1 @c This is part of the Emacs manual.
2 @c Copyright (C) 1985-1987, 1993-1995, 1997, 2000-2014 Free Software
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 The most convenient way is to set the optimal slice by using
415 BoundingBox information automatically determined from the document by
416 typing @kbd{s b} (@code{doc-view-set-slice-using-mouse}).
418 @findex doc-view-reset-slice
419 To cancel the selected slice, type @kbd{s r}
420 (@code{doc-view-reset-slice}). Then DocView shows the entire page
421 including its entire margins.
423 @node DocView Conversion
424 @subsection DocView Conversion
426 @vindex doc-view-cache-directory
427 @findex doc-view-clear-cache
428 For efficiency, DocView caches the images produced by @command{gs}.
429 The name of this directory is given by the variable
430 @code{doc-view-cache-directory}. You can clear the cache directory by
431 typing @code{M-x doc-view-clear-cache}.
433 @findex doc-view-kill-proc
434 @findex doc-view-kill-proc-and-buffer
435 To force reconversion of the currently viewed document, type @kbd{r}
436 or @kbd{g} (@code{revert-buffer}). To kill the converter process
437 associated with the current buffer, type @kbd{K}
438 (@code{doc-view-kill-proc}). The command @kbd{k}
439 (@code{doc-view-kill-proc-and-buffer}) kills the converter process and
443 @section Web Browsing with EWW
446 @findex eww-open-file
447 @dfn{EWW}, the Emacs Web Wowser, is a web browser package for Emacs.
448 It allows browsing URLs within an Emacs buffer. The command @kbd{M-x
449 eww} will open a URL or search the web. You can open a file
450 using the command @kbd{M-x eww-open-file}. You can use EWW as the
451 web browser for @code{browse-url}, @pxref{Browse-URL}. For full
452 details, @pxref{Top, EWW,, eww, The Emacs Web Wowser Manual}.
455 @section Running Shell Commands from Emacs
457 @cindex shell commands
459 Emacs has commands for passing single command lines to shell
460 subprocesses, and for running a shell interactively with input and
461 output to an Emacs buffer, and for running a shell in a terminal
465 @item M-! @var{cmd} @key{RET}
466 Run the shell command @var{cmd} and display the output
467 (@code{shell-command}).
468 @item M-| @var{cmd} @key{RET}
469 Run the shell command @var{cmd} with region contents as input;
470 optionally replace the region with the output
471 (@code{shell-command-on-region}).
472 @item M-& @var{cmd} @key{RET}
473 Run the shell command @var{cmd} asynchronously, and display the output
474 (@code{async-shell-command}).
476 Run a subshell with input and output through an Emacs buffer. You can
477 then give commands interactively.
479 Run a subshell with input and output through an Emacs buffer. You can
480 then give commands interactively. Full terminal emulation is
485 Whenever you specify a relative file name for an executable program
486 (either in the @var{cmd} argument to one of the above commands, or in
487 other contexts), Emacs searches for the program in the directories
488 specified by the variable @code{exec-path}. The value of this
489 variable must be a list of directory names; the default value is
490 initialized from the environment variable @env{PATH} when Emacs is
491 started (@pxref{General Variables}).
493 @kbd{M-x eshell} invokes a shell implemented entirely in Emacs. It
494 is documented in its own manual.
496 @xref{Top,Eshell,Eshell, eshell, Eshell: The Emacs Shell}.
499 See the Eshell Info manual, which is distributed with Emacs.
503 * Single Shell:: How to run one shell command and return.
504 * Interactive Shell:: Permanent shell taking input via Emacs.
505 * Shell Mode:: Special Emacs commands used with permanent shell.
506 * Shell Prompts:: Two ways to recognize shell prompts.
507 * History: Shell History. Repeating previous commands in a shell buffer.
508 * Directory Tracking:: Keeping track when the subshell changes directory.
509 * Options: Shell Options. Options for customizing Shell mode.
510 * Terminal emulator:: An Emacs window as a terminal emulator.
511 * Term Mode:: Special Emacs commands used in Term mode.
512 * Remote Host:: Connecting to another computer.
513 * Serial Terminal:: Connecting to a serial port.
517 @subsection Single Shell Commands
520 @findex shell-command
521 @kbd{M-!} (@code{shell-command}) reads a line of text using the
522 minibuffer and executes it as a shell command, in a subshell made just
523 for that command. Standard input for the command comes from the null
524 device. If the shell command produces any output, the output appears
525 either in the echo area (if it is short), or in an Emacs buffer named
526 @file{*Shell Command Output*}, displayed in another window (if the
529 For instance, one way to decompress a file named @file{foo.gz} is to
530 type @kbd{M-! gunzip foo.gz @key{RET}}. That shell command normally
531 creates the file @file{foo} and produces no terminal output.
533 A numeric argument to @code{shell-command}, e.g., @kbd{M-1 M-!},
534 causes it to insert terminal output into the current buffer instead of
535 a separate buffer. It puts point before the output, and sets the mark
536 after the output. For instance, @kbd{M-1 M-! gunzip < foo.gz
537 @key{RET}} would insert the uncompressed form of the file
538 @file{foo.gz} into the current buffer.
540 Provided the specified shell command does not end with @samp{&}, it
541 runs @dfn{synchronously}, and you must wait for it to exit before
542 continuing to use Emacs. To stop waiting, type @kbd{C-g} to quit;
543 this sends a @code{SIGINT} signal to terminate the shell command (this
544 is the same signal that @kbd{C-c} normally generates in the shell).
545 Emacs then waits until the command actually terminates. If the shell
546 command doesn't stop (because it ignores the @code{SIGINT} signal),
547 type @kbd{C-g} again; this sends the command a @code{SIGKILL} signal,
548 which is impossible to ignore.
551 @findex async-shell-command
552 A shell command that ends in @samp{&} is executed
553 @dfn{asynchronously}, and you can continue to use Emacs as it runs.
554 You can also type @kbd{M-&} (@code{async-shell-command}) to execute a
555 shell command asynchronously; this is exactly like calling @kbd{M-!}
556 with a trailing @samp{&}, except that you do not need the @samp{&}.
557 The default output buffer for asynchronous shell commands is named
558 @samp{*Async Shell Command*}. Emacs inserts the output into this
559 buffer as it comes in, whether or not the buffer is visible in a
562 @vindex async-shell-command-buffer
563 If you want to run more than one asynchronous shell command at the
564 same time, they could end up competing for the output buffer. The
565 option @code{async-shell-command-buffer} specifies what to do about
566 this; e.g., whether to rename the pre-existing output buffer, or to
567 use a different buffer for the new command. Consult the variable's
568 documentation for more possibilities.
571 @findex shell-command-on-region
572 @kbd{M-|} (@code{shell-command-on-region}) is like @kbd{M-!}, but
573 passes the contents of the region as the standard input to the shell
574 command, instead of no input. With a numeric argument, it deletes the
575 old region and replaces it with the output from the shell command.
577 For example, you can use @kbd{M-|} with the @command{gpg} program to
578 see what keys are in the buffer. If the buffer contains a GnuPG key,
579 type @kbd{C-x h M-| gpg @key{RET}} to feed the entire buffer contents
580 to @command{gpg}. This will output the list of keys to the
581 @file{*Shell Command Output*} buffer.
583 @vindex shell-file-name
584 The above commands use the shell specified by the variable
585 @code{shell-file-name}. Its default value is determined by the
586 @env{SHELL} environment variable when Emacs is started. If the file
587 name is relative, Emacs searches the directories listed in
588 @code{exec-path} (@pxref{Shell}).
590 To specify a coding system for @kbd{M-!} or @kbd{M-|}, use the command
591 @kbd{C-x @key{RET} c} immediately beforehand. @xref{Communication Coding}.
593 @vindex shell-command-default-error-buffer
594 By default, error output is intermixed with the regular output in
595 the output buffer. But if you change the value of the variable
596 @code{shell-command-default-error-buffer} to a string, error output is
597 inserted into a buffer of that name.
599 @node Interactive Shell
600 @subsection Interactive Subshell
603 To run a subshell interactively, type @kbd{M-x shell}. This creates
604 (or reuses) a buffer named @file{*shell*}, and runs a shell subprocess
605 with input coming from and output going to that buffer. That is to
606 say, any terminal output from the subshell goes into the buffer,
607 advancing point, and any terminal input for the subshell comes from
608 text in the buffer. To give input to the subshell, go to the end of
609 the buffer and type the input, terminated by @key{RET}.
611 While the subshell is waiting or running a command, you can switch
612 windows or buffers and perform other editing in Emacs. Emacs inserts
613 the output from the subshell into the Shell buffer whenever it has
614 time to process it (e.g., while waiting for keyboard input).
616 @cindex @code{comint-highlight-input} face
617 @cindex @code{comint-highlight-prompt} face
618 In the Shell buffer, prompts are displayed with the face
619 @code{comint-highlight-prompt}, and submitted input lines are
620 displayed with the face @code{comint-highlight-input}. This makes it
621 easier to distinguish input lines from the shell output.
624 To make multiple subshells, invoke @kbd{M-x shell} with a prefix
625 argument (e.g., @kbd{C-u M-x shell}). Then the command will read a
626 buffer name, and create (or reuse) a subshell in that buffer. You can
627 also rename the @file{*shell*} buffer using @kbd{M-x rename-uniquely},
628 then create a new @file{*shell*} buffer using plain @kbd{M-x shell}.
629 Subshells in different buffers run independently and in parallel.
631 @vindex explicit-shell-file-name
632 @cindex environment variables for subshells
633 @cindex @env{ESHELL} environment variable
634 @cindex @env{SHELL} environment variable
635 To specify the shell file name used by @kbd{M-x shell}, customize
636 the variable @code{explicit-shell-file-name}. If this is @code{nil}
637 (the default), Emacs uses the environment variable @env{ESHELL} if it
638 exists. Otherwise, it usually uses the variable
639 @code{shell-file-name} (@pxref{Single Shell}); but if the default
640 directory is remote (@pxref{Remote Files}), it prompts you for the
643 Emacs sends the new shell the contents of the file
644 @file{~/.emacs_@var{shellname}} as input, if it exists, where
645 @var{shellname} is the name of the file that the shell was loaded
646 from. For example, if you use bash, the file sent to it is
647 @file{~/.emacs_bash}. If this file is not found, Emacs tries with
648 @file{~/.emacs.d/init_@var{shellname}.sh}.
650 To specify a coding system for the shell, you can use the command
651 @kbd{C-x @key{RET} c} immediately before @kbd{M-x shell}. You can
652 also change the coding system for a running subshell by typing
653 @kbd{C-x @key{RET} p} in the shell buffer. @xref{Communication
656 @cindex @env{INSIDE_EMACS} environment variable
657 @cindex @env{EMACS} environment variable
658 Emacs sets the environment variable @env{INSIDE_EMACS} in the
659 subshell to @samp{@var{version},comint}, where @var{version} is the
660 Emacs version (e.g., @samp{24.1}). Programs can check this variable
661 to determine whether they are running inside an Emacs subshell. (It
662 also sets the @env{EMACS} environment variable to @code{t}, if that
663 environment variable is not already defined. However, this
664 environment variable is deprecated; programs that use it should switch
665 to using @env{INSIDE_EMACS} instead.)
668 @subsection Shell Mode
672 The major mode for Shell buffers is Shell mode. Many of its special
673 commands are bound to the @kbd{C-c} prefix, and resemble the usual
674 editing and job control characters present in ordinary shells, except
675 that you must type @kbd{C-c} first. Here is a list of Shell mode
680 @kindex RET @r{(Shell mode)}
681 @findex comint-send-input
682 Send the current line as input to the subshell
683 (@code{comint-send-input}). Any shell prompt at the beginning of the
684 line is omitted (@pxref{Shell Prompts}). If point is at the end of
685 buffer, this is like submitting the command line in an ordinary
686 interactive shell. However, you can also invoke @key{RET} elsewhere
687 in the shell buffer to submit the current line as input.
690 @kindex TAB @r{(Shell mode)}
691 @findex completion-at-point
692 @cindex shell completion
693 Complete the command name or file name before point in the shell
694 buffer (@code{completion-at-point}). This uses the usual Emacs
695 completion rules (@pxref{Completion}), with the completion
696 alternatives being file names, environment variable names, the shell
697 command history, and history references (@pxref{History References}).
698 For options controlling the completion, @pxref{Shell Options}.
701 @kindex M-? @r{(Shell mode)}
702 @findex comint-dynamic-list-filename@dots{}
703 Display temporarily a list of the possible completions of the file
704 name before point (@code{comint-dynamic-list-filename-completions}).
707 @kindex C-d @r{(Shell mode)}
708 @findex comint-delchar-or-maybe-eof
709 Either delete a character or send @acronym{EOF}
710 (@code{comint-delchar-or-maybe-eof}). Typed at the end of the shell
711 buffer, this sends @acronym{EOF} to the subshell. Typed at any other
712 position in the buffer, this deletes a character as usual.
715 @kindex C-c C-a @r{(Shell mode)}
716 @findex comint-bol-or-process-mark
717 Move to the beginning of the line, but after the prompt if any
718 (@code{comint-bol-or-process-mark}). If you repeat this command twice
719 in a row, the second time it moves back to the process mark, which is
720 the beginning of the input that you have not yet sent to the subshell.
721 (Normally that is the same place---the end of the prompt on this
722 line---but after @kbd{C-c @key{SPC}} the process mark may be in a
726 Accumulate multiple lines of input, then send them together. This
727 command inserts a newline before point, but does not send the preceding
728 text as input to the subshell---at least, not yet. Both lines, the one
729 before this newline and the one after, will be sent together (along with
730 the newline that separates them), when you type @key{RET}.
733 @kindex C-c C-u @r{(Shell mode)}
734 @findex comint-kill-input
735 Kill all text pending at end of buffer to be sent as input
736 (@code{comint-kill-input}). If point is not at end of buffer,
737 this only kills the part of this text that precedes point.
740 @kindex C-c C-w @r{(Shell mode)}
741 Kill a word before point (@code{backward-kill-word}).
744 @kindex C-c C-c @r{(Shell mode)}
745 @findex comint-interrupt-subjob
746 Interrupt the shell or its current subjob if any
747 (@code{comint-interrupt-subjob}). This command also kills
748 any shell input pending in the shell buffer and not yet sent.
751 @kindex C-c C-z @r{(Shell mode)}
752 @findex comint-stop-subjob
753 Stop the shell or its current subjob if any (@code{comint-stop-subjob}).
754 This command also kills any shell input pending in the shell buffer and
758 @findex comint-quit-subjob
759 @kindex C-c C-\ @r{(Shell mode)}
760 Send quit signal to the shell or its current subjob if any
761 (@code{comint-quit-subjob}). This command also kills any shell input
762 pending in the shell buffer and not yet sent.
765 @kindex C-c C-o @r{(Shell mode)}
766 @findex comint-delete-output
767 Delete the last batch of output from a shell command
768 (@code{comint-delete-output}). This is useful if a shell command spews
769 out lots of output that just gets in the way.
772 @kindex C-c C-s @r{(Shell mode)}
773 @findex comint-write-output
774 Write the last batch of output from a shell command to a file
775 (@code{comint-write-output}). With a prefix argument, the file is
776 appended to instead. Any prompt at the end of the output is not
781 @kindex C-c C-r @r{(Shell mode)}
782 @kindex C-M-l @r{(Shell mode)}
783 @findex comint-show-output
784 Scroll to display the beginning of the last batch of output at the top
785 of the window; also move the cursor there (@code{comint-show-output}).
788 @kindex C-c C-e @r{(Shell mode)}
789 @findex comint-show-maximum-output
790 Scroll to put the end of the buffer at the bottom of the window
791 (@code{comint-show-maximum-output}).
794 @kindex C-c C-f @r{(Shell mode)}
795 @findex shell-forward-command
796 @vindex shell-command-regexp
797 Move forward across one shell command, but not beyond the current line
798 (@code{shell-forward-command}). The variable @code{shell-command-regexp}
799 specifies how to recognize the end of a command.
802 @kindex C-c C-b @r{(Shell mode)}
803 @findex shell-backward-command
804 Move backward across one shell command, but not beyond the current line
805 (@code{shell-backward-command}).
808 Ask the shell for its working directory, and update the Shell buffer's
809 default directory. @xref{Directory Tracking}.
811 @item M-x send-invisible @key{RET} @var{text} @key{RET}
812 @findex send-invisible
813 Send @var{text} as input to the shell, after reading it without
814 echoing. This is useful when a shell command runs a program that asks
817 Please note that Emacs will not echo passwords by default. If you
818 really want them to be echoed, evaluate (@pxref{Lisp Eval}) the
819 following Lisp expression:
822 (remove-hook 'comint-output-filter-functions
823 'comint-watch-for-password-prompt)
826 @item M-x comint-continue-subjob
827 @findex comint-continue-subjob
828 Continue the shell process. This is useful if you accidentally suspend
829 the shell process.@footnote{You should not suspend the shell process.
830 Suspending a subjob of the shell is a completely different matter---that
831 is normal practice, but you must use the shell to continue the subjob;
832 this command won't do it.}
834 @item M-x comint-strip-ctrl-m
835 @findex comint-strip-ctrl-m
836 Discard all control-M characters from the current group of shell output.
837 The most convenient way to use this command is to make it run
838 automatically when you get output from the subshell. To do that,
839 evaluate this Lisp expression:
842 (add-hook 'comint-output-filter-functions
843 'comint-strip-ctrl-m)
846 @item M-x comint-truncate-buffer
847 @findex comint-truncate-buffer
848 This command truncates the shell buffer to a certain maximum number of
849 lines, specified by the variable @code{comint-buffer-maximum-size}.
850 Here's how to do this automatically each time you get output from the
854 (add-hook 'comint-output-filter-functions
855 'comint-truncate-buffer)
861 Shell mode is a derivative of Comint mode, a general-purpose mode for
862 communicating with interactive subprocesses. Most of the features of
863 Shell mode actually come from Comint mode, as you can see from the
864 command names listed above. The special features of Shell mode include
865 the directory tracking feature, and a few user commands.
867 Other Emacs features that use variants of Comint mode include GUD
868 (@pxref{Debuggers}) and @kbd{M-x run-lisp} (@pxref{External Lisp}).
871 You can use @kbd{M-x comint-run} to execute any program of your choice
872 in a subprocess using unmodified Comint mode---without the
873 specializations of Shell mode.
876 @subsection Shell Prompts
878 @cindex prompt, shell
879 A prompt is text output by a program to show that it is ready to
880 accept new user input. Normally, Comint mode (and thus Shell mode)
881 automatically figures out part of the buffer is a prompt, based on the
882 output of the subprocess. (Specifically, it assumes that any received
883 output line which doesn't end with a newline is a prompt.)
885 Comint mode divides the buffer into two types of @dfn{fields}: input
886 fields (where user input is typed) and output fields (everywhere
887 else). Prompts are part of the output fields. Most Emacs motion
888 commands do not cross field boundaries, unless they move over multiple
889 lines. For instance, when point is in the input field on a shell
890 command line, @kbd{C-a} puts point at the beginning of the input
891 field, after the prompt. Internally, the fields are implemented using
892 the @code{field} text property (@pxref{Text Properties,,, elisp, the
893 Emacs Lisp Reference Manual}).
895 @vindex comint-use-prompt-regexp
896 @vindex shell-prompt-pattern
897 If you change the variable @code{comint-use-prompt-regexp} to a
898 non-@code{nil} value, then Comint mode recognize prompts using a
899 regular expression (@pxref{Regexps}). In Shell mode, the regular
900 expression is specified by the variable @code{shell-prompt-pattern}.
901 The default value of @code{comint-use-prompt-regexp} is @code{nil},
902 because this method for recognizing prompts is unreliable, but you may
903 want to set it to a non-@code{nil} value in unusual circumstances. In
904 that case, Emacs does not divide the Comint buffer into fields, so the
905 general motion commands behave as they normally do in buffers without
906 special text properties. However, you can use the paragraph motion
907 commands to conveniently navigate the buffer (@pxref{Paragraphs}); in
908 Shell mode, Emacs uses @code{shell-prompt-pattern} as paragraph
912 @subsection Shell Command History
914 Shell buffers support three ways of repeating earlier commands. You
915 can use keys like those used for the minibuffer history; these work
916 much as they do in the minibuffer, inserting text from prior commands
917 while point remains always at the end of the buffer. You can move
918 through the buffer to previous inputs in their original place, then
919 resubmit them or copy them to the end. Or you can use a
920 @samp{!}-style history reference.
923 * Ring: Shell Ring. Fetching commands from the history list.
924 * Copy: Shell History Copying. Moving to a command and then copying it.
925 * History References:: Expanding @samp{!}-style history references.
929 @subsubsection Shell History Ring
932 @findex comint-previous-input
933 @kindex M-p @r{(Shell mode)}
936 Fetch the next earlier old shell command.
938 @kindex M-n @r{(Shell mode)}
939 @findex comint-next-input
942 Fetch the next later old shell command.
944 @kindex M-r @r{(Shell mode)}
945 @findex comint-history-isearch-backward-regexp
947 Begin an incremental regexp search of old shell commands.
950 @kindex C-c C-x @r{(Shell mode)}
951 @findex comint-get-next-from-history
952 Fetch the next subsequent command from the history.
955 @kindex C-c . @r{(Shell mode)}
956 @findex comint-input-previous-argument
957 Fetch one argument from an old shell command.
960 @kindex C-c C-l @r{(Shell mode)}
961 @findex comint-dynamic-list-input-ring
962 Display the buffer's history of shell commands in another window
963 (@code{comint-dynamic-list-input-ring}).
966 Shell buffers provide a history of previously entered shell
967 commands. To reuse shell commands from the history, use the editing
968 commands @kbd{M-p}, @kbd{M-n}, @kbd{M-r} and @kbd{M-s}. These work
969 just like the minibuffer history commands (@pxref{Minibuffer
970 History}), except that they operate within the Shell buffer rather
973 @kbd{M-p} fetches an earlier shell command to the end of the shell
974 buffer. Successive use of @kbd{M-p} fetches successively earlier
975 shell commands, each replacing any text that was already present as
976 potential shell input. @kbd{M-n} does likewise except that it finds
977 successively more recent shell commands from the buffer.
978 @kbd{C-@key{UP}} works like @kbd{M-p}, and @kbd{C-@key{DOWN}} like
981 The history search command @kbd{M-r} begins an incremental regular
982 expression search of previous shell commands. After typing @kbd{M-r},
983 start typing the desired string or regular expression; the last
984 matching shell command will be displayed in the current line.
985 Incremental search commands have their usual effects---for instance,
986 @kbd{C-s} and @kbd{C-r} search forward and backward for the next match
987 (@pxref{Incremental Search}). When you find the desired input, type
988 @key{RET} to terminate the search. This puts the input in the command
989 line. Any partial input you were composing before navigating the
990 history list is restored when you go to the beginning or end of the
993 Often it is useful to reexecute several successive shell commands that
994 were previously executed in sequence. To do this, first find and
995 reexecute the first command of the sequence. Then type @kbd{C-c C-x};
996 that will fetch the following command---the one that follows the command
997 you just repeated. Then type @key{RET} to reexecute this command. You
998 can reexecute several successive commands by typing @kbd{C-c C-x
999 @key{RET}} over and over.
1001 The command @kbd{C-c .}@: (@code{comint-input-previous-argument})
1002 copies an individual argument from a previous command, like @kbd{ESC
1003 .} in Bash. The simplest use copies the last argument from the
1004 previous shell command. With a prefix argument @var{n}, it copies the
1005 @var{n}th argument instead. Repeating @kbd{C-c .} copies from an
1006 earlier shell command instead, always using the same value of @var{n}
1007 (don't give a prefix argument when you repeat the @kbd{C-c .}
1010 These commands get the text of previous shell commands from a special
1011 history list, not from the shell buffer itself. Thus, editing the shell
1012 buffer, or even killing large parts of it, does not affect the history
1013 that these commands access.
1015 @vindex shell-input-ring-file-name
1016 Some shells store their command histories in files so that you can
1017 refer to commands from previous shell sessions. Emacs reads
1018 the command history file for your chosen shell, to initialize its own
1019 command history. The file name is @file{~/.bash_history} for bash,
1020 @file{~/.sh_history} for ksh, and @file{~/.history} for other shells.
1022 @node Shell History Copying
1023 @subsubsection Shell History Copying
1026 @kindex C-c C-p @r{(Shell mode)}
1027 @findex comint-previous-prompt
1029 Move point to the previous prompt (@code{comint-previous-prompt}).
1031 @kindex C-c C-n @r{(Shell mode)}
1032 @findex comint-next-prompt
1034 Move point to the following prompt (@code{comint-next-prompt}).
1036 @kindex C-c RET @r{(Shell mode)}
1037 @findex comint-copy-old-input
1039 Copy the input command at point, inserting the copy at the end of the
1040 buffer (@code{comint-copy-old-input}). This is useful if you move
1041 point back to a previous command. After you copy the command, you can
1042 submit the copy as input with @key{RET}. If you wish, you can edit
1043 the copy before resubmitting it. If you use this command on an output
1044 line, it copies that line to the end of the buffer.
1047 If @code{comint-use-prompt-regexp} is @code{nil} (the default), copy
1048 the old input command that you click on, inserting the copy at the end
1049 of the buffer (@code{comint-insert-input}). If
1050 @code{comint-use-prompt-regexp} is non-@code{nil}, or if the click is
1051 not over old input, just yank as usual.
1054 Moving to a previous input and then copying it with @kbd{C-c
1055 @key{RET}} or @kbd{Mouse-2} produces the same results---the same
1056 buffer contents---that you would get by using @kbd{M-p} enough times
1057 to fetch that previous input from the history list. However, @kbd{C-c
1058 @key{RET}} copies the text from the buffer, which can be different
1059 from what is in the history list if you edit the input text in the
1060 buffer after it has been sent.
1062 @node History References
1063 @subsubsection Shell History References
1064 @cindex history reference
1066 Various shells including csh and bash support @dfn{history
1067 references} that begin with @samp{!} and @samp{^}. Shell mode
1068 recognizes these constructs, and can perform the history substitution
1071 If you insert a history reference and type @key{TAB}, this searches
1072 the input history for a matching command, performs substitution if
1073 necessary, and places the result in the buffer in place of the history
1074 reference. For example, you can fetch the most recent command
1075 beginning with @samp{mv} with @kbd{! m v @key{TAB}}. You can edit the
1076 command if you wish, and then resubmit the command to the shell by
1079 @vindex comint-input-autoexpand
1080 @findex comint-magic-space
1081 Shell mode can optionally expand history references in the buffer
1082 when you send them to the shell. To request this, set the variable
1083 @code{comint-input-autoexpand} to @code{input}. You can make
1084 @key{SPC} perform history expansion by binding @key{SPC} to the
1085 command @code{comint-magic-space}.
1087 Shell mode recognizes history references when they follow a prompt.
1088 @xref{Shell Prompts}, for how Shell mode recognizes prompts.
1090 @node Directory Tracking
1091 @subsection Directory Tracking
1092 @cindex directory tracking
1094 @vindex shell-pushd-regexp
1095 @vindex shell-popd-regexp
1096 @vindex shell-cd-regexp
1097 Shell mode keeps track of @samp{cd}, @samp{pushd} and @samp{popd}
1098 commands given to the subshell, in order to keep the Shell buffer's
1099 default directory (@pxref{File Names}) the same as the shell's working
1100 directory. It recognizes these commands by examining lines of input
1103 If you use aliases for these commands, you can tell Emacs to
1104 recognize them also, by setting the variables
1105 @code{shell-pushd-regexp}, @code{shell-popd-regexp}, and
1106 @code{shell-cd-regexp} to the appropriate regular expressions
1107 (@pxref{Regexps}). For example, if @code{shell-pushd-regexp} matches
1108 the beginning of a shell command line, that line is regarded as a
1109 @code{pushd} command. These commands are recognized only at the
1110 beginning of a shell command line.
1113 If Emacs gets confused about changes in the working directory of the
1114 subshell, type @kbd{M-x dirs}. This command asks the shell for its
1115 working directory and updates the default directory accordingly. It
1116 works for shells that support the most common command syntax, but may
1117 not work for unusual shells.
1119 @findex dirtrack-mode
1120 @cindex Dirtrack mode
1121 @cindex mode, Dirtrack
1122 @vindex dirtrack-list
1123 You can also use Dirtrack mode, a buffer-local minor mode that
1124 implements an alternative method of tracking the shell's working
1125 directory. To use this method, your shell prompt must contain the
1126 working directory at all times, and you must supply a regular
1127 expression for recognizing which part of the prompt contains the
1128 working directory; see the documentation of the variable
1129 @code{dirtrack-list} for details. To use Dirtrack mode, type @kbd{M-x
1130 dirtrack-mode} in the Shell buffer, or add @code{dirtrack-mode} to
1131 @code{shell-mode-hook} (@pxref{Hooks}).
1134 @subsection Shell Mode Options
1136 @vindex comint-scroll-to-bottom-on-input
1137 If the variable @code{comint-scroll-to-bottom-on-input} is
1138 non-@code{nil}, insertion and yank commands scroll the selected window
1139 to the bottom before inserting. The default is @code{nil}.
1141 @vindex comint-scroll-show-maximum-output
1142 If @code{comint-scroll-show-maximum-output} is non-@code{nil}, then
1143 arrival of output when point is at the end tries to scroll the last
1144 line of text to the bottom line of the window, showing as much useful
1145 text as possible. (This mimics the scrolling behavior of most
1146 terminals.) The default is @code{t}.
1148 @vindex comint-move-point-for-output
1149 By setting @code{comint-move-point-for-output}, you can opt for
1150 having point jump to the end of the buffer whenever output arrives---no
1151 matter where in the buffer point was before. If the value is
1152 @code{this}, point jumps in the selected window. If the value is
1153 @code{all}, point jumps in each window that shows the Comint buffer. If
1154 the value is @code{other}, point jumps in all nonselected windows that
1155 show the current buffer. The default value is @code{nil}, which means
1156 point does not jump to the end.
1158 @vindex comint-prompt-read-only
1159 If you set @code{comint-prompt-read-only}, the prompts in the Comint
1160 buffer are read-only.
1162 @vindex comint-input-ignoredups
1163 The variable @code{comint-input-ignoredups} controls whether successive
1164 identical inputs are stored in the input history. A non-@code{nil}
1165 value means to omit an input that is the same as the previous input.
1166 The default is @code{nil}, which means to store each input even if it is
1167 equal to the previous input.
1169 @vindex comint-completion-addsuffix
1170 @vindex comint-completion-recexact
1171 @vindex comint-completion-autolist
1172 Three variables customize file name completion. The variable
1173 @code{comint-completion-addsuffix} controls whether completion inserts a
1174 space or a slash to indicate a fully completed file or directory name
1175 (non-@code{nil} means do insert a space or slash).
1176 @code{comint-completion-recexact}, if non-@code{nil}, directs @key{TAB}
1177 to choose the shortest possible completion if the usual Emacs completion
1178 algorithm cannot add even a single character.
1179 @code{comint-completion-autolist}, if non-@code{nil}, says to list all
1180 the possible completions whenever completion is not exact.
1182 @vindex shell-completion-execonly
1183 Command completion normally considers only executable files.
1184 If you set @code{shell-completion-execonly} to @code{nil},
1185 it considers nonexecutable files as well.
1187 @vindex shell-completion-fignore
1188 @vindex comint-completion-fignore
1189 The variable @code{shell-completion-fignore} specifies a list of file
1190 name extensions to ignore in Shell mode completion. The default
1191 setting is @code{nil}, but some users prefer @code{("~" "#" "%")} to
1192 ignore file names ending in @samp{~}, @samp{#} or @samp{%}. Other
1193 related Comint modes use the variable @code{comint-completion-fignore}
1196 @findex shell-dynamic-complete-command
1197 Some implementation details of the shell command completion may also be found
1198 in the lisp documentation of the @code{shell-dynamic-complete-command}
1201 @findex shell-pushd-tohome
1202 @findex shell-pushd-dextract
1203 @findex shell-pushd-dunique
1204 You can configure the behavior of @samp{pushd}. Variables control
1205 whether @samp{pushd} behaves like @samp{cd} if no argument is given
1206 (@code{shell-pushd-tohome}), pop rather than rotate with a numeric
1207 argument (@code{shell-pushd-dextract}), and only add directories to the
1208 directory stack if they are not already on it
1209 (@code{shell-pushd-dunique}). The values you choose should match the
1210 underlying shell, of course.
1212 @node Terminal emulator
1213 @subsection Emacs Terminal Emulator
1216 To run a subshell in a text terminal emulator, use @kbd{M-x term}.
1217 This creates (or reuses) a buffer named @file{*terminal*}, and runs a
1218 subshell with input coming from your keyboard, and output going to
1221 @cindex line mode @r{(terminal emulator)}
1222 @cindex char mode @r{(terminal emulator)}
1223 The terminal emulator uses Term mode, which has two input modes. In
1224 @dfn{line mode}, Term basically acts like Shell mode (@pxref{Shell
1225 Mode}). In @dfn{char mode}, each character is sent directly to the
1226 subshell, as terminal input; the sole exception is the terminal escape
1227 character, which by default is @kbd{C-c} (@pxref{Term Mode}). Any
1228 echoing of your input is the responsibility of the subshell; any
1229 terminal output from the subshell goes into the buffer, advancing
1232 Some programs (such as Emacs itself) need to control the appearance
1233 of the terminal screen in detail. They do this by emitting special
1234 control codes. Term mode recognizes and handles ANSI-standard
1235 VT100-style escape sequences, which are accepted by most modern
1236 terminals, including @command{xterm}. (Hence, you can actually run
1237 Emacs inside an Emacs Term window.)
1239 The @code{term} face specifies the default appearance of text
1240 in the terminal emulator (the default is the same appearance as the
1241 @code{default} face). When terminal control codes are used to change
1242 the appearance of text, these are represented in the terminal emulator
1243 by the faces @code{term-color-black}, @code{term-color-red},
1244 @code{term-color-green}, @code{term-color-yellow}
1245 @code{term-color-blue}, @code{term-color-magenta},
1246 @code{term-color-cyan}, @code{term-color-white},
1247 @code{term-color-underline}, and @code{term-color-bold}.
1250 You can also Term mode to communicate with a device connected to a
1251 serial port. @xref{Serial Terminal}.
1253 The file name used to load the subshell is determined the same way
1254 as for Shell mode. To make multiple terminal emulators, rename the
1255 buffer @file{*terminal*} to something different using @kbd{M-x
1256 rename-uniquely}, just as with Shell mode.
1258 Unlike Shell mode, Term mode does not track the current directory by
1259 examining your input. But some shells can tell Term what the current
1260 directory is. This is done automatically by @code{bash} version 1.15
1267 @subsection Term Mode
1271 The terminal emulator uses Term mode, which has two input modes. In
1272 line mode, Term basically acts like Shell mode (@pxref{Shell Mode}).
1273 In char mode, each character is sent directly to the subshell, except
1274 for the Term escape character, normally @kbd{C-c}.
1276 To switch between line and char mode, use these commands:
1279 @kindex C-c C-j @r{(Term mode)}
1280 @findex term-line-mode
1282 Switch to line mode (@code{term-line-mode}). Do nothing if already in
1285 @kindex C-c C-k @r{(Term mode)}
1286 @findex term-char-mode
1288 Switch to char mode (@code{term-char-mode}). Do nothing if already in
1292 The following commands are only available in char mode:
1296 Send a literal @key{C-c} to the sub-shell.
1298 @item C-c @var{char}
1299 This is equivalent to @kbd{C-x @var{char}} in normal Emacs. For
1300 example, @kbd{C-c o} invokes the global binding of @kbd{C-x o}, which
1301 is normally @samp{other-window}.
1304 @cindex paging in Term mode
1305 Term mode has a page-at-a-time feature. When enabled, it makes
1306 output pause at the end of each screenful:
1309 @kindex C-c C-q @r{(Term mode)}
1310 @findex term-pager-toggle
1312 Toggle the page-at-a-time feature. This command works in both line
1313 and char modes. When the feature is enabled, the mode-line displays
1314 the word @samp{page}, and each time Term receives more than a
1315 screenful of output, it pauses and displays @samp{**MORE**} in the
1316 mode-line. Type @key{SPC} to display the next screenful of output, or
1317 @kbd{?} to see your other options. The interface is similar to the
1318 @code{more} program.
1322 @subsection Remote Host Shell
1324 @cindex connecting to remote host
1328 You can login to a remote computer, using whatever commands you
1329 would from a regular terminal (e.g., using the @code{telnet} or
1330 @code{rlogin} commands), from a Term window.
1332 A program that asks you for a password will normally suppress
1333 echoing of the password, so the password will not show up in the
1334 buffer. This will happen just as if you were using a real terminal,
1335 if the buffer is in char mode. If it is in line mode, the password is
1336 temporarily visible, but will be erased when you hit return. (This
1337 happens automatically; there is no special password processing.)
1339 When you log in to a different machine, you need to specify the type
1340 of terminal you're using, by setting the @env{TERM} environment
1341 variable in the environment for the remote login command. (If you use
1342 bash, you do that by writing the variable assignment before the remote
1343 login command, without a separating comma.) Terminal types
1344 @samp{ansi} or @samp{vt100} will work on most systems.
1346 @node Serial Terminal
1347 @subsection Serial Terminal
1348 @cindex terminal, serial
1351 If you have a device connected to a serial port of your computer,
1352 you can communicate with it by typing @kbd{M-x serial-term}. This
1353 command asks for a serial port name and speed, and switches to a new
1354 Term mode buffer. Emacs communicates with the serial device through
1355 this buffer just like it does with a terminal in ordinary Term mode.
1357 The speed of the serial port is measured in bits per second. The
1358 most common speed is 9600 bits per second. You can change the speed
1359 interactively by clicking on the mode line.
1361 A serial port can be configured even more by clicking on ``8N1'' in
1362 the mode line. By default, a serial port is configured as ``8N1'',
1363 which means that each byte consists of 8 data bits, No parity check
1366 If the speed or the configuration is wrong, you cannot communicate
1367 with your device and will probably only see garbage output in the
1371 @section Using Emacs as a Server
1373 @cindex Emacs as a server
1374 @cindex server, using Emacs as
1375 @cindex @env{EDITOR} environment variable
1377 Various programs can invoke your choice of editor to edit a
1378 particular piece of text. For instance, version control programs
1379 invoke an editor to enter version control logs (@pxref{Version
1380 Control}), and the Unix @command{mail} utility invokes an editor to
1381 enter a message to send. By convention, your choice of editor is
1382 specified by the environment variable @env{EDITOR}. If you set
1383 @env{EDITOR} to @samp{emacs}, Emacs would be invoked, but in an
1384 inconvenient way---by starting a new Emacs process. This is
1385 inconvenient because the new Emacs process doesn't share buffers, a
1386 command history, or other kinds of information with any existing Emacs
1389 You can solve this problem by setting up Emacs as an @dfn{edit
1390 server}, so that it ``listens'' for external edit requests and acts
1391 accordingly. There are two ways to start an Emacs server:
1394 @findex server-start
1396 Run the command @code{server-start} in an existing Emacs process:
1397 either type @kbd{M-x server-start}, or put the expression
1398 @code{(server-start)} in your init file (@pxref{Init File}). The
1399 existing Emacs process is the server; when you exit Emacs, the server
1400 dies with the Emacs process.
1402 @cindex daemon, Emacs
1404 Run Emacs as a @dfn{daemon}, using the @samp{--daemon} command-line
1405 option. @xref{Initial Options}. When Emacs is started this way, it
1406 calls @code{server-start} after initialization, and returns control to
1407 the calling terminal instead of opening an initial frame; it then
1408 waits in the background, listening for edit requests.
1411 @cindex @env{TEXEDIT} environment variable
1412 Either way, once an Emacs server is started, you can use a shell
1413 command called @command{emacsclient} to connect to the Emacs process
1414 and tell it to visit a file. You can then set the @env{EDITOR}
1415 environment variable to @samp{emacsclient}, so that external programs
1416 will use the existing Emacs process for editing.@footnote{Some
1417 programs use a different environment variable; for example, to make
1418 @TeX{} use @samp{emacsclient}, set the @env{TEXEDIT} environment
1419 variable to @samp{emacsclient +%d %s}.}
1422 You can run multiple Emacs servers on the same machine by giving
1423 each one a unique ``server name'', using the variable
1424 @code{server-name}. For example, @kbd{M-x set-variable @key{RET}
1425 server-name @key{RET} foo @key{RET}} sets the server name to
1426 @samp{foo}. The @code{emacsclient} program can specify a server by
1427 name, using the @samp{-s} option (@pxref{emacsclient Options}).
1429 @findex server-eval-at
1430 If you have defined a server by a unique server name, it is possible
1431 to connect to the server from another Emacs instance and evaluate Lisp
1432 expressions on the server, using the @code{server-eval-at} function.
1433 For instance, @code{(server-eval-at "foo" '(+ 1 2))} evaluates the
1434 expression @code{(+ 1 2)} on the @samp{foo} server, and returns
1435 @code{3}. (If there is no server with that name, an error is
1436 signaled.) Currently, this feature is mainly useful for developers.
1439 * Invoking emacsclient:: Connecting to the Emacs server.
1440 * emacsclient Options:: Emacs client startup options.
1443 @node Invoking emacsclient
1444 @subsection Invoking @code{emacsclient}
1445 @cindex @code{emacsclient} invocation
1447 The simplest way to use the @command{emacsclient} program is to run
1448 the shell command @samp{emacsclient @var{file}}, where @var{file} is a
1449 file name. This connects to an Emacs server, and tells that Emacs
1450 process to visit @var{file} in one of its existing frames---either a
1451 graphical frame, or one in a text terminal (@pxref{Frames}). You
1452 can then select that frame to begin editing.
1454 If there is no Emacs server, the @command{emacsclient} program halts
1455 with an error message. If the Emacs process has no existing
1456 frame---which can happen if it was started as a daemon (@pxref{Emacs
1457 Server})---then Emacs opens a frame on the terminal in which you
1458 called @command{emacsclient}.
1460 You can also force @command{emacsclient} to open a new frame on a
1461 graphical display, or on a text terminal, using the @samp{-c} and
1462 @samp{-t} options. @xref{emacsclient Options}.
1464 If you are running on a single text terminal, you can switch between
1465 @command{emacsclient}'s shell and the Emacs server using one of two
1466 methods: (i) run the Emacs server and @command{emacsclient} on
1467 different virtual terminals, and switch to the Emacs server's virtual
1468 terminal after calling @command{emacsclient}; or (ii) call
1469 @command{emacsclient} from within the Emacs server itself, using Shell
1470 mode (@pxref{Interactive Shell}) or Term mode (@pxref{Term Mode});
1471 @code{emacsclient} blocks only the subshell under Emacs, and you can
1472 still use Emacs to edit the file.
1476 When you finish editing @var{file} in the Emacs server, type
1477 @kbd{C-x #} (@code{server-edit}) in its buffer. This saves the file
1478 and sends a message back to the @command{emacsclient} program, telling
1479 it to exit. Programs that use @env{EDITOR} usually wait for the
1480 ``editor''---in this case @command{emacsclient}---to exit before doing
1483 You can also call @command{emacsclient} with multiple file name
1484 arguments: @samp{emacsclient @var{file1} @var{file2} ...} tells the
1485 Emacs server to visit @var{file1}, @var{file2}, and so forth. Emacs
1486 selects the buffer visiting @var{file1}, and buries the other buffers
1487 at the bottom of the buffer list (@pxref{Buffers}). The
1488 @command{emacsclient} program exits once all the specified files are
1489 finished (i.e., once you have typed @kbd{C-x #} in each server
1492 @vindex server-kill-new-buffers
1493 @vindex server-temp-file-regexp
1494 Finishing with a server buffer also kills the buffer, unless it
1495 already existed in the Emacs session before the server was asked to
1496 create it. However, if you set @code{server-kill-new-buffers} to
1497 @code{nil}, then a different criterion is used: finishing with a
1498 server buffer kills it if the file name matches the regular expression
1499 @code{server-temp-file-regexp}. This is set up to distinguish certain
1500 ``temporary'' files.
1502 Each @kbd{C-x #} checks for other pending external requests to edit
1503 various files, and selects the next such file. You can switch to a
1504 server buffer manually if you wish; you don't have to arrive at it
1505 with @kbd{C-x #}. But @kbd{C-x #} is the way to tell
1506 @command{emacsclient} that you are finished.
1508 @vindex server-window
1509 If you set the value of the variable @code{server-window} to a
1510 window or a frame, @kbd{C-x #} always displays the next server buffer
1511 in that window or in that frame.
1513 @node emacsclient Options
1514 @subsection @code{emacsclient} Options
1515 @cindex @code{emacsclient} options
1517 You can pass some optional arguments to the @command{emacsclient}
1521 emacsclient -c +12 @var{file1} +4:3 @var{file2}
1525 The @samp{+@var{line}} or @samp{+@var{line}:@var{column}} arguments
1526 specify line numbers, or line and column numbers, for the next file
1527 argument. These behave like the command line arguments for Emacs
1528 itself. @xref{Action Arguments}.
1530 The other optional arguments recognized by @command{emacsclient} are
1534 @item -a @var{command}
1535 @itemx --alternate-editor=@var{command}
1536 Specify a command to run if @code{emacsclient} fails to contact Emacs.
1537 This is useful when running @code{emacsclient} in a script.
1539 As a special exception, if @var{command} is the empty string, then
1540 @code{emacsclient} starts Emacs in daemon mode (as @command{emacs
1541 --daemon}) and then tries connecting again.
1543 @cindex @env{ALTERNATE_EDITOR} environment variable
1544 The environment variable @env{ALTERNATE_EDITOR} has the same effect as
1545 the @samp{-a} option. If both are present, the latter takes
1548 @cindex client frame
1550 Create a new graphical @dfn{client frame}, instead of using an
1551 existing Emacs frame. See below for the special behavior of @kbd{C-x
1552 C-c} in a client frame. If Emacs cannot create a new graphical frame
1553 (e.g., if it cannot connect to the X server), it tries to create a
1554 text terminal client frame, as though you had supplied the @samp{-t}
1557 On MS-Windows, a single Emacs session cannot display frames on both
1558 graphical and text terminals, nor on multiple text terminals. Thus,
1559 if the Emacs server is running on a text terminal, the @samp{-c}
1560 option, like the @samp{-t} option, creates a new frame in the server's
1561 current text terminal. @xref{Windows Startup}.
1563 If you omit a filename argument while supplying the @samp{-c} option,
1564 the new frame displays the @file{*scratch*} buffer by default. This
1565 behavior can be customized using the variable
1566 @code{initial-buffer-choice} (@pxref{Entering Emacs}).
1568 @item -F @var{alist}
1569 @itemx --frame-parameters=@var{alist}
1570 Set the parameters for a newly-created graphical frame
1571 (@pxref{Frame Parameters}).
1573 @item -d @var{display}
1574 @itemx --display=@var{display}
1575 Tell Emacs to open the given files on the X display @var{display}
1576 (assuming there is more than one X display available).
1580 Tell Emacs to evaluate some Emacs Lisp code, instead of visiting some
1581 files. When this option is given, the arguments to
1582 @command{emacsclient} are interpreted as a list of expressions to
1583 evaluate, @emph{not} as a list of files to visit.
1585 @item -f @var{server-file}
1586 @itemx --server-file=@var{server-file}
1587 @cindex @env{EMACS_SERVER_FILE} environment variable
1588 Specify a @dfn{server file} for connecting to an Emacs server via TCP.
1590 An Emacs server usually uses an operating system feature called a
1591 ``local socket'' to listen for connections. Some operating systems,
1592 such as Microsoft Windows, do not support local sockets; in that case,
1593 the server communicates with @command{emacsclient} via TCP.
1595 @vindex server-auth-dir
1598 When you start a TCP Emacs server, Emacs creates a @dfn{server file}
1599 containing the TCP information to be used by @command{emacsclient} to
1600 connect to the server. The variable @code{server-auth-dir} specifies
1601 the directory containing the server file; by default, this is
1602 @file{~/.emacs.d/server/}. To tell @command{emacsclient} to connect
1603 to the server over TCP with a specific server file, use the @samp{-f}
1604 or @samp{--server-file} option, or set the @env{EMACS_SERVER_FILE}
1605 environment variable.
1609 Let @command{emacsclient} exit immediately, instead of waiting until
1610 all server buffers are finished. You can take as long as you like to
1611 edit the server buffers within Emacs, and they are @emph{not} killed
1612 when you type @kbd{C-x #} in them.
1614 @item --parent-id @var{ID}
1615 Open an @command{emacsclient} frame as a client frame in the parent X
1616 window with id @var{ID}, via the XEmbed protocol. Currently, this
1617 option is mainly useful for developers.
1621 Do not let @command{emacsclient} display messages about waiting for
1622 Emacs or connecting to remote server sockets.
1624 @item -s @var{server-name}
1625 @itemx --socket-name=@var{server-name}
1626 Connect to the Emacs server named @var{server-name}. The server name
1627 is given by the variable @code{server-name} on the Emacs server. If
1628 this option is omitted, @command{emacsclient} connects to the first
1629 server it finds. (This option is not supported on MS-Windows.)
1634 Create a new client frame on the current text terminal, instead of
1635 using an existing Emacs frame. This behaves just like the @samp{-c}
1636 option, described above, except that it creates a text terminal frame
1637 (@pxref{Non-Window Terminals}).
1639 On MS-Windows, @samp{-t} behaves just like @samp{-c} if the Emacs
1640 server is using the graphical display, but if the Emacs server is
1641 running on a text terminal, it creates a new frame in the current text
1645 The new graphical or text terminal frames created by the @samp{-c}
1646 or @samp{-t} options are considered @dfn{client frames}. Any new
1647 frame that you create from a client frame is also considered a client
1648 frame. If you type @kbd{C-x C-c} (@code{save-buffers-kill-terminal})
1649 in a client frame, that command does not kill the Emacs session as it
1650 normally does (@pxref{Exiting}). Instead, Emacs deletes the client
1651 frame; furthermore, if the client frame has an @command{emacsclient}
1652 waiting to regain control (i.e., if you did not supply the @samp{-n}
1653 option), Emacs deletes all other frames of the same client, and marks
1654 the client's server buffers as finished, as though you had typed
1655 @kbd{C-x #} in all of them. If it so happens that there are no
1656 remaining frames after the client frame(s) are deleted, the Emacs
1659 As an exception, when Emacs is started as a daemon, all frames are
1660 considered client frames, and @kbd{C-x C-c} never kills Emacs. To
1661 kill a daemon session, type @kbd{M-x kill-emacs}.
1663 Note that the @samp{-t} and @samp{-n} options are contradictory:
1664 @samp{-t} says to take control of the current text terminal to create
1665 a new client frame, while @samp{-n} says not to take control of the
1666 text terminal. If you supply both options, Emacs visits the specified
1667 files(s) in an existing frame rather than a new client frame, negating
1668 the effect of @samp{-t}.
1671 @section Printing Hard Copies
1675 Emacs provides commands for printing hardcopies of either an entire
1676 buffer or part of one. You can invoke the printing commands directly,
1677 as detailed below, or using the @samp{File} menu on the menu bar.
1679 @findex htmlfontify-buffer
1680 Aside from the commands described in this section, you can also
1681 print hardcopies from Dired (@pxref{Operating on Files}) and the diary
1682 (@pxref{Displaying the Diary}). You can also ``print'' an Emacs
1683 buffer to HTML with the command @kbd{M-x htmlfontify-buffer}, which
1684 converts the current buffer to a HTML file, replacing Emacs faces with
1685 CSS-based markup. Furthermore, Org mode allows you to ``print'' Org
1686 files to a variety of formats, such as PDF (@pxref{Org Mode}).
1689 @item M-x print-buffer
1690 Print hardcopy of current buffer with page headings containing the
1691 file name and page number.
1692 @item M-x lpr-buffer
1693 Print hardcopy of current buffer without page headings.
1694 @item M-x print-region
1695 Like @code{print-buffer} but print only the current region.
1696 @item M-x lpr-region
1697 Like @code{lpr-buffer} but print only the current region.
1700 @findex print-buffer
1701 @findex print-region
1704 @vindex lpr-switches
1705 @vindex lpr-commands
1706 On most operating system, the above hardcopy commands submit files
1707 for printing by calling the @command{lpr} program. To change the
1708 printer program, customize the variable @code{lpr-command}. To
1709 specify extra switches to give the printer program, customize the list
1710 variable @code{lpr-switches}. Its value should be a list of option
1711 strings, each of which should start with @samp{-} (e.g., the option
1712 string @code{"-w80"} specifies a line width of 80 columns). The
1713 default is the empty list, @code{nil}.
1715 @vindex printer-name
1716 @vindex lpr-printer-switch
1717 To specify the printer to use, set the variable @code{printer-name}.
1718 The default, @code{nil}, specifies the default printer. If you set it
1719 to a printer name (a string), that name is passed to @command{lpr}
1720 with the @samp{-P} switch; if you are not using @command{lpr}, you
1721 should specify the switch with @code{lpr-printer-switch}.
1723 @vindex lpr-headers-switches
1724 @vindex lpr-add-switches
1725 The variable @code{lpr-headers-switches} similarly specifies the
1726 extra switches to use to make page headers. The variable
1727 @code{lpr-add-switches} controls whether to supply @samp{-T} and
1728 @samp{-J} options (suitable for @command{lpr}) to the printer program:
1729 @code{nil} means don't add them (this should be the value if your
1730 printer program is not compatible with @command{lpr}).
1733 * PostScript:: Printing buffers or regions as PostScript.
1734 * PostScript Variables:: Customizing the PostScript printing commands.
1735 * Printing Package:: An optional advanced printing interface.
1739 @subsection PostScript Hardcopy
1741 These commands convert buffer contents to PostScript,
1742 either printing it or leaving it in another Emacs buffer.
1745 @item M-x ps-print-buffer
1746 Print hardcopy of the current buffer in PostScript form.
1747 @item M-x ps-print-region
1748 Print hardcopy of the current region in PostScript form.
1749 @item M-x ps-print-buffer-with-faces
1750 Print hardcopy of the current buffer in PostScript form, showing the
1751 faces used in the text by means of PostScript features.
1752 @item M-x ps-print-region-with-faces
1753 Print hardcopy of the current region in PostScript form, showing the
1754 faces used in the text.
1755 @item M-x ps-spool-buffer
1756 Generate and spool a PostScript image for the current buffer text.
1757 @item M-x ps-spool-region
1758 Generate and spool a PostScript image for the current region.
1759 @item M-x ps-spool-buffer-with-faces
1760 Generate and spool a PostScript image for the current buffer, showing the faces used.
1761 @item M-x ps-spool-region-with-faces
1762 Generate and spool a PostScript image for the current region, showing the faces used.
1763 @item M-x ps-despool
1764 Send the spooled PostScript to the printer.
1766 Generate/print PostScript for the current buffer as if handwritten.
1769 @findex ps-print-region
1770 @findex ps-print-buffer
1771 @findex ps-print-region-with-faces
1772 @findex ps-print-buffer-with-faces
1773 The @code{ps-print-buffer} and @code{ps-print-region} commands print
1774 buffer contents in PostScript form. One command prints the entire
1775 buffer; the other, just the region. The commands
1776 @code{ps-print-buffer-with-faces} and
1777 @code{ps-print-region-with-faces} behave similarly, but use PostScript
1778 features to show the faces (fonts and colors) of the buffer text.
1780 Interactively, when you use a prefix argument (@kbd{C-u}), the command
1781 prompts the user for a file name, and saves the PostScript image in that file
1782 instead of sending it to the printer.
1784 @findex ps-spool-region
1785 @findex ps-spool-buffer
1786 @findex ps-spool-region-with-faces
1787 @findex ps-spool-buffer-with-faces
1788 The commands whose names have @samp{spool} instead of @samp{print},
1789 generate the PostScript output in an Emacs buffer instead of sending
1793 Use the command @code{ps-despool} to send the spooled images to the
1794 printer. This command sends the PostScript generated by
1795 @samp{-spool-} commands (see commands above) to the printer. With a
1796 prefix argument (@kbd{C-u}), it prompts for a file name, and saves the
1797 spooled PostScript image in that file instead of sending it to the
1802 @kbd{M-x handwrite} is more frivolous. It generates a PostScript
1803 rendition of the current buffer as a cursive handwritten document. It
1804 can be customized in group @code{handwrite}. This function only
1805 supports ISO 8859-1 characters.
1807 @node PostScript Variables
1808 @subsection Variables for PostScript Hardcopy
1810 @vindex ps-lpr-command
1811 @vindex ps-lpr-switches
1812 @vindex ps-printer-name
1813 All the PostScript hardcopy commands use the variables
1814 @code{ps-lpr-command} and @code{ps-lpr-switches} to specify how to print
1815 the output. @code{ps-lpr-command} specifies the command name to run,
1816 @code{ps-lpr-switches} specifies command line options to use, and
1817 @code{ps-printer-name} specifies the printer. If you don't set the
1818 first two variables yourself, they take their initial values from
1819 @code{lpr-command} and @code{lpr-switches}. If @code{ps-printer-name}
1820 is @code{nil}, @code{printer-name} is used.
1822 @vindex ps-print-header
1823 The variable @code{ps-print-header} controls whether these commands
1824 add header lines to each page---set it to @code{nil} to turn headers
1827 @cindex color emulation on black-and-white printers
1828 @vindex ps-print-color-p
1829 If your printer doesn't support colors, you should turn off color
1830 processing by setting @code{ps-print-color-p} to @code{nil}. By
1831 default, if the display supports colors, Emacs produces hardcopy output
1832 with color information; on black-and-white printers, colors are emulated
1833 with shades of gray. This might produce illegible output, even if your
1834 screen colors only use shades of gray.
1836 Alternatively, you can set @code{ps-print-color-p} to @code{black-white} to
1837 print colors on black/white printers.
1839 @vindex ps-use-face-background
1840 By default, PostScript printing ignores the background colors of the
1841 faces, unless the variable @code{ps-use-face-background} is
1842 non-@code{nil}. This is to avoid unwanted interference with the zebra
1843 stripes and background image/text.
1845 @vindex ps-paper-type
1846 @vindex ps-page-dimensions-database
1847 The variable @code{ps-paper-type} specifies which size of paper to
1848 format for; legitimate values include @code{a4}, @code{a3},
1849 @code{a4small}, @code{b4}, @code{b5}, @code{executive}, @code{ledger},
1850 @code{legal}, @code{letter}, @code{letter-small}, @code{statement},
1851 @code{tabloid}. The default is @code{letter}. You can define
1852 additional paper sizes by changing the variable
1853 @code{ps-page-dimensions-database}.
1855 @vindex ps-landscape-mode
1856 The variable @code{ps-landscape-mode} specifies the orientation of
1857 printing on the page. The default is @code{nil}, which stands for
1858 ``portrait'' mode. Any non-@code{nil} value specifies ``landscape''
1861 @vindex ps-number-of-columns
1862 The variable @code{ps-number-of-columns} specifies the number of
1863 columns; it takes effect in both landscape and portrait mode. The
1866 @vindex ps-font-family
1867 @vindex ps-font-size
1868 @vindex ps-font-info-database
1869 The variable @code{ps-font-family} specifies which font family to use
1870 for printing ordinary text. Legitimate values include @code{Courier},
1871 @code{Helvetica}, @code{NewCenturySchlbk}, @code{Palatino} and
1872 @code{Times}. The variable @code{ps-font-size} specifies the size of
1873 the font for ordinary text. It defaults to 8.5 points.
1875 @vindex ps-multibyte-buffer
1876 @cindex Intlfonts for PostScript printing
1877 @cindex fonts for PostScript printing
1878 Emacs supports more scripts and characters than a typical PostScript
1879 printer. Thus, some of the characters in your buffer might not be
1880 printable using the fonts built into your printer. You can augment
1881 the fonts supplied with the printer with those from the GNU Intlfonts
1882 package, or you can instruct Emacs to use Intlfonts exclusively. The
1883 variable @code{ps-multibyte-buffer} controls this: the default value,
1884 @code{nil}, is appropriate for printing @acronym{ASCII} and Latin-1
1885 characters; a value of @code{non-latin-printer} is for printers which
1886 have the fonts for @acronym{ASCII}, Latin-1, Japanese, and Korean
1887 characters built into them. A value of @code{bdf-font} arranges for
1888 the BDF fonts from the Intlfonts package to be used for @emph{all}
1889 characters. Finally, a value of @code{bdf-font-except-latin}
1890 instructs the printer to use built-in fonts for @acronym{ASCII} and Latin-1
1891 characters, and Intlfonts BDF fonts for the rest.
1893 @vindex bdf-directory-list
1894 To be able to use the BDF fonts, Emacs needs to know where to find
1895 them. The variable @code{bdf-directory-list} holds the list of
1896 directories where Emacs should look for the fonts; the default value
1897 includes a single directory @file{/usr/local/share/emacs/fonts/bdf}.
1899 Many other customization variables for these commands are defined and
1900 described in the Lisp files @file{ps-print.el} and @file{ps-mule.el}.
1902 @node Printing Package
1903 @subsection Printing Package
1904 @cindex Printing package
1906 The basic Emacs facilities for printing hardcopy can be extended
1907 using the Printing package. This provides an easy-to-use interface
1908 for choosing what to print, previewing PostScript files before
1909 printing, and setting various printing options such as print headers,
1910 landscape or portrait modes, duplex modes, and so forth. On GNU/Linux
1911 or Unix systems, the Printing package relies on the @file{gs} and
1912 @file{gv} utilities, which are distributed as part of the GhostScript
1913 program. On MS-Windows, the @file{gstools} port of Ghostscript can be
1916 @findex pr-interface
1917 To use the Printing package, add @code{(require 'printing)} to your
1918 init file (@pxref{Init File}), followed by @code{(pr-update-menus)}.
1919 This function replaces the usual printing commands in the menu bar
1920 with a @samp{Printing} submenu that contains various printing options.
1921 You can also type @kbd{M-x pr-interface RET}; this creates a
1922 @file{*Printing Interface*} buffer, similar to a customization buffer,
1923 where you can set the printing options. After selecting what and how
1924 to print, you start the print job using the @samp{Print} button (click
1925 @kbd{mouse-2} on it, or move point over it and type @kbd{RET}). For
1926 further information on the various options, use the @samp{Interface
1930 @section Sorting Text
1933 Emacs provides several commands for sorting text in the buffer. All
1934 operate on the contents of the region.
1935 They divide the text of the region into many @dfn{sort records},
1936 identify a @dfn{sort key} for each record, and then reorder the records
1937 into the order determined by the sort keys. The records are ordered so
1938 that their keys are in alphabetical order, or, for numeric sorting, in
1939 numeric order. In alphabetic sorting, all upper-case letters `A' through
1940 `Z' come before lower-case `a', in accord with the @acronym{ASCII} character
1943 The various sort commands differ in how they divide the text into sort
1944 records and in which part of each record is used as the sort key. Most of
1945 the commands make each line a separate sort record, but some commands use
1946 paragraphs or pages as sort records. Most of the sort commands use each
1947 entire sort record as its own sort key, but some use only a portion of the
1948 record as the sort key.
1951 @findex sort-paragraphs
1954 @findex sort-numeric-fields
1955 @vindex sort-numeric-base
1957 @item M-x sort-lines
1958 Divide the region into lines, and sort by comparing the entire
1959 text of a line. A numeric argument means sort into descending order.
1961 @item M-x sort-paragraphs
1962 Divide the region into paragraphs, and sort by comparing the entire
1963 text of a paragraph (except for leading blank lines). A numeric
1964 argument means sort into descending order.
1966 @item M-x sort-pages
1967 Divide the region into pages, and sort by comparing the entire
1968 text of a page (except for leading blank lines). A numeric
1969 argument means sort into descending order.
1971 @item M-x sort-fields
1972 Divide the region into lines, and sort by comparing the contents of
1973 one field in each line. Fields are defined as separated by
1974 whitespace, so the first run of consecutive non-whitespace characters
1975 in a line constitutes field 1, the second such run constitutes field
1978 Specify which field to sort by with a numeric argument: 1 to sort by
1979 field 1, etc. A negative argument means count fields from the right
1980 instead of from the left; thus, minus 1 means sort by the last field.
1981 If several lines have identical contents in the field being sorted, they
1982 keep the same relative order that they had in the original buffer.
1984 @item M-x sort-numeric-fields
1985 Like @kbd{M-x sort-fields} except the specified field is converted
1986 to an integer for each line, and the numbers are compared. @samp{10}
1987 comes before @samp{2} when considered as text, but after it when
1988 considered as a number. By default, numbers are interpreted according
1989 to @code{sort-numeric-base}, but numbers beginning with @samp{0x} or
1990 @samp{0} are interpreted as hexadecimal and octal, respectively.
1992 @item M-x sort-columns
1993 Like @kbd{M-x sort-fields} except that the text within each line
1994 used for comparison comes from a fixed range of columns. See below
1997 @findex reverse-region
1998 @item M-x reverse-region
1999 Reverse the order of the lines in the region. This is useful for
2000 sorting into descending order by fields or columns, since those sort
2001 commands do not have a feature for doing that.
2004 For example, if the buffer contains this:
2007 On systems where clash detection (locking of files being edited) is
2008 implemented, Emacs also checks the first time you modify a buffer
2009 whether the file has changed on disk since it was last visited or
2010 saved. If it has, you are asked to confirm that you want to change
2015 applying @kbd{M-x sort-lines} to the entire buffer produces this:
2018 On systems where clash detection (locking of files being edited) is
2019 implemented, Emacs also checks the first time you modify a buffer
2020 saved. If it has, you are asked to confirm that you want to change
2022 whether the file has changed on disk since it was last visited or
2026 where the upper-case @samp{O} sorts before all lower-case letters. If
2027 you use @kbd{C-u 2 M-x sort-fields} instead, you get this:
2030 implemented, Emacs also checks the first time you modify a buffer
2031 saved. If it has, you are asked to confirm that you want to change
2033 On systems where clash detection (locking of files being edited) is
2034 whether the file has changed on disk since it was last visited or
2038 where the sort keys were @samp{Emacs}, @samp{If}, @samp{buffer},
2039 @samp{systems} and @samp{the}.
2041 @findex sort-columns
2042 @kbd{M-x sort-columns} requires more explanation. You specify the
2043 columns by putting point at one of the columns and the mark at the other
2044 column. Because this means you cannot put point or the mark at the
2045 beginning of the first line of the text you want to sort, this command
2046 uses an unusual definition of ``region'': all of the line point is in is
2047 considered part of the region, and so is all of the line the mark is in,
2048 as well as all the lines in between.
2050 For example, to sort a table by information found in columns 10 to 15,
2051 you could put the mark on column 10 in the first line of the table, and
2052 point on column 15 in the last line of the table, and then run
2053 @code{sort-columns}. Equivalently, you could run it with the mark on
2054 column 15 in the first line and point on column 10 in the last line.
2056 This can be thought of as sorting the rectangle specified by point and
2057 the mark, except that the text on each line to the left or right of the
2058 rectangle moves along with the text inside the rectangle.
2061 @vindex sort-fold-case
2062 Many of the sort commands ignore case differences when comparing, if
2063 @code{sort-fold-case} is non-@code{nil}.
2065 @c Picture Mode documentation
2067 @include picture-xtra.texi
2071 @node Editing Binary Files
2072 @section Editing Binary Files
2076 @cindex editing binary files
2078 There is a special major mode for editing binary files: Hexl mode. To
2079 use it, use @kbd{M-x hexl-find-file} instead of @kbd{C-x C-f} to visit
2080 the file. This command converts the file's contents to hexadecimal and
2081 lets you edit the translation. When you save the file, it is converted
2082 automatically back to binary.
2084 You can also use @kbd{M-x hexl-mode} to translate an existing buffer
2085 into hex. This is useful if you visit a file normally and then discover
2086 it is a binary file.
2088 Ordinary text characters overwrite in Hexl mode. This is to reduce
2089 the risk of accidentally spoiling the alignment of data in the file.
2090 There are special commands for insertion. Here is a list of the
2091 commands of Hexl mode:
2093 @c I don't think individual index entries for these commands are useful--RMS.
2096 Insert a byte with a code typed in decimal.
2099 Insert a byte with a code typed in octal.
2102 Insert a byte with a code typed in hex.
2105 Move to the beginning of a 1k-byte ``page''.
2108 Move to the end of a 1k-byte ``page''.
2111 Move to an address specified in hex.
2114 Move to an address specified in decimal.
2117 Leave Hexl mode, going back to the major mode this buffer had before you
2118 invoked @code{hexl-mode}.
2122 Other Hexl commands let you insert strings (sequences) of binary
2123 bytes, move by @code{short}s or @code{int}s, etc.; type @kbd{C-h a
2124 hexl-@key{RET}} for details.
2127 @node Saving Emacs Sessions
2128 @section Saving Emacs Sessions
2129 @cindex saving sessions
2130 @cindex restore session
2131 @cindex remember editing session
2132 @cindex reload files
2135 @vindex desktop-restore-frames
2136 Use the desktop library to save the state of Emacs from one session
2137 to another. Once you save the Emacs @dfn{desktop}---the buffers,
2138 their file names, major modes, buffer positions, and so on---then
2139 subsequent Emacs sessions reload the saved desktop. By default,
2140 the desktop also tries to save the frame and window configuration.
2141 To disable this, set @code{desktop-restore-frames} to @code{nil}.
2142 (See that variable's documentation for some related options
2143 that you can customize to fine-tune this behavior.)
2145 @findex desktop-save
2146 @vindex desktop-save-mode
2147 You can save the desktop manually with the command @kbd{M-x
2148 desktop-save}. You can also enable automatic saving of the desktop
2149 when you exit Emacs, and automatic restoration of the last saved
2150 desktop when Emacs starts: use the Customization buffer (@pxref{Easy
2151 Customization}) to set @code{desktop-save-mode} to @code{t} for future
2152 sessions, or add this line in your init file (@pxref{Init File}):
2155 (desktop-save-mode 1)
2158 @vindex desktop-auto-save-timeout
2160 When @code{desktop-save-mode} is active and the desktop file exists,
2161 Emacs auto-saves it every @code{desktop-auto-save-timeout}
2162 seconds, if that is non-@code{nil} and non-zero.
2164 @findex desktop-change-dir
2165 @findex desktop-revert
2166 @vindex desktop-path
2167 If you turn on @code{desktop-save-mode} in your init file, then when
2168 Emacs starts, it looks for a saved desktop in the current directory.
2169 (More precisely, it looks in the directories specified by
2170 @var{desktop-path}, and uses the first desktop it finds.)
2171 Thus, you can have separate saved desktops in different directories,
2172 and the starting directory determines which one Emacs reloads. You
2173 can save the current desktop and reload one saved in another directory
2174 by typing @kbd{M-x desktop-change-dir}. Typing @kbd{M-x
2175 desktop-revert} reverts to the desktop previously reloaded.
2177 Specify the option @samp{--no-desktop} on the command line when you
2178 don't want it to reload any saved desktop. This turns off
2179 @code{desktop-save-mode} for the current session. Starting Emacs with
2180 the @samp{--no-init-file} option also disables desktop reloading,
2181 since it bypasses the init file, where @code{desktop-save-mode} is
2184 @vindex desktop-restore-eager
2185 By default, all the buffers in the desktop are restored at one go.
2186 However, this may be slow if there are a lot of buffers in the
2187 desktop. You can specify the maximum number of buffers to restore
2188 immediately with the variable @code{desktop-restore-eager}; the
2189 remaining buffers are restored ``lazily'', when Emacs is idle.
2191 @findex desktop-clear
2192 @vindex desktop-globals-to-clear
2193 @vindex desktop-clear-preserve-buffers-regexp
2194 Type @kbd{M-x desktop-clear} to empty the Emacs desktop. This kills
2195 all buffers except for internal ones, and clears the global variables
2196 listed in @code{desktop-globals-to-clear}. If you want this to
2197 preserve certain buffers, customize the variable
2198 @code{desktop-clear-preserve-buffers-regexp}, whose value is a regular
2199 expression matching the names of buffers not to kill.
2201 If you want to save minibuffer history from one session to
2202 another, use the @code{savehist} library.
2204 @node Recursive Edit
2205 @section Recursive Editing Levels
2206 @cindex recursive editing level
2207 @cindex editing level, recursive
2209 A @dfn{recursive edit} is a situation in which you are using Emacs
2210 commands to perform arbitrary editing while in the middle of another
2211 Emacs command. For example, when you type @kbd{C-r} inside of a
2212 @code{query-replace}, you enter a recursive edit in which you can change
2213 the current buffer. On exiting from the recursive edit, you go back to
2214 the @code{query-replace}. @xref{Query Replace}.
2217 @findex exit-recursive-edit
2218 @cindex exiting recursive edit
2219 @dfn{Exiting} the recursive edit means returning to the unfinished
2220 command, which continues execution. The command to exit is @kbd{C-M-c}
2221 (@code{exit-recursive-edit}).
2223 You can also @dfn{abort} the recursive edit. This is like exiting,
2224 but also quits the unfinished command immediately. Use the command
2225 @kbd{C-]} (@code{abort-recursive-edit}) to do this. @xref{Quitting}.
2227 The mode line shows you when you are in a recursive edit by displaying
2228 square brackets around the parentheses that always surround the major and
2229 minor mode names. Every window's mode line shows this in the same way,
2230 since being in a recursive edit is true of Emacs as a whole rather than
2231 any particular window or buffer.
2233 It is possible to be in recursive edits within recursive edits. For
2234 example, after typing @kbd{C-r} in a @code{query-replace}, you may type a
2235 command that enters the debugger. This begins a recursive editing level
2236 for the debugger, within the recursive editing level for @kbd{C-r}.
2237 Mode lines display a pair of square brackets for each recursive editing
2238 level currently in progress.
2240 Exiting the inner recursive edit (such as with the debugger @kbd{c}
2241 command) resumes the command running in the next level up. When that
2242 command finishes, you can then use @kbd{C-M-c} to exit another recursive
2243 editing level, and so on. Exiting applies to the innermost level only.
2244 Aborting also gets out of only one level of recursive edit; it returns
2245 immediately to the command level of the previous recursive edit. If you
2246 wish, you can then abort the next recursive editing level.
2248 Alternatively, the command @kbd{M-x top-level} aborts all levels of
2249 recursive edits, returning immediately to the top-level command
2250 reader. It also exits the minibuffer, if it is active.
2252 The text being edited inside the recursive edit need not be the same text
2253 that you were editing at top level. It depends on what the recursive edit
2254 is for. If the command that invokes the recursive edit selects a different
2255 buffer first, that is the buffer you will edit recursively. In any case,
2256 you can switch buffers within the recursive edit in the normal manner (as
2257 long as the buffer-switching keys have not been rebound). You could
2258 probably do all the rest of your editing inside the recursive edit,
2259 visiting files and all. But this could have surprising effects (such as
2260 stack overflow) from time to time. So remember to exit or abort the
2261 recursive edit when you no longer need it.
2263 In general, we try to minimize the use of recursive editing levels in
2264 GNU Emacs. This is because they constrain you to ``go back'' in a
2265 particular order---from the innermost level toward the top level. When
2266 possible, we present different activities in separate buffers so that
2267 you can switch between them as you please. Some commands switch to a
2268 new major mode which provides a command to switch back. These
2269 approaches give you more flexibility to go back to unfinished tasks in
2270 the order you choose.
2274 @cindex emulating other editors
2275 @cindex other editors
2278 @cindex PC key bindings
2279 @cindex scrolling all windows
2280 @cindex PC selection
2281 @cindex Motif key bindings
2282 @cindex Macintosh key bindings
2285 GNU Emacs can be programmed to emulate (more or less) most other
2286 editors. Standard facilities can emulate these:
2289 @item CRiSP/Brief (PC editor)
2291 @vindex crisp-override-meta-x
2292 @findex scroll-all-mode
2294 @cindex Brief emulation
2295 @cindex emulation of Brief
2297 @kbd{M-x crisp-mode} enables key bindings to emulate the CRiSP/Brief
2298 editor. Note that this rebinds @kbd{M-x} to exit Emacs unless you set
2299 the variable @code{crisp-override-meta-x}. You can also use the
2300 command @kbd{M-x scroll-all-mode} or set the variable
2301 @code{crisp-load-scroll-all} to emulate CRiSP's scroll-all feature
2302 (scrolling all windows together).
2304 @item EDT (DEC VMS editor)
2305 @findex edt-emulation-on
2306 @findex edt-emulation-off
2307 Turn on EDT emulation with @kbd{M-x edt-emulation-on}; restore normal
2308 command bindings with @kbd{M-x edt-emulation-off}.
2310 Most of the EDT emulation commands are keypad keys, and most standard
2311 Emacs key bindings are still available. The EDT emulation rebindings
2312 are done in the global keymap, so there is no problem switching
2313 buffers or major modes while in EDT emulation.
2315 @item TPU (DEC VMS editor)
2318 @kbd{M-x tpu-edt-on} turns on emulation of the TPU editor emulating EDT.
2320 @item vi (Berkeley editor)
2322 Viper is the newest emulator for vi. It implements several levels of
2323 emulation; level 1 is closest to vi itself, while level 5 departs
2324 somewhat from strict emulation to take advantage of the capabilities of
2325 Emacs. To invoke Viper, type @kbd{M-x viper-mode}; it will guide you
2326 the rest of the way and ask for the emulation level. @inforef{Top,
2329 @item vi (another emulator)
2331 @kbd{M-x vi-mode} enters a major mode that replaces the previously
2332 established major mode. All of the vi commands that, in real vi, enter
2333 ``input'' mode are programmed instead to return to the previous major
2334 mode. Thus, ordinary Emacs serves as vi's ``input'' mode.
2336 Because vi emulation works through major modes, it does not work
2337 to switch buffers during emulation. Return to normal Emacs first.
2339 If you plan to use vi emulation much, you probably want to bind a key
2340 to the @code{vi-mode} command.
2342 @item vi (alternate emulator)
2344 @kbd{M-x vip-mode} invokes another vi emulator, said to resemble real vi
2345 more thoroughly than @kbd{M-x vi-mode}. ``Input'' mode in this emulator
2346 is changed from ordinary Emacs so you can use @key{ESC} to go back to
2347 emulated vi command mode. To get from emulated vi command mode back to
2348 ordinary Emacs, type @kbd{C-z}.
2350 This emulation does not work through major modes, and it is possible
2351 to switch buffers in various ways within the emulator. It is not
2352 so necessary to assign a key to the command @code{vip-mode} as
2353 it is with @code{vi-mode} because terminating insert mode does
2356 @inforef{Top, VIP, vip}, for full information.
2358 @item WordStar (old wordprocessor)
2359 @findex wordstar-mode
2360 @kbd{M-x wordstar-mode} provides a major mode with WordStar-like
2365 @section Hyperlinking and Navigation Features
2367 The following subsections describe convenience features for handling
2368 URLs and other types of links occurring in Emacs buffer text.
2371 * Browse-URL:: Following URLs.
2372 * Goto Address mode:: Activating URLs.
2373 * FFAP:: Finding files etc. at point.
2377 @subsection Following URLs
2378 @cindex World Wide Web
2381 @findex browse-url-at-point
2382 @findex browse-url-at-mouse
2387 @item M-x browse-url @key{RET} @var{url} @key{RET}
2388 Load a URL into a Web browser.
2391 The Browse-URL package allows you to easily follow URLs from within
2392 Emacs. Most URLs are followed by invoking a web browser;
2393 @samp{mailto:} URLs are followed by invoking the @code{compose-mail}
2394 Emacs command to send mail to the specified address (@pxref{Sending
2397 The command @kbd{M-x browse-url} prompts for a URL, and follows it.
2398 If point is located near a plausible URL, that URL is offered as the
2399 default. The Browse-URL package also provides other commands which
2400 you might like to bind to keys, such as @code{browse-url-at-point} and
2401 @code{browse-url-at-mouse}.
2403 @vindex browse-url-mailto-function
2404 @vindex browse-url-browser-function
2405 You can customize Browse-URL's behavior via various options in the
2406 @code{browse-url} Customize group. In particular, the option
2407 @code{browse-url-mailto-function} lets you define how to follow
2408 @samp{mailto:} URLs, while @code{browse-url-browser-function} lets you
2409 define how to follow other types of URLs. For more information, view
2410 the package commentary by typing @kbd{C-h P browse-url @key{RET}}.
2412 @node Goto Address mode
2413 @subsection Activating URLs
2414 @findex goto-address-mode
2415 @cindex mode, Goto Address
2416 @cindex Goto Address mode
2417 @cindex URLs, activating
2420 @item M-x goto-address-mode
2421 Activate URLs and e-mail addresses in the current buffer.
2424 @kindex C-c RET @r{(Goto Address mode)}
2425 @findex goto-address-at-point
2426 You can make Emacs mark out URLs specially in the current buffer, by
2427 typing @kbd{M-x goto-address-mode}. When this buffer-local minor mode
2428 is enabled, it finds all the URLs in the buffer, highlights them, and
2429 turns them into clickable buttons. You can follow the URL by typing
2430 @kbd{C-c @key{RET}} (@code{goto-address-at-point}) while point is on
2431 its text; or by clicking with @kbd{Mouse-2}, or by clicking
2432 @kbd{Mouse-1} quickly (@pxref{Mouse References}). Following a URL is
2433 done by calling @code{browse-url} as a subroutine
2434 (@pxref{Browse-URL}).
2436 It can be useful to add @code{goto-address-mode} to mode hooks and
2437 hooks for displaying an incoming message
2438 (e.g., @code{rmail-show-message-hook} for Rmail, and
2439 @code{mh-show-mode-hook} for MH-E). This is not needed for Gnus,
2440 which has a similar feature of its own.
2443 @subsection Finding Files and URLs at Point
2444 @findex find-file-at-point
2446 @findex dired-at-point
2449 @cindex finding file at point
2451 The FFAP package replaces certain key bindings for finding files,
2452 such as @kbd{C-x C-f}, with commands that provide more sensitive
2453 defaults. These commands behave like the ordinary ones when given a
2454 prefix argument. Otherwise, they get the default file name or URL
2455 from the text around point. If what is found in the buffer has the
2456 form of a URL rather than a file name, the commands use
2457 @code{browse-url} to view it (@pxref{Browse-URL}).
2459 This feature is useful for following references in mail or news
2460 buffers, @file{README} files, @file{MANIFEST} files, and so on. For
2461 more information, view the package commentary by typing @kbd{C-h P
2464 @cindex FFAP minor mode
2466 To enable FFAP, type @kbd{M-x ffap-bindings}. This makes the
2467 following key bindings, and also installs hooks for additional FFAP
2468 functionality in Rmail, Gnus and VM article buffers.
2471 @item C-x C-f @var{filename} @key{RET}
2472 @kindex C-x C-f @r{(FFAP)}
2473 Find @var{filename}, guessing a default from text around point
2474 (@code{find-file-at-point}).
2476 @kindex C-x C-r @r{(FFAP)}
2477 @code{ffap-read-only}, analogous to @code{find-file-read-only}.
2479 @kindex C-x C-v @r{(FFAP)}
2480 @code{ffap-alternate-file}, analogous to @code{find-alternate-file}.
2481 @item C-x d @var{directory} @key{RET}
2482 @kindex C-x d @r{(FFAP)}
2483 Start Dired on @var{directory}, defaulting to the directory name at
2484 point (@code{dired-at-point}).
2486 @code{ffap-list-directory}, analogous to @code{list-directory}.
2488 @kindex C-x 4 f @r{(FFAP)}
2489 @code{ffap-other-window}, analogous to @code{find-file-other-window}.
2491 @code{ffap-read-only-other-window}, analogous to
2492 @code{find-file-read-only-other-window}.
2494 @code{ffap-dired-other-window}, like @code{dired-other-window}.
2496 @kindex C-x 5 f @r{(FFAP)}
2497 @code{ffap-other-frame}, analogous to @code{find-file-other-frame}.
2499 @code{ffap-read-only-other-frame}, analogous to
2500 @code{find-file-read-only-other-frame}.
2502 @code{ffap-dired-other-frame}, analogous to @code{dired-other-frame}.
2504 Search buffer for next file name or URL, then find that file or URL.
2506 @kindex S-Mouse-3 @r{(FFAP)}
2507 @code{ffap-at-mouse} finds the file guessed from text around the position
2510 @kindex C-S-Mouse-3 @r{(FFAP)}
2511 Display a menu of files and URLs mentioned in current buffer, then
2512 find the one you select (@code{ffap-menu}).
2516 @section Other Amusements
2519 @findex animate-birthday-present
2521 The @code{animate} package makes text dance (e.g., @kbd{M-x
2522 animate-birthday-present}).
2528 @kbd{M-x blackbox}, @kbd{M-x mpuz} and @kbd{M-x 5x5} are puzzles.
2529 @code{blackbox} challenges you to determine the location of objects
2530 inside a box by tomography. @code{mpuz} displays a multiplication
2531 puzzle with letters standing for digits in a code that you must
2532 guess---to guess a value, type a letter and then the digit you think it
2533 stands for. The aim of @code{5x5} is to fill in all the squares.
2536 @kbd{M-x bubbles} is a game in which the object is to remove as many
2537 bubbles as you can in the smallest number of moves.
2541 @cindex cryptanalysis
2542 @kbd{M-x decipher} helps you to cryptanalyze a buffer which is
2543 encrypted in a simple monoalphabetic substitution cipher.
2545 @findex dissociated-press
2546 @kbd{M-x dissociated-press} scrambles the text in the current Emacs
2547 buffer, word by word or character by character, writing its output to
2548 a buffer named @file{*Dissociation*}. A positive argument tells it to
2549 operate character by character, and specifies the number of overlap
2550 characters. A negative argument tells it to operate word by word, and
2551 specifies the number of overlap words. Dissociated Press produces
2552 results fairly like those of a Markov chain, but is however, an
2553 independent, ignoriginal invention; it techniquitously copies several
2554 consecutive characters from the sample text between random jumps,
2555 unlike a Markov chain which would jump randomly after each word or
2556 character. Keep dissociwords out of your documentation, if you want
2557 it to be well userenced and properbose.
2560 @kbd{M-x dunnet} runs an text-based adventure game.
2564 If you want a little more personal involvement, try @kbd{M-x gomoku},
2565 which plays the game Go Moku with you.
2567 @cindex tower of Hanoi
2569 If you are a little bit bored, you can try @kbd{M-x hanoi}. If you are
2570 considerably bored, give it a numeric argument. If you are very, very
2571 bored, try an argument of 9. Sit back and watch.
2575 @kbd{M-x life} runs Conway's ``Life'' cellular automaton.
2578 @cindex landmark game
2579 @kbd{M-x landmark} runs a relatively non-participatory game in which
2580 a robot attempts to maneuver towards a tree at the center of the
2581 window based on unique olfactory cues from each of the four
2584 @findex morse-region
2585 @findex unmorse-region
2588 @cindex --/---/.-./.../.
2589 @kbd{M-x morse-region} converts the text in the region to Morse
2590 code; @kbd{M-x unmorse-region} converts it back. @kbd{M-x
2591 nato-region} converts the text in the region to NATO phonetic
2592 alphabet; @kbd{M-x denato-region} converts it back.
2600 @kbd{M-x pong}, @kbd{M-x snake} and @kbd{M-x tetris} are
2601 implementations of the well-known Pong, Snake and Tetris games.
2605 @kbd{M-x solitaire} plays a game of solitaire in which you jump pegs
2609 The command @kbd{M-x zone} plays games with the display when Emacs
2614 Finally, if you find yourself frustrated, try describing your
2615 problems to the famous psychotherapist Eliza. Just do @kbd{M-x
2616 doctor}. End each input by typing @key{RET} twice.