file for your chosen shell, to initialize its own
1002 command history. The file name is @file{~/.bash_history} for bash,
1003 @file{~/.sh_history} for ksh, and @file{~/.history} for other shells.
1005 @node Shell History Copying
1006 @subsubsection Shell History Copying
1009 @kindex C-c C-p @r{(Shell mode)}
1010 @findex comint-previous-prompt
1012 Move point to the previous prompt (@code{comint-previous-prompt}).
1014 @kindex C-c C-n @r{(Shell mode)}
1015 @findex comint-next-prompt
1017 Move point to the following prompt (@code{comint-next-prompt}).
1019 @kindex C-c RET @r{(Shell mode)}
1020 @findex comint-copy-old-input
1022 Copy the input command at point, inserting the copy at the end of the
1023 buffer (@code{comint-copy-old-input}). This is useful if you move
1024 point back to a previous command. After you copy the command, you can
1025 submit the copy as input with @key{RET}. If you wish, you can edit
1026 the copy before resubmitting it. If you use this command on an output
1027 line, it copies that line to the end of the buffer.
1030 If @code{comint-use-prompt-regexp} is @code{nil} (the default), copy
1031 the old input command that you click on, inserting the copy at the end
1032 of the buffer (@code{comint-insert-input}). If
1033 @code{comint-use-prompt-regexp} is non-@code{nil}, or if the click is
1034 not over old input, just yank as usual.
1037 Moving to a previous input and then copying it with @kbd{C-c
1038 @key{RET}} or @kbd{Mouse-2} produces the same results---the same
1039 buffer contents---that you would get by using @kbd{M-p} enough times
1040 to fetch that previous input from the history list. However, @kbd{C-c
1041 @key{RET}} copies the text from the buffer, which can be different
1042 from what is in the history list if you edit the input text in the
1043 buffer after it has been sent.
1045 @node History References
1046 @subsubsection Shell History References
1047 @cindex history reference
1049 Various shells including csh and bash support @dfn{history
1050 references} that begin with @samp{!} and @samp{^}. Shell mode
1051 recognizes these constructs, and can perform the history substitution
1054 If you insert a history reference and type @key{TAB}, this searches
1055 the input history for a matching command, performs substitution if
1056 necessary, and places the result in the buffer in place of the history
1057 reference. For example, you can fetch the most recent command
1058 beginning with @samp{mv} with @kbd{! m v @key{TAB}}. You can edit the
1059 command if you wish, and then resubmit the command to the shell by
1062 @vindex comint-input-autoexpand
1063 @findex comint-magic-space
1064 Shell mode can optionally expand history references in the buffer
1065 when you send them to the shell. To request this, set the variable
1066 @code{comint-input-autoexpand} to @code{input}. You can make
1067 @key{SPC} perform history expansion by binding @key{SPC} to the
1068 command @code{comint-magic-space}.
1070 Shell mode recognizes history references when they follow a prompt.
1071 @xref{Shell Prompts}, for how Shell mode recognizes prompts.
1073 @node Directory Tracking
1074 @subsection Directory Tracking
1075 @cindex directory tracking
1077 @vindex shell-pushd-regexp
1078 @vindex shell-popd-regexp
1079 @vindex shell-cd-regexp
1080 Shell mode keeps track of @samp{cd}, @samp{pushd} and @samp{popd}
1081 commands given to the subshell, in order to keep the Shell buffer's
1082 default directory (@pxref{File Names}) the same as the shell's working
1083 directory. It recognizes these commands by examining lines of input
1086 If you use aliases for these commands, you can tell Emacs to
1087 recognize them also, by setting the variables
1088 @code{shell-pushd-regexp}, @code{shell-popd-regexp}, and
1089 @code{shell-cd-regexp} to the appropriate regular expressions
1090 (@pxref{Regexps}). For example, if @code{shell-pushd-regexp} matches
1091 the beginning of a shell command line, that line is regarded as a
1092 @code{pushd} command. These commands are recognized only at the
1093 beginning of a shell command line.
1096 If Emacs gets confused about changes in the working directory of the
1097 subshell, type @kbd{M-x dirs}. This command asks the shell for its
1098 working directory and updates the default directory accordingly. It
1099 works for shells that support the most common command syntax, but may
1100 not work for unusual shells.
1102 @findex dirtrack-mode
1103 @cindex Dirtrack mode
1104 @cindex mode, Dirtrack
1105 @vindex dirtrack-list
1106 You can also use Dirtrack mode, a buffer-local minor mode that
1107 implements an alternative method of tracking the shell's working
1108 directory. To use this method, your shell prompt must contain the
1109 working directory at all times, and you must supply a regular
1110 expression for recognizing which part of the prompt contains the
1111 working directory; see the documentation of the variable
1112 @code{dirtrack-list} for details. To use Dirtrack mode, type @kbd{M-x
1113 dirtrack-mode} in the Shell buffer, or add @code{dirtrack-mode} to
1114 @code{shell-mode-hook} (@pxref{Hooks}).
1117 @subsection Shell Mode Options
1119 @vindex comint-scroll-to-bottom-on-input
1120 If the variable @code{comint-scroll-to-bottom-on-input} is
1121 non-@code{nil}, insertion and yank commands scroll the selected window
1122 to the bottom before inserting. The default is @code{nil}.
1124 @vindex comint-scroll-show-maximum-output
1125 If @code{comint-scroll-show-maximum-output} is non-@code{nil}, then
1126 arrival of output when point is at the end tries to scroll the last
1127 line of text to the bottom line of the window, showing as much useful
1128 text as possible. (This mimics the scrolling behavior of most
1129 terminals.) The default is @code{t}.
1131 @vindex comint-move-point-for-output
1132 By setting @code{comint-move-point-for-output}, you can opt for
1133 having point jump to the end of the buffer whenever output arrives---no
1134 matter where in the buffer point was before. If the value is
1135 @code{this}, point jumps in the selected window. If the value is
1136 @code{all}, point jumps in each window that shows the Comint buffer. If
1137 the value is @code{other}, point jumps in all nonselected windows that
1138 show the current buffer. The default value is @code{nil}, which means
1139 point does not jump to the end.
1141 @vindex comint-prompt-read-only
1142 If you set @code{comint-prompt-read-only}, the prompts in the Comint
1143 buffer are read-only.
1145 @vindex comint-input-ignoredups
1146 The variable @code{comint-input-ignoredups} controls whether successive
1147 identical inputs are stored in the input history. A non-@code{nil}
1148 value means to omit an input that is the same as the previous input.
1149 The default is @code{nil}, which means to store each input even if it is
1150 equal to the previous input.
1152 @vindex comint-completion-addsuffix
1153 @vindex comint-completion-recexact
1154 @vindex comint-completion-autolist
1155 Three variables customize file name completion. The variable
1156 @code{comint-completion-addsuffix} controls whether completion inserts a
1157 space or a slash to indicate a fully completed file or directory name
1158 (non-@code{nil} means do insert a space or slash).
1159 @code{comint-completion-recexact}, if non-@code{nil}, directs @key{TAB}
1160 to choose the shortest possible completion if the usual Emacs completion
1161 algorithm cannot add even a single character.
1162 @code{comint-completion-autolist}, if non-@code{nil}, says to list all
1163 the possible completions whenever completion is not exact.
1165 @vindex shell-completion-execonly
1166 Command completion normally considers only executable files.
1167 If you set @code{shell-completion-execonly} to @code{nil},
1168 it considers nonexecutable files as well.
1170 @findex shell-pushd-tohome
1171 @findex shell-pushd-dextract
1172 @findex shell-pushd-dunique
1173 You can configure the behavior of @samp{pushd}. Variables control
1174 whether @samp{pushd} behaves like @samp{cd} if no argument is given
1175 (@code{shell-pushd-tohome}), pop rather than rotate with a numeric
1176 argument (@code{shell-pushd-dextract}), and only add directories to the
1177 directory stack if they are not already on it
1178 (@code{shell-pushd-dunique}). The values you choose should match the
1179 underlying shell, of course.
1181 @node Terminal emulator
1182 @subsection Emacs Terminal Emulator
1185 To run a subshell in a terminal emulator, use @kbd{M-x term}. This
1186 creates (or reuses) a buffer named @file{*terminal*}, and runs a
1187 subshell with input coming from your keyboard, and output going to
1190 The terminal emulator uses Term mode, which has two input modes. In
1191 line mode, Term basically acts like Shell mode (@pxref{Shell Mode}).
1193 In char mode, each character is sent directly to the subshell, as
1194 ``terminal input''. Any ``echoing'' of your input is the
1195 responsibility of the subshell. The sole exception is the terminal
1196 escape character, which by default is @kbd{C-c} (@pxref{Term Mode}).
1197 Any ``terminal output'' from the subshell goes into the buffer,
1200 Some programs (such as Emacs itself) need to control the appearance
1201 on the terminal screen in detail. They do this by sending special
1202 control codes. The exact control codes needed vary from terminal to
1203 terminal, but nowadays most terminals and terminal emulators
1204 (including @code{xterm}) understand the ANSI-standard (VT100-style)
1205 escape sequences. Term mode recognizes these escape sequences, and
1206 handles each one appropriately, changing the buffer so that the
1207 appearance of the window matches what it would be on a real terminal.
1208 You can actually run Emacs inside an Emacs Term window.
1210 You can also Term mode to communicate with a device connected to a
1211 serial port. @xref{Serial Terminal}.
1213 The file name used to load the subshell is determined the same way
1214 as for Shell mode. To make multiple terminal emulators, rename the
1215 buffer @file{*terminal*} to something different using @kbd{M-x
1216 rename-uniquely}, just as with Shell mode.
1218 Unlike Shell mode, Term mode does not track the current directory by
1219 examining your input. But some shells can tell Term what the current
1220 directory is. This is done automatically by @code{bash} version 1.15
1224 @subsection Term Mode
1228 The terminal emulator uses Term mode, which has two input modes. In
1229 line mode, Term basically acts like Shell mode (@pxref{Shell Mode}).
1230 In char mode, each character is sent directly to the subshell, except
1231 for the Term escape character, normally @kbd{C-c}.
1233 To switch between line and char mode, use these commands:
1236 @kindex C-c C-j @r{(Term mode)}
1237 @findex term-line-mode
1239 Switch to line mode (@code{term-line-mode}). Do nothing if already in
1242 @kindex C-c C-k @r{(Term mode)}
1243 @findex term-char-mode
1245 Switch to char mode (@code{term-char-mode}). Do nothing if already in
1249 The following commands are only available in char mode:
1253 Send a literal @key{C-c} to the sub-shell.
1255 @item C-c @var{char}
1256 This is equivalent to @kbd{C-x @var{char}} in normal Emacs. For
1257 example, @kbd{C-c o} invokes the global binding of @kbd{C-x o}, which
1258 is normally @samp{other-window}.
1261 @cindex paging in Term mode
1262 Term mode has a page-at-a-time feature. When enabled, it makes
1263 output pause at the end of each screenful:
1266 @kindex C-c C-q @r{(Term mode)}
1267 @findex term-pager-toggle
1269 Toggle the page-at-a-time feature. This command works in both line
1270 and char modes. When the feature is enabled, the mode-line displays
1271 the word @samp{page}, and each time Term receives more than a
1272 screenful of output, it pauses and displays @samp{**MORE**} in the
1273 mode-line. Type @key{SPC} to display the next screenful of output, or
1274 @kbd{?} to see your other options. The interface is similar to the
1275 @code{more} program.
1279 @subsection Remote Host Shell
1281 @cindex connecting to remote host
1285 You can login to a remote computer, using whatever commands you
1286 would from a regular terminal (e.g.@: using the @code{telnet} or
1287 @code{rlogin} commands), from a Term window.
1289 A program that asks you for a password will normally suppress
1290 echoing of the password, so the password will not show up in the
1291 buffer. This will happen just as if you were using a real terminal,
1292 if the buffer is in char mode. If it is in line mode, the password is
1293 temporarily visible, but will be erased when you hit return. (This
1294 happens automatically; there is no special password processing.)
1296 When you log in to a different machine, you need to specify the type
1297 of terminal you're using, by setting the @env{TERM} environment
1298 variable in the environment for the remote login command. (If you use
1299 bash, you do that by writing the variable assignment before the remote
1300 login command, without a separating comma.) Terminal types
1301 @samp{ansi} or @samp{vt100} will work on most systems.
1303 @node Serial Terminal
1304 @subsection Serial Terminal
1305 @cindex terminal, serial
1308 If you have a device connected to a serial port of your computer,
1309 you can communicate with it by typing @kbd{M-x serial-term}. This
1310 command asks for a serial port name and speed, and switches to a new
1311 Term mode buffer. Emacs communicates with the serial device through
1312 this buffer just like it does with a terminal in ordinary Term mode.
1314 The speed of the serial port is measured in bits per second. The
1315 most common speed is 9600 bits per second. You can change the speed
1316 interactively by clicking on the mode line.
1318 A serial port can be configured even more by clicking on ``8N1'' in
1319 the mode line. By default, a serial port is configured as ``8N1'',
1320 which means that each byte consists of 8 data bits, No parity check
1323 If the speed or the configuration is wrong, you cannot communicate
1324 with your device and will probably only see garbage output in the
1328 @section Using Emacs as a Server
1330 @cindex Emacs as a server
1331 @cindex server, using Emacs as
1332 @cindex @env{EDITOR} environment variable
1334 Various programs can invoke your choice of editor to edit a
1335 particular piece of text. For instance, version control programs
1336 invoke an editor to enter version control logs (@pxref{Version
1337 Control}), and the Unix @command{mail} utility invokes an editor to
1338 enter a message to send. By convention, your choice of editor is
1339 specified by the environment variable @env{EDITOR}. If you set
1340 @env{EDITOR} to @samp{emacs}, Emacs would be invoked, but in an
1341 inconvenient way---by starting a new Emacs process. This is
1342 inconvenient because the new Emacs process doesn't share buffers, a
1343 command history, or other kinds of information with any existing Emacs
1346 You can solve this problem by setting up Emacs as an @dfn{edit
1347 server}, so that it ``listens'' for external edit requests and acts
1348 accordingly. There are two ways to start an Emacs server:
1351 @findex server-start
1353 Run the command @code{server-start} in an existing Emacs process:
1354 either type @kbd{M-x server-start}, or put the expression
1355 @code{(server-start)} in your init file (@pxref{Init File}). The
1356 existing Emacs process is the server; when you exit Emacs, the server
1357 dies with the Emacs process.
1359 @cindex daemon, Emacs
1361 Run Emacs as a @dfn{daemon}, using the @samp{--daemon} command-line
1362 option. @xref{Initial Options}. When Emacs is started this way, it
1363 calls @code{server-start} after initialization, and returns control to
1364 the calling terminal instead of opening an initial frame; it then
1365 waits in the background, listening for edit requests.
1368 @cindex @env{TEXEDIT} environment variable
1369 Either way, once an Emacs server is started, you can use a shell
1370 command called @command{emacsclient} to connect to the Emacs process
1371 and tell it to visit a file. You can then set the @env{EDITOR}
1372 environment variable to @samp{emacsclient}, so that external programs
1373 will use the existing Emacs process for editing.@footnote{Some
1374 programs use a different environment variable; for example, to make
1375 @TeX{} use @samp{emacsclient}, set the @env{TEXEDIT} environment
1376 variable to @samp{emacsclient +%d %s}.}
1379 You can run multiple Emacs servers on the same machine by giving
1380 each one a unique ``server name'', using the variable
1381 @code{server-name}. For example, @kbd{M-x set-variable @key{RET}
1382 server-name @key{RET} foo @key{RET}} sets the server name to
1383 @samp{foo}. The @code{emacsclient} program can specify a server by
1384 name, using the @samp{-s} option (@pxref{emacsclient Options}).
1386 @findex server-eval-at
1387 If you have defined a server by a unique server name, it is possible
1388 to connect to the server from another Emacs instance and evaluate Lisp
1389 expressions on the server, using the @code{server-eval-at} function.
1390 For instance, @code{(server-eval-at "foo" '(+ 1 2))} evaluates the
1391 expression @code{(+ 1 2)} on the @samp{foo} server, and returns
1392 @code{3}. (If there is no server with that name, an error is
1393 signaled.) Currently, this feature is mainly useful for developers.
1396 * Invoking emacsclient:: Connecting to the Emacs server.
1397 * emacsclient Options:: Emacs client startup options.
1400 @node Invoking emacsclient
1401 @subsection Invoking @code{emacsclient}
1402 @cindex @code{emacsclient} invocation
1404 The simplest way to use the @command{emacsclient} program is to run
1405 the shell command @samp{emacsclient @var{file}}, where @var{file} is a
1406 file name. This connects to an Emacs server, and tells that Emacs
1407 process to visit @var{file} in one of its existing frames---either a
1408 graphical frame, or one in a text terminal (@pxref{Frames}). You
1409 can then select that frame to begin editing.
1411 If there is no Emacs server, the @command{emacsclient} program halts
1412 with an error message. If the Emacs process has no existing
1413 frame---which can happen if it was started as a daemon (@pxref{Emacs
1414 Server})---then Emacs opens a frame on the terminal in which you
1415 called @command{emacsclient}.
1417 You can also force @command{emacsclient} to open a new frame on a
1418 graphical display, or on a text terminal, using the @samp{-c} and
1419 @samp{-t} options. @xref{emacsclient Options}.
1421 If you are running on a single text terminal, you can switch between
1422 @command{emacsclient}'s shell and the Emacs server using one of two
1423 methods: (i) run the Emacs server and @command{emacsclient} on
1424 different virtual terminals, and switch to the Emacs server's virtual
1425 terminal after calling @command{emacsclient}; or (ii) call
1426 @command{emacsclient} from within the Emacs server itself, using Shell
1427 mode (@pxref{Interactive Shell}) or Term mode (@pxref{Term Mode});
1428 @code{emacsclient} blocks only the subshell under Emacs, and you can
1429 still use Emacs to edit the file.
1433 When you finish editing @var{file} in the Emacs server, type
1434 @kbd{C-x #} (@code{server-edit}) in its buffer. This saves the file
1435 and sends a message back to the @command{emacsclient} program, telling
1436 it to exit. Programs that use @env{EDITOR} usually wait for the
1437 ``editor''---in this case @command{emacsclient}---to exit before doing
1440 You can also call @command{emacsclient} with multiple file name
1441 arguments: @samp{emacsclient @var{file1} @var{file2} ...} tells the
1442 Emacs server to visit @var{file1}, @var{file2}, and so forth. Emacs
1443 selects the buffer visiting @var{file1}, and buries the other buffers
1444 at the bottom of the buffer list (@pxref{Buffers}). The
1445 @command{emacsclient} program exits once all the specified files are
1446 finished (i.e., once you have typed @kbd{C-x #} in each server
1449 @vindex server-kill-new-buffers
1450 @vindex server-temp-file-regexp
1451 Finishing with a server buffer also kills the buffer, unless it
1452 already existed in the Emacs session before the server was asked to
1453 create it. However, if you set @code{server-kill-new-buffers} to
1454 @code{nil}, then a different criterion is used: finishing with a
1455 server buffer kills it if the file name matches the regular expression
1456 @code{server-temp-file-regexp}. This is set up to distinguish certain
1457 ``temporary'' files.
1459 Each @kbd{C-x #} checks for other pending external requests to edit
1460 various files, and selects the next such file. You can switch to a
1461 server buffer manually if you wish; you don't have to arrive at it
1462 with @kbd{C-x #}. But @kbd{C-x #} is the way to tell
1463 @command{emacsclient} that you are finished.
1465 @vindex server-window
1466 If you set the value of the variable @code{server-window} to a
1467 window or a frame, @kbd{C-x #} always displays the next server buffer
1468 in that window or in that frame.
1470 @node emacsclient Options
1471 @subsection @code{emacsclient} Options
1472 @cindex @code{emacsclient} options
1474 You can pass some optional arguments to the @command{emacsclient}
1478 emacsclient -c +12 @var{file1} +4:3 @var{file2}
1482 The @samp{+@var{line}} or @samp{+@var{line}:@var{column}} arguments
1483 specify line numbers, or line and column numbers, for the next file
1484 argument. These behave like the command line arguments for Emacs
1485 itself. @xref{Action Arguments}.
1487 The other optional arguments recognized by @command{emacsclient} are
1491 @item -a @var{command}
1492 @itemx --alternate-editor=@var{command}
1493 Specify a command to run if @code{emacsclient} fails to contact Emacs.
1494 This is useful when running @code{emacsclient} in a script.
1496 As a special exception, if @var{command} is the empty string, then
1497 @code{emacsclient} starts Emacs in daemon mode (as @command{emacs
1498 --daemon}) and then tries connecting again.
1500 @cindex @env{ALTERNATE_EDITOR} environment variable
1501 The environment variable @env{ALTERNATE_EDITOR} has the same effect as
1502 the @samp{-a} option. If both are present, the latter takes
1505 @cindex client frame
1507 Create a new graphical @dfn{client frame}, instead of using an
1508 existing Emacs frame. If you omit a filename argument while supplying
1509 the @samp{-c} option, the new frame displays the @file{*scratch*}
1510 buffer (@pxref{Buffers}). See below for the special behavior of
1511 @kbd{C-x C-c} in a client frame.
1513 If Emacs is unable to create a new graphical frame (e.g.@: if it is
1514 unable to connect to the X server), it tries to create a text terminal
1515 client frame, as though you had supplied the @samp{-t} option instead
1518 On MS-Windows, a single Emacs session cannot display frames on both
1519 graphical and text terminals, nor on multiple text terminals. Thus,
1520 if the Emacs server is running on a text terminal, the @samp{-c}
1521 option, like the @samp{-t} option, creates a new frame in the server's
1522 current text terminal. @xref{Windows Startup}.
1524 @item -F @var{alist}
1525 @itemx --frame-parameters=@var{alist}
1526 Set the parameters for a newly-created graphical frame
1527 (@pxref{Frame Parameters}).
1529 @item -d @var{display}
1530 @itemx --display=@var{display}
1531 Tell Emacs to open the given files on the X display @var{display}
1532 (assuming there is more than one X display available).
1536 Tell Emacs to evaluate some Emacs Lisp code, instead of visiting some
1537 files. When this option is given, the arguments to
1538 @command{emacsclient} are interpreted as a list of expressions to
1539 evaluate, @emph{not} as a list of files to visit.
1541 @item -f @var{server-file}
1542 @itemx --server-file=@var{server-file}
1543 @cindex @env{EMACS_SERVER_FILE} environment variable
1545 @vindex server-use-tcp
1547 Specify a @dfn{server file} for connecting to an Emacs server via TCP.
1549 An Emacs server usually uses an operating system feature called a
1550 ``local socket'' to listen for connections. Some operating systems,
1551 such as Microsoft Windows, do not support local sockets; in that case,
1552 Emacs uses TCP instead. When you start the Emacs server, Emacs
1553 creates a server file containing some TCP information that
1554 @command{emacsclient} needs for making the connection. By default,
1555 the server file is in @file{~/.emacs.d/server/}. On Microsoft
1556 Windows, if @command{emacsclient} does not find the server file there,
1557 it looks in the @file{.emacs.d/server/} subdirectory of the directory
1558 pointed to by the @env{APPDATA} environment variable. You can tell
1559 @command{emacsclient} to use a specific server file with the @samp{-f}
1560 or @samp{--server-file} option, or by setting the
1561 @env{EMACS_SERVER_FILE} environment variable.
1563 Even if local sockets are available, you can tell Emacs to use TCP by
1564 setting the variable @code{server-use-tcp} to @code{t}. One advantage
1565 of TCP is that the server can accept connections from remote machines.
1566 For this to work, you must (i) set the variable @code{server-host} to
1567 the hostname or IP address of the machine on which the Emacs server
1568 runs, and (ii) provide @command{emacsclient} with the server file.
1569 (One convenient way to do the latter is to put the server file on a
1570 networked file system such as NFS.)
1573 When the Emacs server is using TCP, the variable @code{server-port}
1574 determines the port number to listen on; the default value,
1575 @code{nil}, means to choose a random port when the server starts.
1579 Let @command{emacsclient} exit immediately, instead of waiting until
1580 all server buffers are finished. You can take as long as you like to
1581 edit the server buffers within Emacs, and they are @emph{not} killed
1582 when you type @kbd{C-x #} in them.
1584 @item --parent-id @var{ID}
1585 Open an @command{emacsclient} frame as a client frame in the parent X
1586 window with id @var{ID}, via the XEmbed protocol. Currently, this
1587 option is mainly useful for developers.
1591 Do not let @command{emacsclient} display messages about waiting for
1592 Emacs or connecting to remote server sockets.
1594 @item -s @var{server-name}
1595 @itemx --socket-name=@var{server-name}
1596 Connect to the Emacs server named @var{server-name}. The server name
1597 is given by the variable @code{server-name} on the Emacs server. If
1598 this option is omitted, @command{emacsclient} connects to the first
1599 server it finds. (This option is not supported on MS-Windows.)
1604 Create a new client frame on the current text terminal, instead of
1605 using an existing Emacs frame. This is similar to the @samp{-c}
1606 option, above, except that it creates a text terminal frame
1607 (@pxref{Non-Window Terminals}). If you omit a filename argument while
1608 supplying this option, the new frame displays the @file{*scratch*}
1609 buffer (@pxref{Buffers}). See below for the special behavior of
1610 @kbd{C-x C-c} in a client frame.
1612 On MS-Windows, a single Emacs session cannot display frames on both
1613 graphical and text terminals, nor on multiple text terminals. Thus,
1614 if the Emacs server is using the graphical display, @samp{-t} behaves
1615 like @samp{-c} (see above); whereas if the Emacs server is running on
1616 a text terminal, it creates a new frame in its current text terminal.
1617 @xref{Windows Startup}.
1620 The new graphical or text terminal frames created by the @samp{-c}
1621 or @samp{-t} options are considered @dfn{client frames}. Any new
1622 frame that you create from a client frame is also considered a client
1623 frame. If you type @kbd{C-x C-c} (@code{save-buffers-kill-terminal})
1624 in a client frame, that command does not kill the Emacs session as it
1625 normally does (@pxref{Exiting}). Instead, Emacs deletes the client
1626 frame; furthermore, if the client frame has an @command{emacsclient}
1627 waiting to regain control (i.e.@: if you did not supply the @samp{-n}
1628 option), Emacs deletes all other frames of the same client, and marks
1629 the client's server buffers as finished, as though you had typed
1630 @kbd{C-x #} in all of them. If it so happens that there are no
1631 remaining frames after the client frame(s) are deleted, the Emacs
1634 As an exception, when Emacs is started as a daemon, all frames are
1635 considered client frames, and @kbd{C-x C-c} never kills Emacs. To
1636 kill a daemon session, type @kbd{M-x kill-emacs}.
1638 Note that the @samp{-t} and @samp{-n} options are contradictory:
1639 @samp{-t} says to take control of the current text terminal to create
1640 a new client frame, while @samp{-n} says not to take control of the
1641 text terminal. If you supply both options, Emacs visits the specified
1642 files(s) in an existing frame rather than a new client frame, negating
1643 the effect of @samp{-t}.
1646 @section Printing Hard Copies
1650 Emacs provides commands for printing hardcopies of either an entire
1651 buffer or part of one. You can invoke the printing commands directly,
1652 as detailed below, or using the @samp{File} menu on the menu bar.
1654 @findex htmlfontify-buffer
1655 Aside from the commands described in this section, you can also
1656 print hardcopies from Dired (@pxref{Operating on Files}) and the diary
1657 (@pxref{Displaying the Diary}). You can also ``print'' an Emacs
1658 buffer to HTML with the command @kbd{M-x htmlfontify-buffer}, which
1659 converts the current buffer to a HTML file, replacing Emacs faces with
1660 CSS-based markup. Furthermore, Org mode allows you to ``print'' Org
1661 files to a variety of formats, such as PDF (@pxref{Org Mode}).
1664 @item M-x print-buffer
1665 Print hardcopy of current buffer with page headings containing the
1666 file name and page number.
1667 @item M-x lpr-buffer
1668 Print hardcopy of current buffer without page headings.
1669 @item M-x print-region
1670 Like @code{print-buffer} but print only the current region.
1671 @item M-x lpr-region
1672 Like @code{lpr-buffer} but print only the current region.
1675 @findex print-buffer
1676 @findex print-region
1679 @vindex lpr-switches
1680 @vindex lpr-commands
1681 On most operating system, the above hardcopy commands submit files
1682 for printing by calling the @command{lpr} program. To change the
1683 printer program, customize the variable @code{lpr-command}. To
1684 specify extra switches to give the printer program, customize the list
1685 variable @code{lpr-switches}. Its value should be a list of option
1686 strings, each of which should start with @samp{-} (e.g.@: the option
1687 string @code{"-w80"} specifies a line width of 80 columns). The
1688 default is the empty list, @code{nil}.
1690 @vindex printer-name
1691 @vindex lpr-printer-switch
1692 To specify the printer to use, set the variable @code{printer-name}.
1693 The default, @code{nil}, specifies the default printer. If you set it
1694 to a printer name (a string), that name is passed to @command{lpr}
1695 with the @samp{-P} switch; if you are not using @command{lpr}, you
1696 should specify the switch with @code{lpr-printer-switch}.
1698 @vindex lpr-headers-switches
1699 @vindex lpr-add-switches
1700 The variable @code{lpr-headers-switches} similarly specifies the
1701 extra switches to use to make page headers. The variable
1702 @code{lpr-add-switches} controls whether to supply @samp{-T} and
1703 @samp{-J} options (suitable for @command{lpr}) to the printer program:
1704 @code{nil} means don't add them (this should be the value if your
1705 printer program is not compatible with @command{lpr}).
1708 * PostScript:: Printing buffers or regions as PostScript.
1709 * PostScript Variables:: Customizing the PostScript printing commands.
1710 * Printing Package:: An optional advanced printing interface.
1714 @subsection PostScript Hardcopy
1716 These commands convert buffer contents to PostScript,
1717 either printing it or leaving it in another Emacs buffer.
1720 @item M-x ps-print-buffer
1721 Print hardcopy of the current buffer in PostScript form.
1722 @item M-x ps-print-region
1723 Print hardcopy of the current region in PostScript form.
1724 @item M-x ps-print-buffer-with-faces
1725 Print hardcopy of the current buffer in PostScript form, showing the
1726 faces used in the text by means of PostScript features.
1727 @item M-x ps-print-region-with-faces
1728 Print hardcopy of the current region in PostScript form, showing the
1729 faces used in the text.
1730 @item M-x ps-spool-buffer
1731 Generate and spool a PostScript image for the current buffer text.
1732 @item M-x ps-spool-region
1733 Generate and spool a PostScript image for the current region.
1734 @item M-x ps-spool-buffer-with-faces
1735 Generate and spool a PostScript image for the current buffer, showing the faces used.
1736 @item M-x ps-spool-region-with-faces
1737 Generate and spool a PostScript image for the current region, showing the faces used.
1738 @item M-x ps-despool
1739 Send the spooled PostScript to the printer.
1741 Generate/print PostScript for the current buffer as if handwritten.
1744 @findex ps-print-region
1745 @findex ps-print-buffer
1746 @findex ps-print-region-with-faces
1747 @findex ps-print-buffer-with-faces
1748 The @code{ps-print-buffer} and @code{ps-print-region} commands print
1749 buffer contents in PostScript form. One command prints the entire
1750 buffer; the other, just the region. The commands
1751 @code{ps-print-buffer-with-faces} and
1752 @code{ps-print-region-with-faces} behave similarly, but use PostScript
1753 features to show the faces (fonts and colors) of the buffer text.
1755 Interactively, when you use a prefix argument (@kbd{C-u}), the command
1756 prompts the user for a file name, and saves the PostScript image in that file
1757 instead of sending it to the printer.
1759 @findex ps-spool-region
1760 @findex ps-spool-buffer
1761 @findex ps-spool-region-with-faces
1762 @findex ps-spool-buffer-with-faces
1763 The commands whose names have @samp{spool} instead of @samp{print},
1764 generate the PostScript output in an Emacs buffer instead of sending
1768 Use the command @code{ps-despool} to send the spooled images to the
1769 printer. This command sends the PostScript generated by
1770 @samp{-spool-} commands (see commands above) to the printer. With a
1771 prefix argument (@kbd{C-u}), it prompts for a file name, and saves the
1772 spooled PostScript image in that file instead of sending it to the
1777 @kbd{M-x handwrite} is more frivolous. It generates a PostScript
1778 rendition of the current buffer as a cursive handwritten document. It
1779 can be customized in group @code{handwrite}. This function only
1780 supports ISO 8859-1 characters.
1782 @node PostScript Variables
1783 @subsection Variables for PostScript Hardcopy
1785 @vindex ps-lpr-command
1786 @vindex ps-lpr-switches
1787 @vindex ps-printer-name
1788 All the PostScript hardcopy commands use the variables
1789 @code{ps-lpr-command} and @code{ps-lpr-switches} to specify how to print
1790 the output. @code{ps-lpr-command} specifies the command name to run,
1791 @code{ps-lpr-switches} specifies command line options to use, and
1792 @code{ps-printer-name} specifies the printer. If you don't set the
1793 first two variables yourself, they take their initial values from
1794 @code{lpr-command} and @code{lpr-switches}. If @code{ps-printer-name}
1795 is @code{nil}, @code{printer-name} is used.
1797 @vindex ps-print-header
1798 The variable @code{ps-print-header} controls whether these commands
1799 add header lines to each page---set it to @code{nil} to turn headers
1802 @cindex color emulation on black-and-white printers
1803 @vindex ps-print-color-p
1804 If your printer doesn't support colors, you should turn off color
1805 processing by setting @code{ps-print-color-p} to @code{nil}. By
1806 default, if the display supports colors, Emacs produces hardcopy output
1807 with color information; on black-and-white printers, colors are emulated
1808 with shades of gray. This might produce illegible output, even if your
1809 screen colors only use shades of gray.
1811 Alternatively, you can set @code{ps-print-color-p} to @code{black-white} to
1812 print colors on black/white printers.
1814 @vindex ps-use-face-background
1815 By default, PostScript printing ignores the background colors of the
1816 faces, unless the variable @code{ps-use-face-background} is
1817 non-@code{nil}. This is to avoid unwanted interference with the zebra
1818 stripes and background image/text.
1820 @vindex ps-paper-type
1821 @vindex ps-page-dimensions-database
1822 The variable @code{ps-paper-type} specifies which size of paper to
1823 format for; legitimate values include @code{a4}, @code{a3},
1824 @code{a4small}, @code{b4}, @code{b5}, @code{executive}, @code{ledger},
1825 @code{legal}, @code{letter}, @code{letter-small}, @code{statement},
1826 @code{tabloid}. The default is @code{letter}. You can define
1827 additional paper sizes by changing the variable
1828 @code{ps-page-dimensions-database}.
1830 @vindex ps-landscape-mode
1831 The variable @code{ps-landscape-mode} specifies the orientation of
1832 printing on the page. The default is @code{nil}, which stands for
1833 ``portrait'' mode. Any non-@code{nil} value specifies ``landscape''
1836 @vindex ps-number-of-columns
1837 The variable @code{ps-number-of-columns} specifies the number of
1838 columns; it takes effect in both landscape and portrait mode. The
1841 @vindex ps-font-family
1842 @vindex ps-font-size
1843 @vindex ps-font-info-database
1844 The variable @code{ps-font-family} specifies which font family to use
1845 for printing ordinary text. Legitimate values include @code{Courier},
1846 @code{Helvetica}, @code{NewCenturySchlbk}, @code{Palatino} and
1847 @code{Times}. The variable @code{ps-font-size} specifies the size of
1848 the font for ordinary text. It defaults to 8.5 points.
1850 @vindex ps-multibyte-buffer
1851 @cindex Intlfonts for PostScript printing
1852 @cindex fonts for PostScript printing
1853 Emacs supports more scripts and characters than a typical PostScript
1854 printer. Thus, some of the characters in your buffer might not be
1855 printable using the fonts built into your printer. You can augment
1856 the fonts supplied with the printer with those from the GNU Intlfonts
1857 package, or you can instruct Emacs to use Intlfonts exclusively. The
1858 variable @code{ps-multibyte-buffer} controls this: the default value,
1859 @code{nil}, is appropriate for printing @acronym{ASCII} and Latin-1
1860 characters; a value of @code{non-latin-printer} is for printers which
1861 have the fonts for @acronym{ASCII}, Latin-1, Japanese, and Korean
1862 characters built into them. A value of @code{bdf-font} arranges for
1863 the BDF fonts from the Intlfonts package to be used for @emph{all}
1864 characters. Finally, a value of @code{bdf-font-except-latin}
1865 instructs the printer to use built-in fonts for @acronym{ASCII} and Latin-1
1866 characters, and Intlfonts BDF fonts for the rest.
1868 @vindex bdf-directory-list
1869 To be able to use the BDF fonts, Emacs needs to know where to find
1870 them. The variable @code{bdf-directory-list} holds the list of
1871 directories where Emacs should look for the fonts; the default value
1872 includes a single directory @file{/usr/local/share/emacs/fonts/bdf}.
1874 Many other customization variables for these commands are defined and
1875 described in the Lisp files @file{ps-print.el} and @file{ps-mule.el}.
1877 @node Printing Package
1878 @subsection Printing Package
1879 @cindex Printing package
1881 The basic Emacs facilities for printing hardcopy can be extended
1882 using the Printing package. This provides an easy-to-use interface
1883 for choosing what to print, previewing PostScript files before
1884 printing, and setting various printing options such as print headers,
1885 landscape or portrait modes, duplex modes, and so forth. On GNU/Linux
1886 or Unix systems, the Printing package relies on the @file{gs} and
1887 @file{gv} utilities, which are distributed as part of the GhostScript
1888 program. On MS-Windows, the @file{gstools} port of Ghostscript can be
1891 @findex pr-interface
1892 To use the Printing package, add @code{(require 'printing)} to your
1893 init file (@pxref{Init File}), followed by @code{(pr-update-menus)}.
1894 This function replaces the usual printing commands in the menu bar
1895 with a @samp{Printing} submenu that contains various printing options.
1896 You can also type @kbd{M-x pr-interface RET}; this creates a
1897 @file{*Printing Interface*} buffer, similar to a customization buffer,
1898 where you can set the printing options. After selecting what and how
1899 to print, you start the print job using the @samp{Print} button (click
1900 @kbd{mouse-2} on it, or move point over it and type @kbd{RET}). For
1901 further information on the various options, use the @samp{Interface
1905 @section Sorting Text
1908 Emacs provides several commands for sorting text in the buffer. All
1909 operate on the contents of the region.
1910 They divide the text of the region into many @dfn{sort records},
1911 identify a @dfn{sort key} for each record, and then reorder the records
1912 into the order determined by the sort keys. The records are ordered so
1913 that their keys are in alphabetical order, or, for numeric sorting, in
1914 numeric order. In alphabetic sorting, all upper-case letters `A' through
1915 `Z' come before lower-case `a', in accord with the @acronym{ASCII} character
1918 The various sort commands differ in how they divide the text into sort
1919 records and in which part of each record is used as the sort key. Most of
1920 the commands make each line a separate sort record, but some commands use
1921 paragraphs or pages as sort records. Most of the sort commands use each
1922 entire sort record as its own sort key, but some use only a portion of the
1923 record as the sort key.
1926 @findex sort-paragraphs
1929 @findex sort-numeric-fields
1930 @vindex sort-numeric-base
1932 @item M-x sort-lines
1933 Divide the region into lines, and sort by comparing the entire
1934 text of a line. A numeric argument means sort into descending order.
1936 @item M-x sort-paragraphs
1937 Divide the region into paragraphs, and sort by comparing the entire
1938 text of a paragraph (except for leading blank lines). A numeric
1939 argument means sort into descending order.
1941 @item M-x sort-pages
1942 Divide the region into pages, and sort by comparing the entire
1943 text of a page (except for leading blank lines). A numeric
1944 argument means sort into descending order.
1946 @item M-x sort-fields
1947 Divide the region into lines, and sort by comparing the contents of
1948 one field in each line. Fields are defined as separated by
1949 whitespace, so the first run of consecutive non-whitespace characters
1950 in a line constitutes field 1, the second such run constitutes field
1953 Specify which field to sort by with a numeric argument: 1 to sort by
1954 field 1, etc. A negative argument means count fields from the right
1955 instead of from the left; thus, minus 1 means sort by the last field.
1956 If several lines have identical contents in the field being sorted, they
1957 keep the same relative order that they had in the original buffer.
1959 @item M-x sort-numeric-fields
1960 Like @kbd{M-x sort-fields} except the specified field is converted
1961 to an integer for each line, and the numbers are compared. @samp{10}
1962 comes before @samp{2} when considered as text, but after it when
1963 considered as a number. By default, numbers are interpreted according
1964 to @code{sort-numeric-base}, but numbers beginning with @samp{0x} or
1965 @samp{0} are interpreted as hexadecimal and octal, respectively.
1967 @item M-x sort-columns
1968 Like @kbd{M-x sort-fields} except that the text within each line
1969 used for comparison comes from a fixed range of columns. See below
1972 @item M-x reverse-region
1973 Reverse the order of the lines in the region. This is useful for
1974 sorting into descending order by fields or columns, since those sort
1975 commands do not have a feature for doing that.
1978 For example, if the buffer contains this:
1981 On systems where clash detection (locking of files being edited) is
1982 implemented, Emacs also checks the first time you modify a buffer
1983 whether the file has changed on disk since it was last visited or
1984 saved. If it has, you are asked to confirm that you want to change
1989 applying @kbd{M-x sort-lines} to the entire buffer produces this:
1992 On systems where clash detection (locking of files being edited) is
1993 implemented, Emacs also checks the first time you modify a buffer
1994 saved. If it has, you are asked to confirm that you want to change
1996 whether the file has changed on disk since it was last visited or
2000 where the upper-case @samp{O} sorts before all lower-case letters. If
2001 you use @kbd{C-u 2 M-x sort-fields} instead, you get this:
2004 implemented, Emacs also checks the first time you modify a buffer
2005 saved. If it has, you are asked to confirm that you want to change
2007 On systems where clash detection (locking of files being edited) is
2008 whether the file has changed on disk since it was last visited or
2012 where the sort keys were @samp{Emacs}, @samp{If}, @samp{buffer},
2013 @samp{systems} and @samp{the}.
2015 @findex sort-columns
2016 @kbd{M-x sort-columns} requires more explanation. You specify the
2017 columns by putting point at one of the columns and the mark at the other
2018 column. Because this means you cannot put point or the mark at the
2019 beginning of the first line of the text you want to sort, this command
2020 uses an unusual definition of ``region'': all of the line point is in is
2021 considered part of the region, and so is all of the line the mark is in,
2022 as well as all the lines in between.
2024 For example, to sort a table by information found in columns 10 to 15,
2025 you could put the mark on column 10 in the first line of the table, and
2026 point on column 15 in the last line of the table, and then run
2027 @code{sort-columns}. Equivalently, you could run it with the mark on
2028 column 15 in the first line and point on column 10 in the last line.
2030 This can be thought of as sorting the rectangle specified by point and
2031 the mark, except that the text on each line to the left or right of the
2032 rectangle moves along with the text inside the rectangle.
2035 @vindex sort-fold-case
2036 Many of the sort commands ignore case differences when comparing, if
2037 @code{sort-fold-case} is non-@code{nil}.
2039 @c Picture Mode documentation
2041 @include picture-xtra.texi
2045 @node Editing Binary Files
2046 @section Editing Binary Files
2050 @cindex editing binary files
2052 There is a special major mode for editing binary files: Hexl mode. To
2053 use it, use @kbd{M-x hexl-find-file} instead of @kbd{C-x C-f} to visit
2054 the file. This command converts the file's contents to hexadecimal and
2055 lets you edit the translation. When you save the file, it is converted
2056 automatically back to binary.
2058 You can also use @kbd{M-x hexl-mode} to translate an existing buffer
2059 into hex. This is useful if you visit a file normally and then discover
2060 it is a binary file.
2062 Ordinary text characters overwrite in Hexl mode. This is to reduce
2063 the risk of accidentally spoiling the alignment of data in the file.
2064 There are special commands for insertion. Here is a list of the
2065 commands of Hexl mode:
2067 @c I don't think individual index entries for these commands are useful--RMS.
2070 Insert a byte with a code typed in decimal.
2073 Insert a byte with a code typed in octal.
2076 Insert a byte with a code typed in hex.
2079 Move to the beginning of a 1k-byte ``page''.
2082 Move to the end of a 1k-byte ``page''.
2085 Move to an address specified in hex.
2088 Move to an address specified in decimal.
2091 Leave Hexl mode, going back to the major mode this buffer had before you
2092 invoked @code{hexl-mode}.
2096 Other Hexl commands let you insert strings (sequences) of binary
2097 bytes, move by @code{short}s or @code{int}s, etc.; type @kbd{C-h a
2098 hexl-@key{RET}} for details.
2101 @node Saving Emacs Sessions
2102 @section Saving Emacs Sessions
2103 @cindex saving sessions
2104 @cindex restore session
2105 @cindex remember editing session
2106 @cindex reload files
2109 Use the desktop library to save the state of Emacs from one session
2110 to another. Once you save the Emacs @dfn{desktop}---the buffers,
2111 their file names, major modes, buffer positions, and so on---then
2112 subsequent Emacs sessions reload the saved desktop.
2114 @findex desktop-save
2115 @vindex desktop-save-mode
2116 You can save the desktop manually with the command @kbd{M-x
2117 desktop-save}. You can also enable automatic saving of the desktop
2118 when you exit Emacs, and automatic restoration of the last saved
2119 desktop when Emacs starts: use the Customization buffer (@pxref{Easy
2120 Customization}) to set @code{desktop-save-mode} to @code{t} for future
2121 sessions, or add this line in your init file (@pxref{Init File}):
2124 (desktop-save-mode 1)
2127 @findex desktop-change-dir
2128 @findex desktop-revert
2129 @vindex desktop-path
2130 If you turn on @code{desktop-save-mode} in your init file, then when
2131 Emacs starts, it looks for a saved desktop in the current directory.
2132 (More precisely, it looks in the directories specified by
2133 @var{desktop-path}, and uses the first desktop it finds.)
2134 Thus, you can have separate saved desktops in different directories,
2135 and the starting directory determines which one Emacs reloads. You
2136 can save the current desktop and reload one saved in another directory
2137 by typing @kbd{M-x desktop-change-dir}. Typing @kbd{M-x
2138 desktop-revert} reverts to the desktop previously reloaded.
2140 Specify the option @samp{--no-desktop} on the command line when you
2141 don't want it to reload any saved desktop. This turns off
2142 @code{desktop-save-mode} for the current session. Starting Emacs with
2143 the @samp{--no-init-file} option also disables desktop reloading,
2144 since it bypasses the init file, where @code{desktop-save-mode} is
2147 @vindex desktop-restore-eager
2148 By default, all the buffers in the desktop are restored at one go.
2149 However, this may be slow if there are a lot of buffers in the
2150 desktop. You can specify the maximum number of buffers to restore
2151 immediately with the variable @code{desktop-restore-eager}; the
2152 remaining buffers are restored ``lazily'', when Emacs is idle.
2154 @findex desktop-clear
2155 @vindex desktop-globals-to-clear
2156 @vindex desktop-clear-preserve-buffers-regexp
2157 Type @kbd{M-x desktop-clear} to empty the Emacs desktop. This kills
2158 all buffers except for internal ones, and clears the global variables
2159 listed in @code{desktop-globals-to-clear}. If you want this to
2160 preserve certain buffers, customize the variable
2161 @code{desktop-clear-preserve-buffers-regexp}, whose value is a regular
2162 expression matching the names of buffers not to kill.
2164 If you want to save minibuffer history from one session to
2165 another, use the @code{savehist} library.
2167 @node Recursive Edit
2168 @section Recursive Editing Levels
2169 @cindex recursive editing level
2170 @cindex editing level, recursive
2172 A @dfn{recursive edit} is a situation in which you are using Emacs
2173 commands to perform arbitrary editing while in the middle of another
2174 Emacs command. For example, when you type @kbd{C-r} inside of a
2175 @code{query-replace}, you enter a recursive edit in which you can change
2176 the current buffer. On exiting from the recursive edit, you go back to
2177 the @code{query-replace}.
2180 @findex exit-recursive-edit
2181 @cindex exiting recursive edit
2182 @dfn{Exiting} the recursive edit means returning to the unfinished
2183 command, which continues execution. The command to exit is @kbd{C-M-c}
2184 (@code{exit-recursive-edit}).
2186 You can also @dfn{abort} the recursive edit. This is like exiting,
2187 but also quits the unfinished command immediately. Use the command
2188 @kbd{C-]} (@code{abort-recursive-edit}) to do this. @xref{Quitting}.
2190 The mode line shows you when you are in a recursive edit by displaying
2191 square brackets around the parentheses that always surround the major and
2192 minor mode names. Every window's mode line shows this in the same way,
2193 since being in a recursive edit is true of Emacs as a whole rather than
2194 any particular window or buffer.
2196 It is possible to be in recursive edits within recursive edits. For
2197 example, after typing @kbd{C-r} in a @code{query-replace}, you may type a
2198 command that enters the debugger. This begins a recursive editing level
2199 for the debugger, within the recursive editing level for @kbd{C-r}.
2200 Mode lines display a pair of square brackets for each recursive editing
2201 level currently in progress.
2203 Exiting the inner recursive edit (such as with the debugger @kbd{c}
2204 command) resumes the command running in the next level up. When that
2205 command finishes, you can then use @kbd{C-M-c} to exit another recursive
2206 editing level, and so on. Exiting applies to the innermost level only.
2207 Aborting also gets out of only one level of recursive edit; it returns
2208 immediately to the command level of the previous recursive edit. If you
2209 wish, you can then abort the next recursive editing level.
2211 Alternatively, the command @kbd{M-x top-level} aborts all levels of
2212 recursive edits, returning immediately to the top-level command
2213 reader. It also exits the minibuffer, if it is active.
2215 The text being edited inside the recursive edit need not be the same text
2216 that you were editing at top level. It depends on what the recursive edit
2217 is for. If the command that invokes the recursive edit selects a different
2218 buffer first, that is the buffer you will edit recursively. In any case,
2219 you can switch buffers within the recursive edit in the normal manner (as
2220 long as the buffer-switching keys have not been rebound). You could
2221 probably do all the rest of your editing inside the recursive edit,
2222 visiting files and all. But this could have surprising effects (such as
2223 stack overflow) from time to time. So remember to exit or abort the
2224 recursive edit when you no longer need it.
2226 In general, we try to minimize the use of recursive editing levels in
2227 GNU Emacs. This is because they constrain you to ``go back'' in a
2228 particular order---from the innermost level toward the top level. When
2229 possible, we present different activities in separate buffers so that
2230 you can switch between them as you please. Some commands switch to a
2231 new major mode which provides a command to switch back. These
2232 approaches give you more flexibility to go back to unfinished tasks in
2233 the order you choose.
2237 @cindex emulating other editors
2238 @cindex other editors
2241 @cindex PC key bindings
2242 @cindex scrolling all windows
2243 @cindex PC selection
2244 @cindex Motif key bindings
2245 @cindex Macintosh key bindings
2248 GNU Emacs can be programmed to emulate (more or less) most other
2249 editors. Standard facilities can emulate these:
2252 @item CRiSP/Brief (PC editor)
2254 @vindex crisp-override-meta-x
2255 @findex scroll-all-mode
2257 @cindex Brief emulation
2258 @cindex emulation of Brief
2260 You can turn on key bindings to emulate the CRiSP/Brief editor with
2261 @kbd{M-x crisp-mode}. Note that this rebinds @kbd{M-x} to exit Emacs
2262 unless you set the variable @code{crisp-override-meta-x}. You can
2263 also use the command @kbd{M-x scroll-all-mode} or set the variable
2264 @code{crisp-load-scroll-all} to emulate CRiSP's scroll-all feature
2265 (scrolling all windows together).
2267 @item EDT (DEC VMS editor)
2268 @findex edt-emulation-on
2269 @findex edt-emulation-off
2270 Turn on EDT emulation @kbd{M-x edt-emulation-on}; use @kbd{M-x
2271 edt-emulation-off} to restore normal Emacs command bindings.
2273 Most of the EDT emulation commands are keypad keys, and most standard
2274 Emacs key bindings are still available. The EDT emulation rebindings
2275 are done in the global keymap, so there is no problem switching
2276 buffers or major modes while in EDT emulation.
2278 @item TPU (DEC VMS editor)
2281 @kbd{M-x tpu-edt-on} turns on emulation of the TPU editor emulating EDT.
2283 @item vi (Berkeley editor)
2285 Viper is the newest emulator for vi. It implements several levels of
2286 emulation; level 1 is closest to vi itself, while level 5 departs
2287 somewhat from strict emulation to take advantage of the capabilities of
2288 Emacs. To invoke Viper, type @kbd{M-x viper-mode}; it will guide you
2289 the rest of the way and ask for the emulation level. @inforef{Top,
2292 @item vi (another emulator)
2294 @kbd{M-x vi-mode} enters a major mode that replaces the previously
2295 established major mode. All of the vi commands that, in real vi, enter
2296 ``input'' mode are programmed instead to return to the previous major
2297 mode. Thus, ordinary Emacs serves as vi's ``input'' mode.
2299 Because vi emulation works through major modes, it does not work
2300 to switch buffers during emulation. Return to normal Emacs first.
2302 If you plan to use vi emulation much, you probably want to bind a key
2303 to the @code{vi-mode} command.
2305 @item vi (alternate emulator)
2307 @kbd{M-x vip-mode} invokes another vi emulator, said to resemble real vi
2308 more thoroughly than @kbd{M-x vi-mode}. ``Input'' mode in this emulator
2309 is changed from ordinary Emacs so you can use @key{ESC} to go back to
2310 emulated vi command mode. To get from emulated vi command mode back to
2311 ordinary Emacs, type @kbd{C-z}.
2313 This emulation does not work through major modes, and it is possible
2314 to switch buffers in various ways within the emulator. It is not
2315 so necessary to assign a key to the command @code{vip-mode} as
2316 it is with @code{vi-mode} because terminating insert mode does
2319 @inforef{Top, VIP, vip}, for full information.
2321 @item WordStar (old wordprocessor)
2322 @findex wordstar-mode
2323 @kbd{M-x wordstar-mode} provides a major mode with WordStar-like
2328 @section Hyperlinking and Navigation Features
2330 The following subsections describe convenience features for handling
2331 URLs and other types of links occurring in Emacs buffer text.
2334 * Browse-URL:: Following URLs.
2335 * Goto Address mode:: Activating URLs.
2336 * FFAP:: Finding files etc. at point.
2340 @subsection Following URLs
2341 @cindex World Wide Web
2344 @findex browse-url-at-point
2345 @findex browse-url-at-mouse
2350 @item M-x browse-url @key{RET} @var{url} @key{RET}
2351 Load a URL into a Web browser.
2354 The Browse-URL package allows you to easily follow URLs from within
2355 Emacs. Most URLs are followed by invoking a web browser;
2356 @samp{mailto:} URLs are followed by invoking the @code{compose-mail}
2357 Emacs command to send mail to the specified address (@pxref{Sending
2360 The command @kbd{M-x browse-url} prompts for a URL, and follows it.
2361 If point is located near a plausible URL, that URL is offered as the
2362 default. The Browse-URL package also provides other commands which
2363 you might like to bind to keys, such as @code{browse-url-at-point} and
2364 @code{browse-url-at-mouse}.
2366 @vindex browse-url-mailto-function
2367 @vindex browse-url-browser-function
2368 You can customize Browse-URL's behavior via various options in the
2369 @code{browse-url} Customize group. In particular, the option
2370 @code{browse-url-mailto-function} lets you define how to follow
2371 @samp{mailto:} URLs, while @code{browse-url-browser-function} lets you
2372 define how to follow other types of URLs. For more information, view
2373 the package commentary by typing @kbd{C-h P browse-url @key{RET}}.
2375 @node Goto Address mode
2376 @subsection Activating URLs
2377 @findex goto-address-mode
2378 @cindex mode, Goto Address
2379 @cindex Goto Address mode
2380 @cindex URLs, activating
2383 @item M-x goto-address-mode
2384 Activate URLs and e-mail addresses in the current buffer.
2387 @kindex C-c RET @r{(Goto Address mode)}
2388 @findex goto-address-at-point
2389 You can make Emacs mark out URLs specially in the current buffer, by
2390 typing @kbd{M-x goto-address-mode}. When this buffer-local minor mode
2391 is enabled, it finds all the URLs in the buffer, highlights them, and
2392 turns them into clickable buttons. You can follow the URL by typing
2393 @kbd{C-c @key{RET}} (@code{goto-address-at-point}) while point is on
2394 its text; or by clicking with @kbd{Mouse-2}, or by clicking
2395 @kbd{Mouse-1} quickly (@pxref{Mouse References}). Following a URL is
2396 done by calling @code{browse-url} as a subroutine
2397 (@pxref{Browse-URL}).
2399 It can be useful to add @code{goto-address-mode} to mode hooks and
2400 hooks for displaying an incoming message
2401 (e.g.@: @code{rmail-show-message-hook} for Rmail, and
2402 @code{mh-show-mode-hook} for MH-E). This is not needed for Gnus,
2403 which has a similar feature of its own.
2406 @subsection Finding Files and URLs at Point
2407 @findex find-file-at-point
2409 @findex dired-at-point
2412 @cindex finding file at point
2414 The FFAP package replaces certain key bindings for finding files,
2415 such as @kbd{C-x C-f}, with commands that provide more sensitive
2416 defaults. These commands behave like the ordinary ones when given a
2417 prefix argument. Otherwise, they get the default file name or URL
2418 from the text around point. If what is found in the buffer has the
2419 form of a URL rather than a file name, the commands use
2420 @code{browse-url} to view it (@pxref{Browse-URL}).
2422 This feature is useful for following references in mail or news
2423 buffers, @file{README} files, @file{MANIFEST} files, and so on. For
2424 more information, view the package commentary by typing @kbd{C-h P
2427 @cindex FFAP minor mode
2429 To enable FFAP, type @kbd{M-x ffap-bindings}. This makes the
2430 following key bindings, and also installs hooks for additional FFAP
2431 functionality in Rmail, Gnus and VM article buffers.
2434 @item C-x C-f @var{filename} @key{RET}
2435 @kindex C-x C-f @r{(FFAP)}
2436 Find @var{filename}, guessing a default from text around point
2437 (@code{find-file-at-point}).
2439 @kindex C-x C-r @r{(FFAP)}
2440 @code{ffap-read-only}, analogous to @code{find-file-read-only}.
2442 @kindex C-x C-v @r{(FFAP)}
2443 @code{ffap-alternate-file}, analogous to @code{find-alternate-file}.
2444 @item C-x d @var{directory} @key{RET}
2445 @kindex C-x d @r{(FFAP)}
2446 Start Dired on @var{directory}, defaulting to the directory name at
2447 point (@code{dired-at-point}).
2449 @code{ffap-list-directory}, analogous to @code{list-directory}.
2451 @kindex C-x 4 f @r{(FFAP)}
2452 @code{ffap-other-window}, analogous to @code{find-file-other-window}.
2454 @code{ffap-read-only-other-window}, analogous to
2455 @code{find-file-read-only-other-window}.
2457 @code{ffap-dired-other-window}, analogous to @code{dired-other-window}.
2459 @kindex C-x 5 f @r{(FFAP)}
2460 @code{ffap-other-frame}, analogous to @code{find-file-other-frame}.
2462 @code{ffap-read-only-other-frame}, analogous to
2463 @code{find-file-read-only-other-frame}.
2465 @code{ffap-dired-other-frame}, analogous to @code{dired-other-frame}.
2467 Search buffer for next file name or URL, then find that file or URL.
2469 @kindex S-Mouse-3 @r{(FFAP)}
2470 @code{ffap-at-mouse} finds the file guessed from text around the position
2473 @kindex C-S-Mouse-3 @r{(FFAP)}
2474 Display a menu of files and URLs mentioned in current buffer, then
2475 find the one you select (@code{ffap-menu}).
2479 @section Other Amusements
2482 @findex animate-birthday-present
2484 The @code{animate} package makes text dance (e.g. try
2485 @kbd{M-x animate-birthday-present}).
2491 @kbd{M-x blackbox}, @kbd{M-x mpuz} and @kbd{M-x 5x5} are puzzles.
2492 @code{blackbox} challenges you to determine the location of objects
2493 inside a box by tomography. @code{mpuz} displays a multiplication
2494 puzzle with letters standing for digits in a code that you must
2495 guess---to guess a value, type a letter and then the digit you think it
2496 stands for. The aim of @code{5x5} is to fill in all the squares.
2499 @kbd{M-x bubbles} is a game in which the object is to remove as many
2500 bubbles as you can in the smallest number of moves.
2504 @cindex cryptanalysis
2505 @kbd{M-x decipher} helps you to cryptanalyze a buffer which is
2506 encrypted in a simple monoalphabetic substitution cipher.
2508 @findex dissociated-press
2509 @kbd{M-x dissociated-press} scrambles the text in the current Emacs
2510 buffer, word by word or character by character, writing its output to
2511 a buffer named @file{*Dissociation*}. A positive argument tells it to
2512 operate character by character, and specifies the number of overlap
2513 characters. A negative argument tells it to operate word by word, and
2514 specifies the number of overlap words. Dissociated Press produces
2515 results fairly like those of a Markov chain, but is however, an
2516 independent, ignoriginal invention; it techniquitously copies several
2517 consecutive characters from the sample text between random jumps,
2518 unlike a Markov chain which would jump randomly after each word or
2519 character. Keep dissociwords out of your documentation, if you want
2520 it to be well userenced and properbose.
2523 @kbd{M-x dunnet} runs an text-based adventure game.
2527 If you want a little more personal involvement, try @kbd{M-x gomoku},
2528 which plays the game Go Moku with you.
2530 @cindex tower of Hanoi
2532 If you are a little bit bored, you can try @kbd{M-x hanoi}. If you are
2533 considerably bored, give it a numeric argument. If you are very, very
2534 bored, try an argument of 9. Sit back and watch.
2538 @kbd{M-x life} runs Conway's ``Life'' cellular automaton.
2541 @cindex landmark game
2542 @kbd{M-x landmark} runs a relatively non-participatory game in which
2543 a robot attempts to maneuver towards a tree at the center of the
2544 window based on unique olfactory cues from each of the four
2547 @findex morse-region
2548 @findex unmorse-region
2551 @cindex --/---/.-./.../.
2552 @kbd{M-x morse-region} converts the text in the region to Morse
2553 code; @kbd{M-x unmorse-region} converts it back. @kbd{M-x
2554 nato-region} converts the text in the region to NATO phonetic
2555 alphabet; @kbd{M-x denato-region} converts it back.
2563 @kbd{M-x pong}, @kbd{M-x snake} and @kbd{M-x tetris} are
2564 implementations of the well-known Pong, Snake and Tetris games.
2568 @kbd{M-x solitaire} plays a game of solitaire in which you jump pegs
2572 The command @kbd{M-x zone} plays games with the display when Emacs
2577 Finally, if you find yourself frustrated, try describing your
2578 problems to the famous psychotherapist Eliza. Just do @kbd{M-x
2579 doctor}. End each input by typing @key{RET} twice.