1 @c This is part of the Emacs manual.
2 @c Copyright (C) 1985, 1986, 1987, 1993, 1994, 1995, 1997, 2000, 2001,
3 @c 2002, 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
4 @c See file emacs.texi for copying conditions.
6 @chapter Miscellaneous Commands
8 This chapter contains several brief topics that do not fit anywhere
9 else: reading netnews, running shell commands and shell subprocesses,
10 using a single shared Emacs for utilities that expect to run an editor
11 as a subprocess, printing hardcopy, sorting text, narrowing display to
12 part of the buffer, editing double-column files and binary files,
13 saving an Emacs session for later resumption, following hyperlinks,
14 browsing images, emulating other editors, and various diversions and
23 @node Gnus, Shell, Calendar/Diary, Top
26 @cindex reading netnews
28 Gnus is an Emacs package primarily designed for reading and posting
29 Usenet news. It can also be used to read and respond to messages from a
30 number of other sources---mail, remote directories, digests, and so on.
32 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{M-x info} and then select the Gnus
42 To start Gnus, type @kbd{M-x gnus @key{RET}}.
45 * Buffers of Gnus:: The group, summary, and article buffers.
46 * Gnus Startup:: What you should know about starting Gnus.
47 * Summary of Gnus:: A short description of the basic Gnus commands.
51 @subsection Gnus Buffers
53 Unlike most Emacs packages, Gnus uses several buffers to display
54 information and to receive commands. The three Gnus buffers users use
55 most are the @dfn{group buffer}, the @dfn{summary buffer} and the
58 The @dfn{group buffer} contains a list of newsgroups. This is the
59 first buffer Gnus displays when it starts up. It normally displays
60 only the groups to which you subscribe and that contain unread
61 articles. Use this buffer to select a specific group.
63 The @dfn{summary buffer} lists one line for each article in a single
64 group. By default, the author, the subject and the line number are
65 displayed for each article, but this is customizable, like most aspects
66 of Gnus display. The summary buffer is created when you select a group
67 in the group buffer, and is killed when you exit the group. Use this
68 buffer to select an article.
70 The @dfn{article buffer} displays the article. In normal Gnus usage,
71 you see this buffer but you don't select it---all useful
72 article-oriented commands work in the summary buffer. But you can
73 select the article buffer, and execute all Gnus commands from that
74 buffer, if you want to.
77 @subsection When Gnus Starts Up
79 At startup, Gnus reads your @file{.newsrc} news initialization file
80 and attempts to communicate with the local news server, which is a
81 repository of news articles. The news server need not be the same
82 computer you are logged in on.
84 If you start Gnus and connect to the server, but do not see any
85 newsgroups listed in the group buffer, type @kbd{L} or @kbd{A k} to get
86 a listing of all the groups. Then type @kbd{u} to toggle
87 subscription to groups.
89 The first time you start Gnus, Gnus subscribes you to a few selected
90 groups. All other groups start out as @dfn{killed groups} for you; you
91 can list them with @kbd{A k}. All new groups that subsequently come to
92 exist at the news server become @dfn{zombie groups} for you; type @kbd{A
93 z} to list them. You can subscribe to a group shown in these lists
94 using the @kbd{u} command.
96 When you quit Gnus with @kbd{q}, it automatically records in your
97 @file{.newsrc} and @file{.newsrc.eld} initialization files the
98 subscribed or unsubscribed status of all groups. You should normally
99 not edit these files manually, but you may if you know how.
101 @node Summary of Gnus
102 @subsection Summary of Gnus Commands
104 Reading news is a two-step process:
108 Choose a group in the group buffer.
111 Select articles from the summary buffer. Each article selected is
112 displayed in the article buffer in a large window, below the summary
113 buffer in its small window.
116 Each Gnus buffer has its own special commands; the meanings of any
117 given key in the various Gnus buffers are usually analogous, even if
118 not identical. Here are commands for the group and summary buffers:
121 @kindex q @r{(Gnus Group mode)}
122 @findex gnus-group-exit
124 In the group buffer, update your @file{.newsrc} initialization file
127 In the summary buffer, exit the current group and return to the
128 group buffer. Thus, typing @kbd{q} twice quits Gnus.
130 @kindex L @r{(Gnus Group mode)}
131 @findex gnus-group-list-all-groups
133 In the group buffer, list all the groups available on your news
134 server (except those you have killed). This may be a long list!
136 @kindex l @r{(Gnus Group mode)}
137 @findex gnus-group-list-groups
139 In the group buffer, list only the groups to which you subscribe and
140 which contain unread articles.
142 @kindex u @r{(Gnus Group mode)}
143 @findex gnus-group-unsubscribe-current-group
144 @cindex subscribe groups
145 @cindex unsubscribe groups
147 In the group buffer, unsubscribe from (or subscribe to) the group listed
148 in the line that point is on. When you quit Gnus by typing @kbd{q},
149 Gnus lists in your @file{.newsrc} file which groups you have subscribed
150 to. The next time you start Gnus, you won't see this group,
151 because Gnus normally displays only subscribed-to groups.
153 @kindex C-k @r{(Gnus)}
154 @findex gnus-group-kill-group
156 In the group buffer, ``kill'' the current line's group---don't
157 even list it in @file{.newsrc} from now on. This affects future
158 Gnus sessions as well as the present session.
160 When you quit Gnus by typing @kbd{q}, Gnus writes information
161 in the file @file{.newsrc} describing all newsgroups except those you
164 @kindex SPC @r{(Gnus)}
165 @findex gnus-group-read-group
167 In the group buffer, select the group on the line under the cursor
168 and display the first unread article in that group.
171 In the summary buffer,
175 Select the article on the line under the cursor if none is selected.
178 Scroll the text of the selected article (if there is one).
181 Select the next unread article if at the end of the current article.
184 Thus, you can move through all the articles by repeatedly typing @key{SPC}.
186 @kindex DEL @r{(Gnus)}
188 In the group buffer, move point to the previous group containing
191 @findex gnus-summary-prev-page
192 In the summary buffer, scroll the text of the article backwards.
195 @findex gnus-group-next-unread-group
196 @findex gnus-summary-next-unread-article
198 Move point to the next unread group, or select the next unread article.
201 @findex gnus-group-prev-unread-group
202 @findex gnus-summary-prev-unread-article
204 Move point to the previous unread group, or select the previous
207 @kindex C-n @r{(Gnus Group mode)}
208 @findex gnus-group-next-group
209 @kindex C-p @r{(Gnus Group mode)}
210 @findex gnus-group-prev-group
211 @kindex C-n @r{(Gnus Summary mode)}
212 @findex gnus-summary-next-subject
213 @kindex C-p @r{(Gnus Summary mode)}
214 @findex gnus-summary-prev-subject
217 Move point to the next or previous item, even if it is marked as read.
218 This does not select the article or group on that line.
220 @kindex s @r{(Gnus Summary mode)}
221 @findex gnus-summary-isearch-article
223 In the summary buffer, do an incremental search of the current text in
224 the article buffer, just as if you switched to the article buffer and
227 @kindex M-s @r{(Gnus Summary mode)}
228 @findex gnus-summary-search-article-forward
229 @item M-s @var{regexp} @key{RET}
230 In the summary buffer, search forward for articles containing a match
237 @subsection Where to Look Further
239 @c Too many references to the name of the manual if done with xref in TeX!
240 Gnus is powerful and customizable. Here are references to a few
246 additional topics in @cite{The Gnus Manual}:
250 Follow discussions on specific topics.@*
251 See section ``Threading.''
254 Read digests. See section ``Document Groups.''
257 Refer to and jump to the parent of the current article.@*
258 See section ``Finding the Parent.''
261 Refer to articles by using Message-IDs included in the messages.@*
262 See section ``Article Keymap.''
265 Save articles. See section ``Saving Articles.''
268 Have Gnus score articles according to various criteria, like author
269 name, subject, or string in the body of the articles.@*
270 See section ``Scoring.''
273 Send an article to a newsgroup.@*
274 See section ``Composing Messages.''
280 Follow discussions on specific topics.@*
281 @xref{Threading, , Reading Based on Conversation Threads,
282 gnus, The Gnus Manual}.
285 Read digests. @xref{Document Groups, , , gnus, The Gnus Manual}.
288 Refer to and jump to the parent of the current article.@*
289 @xref{Finding the Parent, , , gnus, The Gnus Manual}.
292 Refer to articles by using Message-IDs included in the messages.@*
293 @xref{Article Keymap, , , gnus, The Gnus Manual}.
296 Save articles. @xref{Saving Articles, , , gnus, The Gnus Manual}.
299 Have Gnus score articles according to various criteria, like author
300 name, subject, or string in the body of the articles.@*
301 @xref{Scoring, , , gnus, The Gnus Manual}.
304 Send an article to a newsgroup.@*
305 @xref{Composing Messages, , , gnus, The Gnus Manual}.
310 @node Shell, Emacs Server, Gnus, Top
311 @section Running Shell Commands from Emacs
313 @cindex shell commands
315 Emacs has commands for passing single command lines to inferior shell
316 processes; it can also run a shell interactively with input and output
317 to an Emacs buffer named @samp{*shell*} or run a shell inside a terminal
321 @item M-! @var{cmd} @key{RET}
322 Run the shell command line @var{cmd} and display the output
323 (@code{shell-command}).
324 @item M-| @var{cmd} @key{RET}
325 Run the shell command line @var{cmd} with region contents as input;
326 optionally replace the region with the output
327 (@code{shell-command-on-region}).
329 Run a subshell with input and output through an Emacs buffer.
330 You can then give commands interactively.
332 Run a subshell with input and output through an Emacs buffer.
333 You can then give commands interactively.
334 Full terminal emulation is available.
337 @kbd{M-x eshell} invokes a shell implemented entirely in Emacs. It
338 is documented in a separate manual. @xref{Top,Eshell,Eshell, eshell,
339 Eshell: The Emacs Shell}.
342 * Single Shell:: How to run one shell command and return.
343 * Interactive Shell:: Permanent shell taking input via Emacs.
344 * Shell Mode:: Special Emacs commands used with permanent shell.
345 * Shell Prompts:: Two ways to recognize shell prompts.
346 * History: Shell History. Repeating previous commands in a shell buffer.
347 * Directory Tracking:: Keeping track when the subshell changes directory.
348 * Options: Shell Options. Options for customizing Shell mode.
349 * Terminal emulator:: An Emacs window as a terminal emulator.
350 * Term Mode:: Special Emacs commands used in Term mode.
351 * Paging in Term:: Paging in the terminal emulator.
352 * Remote Host:: Connecting to another computer.
356 @subsection Single Shell Commands
359 @findex shell-command
360 @kbd{M-!} (@code{shell-command}) reads a line of text using the
361 minibuffer and executes it as a shell command in a subshell made just
362 for that command. Standard input for the command comes from the null
363 device. If the shell command produces any output, the output appears
364 either in the echo area (if it is short), or in an Emacs buffer named
365 @samp{*Shell Command Output*}, which is displayed in another window
366 but not selected (if the output is long).
368 For instance, one way to decompress a file @file{foo.gz} from Emacs
369 is to type @kbd{M-! gunzip foo.gz @key{RET}}. That shell command
370 normally creates the file @file{foo} and produces no terminal output.
372 A numeric argument, as in @kbd{M-1 M-!}, says to insert terminal
373 output into the current buffer instead of a separate buffer. It puts
374 point before the output, and sets the mark after the output. For
375 instance, @kbd{M-1 M-! gunzip < foo.gz @key{RET}} would insert the
376 uncompressed equivalent of @file{foo.gz} into the current buffer.
378 If the shell command line ends in @samp{&}, it runs asynchronously.
379 For a synchronous shell command, @code{shell-command} returns the
380 command's exit status (0 means success), when it is called from a Lisp
381 program. You do not get any status information for an asynchronous
382 command, since it hasn't finished yet when @code{shell-command} returns.
385 @findex shell-command-on-region
386 @kbd{M-|} (@code{shell-command-on-region}) is like @kbd{M-!} but
387 passes the contents of the region as the standard input to the shell
388 command, instead of no input. With a numeric argument, meaning insert
389 the output in the current buffer, it deletes the old region and the
390 output replaces it as the contents of the region. It returns the
391 command's exit status, like @kbd{M-!}.
393 One use for @kbd{M-|} is to run @code{gpg} to see what keys are in
394 the buffer. For instance, if the buffer contains a GPG key, type
395 @kbd{C-x h M-| gpg @key{RET}} to feed the entire buffer contents to
396 the @code{gpg} program. That program will ignore everything except
397 the encoded keys, and will output a list of the keys the buffer
400 @vindex shell-file-name
401 Both @kbd{M-!} and @kbd{M-|} use @code{shell-file-name} to specify
402 the shell to use. This variable is initialized based on your
403 @env{SHELL} environment variable when Emacs is started. If the file
404 name is relative, Emacs searches the directories in the list
405 @code{exec-path}; this list is initialized based on the environment
406 variable @env{PATH} when Emacs is started. Your @file{.emacs} file
407 can override either or both of these default initializations.
409 Both @kbd{M-!} and @kbd{M-|} wait for the shell command to complete,
410 unless you end the command with @samp{&} to make it asynchronous. To
411 stop waiting, type @kbd{C-g} to quit; that terminates the shell
412 command with the signal @code{SIGINT}---the same signal that @kbd{C-c}
413 normally generates in the shell. Emacs then waits until the command
414 actually terminates. If the shell command doesn't stop (because it
415 ignores the @code{SIGINT} signal), type @kbd{C-g} again; this sends
416 the command a @code{SIGKILL} signal which is impossible to ignore.
418 Asynchronous commands ending in @samp{&} feed their output into
419 the buffer @samp{*Async Shell Command*}. Output arrives in that
420 buffer regardless of whether it is visible in a window.
422 To specify a coding system for @kbd{M-!} or @kbd{M-|}, use the command
423 @kbd{C-x @key{RET} c} immediately beforehand. @xref{Communication Coding}.
425 @vindex shell-command-default-error-buffer
426 Error output from these commands is normally intermixed with the
427 regular output. But if the variable
428 @code{shell-command-default-error-buffer} has a string as value, and
429 it's the name of a buffer, @kbd{M-!} and @kbd{M-|} insert error output
430 before point in that buffer.
432 @node Interactive Shell
433 @subsection Interactive Inferior Shell
436 To run a subshell interactively, putting its typescript in an Emacs
437 buffer, use @kbd{M-x shell}. This creates (or reuses) a buffer named
438 @samp{*shell*} and runs a subshell with input coming from and output going
439 to that buffer. That is to say, any ``terminal output'' from the subshell
440 goes into the buffer, advancing point, and any ``terminal input'' for
441 the subshell comes from text in the buffer. To give input to the subshell,
442 go to the end of the buffer and type the input, terminated by @key{RET}.
444 Emacs does not wait for the subshell to do anything. You can switch
445 windows or buffers and edit them while the shell is waiting, or while it is
446 running a command. Output from the subshell waits until Emacs has time to
447 process it; this happens whenever Emacs is waiting for keyboard input or
450 @cindex @code{comint-highlight-input} face
451 @cindex @code{comint-highlight-prompt} face
452 Input lines, once you submit them, are displayed using the face
453 @code{comint-highlight-input}, and prompts are displayed using the
454 face @code{comint-highlight-prompt}. This makes it easier to see
455 previous input lines in the buffer. @xref{Faces}.
457 To make multiple subshells, you can invoke @kbd{M-x shell} with a
458 prefix argument (e.g. @kbd{C-u M-x shell}), which will read a buffer
459 name and create (or reuse) a subshell in that buffer. You can also
460 rename the @samp{*shell*} buffer using @kbd{M-x rename-uniquely}, then
461 create a new @samp{*shell*} buffer using plain @kbd{M-x shell}.
462 Subshells in different buffers run independently and in parallel.
464 @vindex explicit-shell-file-name
465 @cindex environment variables for subshells
466 @cindex @env{ESHELL} environment variable
467 @cindex @env{SHELL} environment variable
468 The file name used to load the subshell is the value of the variable
469 @code{explicit-shell-file-name}, if that is non-@code{nil}. Otherwise,
470 the environment variable @env{ESHELL} is used, or the environment
471 variable @env{SHELL} if there is no @env{ESHELL}. If the file name
472 specified is relative, the directories in the list @code{exec-path} are
473 searched; this list is initialized based on the environment variable
474 @env{PATH} when Emacs is started. Your @file{.emacs} file can override
475 either or both of these default initializations.
477 Emacs sends the new shell the contents of the file
478 @file{~/.emacs_@var{shellname}} as input, if it exists, where
479 @var{shellname} is the name of the file that the shell was loaded
480 from. For example, if you use bash, the file sent to it is
481 @file{~/.emacs_bash}.
483 To specify a coding system for the shell, you can use the command
484 @kbd{C-x @key{RET} c} immediately before @kbd{M-x shell}. You can
485 also change the coding system for a running subshell by typing
486 @kbd{C-x @key{RET} p} in the shell buffer. @xref{Communication
489 @cindex @env{EMACS} environment variable
490 Unless the environment variable @env{EMACS} is already defined,
491 Emacs defines it in the subshell, with value @code{t}. A shell script
492 can check this variable to determine whether it has been run from an
496 @subsection Shell Mode
500 Shell buffers use Shell mode, which defines several special keys
501 attached to the @kbd{C-c} prefix. They are chosen to resemble the usual
502 editing and job control characters present in shells that are not under
503 Emacs, except that you must type @kbd{C-c} first. Here is a complete list
504 of the special key bindings of Shell mode:
508 @kindex RET @r{(Shell mode)}
509 @findex comint-send-input
510 At end of buffer send line as input; otherwise, copy current line to
511 end of buffer and send it (@code{comint-send-input}). Copying a line
512 in this way omits any prompt at the beginning of the line (text output
513 by programs preceding your input). @xref{Shell Prompts}, for how
514 Shell mode recognizes prompts.
517 @kindex TAB @r{(Shell mode)}
518 @findex comint-dynamic-complete
519 Complete the command name or file name before point in the shell buffer
520 (@code{comint-dynamic-complete}). @key{TAB} also completes history
521 references (@pxref{History References}) and environment variable names.
523 @vindex shell-completion-fignore
524 @vindex comint-completion-fignore
525 The variable @code{shell-completion-fignore} specifies a list of file
526 name extensions to ignore in Shell mode completion. The default
527 setting is @code{nil}, but some users prefer @code{("~" "#" "%")} to
528 ignore file names ending in @samp{~}, @samp{#} or @samp{%}. Other
529 related Comint modes use the variable @code{comint-completion-fignore}
533 @kindex M-? @r{(Shell mode)}
534 @findex comint-dynamic-list-filename@dots{}
535 Display temporarily a list of the possible completions of the file name
536 before point in the shell buffer
537 (@code{comint-dynamic-list-filename-completions}).
540 @kindex C-d @r{(Shell mode)}
541 @findex comint-delchar-or-maybe-eof
542 Either delete a character or send @acronym{EOF}
543 (@code{comint-delchar-or-maybe-eof}). Typed at the end of the shell
544 buffer, @kbd{C-d} sends @acronym{EOF} to the subshell. Typed at any other
545 position in the buffer, @kbd{C-d} deletes a character as usual.
548 @kindex C-c C-a @r{(Shell mode)}
549 @findex comint-bol-or-process-mark
550 Move to the beginning of the line, but after the prompt if any
551 (@code{comint-bol-or-process-mark}). If you repeat this command twice
552 in a row, the second time it moves back to the process mark, which is
553 the beginning of the input that you have not yet sent to the subshell.
554 (Normally that is the same place---the end of the prompt on this
555 line---but after @kbd{C-c @key{SPC}} the process mark may be in a
559 Accumulate multiple lines of input, then send them together. This
560 command inserts a newline before point, but does not send the preceding
561 text as input to the subshell---at least, not yet. Both lines, the one
562 before this newline and the one after, will be sent together (along with
563 the newline that separates them), when you type @key{RET}.
566 @kindex C-c C-u @r{(Shell mode)}
567 @findex comint-kill-input
568 Kill all text pending at end of buffer to be sent as input
569 (@code{comint-kill-input}). If point is not at end of buffer,
570 this only kills the part of this text that precedes point.
573 @kindex C-c C-w @r{(Shell mode)}
574 Kill a word before point (@code{backward-kill-word}).
577 @kindex C-c C-c @r{(Shell mode)}
578 @findex comint-interrupt-subjob
579 Interrupt the shell or its current subjob if any
580 (@code{comint-interrupt-subjob}). This command also kills
581 any shell input pending in the shell buffer and not yet sent.
584 @kindex C-c C-z @r{(Shell mode)}
585 @findex comint-stop-subjob
586 Stop the shell or its current subjob if any (@code{comint-stop-subjob}).
587 This command also kills any shell input pending in the shell buffer and
591 @findex comint-quit-subjob
592 @kindex C-c C-\ @r{(Shell mode)}
593 Send quit signal to the shell or its current subjob if any
594 (@code{comint-quit-subjob}). This command also kills any shell input
595 pending in the shell buffer and not yet sent.
598 @kindex C-c C-o @r{(Shell mode)}
599 @findex comint-delete-output
600 Delete the last batch of output from a shell command
601 (@code{comint-delete-output}). This is useful if a shell command spews
602 out lots of output that just gets in the way. This command used to be
603 called @code{comint-kill-output}.
606 @kindex C-c C-s @r{(Shell mode)}
607 @findex comint-write-output
608 Write the last batch of output from a shell command to a file
609 (@code{comint-write-output}). With a prefix argument, the file is
610 appended to instead. Any prompt at the end of the output is not
615 @kindex C-c C-r @r{(Shell mode)}
616 @kindex C-M-l @r{(Shell mode)}
617 @findex comint-show-output
618 Scroll to display the beginning of the last batch of output at the top
619 of the window; also move the cursor there (@code{comint-show-output}).
622 @kindex C-c C-e @r{(Shell mode)}
623 @findex comint-show-maximum-output
624 Scroll to put the end of the buffer at the bottom of the window
625 (@code{comint-show-maximum-output}).
628 @kindex C-c C-f @r{(Shell mode)}
629 @findex shell-forward-command
630 @vindex shell-command-regexp
631 Move forward across one shell command, but not beyond the current line
632 (@code{shell-forward-command}). The variable @code{shell-command-regexp}
633 specifies how to recognize the end of a command.
636 @kindex C-c C-b @r{(Shell mode)}
637 @findex shell-backward-command
638 Move backward across one shell command, but not beyond the current line
639 (@code{shell-backward-command}).
642 Ask the shell what its current directory is, so that Emacs can agree
645 @item M-x send-invisible @key{RET} @var{text} @key{RET}
646 @findex send-invisible
647 Send @var{text} as input to the shell, after reading it without
648 echoing. This is useful when a shell command runs a program that asks
651 Please note that Emacs will not echo passwords by default. If you
652 really want them to be echoed, evaluate the following Lisp
656 (remove-hook 'comint-output-filter-functions
657 'comint-watch-for-password-prompt)
660 @item M-x comint-continue-subjob
661 @findex comint-continue-subjob
662 Continue the shell process. This is useful if you accidentally suspend
663 the shell process.@footnote{You should not suspend the shell process.
664 Suspending a subjob of the shell is a completely different matter---that
665 is normal practice, but you must use the shell to continue the subjob;
666 this command won't do it.}
668 @item M-x comint-strip-ctrl-m
669 @findex comint-strip-ctrl-m
670 Discard all control-M characters from the current group of shell output.
671 The most convenient way to use this command is to make it run
672 automatically when you get output from the subshell. To do that,
673 evaluate this Lisp expression:
676 (add-hook 'comint-output-filter-functions
677 'comint-strip-ctrl-m)
680 @item M-x comint-truncate-buffer
681 @findex comint-truncate-buffer
682 This command truncates the shell buffer to a certain maximum number of
683 lines, specified by the variable @code{comint-buffer-maximum-size}.
684 Here's how to do this automatically each time you get output from the
688 (add-hook 'comint-output-filter-functions
689 'comint-truncate-buffer)
695 Shell mode is a derivative of Comint mode, a general-purpose mode for
696 communicating with interactive subprocesses. Most of the features of
697 Shell mode actually come from Comint mode, as you can see from the
698 command names listed above. The special features of Shell mode include
699 the directory tracking feature, and a few user commands.
701 Other Emacs features that use variants of Comint mode include GUD
702 (@pxref{Debuggers}) and @kbd{M-x run-lisp} (@pxref{External Lisp}).
705 You can use @kbd{M-x comint-run} to execute any program of your choice
706 in a subprocess using unmodified Comint mode---without the
707 specializations of Shell mode.
710 @subsection Shell Prompts
712 @vindex shell-prompt-pattern
713 @vindex comint-prompt-regexp
714 @vindex comint-use-prompt-regexp
715 @cindex prompt, shell
716 A prompt is text output by a program to show that it is ready to
717 accept new user input. Normally, Comint mode (and thus Shell mode)
718 considers the prompt to be any text output by a program at the
719 beginning of an input line. However, if the variable
720 @code{comint-use-prompt-regexp} is non-@code{nil}, then Comint mode
721 uses a regular expression to recognize prompts. In Shell mode,
722 @code{shell-prompt-pattern} specifies the regular expression.
724 The value of @code{comint-use-prompt-regexp} also affects many
725 motion and paragraph commands. If the value is non-@code{nil}, the
726 general Emacs motion commands behave as they normally do in buffers
727 without special text properties. However, if the value is @code{nil},
728 the default, then Comint mode divides the buffer into two types of
729 ``fields'' (ranges of consecutive characters having the same
730 @code{field} text property): input and output. Prompts are part of
731 the output. Most Emacs motion commands do not cross field boundaries,
732 unless they move over multiple lines. For instance, when point is in
733 input on the same line as a prompt, @kbd{C-a} puts point at the
734 beginning of the input if @code{comint-use-prompt-regexp} is
735 @code{nil} and at the beginning of the line otherwise.
737 In Shell mode, only shell prompts start new paragraphs. Thus, a
738 paragraph consists of a prompt and the input and output that follow
739 it. However, if @code{comint-use-prompt-regexp} is @code{nil}, the
740 default, most paragraph commands do not cross field boundaries. This
741 means that prompts, ranges of input, and ranges of non-prompt output
742 behave mostly like separate paragraphs; with this setting, numeric
743 arguments to most paragraph commands yield essentially undefined
744 behavior. For the purpose of finding paragraph boundaries, Shell mode
745 uses @code{shell-prompt-pattern}, regardless of
746 @code{comint-use-prompt-regexp}.
749 @subsection Shell Command History
751 Shell buffers support three ways of repeating earlier commands. You
752 can use keys like those used for the minibuffer history; these work
753 much as they do in the minibuffer, inserting text from prior commands
754 while point remains always at the end of the buffer. You can move
755 through the buffer to previous inputs in their original place, then
756 resubmit them or copy them to the end. Or you can use a
757 @samp{!}-style history reference.
760 * Ring: Shell Ring. Fetching commands from the history list.
761 * Copy: Shell History Copying. Moving to a command and then copying it.
762 * History References:: Expanding @samp{!}-style history references.
766 @subsubsection Shell History Ring
769 @findex comint-previous-input
770 @kindex M-p @r{(Shell mode)}
773 Fetch the next earlier old shell command.
775 @kindex M-n @r{(Shell mode)}
776 @findex comint-next-input
779 Fetch the next later old shell command.
781 @kindex M-r @r{(Shell mode)}
782 @kindex M-s @r{(Shell mode)}
783 @findex comint-previous-matching-input
784 @findex comint-next-matching-input
785 @item M-r @var{regexp} @key{RET}
786 @itemx M-s @var{regexp} @key{RET}
787 Search backwards or forwards for old shell commands that match @var{regexp}.
790 @kindex C-c C-x @r{(Shell mode)}
791 @findex comint-get-next-from-history
792 Fetch the next subsequent command from the history.
795 @kindex C-c . @r{(Shell mode)}
796 @findex comint-input-previous-argument
797 Fetch one argument from an old shell command.
800 @kindex C-c C-l @r{(Shell mode)}
801 @findex comint-dynamic-list-input-ring
802 Display the buffer's history of shell commands in another window
803 (@code{comint-dynamic-list-input-ring}).
806 Shell buffers provide a history of previously entered shell commands. To
807 reuse shell commands from the history, use the editing commands @kbd{M-p},
808 @kbd{M-n}, @kbd{M-r} and @kbd{M-s}. These work just like the minibuffer
809 history commands except that they operate on the text at the end of the
810 shell buffer, where you would normally insert text to send to the shell.
812 @kbd{M-p} fetches an earlier shell command to the end of the shell
813 buffer. Successive use of @kbd{M-p} fetches successively earlier
814 shell commands, each replacing any text that was already present as
815 potential shell input. @kbd{M-n} does likewise except that it finds
816 successively more recent shell commands from the buffer.
817 @kbd{C-@key{UP}} works like @kbd{M-p}, and @kbd{C-@key{DOWN}} like
820 The history search commands @kbd{M-r} and @kbd{M-s} read a regular
821 expression and search through the history for a matching command. Aside
822 from the choice of which command to fetch, they work just like @kbd{M-p}
823 and @kbd{M-n}. If you enter an empty regexp, these commands reuse the
824 same regexp used last time.
826 When you find the previous input you want, you can resubmit it by
827 typing @key{RET}, or you can edit it first and then resubmit it if you
828 wish. Any partial input you were composing before navigating the
829 history list is restored when you go to the beginning or end of the
832 Often it is useful to reexecute several successive shell commands that
833 were previously executed in sequence. To do this, first find and
834 reexecute the first command of the sequence. Then type @kbd{C-c C-x};
835 that will fetch the following command---the one that follows the command
836 you just repeated. Then type @key{RET} to reexecute this command. You
837 can reexecute several successive commands by typing @kbd{C-c C-x
838 @key{RET}} over and over.
840 The command @kbd{C-c .}@: (@code{comint-input-previous-argument})
841 copies an individual argument from a previous command, like @kbd{ESC
842 .} in Bash. The simplest use copies the last argument from the
843 previous shell command. With a prefix argument @var{n}, it copies the
844 @var{n}th argument instead. Repeating @kbd{C-c .} copies from an
845 earlier shell command instead, always using the same value of @var{n}
846 (don't give a prefix argument when you repeat the @kbd{C-c .}
849 These commands get the text of previous shell commands from a special
850 history list, not from the shell buffer itself. Thus, editing the shell
851 buffer, or even killing large parts of it, does not affect the history
852 that these commands access.
854 @vindex shell-input-ring-file-name
855 Some shells store their command histories in files so that you can
856 refer to commands from previous shell sessions. Emacs reads
857 the command history file for your chosen shell, to initialize its own
858 command history. The file name is @file{~/.bash_history} for bash,
859 @file{~/.sh_history} for ksh, and @file{~/.history} for other shells.
861 @node Shell History Copying
862 @subsubsection Shell History Copying
865 @kindex C-c C-p @r{(Shell mode)}
866 @findex comint-previous-prompt
868 Move point to the previous prompt (@code{comint-previous-prompt}).
870 @kindex C-c C-n @r{(Shell mode)}
871 @findex comint-next-prompt
873 Move point to the following prompt (@code{comint-next-prompt}).
875 @kindex C-c RET @r{(Shell mode)}
876 @findex comint-copy-old-input
878 Copy the input command which point is in, inserting the copy at the end
879 of the buffer (@code{comint-copy-old-input}). This is useful if you
880 move point back to a previous command. After you copy the command, you
881 can submit the copy as input with @key{RET}. If you wish, you can
882 edit the copy before resubmitting it. If you use this command on an
883 output line, it copies that line to the end of the buffer.
886 If @code{comint-use-prompt-regexp} is @code{nil} (the default), copy
887 the old input command that you click on, inserting the copy at the end
888 of the buffer (@code{comint-insert-input}). If
889 @code{comint-use-prompt-regexp} is non-@code{nil}, or if the click is
890 not over old input, just yank as usual.
893 Moving to a previous input and then copying it with @kbd{C-c
894 @key{RET}} or @kbd{Mouse-2} produces the same results---the same
895 buffer contents---that you would get by using @kbd{M-p} enough times
896 to fetch that previous input from the history list. However, @kbd{C-c
897 @key{RET}} copies the text from the buffer, which can be different
898 from what is in the history list if you edit the input text in the
899 buffer after it has been sent.
901 @node History References
902 @subsubsection Shell History References
903 @cindex history reference
905 Various shells including csh and bash support @dfn{history
906 references} that begin with @samp{!} and @samp{^}. Shell mode
907 recognizes these constructs, and can perform the history substitution
910 If you insert a history reference and type @key{TAB}, this searches
911 the input history for a matching command, performs substitution if
912 necessary, and places the result in the buffer in place of the history
913 reference. For example, you can fetch the most recent command
914 beginning with @samp{mv} with @kbd{! m v @key{TAB}}. You can edit the
915 command if you wish, and then resubmit the command to the shell by
918 @vindex comint-input-autoexpand
919 @findex comint-magic-space
920 Shell mode can optionally expand history references in the buffer
921 when you send them to the shell. To request this, set the variable
922 @code{comint-input-autoexpand} to @code{input}. You can make
923 @key{SPC} perform history expansion by binding @key{SPC} to the
924 command @code{comint-magic-space}.
926 Shell mode recognizes history references when they follow a prompt.
927 @xref{Shell Prompts}, for how Shell mode recognizes prompts.
929 @node Directory Tracking
930 @subsection Directory Tracking
931 @cindex directory tracking
933 @vindex shell-pushd-regexp
934 @vindex shell-popd-regexp
935 @vindex shell-cd-regexp
936 Shell mode keeps track of @samp{cd}, @samp{pushd} and @samp{popd}
937 commands given to the inferior shell, so it can keep the
938 @samp{*shell*} buffer's default directory the same as the shell's
939 working directory. It recognizes these commands syntactically, by
940 examining lines of input that are sent.
942 If you use aliases for these commands, you can tell Emacs to
943 recognize them also. For example, if the value of the variable
944 @code{shell-pushd-regexp} matches the beginning of a shell command
945 line, that line is regarded as a @code{pushd} command. Change this
946 variable when you add aliases for @samp{pushd}. Likewise,
947 @code{shell-popd-regexp} and @code{shell-cd-regexp} are used to
948 recognize commands with the meaning of @samp{popd} and @samp{cd}.
949 These commands are recognized only at the beginning of a shell command
952 @ignore @c This seems to have been deleted long ago.
953 @vindex shell-set-directory-error-hook
954 If Emacs gets an error while trying to handle what it believes is a
955 @samp{cd}, @samp{pushd} or @samp{popd} command, it runs the hook
956 @code{shell-set-directory-error-hook} (@pxref{Hooks}).
960 If Emacs gets confused about changes in the current directory of the
961 subshell, use the command @kbd{M-x dirs} to ask the shell what its
962 current directory is. This command works for shells that support the
963 most common command syntax; it may not work for unusual shells.
965 @findex dirtrack-mode
966 You can also use @kbd{M-x dirtrack-mode} to enable (or disable) an
967 alternative and more aggressive method of tracking changes in the
971 @subsection Shell Mode Options
973 @vindex comint-scroll-to-bottom-on-input
974 If the variable @code{comint-scroll-to-bottom-on-input} is
975 non-@code{nil}, insertion and yank commands scroll the selected window
976 to the bottom before inserting. The default is @code{nil}.
978 @vindex comint-scroll-show-maximum-output
979 If @code{comint-scroll-show-maximum-output} is non-@code{nil}, then
980 arrival of output when point is at the end tries to place the last line of
981 text at the bottom line of the window, so as to show as much useful
982 text as possible. (This mimics the scrolling behavior of most
983 terminals.) The default is @code{t}.
985 @vindex comint-move-point-for-output
986 By setting @code{comint-move-point-for-output}, you can opt for
987 having point jump to the end of the buffer whenever output arrives---no
988 matter where in the buffer point was before. If the value is
989 @code{this}, point jumps in the selected window. If the value is
990 @code{all}, point jumps in each window that shows the Comint buffer. If
991 the value is @code{other}, point jumps in all nonselected windows that
992 show the current buffer. The default value is @code{nil}, which means
993 point does not jump to the end.
995 @vindex comint-prompt-read-only
996 If you set @code{comint-prompt-read-only}, the prompts in the Comint
997 buffer are read-only.
999 @vindex comint-input-ignoredups
1000 The variable @code{comint-input-ignoredups} controls whether successive
1001 identical inputs are stored in the input history. A non-@code{nil}
1002 value means to omit an input that is the same as the previous input.
1003 The default is @code{nil}, which means to store each input even if it is
1004 equal to the previous input.
1006 @vindex comint-completion-addsuffix
1007 @vindex comint-completion-recexact
1008 @vindex comint-completion-autolist
1009 Three variables customize file name completion. The variable
1010 @code{comint-completion-addsuffix} controls whether completion inserts a
1011 space or a slash to indicate a fully completed file or directory name
1012 (non-@code{nil} means do insert a space or slash).
1013 @code{comint-completion-recexact}, if non-@code{nil}, directs @key{TAB}
1014 to choose the shortest possible completion if the usual Emacs completion
1015 algorithm cannot add even a single character.
1016 @code{comint-completion-autolist}, if non-@code{nil}, says to list all
1017 the possible completions whenever completion is not exact.
1019 @vindex shell-completion-execonly
1020 Command completion normally considers only executable files.
1021 If you set @code{shell-completion-execonly} to @code{nil},
1022 it considers nonexecutable files as well.
1024 @findex shell-pushd-tohome
1025 @findex shell-pushd-dextract
1026 @findex shell-pushd-dunique
1027 You can configure the behavior of @samp{pushd}. Variables control
1028 whether @samp{pushd} behaves like @samp{cd} if no argument is given
1029 (@code{shell-pushd-tohome}), pop rather than rotate with a numeric
1030 argument (@code{shell-pushd-dextract}), and only add directories to the
1031 directory stack if they are not already on it
1032 (@code{shell-pushd-dunique}). The values you choose should match the
1033 underlying shell, of course.
1035 If you want Shell mode to handle color output from shell commands,
1036 you can enable ANSI Color mode. Here is how to do this:
1039 (add-hook 'shell-mode-hook 'ansi-color-for-comint-mode-on)
1042 @node Terminal emulator
1043 @subsection Emacs Terminal Emulator
1046 To run a subshell in a terminal emulator, putting its typescript in
1047 an Emacs buffer, use @kbd{M-x term}. This creates (or reuses) a
1048 buffer named @samp{*terminal*}, and runs a subshell with input coming
1049 from your keyboard, and output going to that buffer.
1051 The terminal emulator uses Term mode, which has two input modes. In
1052 line mode, Term basically acts like Shell mode; see @ref{Shell Mode}.
1054 In char mode, each character is sent directly to the inferior
1055 subshell, as ``terminal input.'' Any ``echoing'' of your input is the
1056 responsibility of the subshell. The sole exception is the terminal
1057 escape character, which by default is @kbd{C-c} (@pxref{Term Mode}).
1058 Any ``terminal output'' from the subshell goes into the buffer,
1061 Some programs (such as Emacs itself) need to control the appearance
1062 on the terminal screen in detail. They do this by sending special
1063 control codes. The exact control codes needed vary from terminal to
1064 terminal, but nowadays most terminals and terminal emulators
1065 (including @code{xterm}) understand the ANSI-standard (VT100-style)
1066 escape sequences. Term mode recognizes these escape sequences, and
1067 handles each one appropriately, changing the buffer so that the
1068 appearance of the window matches what it would be on a real terminal.
1069 You can actually run Emacs inside an Emacs Term window.
1071 The file name used to load the subshell is determined the same way
1072 as for Shell mode. To make multiple terminal emulators, rename the
1073 buffer @samp{*terminal*} to something different using @kbd{M-x
1074 rename-uniquely}, just as with Shell mode.
1076 Unlike Shell mode, Term mode does not track the current directory by
1077 examining your input. But some shells can tell Term what the current
1078 directory is. This is done automatically by @code{bash} version 1.15
1082 @subsection Term Mode
1086 The terminal emulator uses Term mode, which has two input modes. In
1087 line mode, Term basically acts like Shell mode; see @ref{Shell Mode}.
1088 In char mode, each character is sent directly to the inferior
1089 subshell, except for the Term escape character, normally @kbd{C-c}.
1091 To switch between line and char mode, use these commands:
1094 @kindex C-c C-j @r{(Term mode)}
1095 @findex term-char-mode
1097 Switch to line mode. Do nothing if already in line mode.
1099 @kindex C-c C-k @r{(Term mode)}
1100 @findex term-line-mode
1102 Switch to char mode. Do nothing if already in char mode.
1105 The following commands are only available in char mode:
1109 Send a literal @key{C-c} to the sub-shell.
1111 @item C-c @var{char}
1112 This is equivalent to @kbd{C-x @var{char}} in normal Emacs. For
1113 example, @kbd{C-c o} invokes the global binding of @kbd{C-x o}, which
1114 is normally @samp{other-window}.
1117 @node Paging in Term
1118 @subsection Page-At-A-Time Output
1119 @cindex page-at-a-time
1121 Term mode has a page-at-a-time feature. When enabled it makes
1122 output pause at the end of each screenful.
1125 @kindex C-c C-q @r{(Term mode)}
1126 @findex term-pager-toggle
1128 Toggle the page-at-a-time feature. This command works in both line
1129 and char modes. When page-at-a-time is enabled, the mode-line
1130 displays the word @samp{page}.
1133 With page-at-a-time enabled, whenever Term receives more than a
1134 screenful of output since your last input, it pauses, displaying
1135 @samp{**MORE**} in the mode-line. Type @key{SPC} to display the next
1136 screenful of output. Type @kbd{?} to see your other options. The
1137 interface is similar to the @code{more} program.
1140 @subsection Remote Host Shell
1142 @cindex connecting to remote host
1146 You can login to a remote computer, using whatever commands you
1147 would from a regular terminal (e.g.@: using the @code{telnet} or
1148 @code{rlogin} commands), from a Term window.
1150 A program that asks you for a password will normally suppress
1151 echoing of the password, so the password will not show up in the
1152 buffer. This will happen just as if you were using a real terminal,
1153 if the buffer is in char mode. If it is in line mode, the password is
1154 temporarily visible, but will be erased when you hit return. (This
1155 happens automatically; there is no special password processing.)
1157 When you log in to a different machine, you need to specify the type
1158 of terminal you're using, by setting the @env{TERM} environment
1159 variable in the environment for the remote login command. (If you use
1160 bash, you do that by writing the variable assignment before the remote
1161 login command, without separating comma.) Terminal types @samp{ansi}
1162 or @samp{vt100} will work on most systems.
1164 @c If you are talking to a Bourne-compatible
1165 @c shell, and your system understands the @env{TERMCAP} variable,
1166 @c you can use the command @kbd{M-x shell-send-termcap}, which
1167 @c sends a string specifying the terminal type and size.
1168 @c (This command is also useful after the window has changed size.)
1170 @c You can of course run @samp{gdb} on that remote computer. One useful
1171 @c trick: If you invoke gdb with the @code{--fullname} option,
1172 @c it will send special commands to Emacs that will cause Emacs to
1173 @c pop up the source files you're debugging. This will work
1174 @c whether or not gdb is running on a different computer than Emacs,
1175 @c as long as Emacs can access the source files specified by gdb.
1178 You cannot log in to a remote computer using the Shell mode.
1179 @c (This will change when Shell is re-written to use Term.)
1180 Instead, Emacs provides two commands for logging in to another computer
1181 and communicating with it through an Emacs buffer using Comint mode:
1184 @item M-x telnet @key{RET} @var{hostname} @key{RET}
1185 Set up a Telnet connection to the computer named @var{hostname}.
1186 @item M-x rlogin @key{RET} @var{hostname} @key{RET}
1187 Set up an Rlogin connection to the computer named @var{hostname}.
1191 Use @kbd{M-x telnet} to set up a Telnet connection to another
1192 computer. (Telnet is the standard Internet protocol for remote login.)
1193 It reads the host name of the other computer as an argument with the
1194 minibuffer. Once the connection is established, talking to the other
1195 computer works like talking to a subshell: you can edit input with the
1196 usual Emacs commands, and send it a line at a time by typing @key{RET}.
1197 The output is inserted in the Telnet buffer interspersed with the input.
1200 @vindex rlogin-explicit-args
1201 Use @kbd{M-x rlogin} to set up an Rlogin connection. Rlogin is
1202 another remote login communication protocol, essentially much like the
1203 Telnet protocol but incompatible with it, and supported only by certain
1204 systems. Rlogin's advantages are that you can arrange not to have to
1205 give your user name and password when communicating between two machines
1206 you frequently use, and that you can make an 8-bit-clean connection.
1207 (To do that in Emacs, set @code{rlogin-explicit-args} to @code{("-8")}
1208 before you run Rlogin.)
1210 @kbd{M-x rlogin} sets up the default file directory of the Emacs
1211 buffer to access the remote host via FTP (@pxref{File Names}), and it
1212 tracks the shell commands that change the current directory, just like
1215 @findex rlogin-directory-tracking-mode
1216 There are two ways of doing directory tracking in an Rlogin
1217 buffer---either with remote directory names
1218 @file{/@var{host}:@var{dir}/} or with local names (that works if the
1219 ``remote'' machine shares file systems with your machine of origin).
1220 You can use the command @code{rlogin-directory-tracking-mode} to switch
1221 modes. No argument means use remote directory names, a positive
1222 argument means use local names, and a negative argument means turn
1223 off directory tracking.
1227 @node Emacs Server, Printing, Shell, Top
1228 @section Using Emacs as a Server
1230 @cindex Emacs as a server
1231 @cindex server, using Emacs as
1232 @cindex @env{EDITOR} environment variable
1234 Various programs such as @code{mail} can invoke your choice of editor
1235 to edit a particular piece of text, such as a message that you are
1236 sending. By convention, most of these programs use the environment
1237 variable @env{EDITOR} to specify which editor to run. If you set
1238 @env{EDITOR} to @samp{emacs}, they invoke Emacs---but in an
1239 inconvenient fashion, by starting a new, separate Emacs process. This
1240 is inconvenient because it takes time and because the new Emacs process
1241 doesn't share the buffers in any existing Emacs process.
1243 You can arrange to use your existing Emacs process as the editor for
1244 programs like @code{mail} by using the Emacs client and Emacs server
1245 programs. Here is how.
1247 @cindex @env{TEXEDIT} environment variable
1248 First, the preparation. Within Emacs, call the function
1249 @code{server-start}. (Your @file{.emacs} file can do this automatically
1250 if you add the expression @code{(server-start)} to it.) Then, outside
1251 Emacs, set the @env{EDITOR} environment variable to @samp{emacsclient}.
1252 (Note that some programs use a different environment variable; for
1253 example, to make @TeX{} use @samp{emacsclient}, you should set the
1254 @env{TEXEDIT} environment variable to @samp{emacsclient +%d %s}.)
1258 Then, whenever any program invokes your specified @env{EDITOR}
1259 program, the effect is to send a message to your principal Emacs telling
1260 it to visit a file. (That's what the program @code{emacsclient} does.)
1261 Emacs displays the buffer immediately and you can immediately begin
1264 When you've finished editing that buffer, type @kbd{C-x #}
1265 (@code{server-edit}). This saves the file and sends a message back to
1266 the @code{emacsclient} program telling it to exit. The programs that
1267 use @env{EDITOR} wait for the ``editor'' (actually, @code{emacsclient})
1268 to exit. @kbd{C-x #} also checks for other pending external requests
1269 to edit various files, and selects the next such file.
1271 You can switch to a server buffer manually if you wish; you don't
1272 have to arrive at it with @kbd{C-x #}. But @kbd{C-x #} is the way to
1273 say that you are finished with one.
1275 @vindex server-kill-new-buffers
1276 @vindex server-temp-file-regexp
1277 Finishing with a server buffer also kills the buffer, unless it
1278 already existed in the Emacs session before the server asked to create
1279 it. However, if you set @code{server-kill-new-buffers} to @code{nil},
1280 then a different criterion is used: finishing with a server buffer
1281 kills it if the file name matches the regular expression
1282 @code{server-temp-file-regexp}. This is set up to distinguish certain
1283 ``temporary'' files.
1285 @vindex server-window
1286 If you set the variable @code{server-window} to a window or a frame,
1287 @kbd{C-x #} displays the server buffer in that window or in that frame.
1290 You can run multiple Emacs servers on the same machine by giving
1291 each one a unique ``server name'', using the variable
1292 @code{server-name}. For example, @kbd{M-x set-variable @key{RET}
1293 server-name @key{RET} foo @key{RET}} sets the server name to
1294 @samp{foo}. The @code{emacsclient} program can visit a server by name
1295 using the @samp{-s} option. @xref{Invoking emacsclient}.
1297 While @code{mail} or another application is waiting for
1298 @code{emacsclient} to finish, @code{emacsclient} does not read terminal
1299 input. So the terminal that @code{mail} was using is effectively
1300 blocked for the duration. In order to edit with your principal Emacs,
1301 you need to be able to use it without using that terminal. There are
1302 three ways to do this:
1306 Using a window system, run @code{mail} and the principal Emacs in two
1307 separate windows. While @code{mail} is waiting for @code{emacsclient},
1308 the window where it was running is blocked, but you can use Emacs by
1312 Using virtual terminals, run @code{mail} in one virtual terminal
1313 and run Emacs in another.
1316 Use Shell mode or Term mode in Emacs to run the other program such as
1317 @code{mail}; then, @code{emacsclient} blocks only the subshell under
1318 Emacs, and you can still use Emacs to edit the file.
1321 If you run @code{emacsclient} with the option @samp{--no-wait}, it
1322 returns immediately without waiting for you to ``finish'' the buffer
1323 in Emacs. Note that server buffers created in this way are not killed
1324 automatically when you finish with them.
1327 * Invoking emacsclient:: Emacs client startup options.
1330 @node Invoking emacsclient,, Emacs Server, Emacs Server
1331 @subsection Invoking @code{emacsclient}
1333 To run the @code{emacsclient} program, specify file names as arguments,
1334 and optionally line numbers as well, like this:
1337 emacsclient @r{@{}@r{[}+@var{line}@r{[}@var{column}@r{]}@r{]} @var{filename}@r{@}}@dots{}
1341 This tells Emacs to visit each of the specified files; if you specify a
1342 line number for a certain file, Emacs moves to that line in the file.
1343 If you specify a column number as well, Emacs puts point on that column
1346 Ordinarily, @code{emacsclient} does not return until you use the
1347 @kbd{C-x #} command on each of these buffers. When that happens,
1348 Emacs sends a message to the @code{emacsclient} program telling it to
1351 If you invoke @code{emacsclient} for more than one file, the
1352 additional client buffers are buried at the bottom of the buffer list
1353 (@pxref{Buffers}). If you call @kbd{C-x #} after you are done editing
1354 a client buffer, the next client buffer is automatically selected.
1356 But if you use the option @samp{-n} or @samp{--no-wait} when running
1357 @code{emacsclient}, then it returns immediately. (You can take as
1358 long as you like to edit the files in Emacs.)
1360 The option @samp{--alternate-editor=@var{command}} specifies a
1361 command to run if @code{emacsclient} fails to contact Emacs. This is
1362 useful when running @code{emacsclient} in a script. For example, the
1363 following setting for the @env{EDITOR} environment variable will
1364 always give you an editor, even if no Emacs server is running:
1367 EDITOR="emacsclient --alternate-editor emacs +%d %s"
1371 The environment variable @env{ALTERNATE_EDITOR} has the same effect, with
1372 the value of the @samp{--alternate-editor} option taking precedence.
1375 Alternatively, the file @file{etc/emacs.bash} defines a bash
1376 function which will communicate with a running Emacs server, or start
1379 If you use several displays, you can tell Emacs on which display to
1380 open the given files with the option @samp{--display=@var{DISPLAY}}.
1381 This can be used typically when connecting from home to an Emacs
1382 server running on your machine at your workplace.
1384 If there is more than one Emacs server running, you can specify a
1385 server name with the option @samp{-s @var{name}}.
1387 You can also use @code{emacsclient} to execute any piece of Emacs Lisp
1388 code, using the option @samp{--eval}. When this option is given, the
1389 rest of the arguments is not taken as a list of files to visit but as
1390 a list of expressions to evaluate.
1392 @node Printing, Sorting, Emacs Server, Top
1393 @section Printing Hard Copies
1397 Emacs provides commands for printing hard copies of either an entire
1398 buffer or just part of one, with or without page headers. You can
1399 invoke the printing commands directly, as detailed in the following
1400 section, or using the @samp{File} menu on the menu bar. See also the
1401 hardcopy commands of Dired (@pxref{Misc File Ops}) and the diary
1402 (@pxref{Displaying the Diary}).
1405 @item M-x print-buffer
1406 Print hardcopy of current buffer with page headings containing the file
1407 name and page number.
1408 @item M-x lpr-buffer
1409 Print hardcopy of current buffer without page headings.
1410 @item M-x print-region
1411 Like @code{print-buffer} but print only the current region.
1412 @item M-x lpr-region
1413 Like @code{lpr-buffer} but print only the current region.
1416 @findex print-buffer
1417 @findex print-region
1420 @vindex lpr-switches
1421 The hardcopy commands (aside from the Postscript commands) pass extra
1422 switches to the @code{lpr} program based on the value of the variable
1423 @code{lpr-switches}. Its value should be a list of strings, each string
1424 an option starting with @samp{-}. For example, to specify a line width
1425 of 80 columns for all the printing you do in Emacs, set
1426 @code{lpr-switches} like this:
1429 (setq lpr-switches '("-w80"))
1432 @vindex printer-name
1433 You can specify the printer to use by setting the variable
1434 @code{printer-name}.
1436 @vindex lpr-headers-switches
1437 @vindex lpr-commands
1438 @vindex lpr-add-switches
1439 The variable @code{lpr-command} specifies the name of the printer
1440 program to run; the default value depends on your operating system type.
1441 On most systems, the default is @code{"lpr"}. The variable
1442 @code{lpr-headers-switches} similarly specifies the extra switches to
1443 use to make page headers. The variable @code{lpr-add-switches} controls
1444 whether to supply @samp{-T} and @samp{-J} options (suitable for
1445 @code{lpr}) to the printer program: @code{nil} means don't add them.
1446 @code{lpr-add-switches} should be @code{nil} if your printer program is
1447 not compatible with @code{lpr}.
1450 * PostScript:: Printing buffers or regions as PostScript.
1451 * PostScript Variables:: Customizing the PostScript printing commands.
1452 * Printing Package:: An optional advanced printing interface.
1455 @node PostScript, PostScript Variables,, Printing
1456 @section PostScript Hardcopy
1458 These commands convert buffer contents to PostScript,
1459 either printing it or leaving it in another Emacs buffer.
1462 @item M-x ps-print-buffer
1463 Print hardcopy of the current buffer in PostScript form.
1464 @item M-x ps-print-region
1465 Print hardcopy of the current region in PostScript form.
1466 @item M-x ps-print-buffer-with-faces
1467 Print hardcopy of the current buffer in PostScript form, showing the
1468 faces used in the text by means of PostScript features.
1469 @item M-x ps-print-region-with-faces
1470 Print hardcopy of the current region in PostScript form, showing the
1471 faces used in the text.
1472 @item M-x ps-spool-buffer
1473 Generate PostScript for the current buffer text.
1474 @item M-x ps-spool-region
1475 Generate PostScript for the current region.
1476 @item M-x ps-spool-buffer-with-faces
1477 Generate PostScript for the current buffer, showing the faces used.
1478 @item M-x ps-spool-region-with-faces
1479 Generate PostScript for the current region, showing the faces used.
1481 Generates/prints PostScript for the current buffer as if handwritten.
1484 @findex ps-print-region
1485 @findex ps-print-buffer
1486 @findex ps-print-region-with-faces
1487 @findex ps-print-buffer-with-faces
1488 The PostScript commands, @code{ps-print-buffer} and
1489 @code{ps-print-region}, print buffer contents in PostScript form. One
1490 command prints the entire buffer; the other, just the region. The
1491 corresponding @samp{-with-faces} commands,
1492 @code{ps-print-buffer-with-faces} and @code{ps-print-region-with-faces},
1493 use PostScript features to show the faces (fonts and colors) in the text
1494 properties of the text being printed.
1496 If you are using a color display, you can print a buffer of program
1497 code with color highlighting by turning on Font-Lock mode in that
1498 buffer, and using @code{ps-print-buffer-with-faces}.
1500 @findex ps-spool-region
1501 @findex ps-spool-buffer
1502 @findex ps-spool-region-with-faces
1503 @findex ps-spool-buffer-with-faces
1504 The commands whose names have @samp{spool} instead of @samp{print}
1505 generate the PostScript output in an Emacs buffer instead of sending
1510 @kbd{M-x handwrite} is more frivolous. It generates a PostScript
1511 rendition of the current buffer as a cursive handwritten document. It
1512 can be customized in group @code{handwrite}. This function only
1513 supports ISO 8859-1 characters.
1516 The following section describes variables for customizing these commands.
1519 @node PostScript Variables, Printing Package, PostScript, Printing
1520 @section Variables for PostScript Hardcopy
1522 @vindex ps-lpr-command
1523 @vindex ps-lpr-switches
1524 @vindex ps-printer-name
1525 All the PostScript hardcopy commands use the variables
1526 @code{ps-lpr-command} and @code{ps-lpr-switches} to specify how to print
1527 the output. @code{ps-lpr-command} specifies the command name to run,
1528 @code{ps-lpr-switches} specifies command line options to use, and
1529 @code{ps-printer-name} specifies the printer. If you don't set the
1530 first two variables yourself, they take their initial values from
1531 @code{lpr-command} and @code{lpr-switches}. If @code{ps-printer-name}
1532 is @code{nil}, @code{printer-name} is used.
1534 @vindex ps-print-header
1535 The variable @code{ps-print-header} controls whether these commands
1536 add header lines to each page---set it to @code{nil} to turn headers
1539 @cindex color emulation on black-and-white printers
1540 @vindex ps-print-color-p
1541 If your printer doesn't support colors, you should turn off color
1542 processing by setting @code{ps-print-color-p} to @code{nil}. By
1543 default, if the display supports colors, Emacs produces hardcopy output
1544 with color information; on black-and-white printers, colors are emulated
1545 with shades of gray. This might produce illegible output, even if your
1546 screen colors only use shades of gray.
1548 @vindex ps-use-face-background
1549 By default, PostScript printing ignores the background colors of the
1550 faces, unless the variable @code{ps-use-face-background} is
1551 non-@code{nil}. This is to avoid unwanted interference with the zebra
1552 stripes and background image/text.
1554 @vindex ps-paper-type
1555 @vindex ps-page-dimensions-database
1556 The variable @code{ps-paper-type} specifies which size of paper to
1557 format for; legitimate values include @code{a4}, @code{a3},
1558 @code{a4small}, @code{b4}, @code{b5}, @code{executive}, @code{ledger},
1559 @code{legal}, @code{letter}, @code{letter-small}, @code{statement},
1560 @code{tabloid}. The default is @code{letter}. You can define
1561 additional paper sizes by changing the variable
1562 @code{ps-page-dimensions-database}.
1564 @vindex ps-landscape-mode
1565 The variable @code{ps-landscape-mode} specifies the orientation of
1566 printing on the page. The default is @code{nil}, which stands for
1567 ``portrait'' mode. Any non-@code{nil} value specifies ``landscape''
1570 @vindex ps-number-of-columns
1571 The variable @code{ps-number-of-columns} specifies the number of
1572 columns; it takes effect in both landscape and portrait mode. The
1575 @vindex ps-font-family
1576 @vindex ps-font-size
1577 @vindex ps-font-info-database
1578 The variable @code{ps-font-family} specifies which font family to use
1579 for printing ordinary text. Legitimate values include @code{Courier},
1580 @code{Helvetica}, @code{NewCenturySchlbk}, @code{Palatino} and
1581 @code{Times}. The variable @code{ps-font-size} specifies the size of
1582 the font for ordinary text. It defaults to 8.5 points.
1584 @vindex ps-multibyte-buffer
1585 @cindex Intlfonts for PostScript printing
1586 @cindex fonts for PostScript printing
1587 Emacs supports more scripts and characters than a typical PostScript
1588 printer. Thus, some of the characters in your buffer might not be
1589 printable using the fonts built into your printer. You can augment
1590 the fonts supplied with the printer with those from the GNU Intlfonts
1591 package, or you can instruct Emacs to use Intlfonts exclusively. The
1592 variable @code{ps-multibyte-buffer} controls this: the default value,
1593 @code{nil}, is appropriate for printing @acronym{ASCII} and Latin-1
1594 characters; a value of @code{non-latin-printer} is for printers which
1595 have the fonts for @acronym{ASCII}, Latin-1, Japanese, and Korean
1596 characters built into them. A value of @code{bdf-font} arranges for
1597 the BDF fonts from the Intlfonts package to be used for @emph{all}
1598 characters. Finally, a value of @code{bdf-font-except-latin}
1599 instructs the printer to use built-in fonts for @acronym{ASCII} and Latin-1
1600 characters, and Intlfonts BDF fonts for the rest.
1602 @vindex bdf-directory-list
1603 To be able to use the BDF fonts, Emacs needs to know where to find
1604 them. The variable @code{bdf-directory-list} holds the list of
1605 directories where Emacs should look for the fonts; the default value
1606 includes a single directory @file{/usr/local/share/emacs/fonts/bdf}.
1608 Many other customization variables for these commands are defined and
1609 described in the Lisp files @file{ps-print.el} and @file{ps-mule.el}.
1611 @node Printing Package,, PostScript Variables, Printing
1612 @section Printing Package
1613 @cindex Printing package
1615 The basic Emacs facilities for printing hardcopy can be extended
1616 using the Printing package. This provides an easy-to-use interface
1617 for choosing what to print, previewing PostScript files before
1618 printing, and setting various printing options such as print headers,
1619 landscape or portrait modes, duplex modes, and so forth. On GNU/Linux
1620 or Unix systems, the Printing package relies on the @file{gs} and
1621 @file{gv} utilities, which are distributed as part of the GhostScript
1622 program. On MS-Windows, the @file{gstools} port of Ghostscript can be
1625 @findex pr-interface
1626 To use the Printing package, add @code{(require 'printing)} to your
1627 init file (@pxref{Init File}), followed by @code{(pr-update-menus)}.
1628 This function replaces the usual printing commands in the menu bar
1629 with a @samp{Printing} submenu that contains various printing options.
1630 You can also type @kbd{M-x pr-interface RET}; this creates a
1631 @samp{*Printing Interface*} buffer, similar to a customization buffer,
1632 where you can set the printing options. After selecting what and how
1633 to print, you start the print job using the @samp{Print} button (click
1634 @kbd{mouse-2} on it, or move point over it and type @kbd{RET}). For
1635 further information on the various options, use the @samp{Interface
1638 @node Sorting, Narrowing, Printing, Top
1639 @section Sorting Text
1642 Emacs provides several commands for sorting text in the buffer. All
1643 operate on the contents of the region.
1644 They divide the text of the region into many @dfn{sort records},
1645 identify a @dfn{sort key} for each record, and then reorder the records
1646 into the order determined by the sort keys. The records are ordered so
1647 that their keys are in alphabetical order, or, for numeric sorting, in
1648 numeric order. In alphabetic sorting, all upper-case letters `A' through
1649 `Z' come before lower-case `a', in accord with the @acronym{ASCII} character
1652 The various sort commands differ in how they divide the text into sort
1653 records and in which part of each record is used as the sort key. Most of
1654 the commands make each line a separate sort record, but some commands use
1655 paragraphs or pages as sort records. Most of the sort commands use each
1656 entire sort record as its own sort key, but some use only a portion of the
1657 record as the sort key.
1660 @findex sort-paragraphs
1663 @findex sort-numeric-fields
1664 @vindex sort-numeric-base
1666 @item M-x sort-lines
1667 Divide the region into lines, and sort by comparing the entire
1668 text of a line. A numeric argument means sort into descending order.
1670 @item M-x sort-paragraphs
1671 Divide the region into paragraphs, and sort by comparing the entire
1672 text of a paragraph (except for leading blank lines). A numeric
1673 argument means sort into descending order.
1675 @item M-x sort-pages
1676 Divide the region into pages, and sort by comparing the entire
1677 text of a page (except for leading blank lines). A numeric
1678 argument means sort into descending order.
1680 @item M-x sort-fields
1681 Divide the region into lines, and sort by comparing the contents of
1682 one field in each line. Fields are defined as separated by
1683 whitespace, so the first run of consecutive non-whitespace characters
1684 in a line constitutes field 1, the second such run constitutes field
1687 Specify which field to sort by with a numeric argument: 1 to sort by
1688 field 1, etc. A negative argument means count fields from the right
1689 instead of from the left; thus, minus 1 means sort by the last field.
1690 If several lines have identical contents in the field being sorted, they
1691 keep the same relative order that they had in the original buffer.
1693 @item M-x sort-numeric-fields
1694 Like @kbd{M-x sort-fields} except the specified field is converted
1695 to an integer for each line, and the numbers are compared. @samp{10}
1696 comes before @samp{2} when considered as text, but after it when
1697 considered as a number. By default, numbers are interpreted according
1698 to @code{sort-numeric-base}, but numbers beginning with @samp{0x} or
1699 @samp{0} are interpreted as hexadecimal and octal, respectively.
1701 @item M-x sort-columns
1702 Like @kbd{M-x sort-fields} except that the text within each line
1703 used for comparison comes from a fixed range of columns. See below
1706 @item M-x reverse-region
1707 Reverse the order of the lines in the region. This is useful for
1708 sorting into descending order by fields or columns, since those sort
1709 commands do not have a feature for doing that.
1712 For example, if the buffer contains this:
1715 On systems where clash detection (locking of files being edited) is
1716 implemented, Emacs also checks the first time you modify a buffer
1717 whether the file has changed on disk since it was last visited or
1718 saved. If it has, you are asked to confirm that you want to change
1723 applying @kbd{M-x sort-lines} to the entire buffer produces this:
1726 On systems where clash detection (locking of files being edited) is
1727 implemented, Emacs also checks the first time you modify a buffer
1728 saved. If it has, you are asked to confirm that you want to change
1730 whether the file has changed on disk since it was last visited or
1734 where the upper-case @samp{O} sorts before all lower-case letters. If
1735 you use @kbd{C-u 2 M-x sort-fields} instead, you get this:
1738 implemented, Emacs also checks the first time you modify a buffer
1739 saved. If it has, you are asked to confirm that you want to change
1741 On systems where clash detection (locking of files being edited) is
1742 whether the file has changed on disk since it was last visited or
1746 where the sort keys were @samp{Emacs}, @samp{If}, @samp{buffer},
1747 @samp{systems} and @samp{the}.
1749 @findex sort-columns
1750 @kbd{M-x sort-columns} requires more explanation. You specify the
1751 columns by putting point at one of the columns and the mark at the other
1752 column. Because this means you cannot put point or the mark at the
1753 beginning of the first line of the text you want to sort, this command
1754 uses an unusual definition of ``region'': all of the line point is in is
1755 considered part of the region, and so is all of the line the mark is in,
1756 as well as all the lines in between.
1758 For example, to sort a table by information found in columns 10 to 15,
1759 you could put the mark on column 10 in the first line of the table, and
1760 point on column 15 in the last line of the table, and then run
1761 @code{sort-columns}. Equivalently, you could run it with the mark on
1762 column 15 in the first line and point on column 10 in the last line.
1764 This can be thought of as sorting the rectangle specified by point and
1765 the mark, except that the text on each line to the left or right of the
1766 rectangle moves along with the text inside the rectangle.
1769 @vindex sort-fold-case
1770 Many of the sort commands ignore case differences when comparing, if
1771 @code{sort-fold-case} is non-@code{nil}.
1773 @node Narrowing, Two-Column, Sorting, Top
1778 @cindex accessible portion
1780 @dfn{Narrowing} means focusing in on some portion of the buffer,
1781 making the rest temporarily inaccessible. The portion which you can
1782 still get to is called the @dfn{accessible portion}. Canceling the
1783 narrowing, which makes the entire buffer once again accessible, is
1784 called @dfn{widening}. The bounds of narrowing in effect in a buffer
1785 are called the buffer's @dfn{restriction}.
1787 Narrowing can make it easier to concentrate on a single subroutine or
1788 paragraph by eliminating clutter. It can also be used to limit the
1789 range of operation of a replace command or repeating keyboard macro.
1793 Narrow down to between point and mark (@code{narrow-to-region}).
1795 Widen to make the entire buffer accessible again (@code{widen}).
1797 Narrow down to the current page (@code{narrow-to-page}).
1799 Narrow down to the current defun (@code{narrow-to-defun}).
1802 When you have narrowed down to a part of the buffer, that part appears
1803 to be all there is. You can't see the rest, you can't move into it
1804 (motion commands won't go outside the accessible part), you can't change
1805 it in any way. However, it is not gone, and if you save the file all
1806 the inaccessible text will be saved. The word @samp{Narrow} appears in
1807 the mode line whenever narrowing is in effect.
1810 @findex narrow-to-region
1811 The primary narrowing command is @kbd{C-x n n} (@code{narrow-to-region}).
1812 It sets the current buffer's restrictions so that the text in the current
1813 region remains accessible, but all text before the region or after the
1814 region is inaccessible. Point and mark do not change.
1817 @findex narrow-to-page
1819 @findex narrow-to-defun
1820 Alternatively, use @kbd{C-x n p} (@code{narrow-to-page}) to narrow
1821 down to the current page. @xref{Pages}, for the definition of a page.
1822 @kbd{C-x n d} (@code{narrow-to-defun}) narrows down to the defun
1823 containing point (@pxref{Defuns}).
1827 The way to cancel narrowing is to widen with @kbd{C-x n w}
1828 (@code{widen}). This makes all text in the buffer accessible again.
1830 You can get information on what part of the buffer you are narrowed down
1831 to using the @kbd{C-x =} command. @xref{Position Info}.
1833 Because narrowing can easily confuse users who do not understand it,
1834 @code{narrow-to-region} is normally a disabled command. Attempting to use
1835 this command asks for confirmation and gives you the option of enabling it;
1836 if you enable the command, confirmation will no longer be required for
1837 it. @xref{Disabling}.
1839 @node Two-Column, Editing Binary Files, Narrowing, Top
1840 @section Two-Column Editing
1841 @cindex two-column editing
1842 @cindex splitting columns
1843 @cindex columns, splitting
1845 Two-column mode lets you conveniently edit two side-by-side columns of
1846 text. It uses two side-by-side windows, each showing its own
1849 There are three ways to enter two-column mode:
1852 @item @kbd{@key{F2} 2} or @kbd{C-x 6 2}
1855 @findex 2C-two-columns
1856 Enter two-column mode with the current buffer on the left, and on the
1857 right, a buffer whose name is based on the current buffer's name
1858 (@code{2C-two-columns}). If the right-hand buffer doesn't already
1859 exist, it starts out empty; the current buffer's contents are not
1862 This command is appropriate when the current buffer is empty or contains
1863 just one column and you want to add another column.
1865 @item @kbd{@key{F2} s} or @kbd{C-x 6 s}
1869 Split the current buffer, which contains two-column text, into two
1870 buffers, and display them side by side (@code{2C-split}). The current
1871 buffer becomes the left-hand buffer, but the text in the right-hand
1872 column is moved into the right-hand buffer. The current column
1873 specifies the split point. Splitting starts with the current line and
1874 continues to the end of the buffer.
1876 This command is appropriate when you have a buffer that already contains
1877 two-column text, and you wish to separate the columns temporarily.
1879 @item @kbd{@key{F2} b @var{buffer} @key{RET}}
1880 @itemx @kbd{C-x 6 b @var{buffer} @key{RET}}
1883 @findex 2C-associate-buffer
1884 Enter two-column mode using the current buffer as the left-hand buffer,
1885 and using buffer @var{buffer} as the right-hand buffer
1886 (@code{2C-associate-buffer}).
1889 @kbd{@key{F2} s} or @kbd{C-x 6 s} looks for a column separator, which
1890 is a string that appears on each line between the two columns. You can
1891 specify the width of the separator with a numeric argument to
1892 @kbd{@key{F2} s}; that many characters, before point, constitute the
1893 separator string. By default, the width is 1, so the column separator
1894 is the character before point.
1896 When a line has the separator at the proper place, @kbd{@key{F2} s}
1897 puts the text after the separator into the right-hand buffer, and
1898 deletes the separator. Lines that don't have the column separator at
1899 the proper place remain unsplit; they stay in the left-hand buffer, and
1900 the right-hand buffer gets an empty line to correspond. (This is the
1901 way to write a line that ``spans both columns while in two-column
1902 mode'': write it in the left-hand buffer, and put an empty line in the
1908 The command @kbd{C-x 6 @key{RET}} or @kbd{@key{F2} @key{RET}}
1909 (@code{2C-newline}) inserts a newline in each of the two buffers at
1910 corresponding positions. This is the easiest way to add a new line to
1911 the two-column text while editing it in split buffers.
1916 When you have edited both buffers as you wish, merge them with
1917 @kbd{@key{F2} 1} or @kbd{C-x 6 1} (@code{2C-merge}). This copies the
1918 text from the right-hand buffer as a second column in the other buffer.
1919 To go back to two-column editing, use @kbd{@key{F2} s}.
1923 @findex 2C-dissociate
1924 Use @kbd{@key{F2} d} or @kbd{C-x 6 d} to dissociate the two buffers,
1925 leaving each as it stands (@code{2C-dissociate}). If the other buffer,
1926 the one not current when you type @kbd{@key{F2} d}, is empty,
1927 @kbd{@key{F2} d} kills it.
1929 @node Editing Binary Files, Saving Emacs Sessions, Two-Column, Top
1930 @section Editing Binary Files
1934 @cindex editing binary files
1936 There is a special major mode for editing binary files: Hexl mode. To
1937 use it, use @kbd{M-x hexl-find-file} instead of @kbd{C-x C-f} to visit
1938 the file. This command converts the file's contents to hexadecimal and
1939 lets you edit the translation. When you save the file, it is converted
1940 automatically back to binary.
1942 You can also use @kbd{M-x hexl-mode} to translate an existing buffer
1943 into hex. This is useful if you visit a file normally and then discover
1944 it is a binary file.
1946 Ordinary text characters overwrite in Hexl mode. This is to reduce
1947 the risk of accidentally spoiling the alignment of data in the file.
1948 There are special commands for insertion. Here is a list of the
1949 commands of Hexl mode:
1951 @c I don't think individual index entries for these commands are useful--RMS.
1954 Insert a byte with a code typed in decimal.
1957 Insert a byte with a code typed in octal.
1960 Insert a byte with a code typed in hex.
1963 Move to the beginning of a 1k-byte ``page.''
1966 Move to the end of a 1k-byte ``page.''
1969 Move to an address specified in hex.
1972 Move to an address specified in decimal.
1975 Leave Hexl mode, going back to the major mode this buffer had before you
1976 invoked @code{hexl-mode}.
1980 Other Hexl commands let you insert strings (sequences) of binary
1981 bytes, move by @code{short}s or @code{int}s, etc.; type @kbd{C-h a
1982 hexl-@key{RET}} for details.
1985 @node Saving Emacs Sessions, Recursive Edit, Editing Binary Files, Top
1986 @section Saving Emacs Sessions
1987 @cindex saving sessions
1988 @cindex restore session
1989 @cindex remember editing session
1990 @cindex reload files
1993 Use the desktop library to save the state of Emacs from one session
1994 to another. Once you save the Emacs @dfn{desktop}---the buffers,
1995 their file names, major modes, buffer positions, and so on---then
1996 subsequent Emacs sessions reload the saved desktop.
1998 @findex desktop-save
1999 @vindex desktop-save-mode
2000 You can save the desktop manually with the command @kbd{M-x
2001 desktop-save}. You can also enable automatic desktop saving when
2002 you exit Emacs: use the Customization buffer (@pxref{Easy
2003 Customization}) to set @code{desktop-save-mode} to @code{t} for future
2004 sessions, or add this line in your @file{~/.emacs} file:
2007 (desktop-save-mode 1)
2010 @findex desktop-change-dir
2011 @findex desktop-revert
2012 When Emacs starts, it looks for a saved desktop in the current
2013 directory. Thus, you can have separate saved desktops in different
2014 directories, and the starting directory determines which one Emacs
2015 reloads. You can save the current desktop and reload one saved in
2016 another directory by typing @kbd{M-x desktop-change-dir}. Typing
2017 @kbd{M-x desktop-revert} reverts to the desktop previously reloaded.
2019 Specify the option @samp{--no-desktop} on the command line when you
2020 don't want it to reload any saved desktop. This turns off
2021 @code{desktop-save-mode} for the current session.
2023 @vindex desktop-restore-eager
2024 By default, all the buffers in the desktop are restored at one go.
2025 However, this may be slow if there are a lot of buffers in the
2026 desktop. You can specify the maximum number of buffers to restore
2027 immediately with the variable @code{desktop-restore-eager}; the
2028 remaining buffers are restored ``lazily,'' when Emacs is idle.
2030 @findex desktop-clear
2031 @vindex desktop-globals-to-clear
2032 @vindex desktop-clear-preserve-buffers-regexp
2033 Type @kbd{M-x desktop-clear} to empty the Emacs desktop. This kills
2034 all buffers except for internal ones, and clears the global variables
2035 listed in @code{desktop-globals-to-clear}. If you want this to
2036 preserve certain buffers, customize the variable
2037 @code{desktop-clear-preserve-buffers-regexp}, whose value is a regular
2038 expression matching the names of buffers not to kill.
2040 If you want to save minibuffer history from one session to
2041 another, use the @code{savehist} library.
2043 @node Recursive Edit, Emulation, Saving Emacs Sessions, Top
2044 @section Recursive Editing Levels
2045 @cindex recursive editing level
2046 @cindex editing level, recursive
2048 A @dfn{recursive edit} is a situation in which you are using Emacs
2049 commands to perform arbitrary editing while in the middle of another
2050 Emacs command. For example, when you type @kbd{C-r} inside of a
2051 @code{query-replace}, you enter a recursive edit in which you can change
2052 the current buffer. On exiting from the recursive edit, you go back to
2053 the @code{query-replace}.
2056 @findex exit-recursive-edit
2057 @cindex exiting recursive edit
2058 @dfn{Exiting} the recursive edit means returning to the unfinished
2059 command, which continues execution. The command to exit is @kbd{C-M-c}
2060 (@code{exit-recursive-edit}).
2062 You can also @dfn{abort} the recursive edit. This is like exiting,
2063 but also quits the unfinished command immediately. Use the command
2064 @kbd{C-]} (@code{abort-recursive-edit}) to do this. @xref{Quitting}.
2066 The mode line shows you when you are in a recursive edit by displaying
2067 square brackets around the parentheses that always surround the major and
2068 minor mode names. Every window's mode line shows this in the same way,
2069 since being in a recursive edit is true of Emacs as a whole rather than
2070 any particular window or buffer.
2072 It is possible to be in recursive edits within recursive edits. For
2073 example, after typing @kbd{C-r} in a @code{query-replace}, you may type a
2074 command that enters the debugger. This begins a recursive editing level
2075 for the debugger, within the recursive editing level for @kbd{C-r}.
2076 Mode lines display a pair of square brackets for each recursive editing
2077 level currently in progress.
2079 Exiting the inner recursive edit (such as with the debugger @kbd{c}
2080 command) resumes the command running in the next level up. When that
2081 command finishes, you can then use @kbd{C-M-c} to exit another recursive
2082 editing level, and so on. Exiting applies to the innermost level only.
2083 Aborting also gets out of only one level of recursive edit; it returns
2084 immediately to the command level of the previous recursive edit. If you
2085 wish, you can then abort the next recursive editing level.
2087 Alternatively, the command @kbd{M-x top-level} aborts all levels of
2088 recursive edits, returning immediately to the top-level command reader.
2090 The text being edited inside the recursive edit need not be the same text
2091 that you were editing at top level. It depends on what the recursive edit
2092 is for. If the command that invokes the recursive edit selects a different
2093 buffer first, that is the buffer you will edit recursively. In any case,
2094 you can switch buffers within the recursive edit in the normal manner (as
2095 long as the buffer-switching keys have not been rebound). You could
2096 probably do all the rest of your editing inside the recursive edit,
2097 visiting files and all. But this could have surprising effects (such as
2098 stack overflow) from time to time. So remember to exit or abort the
2099 recursive edit when you no longer need it.
2101 In general, we try to minimize the use of recursive editing levels in
2102 GNU Emacs. This is because they constrain you to ``go back'' in a
2103 particular order---from the innermost level toward the top level. When
2104 possible, we present different activities in separate buffers so that
2105 you can switch between them as you please. Some commands switch to a
2106 new major mode which provides a command to switch back. These
2107 approaches give you more flexibility to go back to unfinished tasks in
2108 the order you choose.
2110 @node Emulation, Hyperlinking, Recursive Edit, Top
2112 @cindex emulating other editors
2113 @cindex other editors
2116 @cindex PC key bindings
2117 @cindex scrolling all windows
2118 @cindex PC selection
2119 @cindex Motif key bindings
2120 @cindex Macintosh key bindings
2123 GNU Emacs can be programmed to emulate (more or less) most other
2124 editors. Standard facilities can emulate these:
2127 @item CRiSP/Brief (PC editor)
2129 @vindex crisp-override-meta-x
2130 @findex scroll-all-mode
2132 @cindex Brief emulation
2133 @cindex emulation of Brief
2135 You can turn on key bindings to emulate the CRiSP/Brief editor with
2136 @kbd{M-x crisp-mode}. Note that this rebinds @kbd{M-x} to exit Emacs
2137 unless you set the variable @code{crisp-override-meta-x}. You can
2138 also use the command @kbd{M-x scroll-all-mode} or set the variable
2139 @code{crisp-load-scroll-all} to emulate CRiSP's scroll-all feature
2140 (scrolling all windows together).
2142 @item EDT (DEC VMS editor)
2143 @findex edt-emulation-on
2144 @findex edt-emulation-off
2145 Turn on EDT emulation with @kbd{M-x edt-emulation-on}. @kbd{M-x
2146 edt-emulation-off} restores normal Emacs command bindings.
2148 Most of the EDT emulation commands are keypad keys, and most standard
2149 Emacs key bindings are still available. The EDT emulation rebindings
2150 are done in the global keymap, so there is no problem switching
2151 buffers or major modes while in EDT emulation.
2153 @item TPU (DEC VMS editor)
2156 @kbd{M-x tpu-edt-on} turns on emulation of the TPU editor emulating EDT.
2158 @item vi (Berkeley editor)
2160 Viper is the newest emulator for vi. It implements several levels of
2161 emulation; level 1 is closest to vi itself, while level 5 departs
2162 somewhat from strict emulation to take advantage of the capabilities of
2163 Emacs. To invoke Viper, type @kbd{M-x viper-mode}; it will guide you
2164 the rest of the way and ask for the emulation level. @inforef{Top,
2167 @item vi (another emulator)
2169 @kbd{M-x vi-mode} enters a major mode that replaces the previously
2170 established major mode. All of the vi commands that, in real vi, enter
2171 ``input'' mode are programmed instead to return to the previous major
2172 mode. Thus, ordinary Emacs serves as vi's ``input'' mode.
2174 Because vi emulation works through major modes, it does not work
2175 to switch buffers during emulation. Return to normal Emacs first.
2177 If you plan to use vi emulation much, you probably want to bind a key
2178 to the @code{vi-mode} command.
2180 @item vi (alternate emulator)
2182 @kbd{M-x vip-mode} invokes another vi emulator, said to resemble real vi
2183 more thoroughly than @kbd{M-x vi-mode}. ``Input'' mode in this emulator
2184 is changed from ordinary Emacs so you can use @key{ESC} to go back to
2185 emulated vi command mode. To get from emulated vi command mode back to
2186 ordinary Emacs, type @kbd{C-z}.
2188 This emulation does not work through major modes, and it is possible
2189 to switch buffers in various ways within the emulator. It is not
2190 so necessary to assign a key to the command @code{vip-mode} as
2191 it is with @code{vi-mode} because terminating insert mode does
2194 @inforef{Top, VIP, vip}, for full information.
2196 @item WordStar (old wordprocessor)
2197 @findex wordstar-mode
2198 @kbd{M-x wordstar-mode} provides a major mode with WordStar-like
2202 @node Hyperlinking, Thumbnails, Emulation, Top
2203 @section Hyperlinking and Navigation Features
2205 @cindex hyperlinking
2207 Various modes documented elsewhere have hypertext features so that
2208 you can follow links, usually by clicking @kbd{Mouse-2} on the link or
2209 typing @key{RET} while point is on the link. Clicking @kbd{Mouse-1}
2210 quickly on the link also follows it. (Hold @kbd{Mouse-1} for longer
2211 if you want to set point instead.)
2213 Info mode, Help mode and the Dired-like modes are examples of modes
2214 that have links in the buffer. The Tags facility links between uses
2215 and definitions in source files, see @ref{Tags}. Imenu provides
2216 navigation amongst items indexed in the current buffer, see
2217 @ref{Imenu}. Info-lookup provides mode-specific lookup of definitions
2218 in Info indexes, see @ref{Documentation}. Speedbar maintains a frame
2219 in which links to files, and locations in files are displayed, see
2222 Other non-mode-specific facilities described in this section enable
2223 following links from the current buffer in a context-sensitive
2227 * Browse-URL:: Following URLs.
2228 * Goto-address:: Activating URLs.
2229 * FFAP:: Finding files etc. at point.
2233 @subsection Following URLs
2234 @cindex World Wide Web
2237 @findex browse-url-at-point
2238 @findex browse-url-at-mouse
2243 @item M-x browse-url @key{RET} @var{url} @key{RET}
2244 Load a URL into a Web browser.
2247 The Browse-URL package provides facilities for following URLs specifying
2248 links on the World Wide Web. Usually this works by invoking a web
2249 browser, but you can, for instance, arrange to invoke @code{compose-mail}
2250 from @samp{mailto:} URLs.
2252 The general way to use this feature is to type @kbd{M-x browse-url},
2253 which displays a specified URL. If point is located near a plausible
2254 URL, that URL is used as the default. Other commands are available
2255 which you might like to bind to keys, such as
2256 @code{browse-url-at-point} and @code{browse-url-at-mouse}.
2258 @vindex browse-url-browser-function
2259 You can customize Browse-URL's behavior via various options in the
2260 @code{browse-url} Customize group, particularly
2261 @code{browse-url-browser-function}. You can invoke actions dependent
2262 on the type of URL by defining @code{browse-url-browser-function} as
2263 an association list. The package's commentary available via @kbd{C-h
2264 p} under the @samp{hypermedia} keyword provides more information.
2265 Packages with facilities for following URLs should always go through
2266 Browse-URL, so that the customization options for Browse-URL will
2267 affect all browsing in Emacs.
2270 @subsection Activating URLs
2271 @findex goto-address
2272 @cindex Goto-address
2273 @cindex URLs, activating
2276 @item M-x goto-address
2277 Activate URLs and e-mail addresses in the current buffer.
2280 You can make URLs in the current buffer active with @kbd{M-x
2281 goto-address}. This finds all the URLs in the buffer, and establishes
2282 bindings for @kbd{Mouse-2} and @kbd{C-c @key{RET}} on them. After
2283 activation, if you click on a URL with @kbd{Mouse-2}, or move to a URL
2284 and type @kbd{C-c @key{RET}}, that will display the web page that the URL
2285 specifies. For a @samp{mailto} URL, it sends mail instead, using your
2286 selected mail-composition method (@pxref{Mail Methods}).
2288 It can be useful to add @code{goto-address} to mode hooks and the
2289 hooks used to display an incoming message.
2290 @code{rmail-show-message-hook} is the appropriate hook for Rmail, and
2291 @code{mh-show-mode-hook} for MH-E. This is not needed for Gnus,
2292 which has a similar feature of its own.
2296 @subsection Finding Files and URLs at Point
2297 @findex find-file-at-point
2299 @findex dired-at-point
2302 @cindex finding file at point
2304 FFAP mode replaces certain key bindings for finding files, including
2305 @kbd{C-x C-f}, with commands that provide more sensitive defaults.
2306 These commands behave like the ordinary ones when given a prefix
2307 argument. Otherwise, they get the default file name or URL from the
2308 text around point. If what is found in the buffer has the form of a
2309 URL rather than a file name, the commands use @code{browse-url} to
2312 This feature is useful for following references in mail or news
2313 buffers, @file{README} files, @file{MANIFEST} files, and so on. The
2314 @samp{ffap} package's commentary available via @kbd{C-h p} under the
2315 @samp{files} keyword and the @code{ffap} Custom group provide details.
2317 @cindex FFAP minor mode
2319 You can turn on FFAP minor mode by calling @code{ffap-bindings} to
2320 make the following key bindings and to install hooks for using
2321 @code{ffap} in Rmail, Gnus and VM article buffers.
2324 @item C-x C-f @var{filename} @key{RET}
2325 @kindex C-x C-f @r{(FFAP)}
2326 Find @var{filename}, guessing a default from text around point
2327 (@code{find-file-at-point}).
2329 @kindex C-x C-r @r{(FFAP)}
2330 @code{ffap-read-only}, analogous to @code{find-file-read-only}.
2332 @kindex C-x C-v @r{(FFAP)}
2333 @code{ffap-alternate-file}, analogous to @code{find-alternate-file}.
2334 @item C-x d @var{directory} @key{RET}
2335 @kindex C-x d @r{(FFAP)}
2336 Start Dired on @var{directory}, defaulting to the directory name at
2337 point (@code{dired-at-point}).
2339 @code{ffap-list-directory}, analogous to @code{list-directory}.
2341 @kindex C-x 4 f @r{(FFAP)}
2342 @code{ffap-other-window}, analogous to @code{find-file-other-window}.
2344 @code{ffap-read-only-other-window}, analogous to
2345 @code{find-file-read-only-other-window}.
2347 @code{ffap-dired-other-window}, analogous to @code{dired-other-window}.
2349 @kindex C-x 5 f @r{(FFAP)}
2350 @code{ffap-other-frame}, analogous to @code{find-file-other-frame}.
2352 @code{ffap-read-only-other-frame}, analogous to
2353 @code{find-file-read-only-other-frame}.
2355 @code{ffap-dired-other-frame}, analogous to @code{dired-other-frame}.
2357 Search buffer for next file name or URL, then find that file or URL.
2359 @kindex S-Mouse-3 @r{(FFAP)}
2360 @code{ffap-at-mouse} finds the file guessed from text around the position
2363 @kindex C-S-Mouse-3 @r{(FFAP)}
2364 Display a menu of files and URLs mentioned in current buffer, then
2365 find the one you select (@code{ffap-menu}).
2368 @node Thumbnails, Dissociated Press, Hyperlinking, Top
2369 @section Viewing Images as Thumbnails
2373 Tumme is a facility for browsing image files. It provides viewing
2374 the images either as thumbnails or in full size, either inside Emacs
2375 or through an external viewer.
2377 To enter Tumme, type @kbd{M-x tumme}. It prompts for a directory;
2378 specify one that has images files. This creates thumbnails for all
2379 the images in that directory, and displays them all in the ``thumbnail
2380 buffer.'' This takes a long time if the directory contains many image
2381 files, and it asks for confirmation if the number of image files
2382 exceeds @code{tumme-show-all-from-dir-max-files}.
2384 @kindex C-t d @r{(Tumme)}
2385 @findex tumme-display-thumbs
2386 You can also enter Tumme through Dired. Mark the image files you
2387 want to look at, using @kbd{m} as usual, then type @kbd{C-t d}
2388 (@code{tumme-display-thumbs}). This too creates and switches to
2389 a buffer containing thumbnails, corresponding to the marked files.
2391 With point in the thumbnail buffer, type @kbd{RET}
2392 (@code{tumme-display-thumbnail-original-image}) to display a sized
2393 version of it in another window. This sizes the image to fit the
2394 window. Use the arrow keys to move around in the buffer. For easy
2395 browsing, type @kbd{SPC} (@code{tumme-display-next-thumbnail-original})
2396 to advance and display the next image. Typing @kbd{DEL}
2397 (@code{tumme-display-previous-thumbnail-original}) backs up to the
2398 previous thumbnail and displays that instead.
2400 @vindex tumme-external-viewer
2401 To view and the image in its original size, either provide a prefix
2402 argument (@kbd{C-u}) before pressing @kbd{RET}, or type @kbd{C-@key{RET}}
2403 (@code{tumme-thumbnail-display-external}) to display the image in an
2404 external viewer. You must first configure
2405 @code{tumme-external-viewer}.
2407 You can delete images through Tumme also. Type @kbd{d}
2408 (@code{tumme-flag-thumb-original-file}) to flag the image file for
2409 deletion in the Dired buffer. You can also delete the thumbnail image
2410 from the thumbnail buffer with @kbd{C-d} (@code{tumme-delete-char}).
2412 More advanced features include @dfn{image tags}, which are metadata
2413 used to categorize image files. The tags are stored in a plain text
2414 file configured by @code{tumme-db-file}.
2416 To tag image files, mark them in the dired buffer (you can also mark
2417 files in Dired from the thumbnail buffer by typing @kbd{m}) and type
2418 @kbd{C-t t} (@code{tumme-tag-files}). You will be prompted for a tag.
2419 To mark files having a certain tag, type @kbd{C-t f}
2420 (@code{tumme-mark-tagged-files}). After marking image files with a
2421 certain tag, you can use @kbd{C-t d} to view them.
2423 You can also tag a file directly from the thumbnail buffer by typing
2424 @kbd{t t} and you can remove a tag by typing @kbd{t r}. There is also
2425 a special ``tag'' called ``comment'' for each file (it is not a tag in
2426 the exact same sense as the other tags, it is handled slightly
2427 different). That is used to enter a comment or description about the
2428 image. You comment a file from the thumbnail buffer by typing
2429 @kbd{c}. You will be prompted for a comment. Type @kbd{C-t c} to add
2430 a comment from Dired (@code{tumme-dired-comment-files}).
2432 Tumme also provides simple image manipulation. In the thumbnail
2433 buffer, type @kbd{L} to rotate the original image 90 degrees anti
2434 clockwise, and @kbd{R} to rotate it 90 degrees clockwise. This
2435 rotation is lossless, and uses an external utility called JpegTRAN.
2437 @node Dissociated Press, Amusements, Thumbnails, Top
2438 @section Dissociated Press
2440 @findex dissociated-press
2441 @kbd{M-x dissociated-press} is a command for scrambling a file of text
2442 either word by word or character by character. Starting from a buffer of
2443 straight English, it produces extremely amusing output. The input comes
2444 from the current Emacs buffer. Dissociated Press writes its output in a
2445 buffer named @samp{*Dissociation*}, and redisplays that buffer after every
2446 couple of lines (approximately) so you can read the output as it comes out.
2448 Dissociated Press asks every so often whether to continue generating
2449 output. Answer @kbd{n} to stop it. You can also stop at any time by
2450 typing @kbd{C-g}. The dissociation output remains in the
2451 @samp{*Dissociation*} buffer for you to copy elsewhere if you wish.
2453 @cindex presidentagon
2454 Dissociated Press operates by jumping at random from one point in the
2455 buffer to another. In order to produce plausible output rather than
2456 gibberish, it insists on a certain amount of overlap between the end of
2457 one run of consecutive words or characters and the start of the next.
2458 That is, if it has just output `president' and then decides to jump
2459 to a different point in the file, it might spot the `ent' in `pentagon'
2460 and continue from there, producing `presidentagon'.@footnote{This
2461 dissociword actually appeared during the Vietnam War, when it was very
2462 appropriate. Bush has made it appropriate again.} Long sample texts
2463 produce the best results.
2465 @cindex againformation
2466 A positive argument to @kbd{M-x dissociated-press} tells it to operate
2467 character by character, and specifies the number of overlap characters. A
2468 negative argument tells it to operate word by word, and specifies the number
2469 of overlap words. In this mode, whole words are treated as the elements to
2470 be permuted, rather than characters. No argument is equivalent to an
2471 argument of two. For your againformation, the output goes only into the
2472 buffer @samp{*Dissociation*}. The buffer you start with is not changed.
2474 @cindex Markov chain
2476 @cindex techniquitous
2477 Dissociated Press produces results fairly like those of a Markov
2478 chain based on a frequency table constructed from the sample text. It
2479 is, however, an independent, ignoriginal invention. Dissociated Press
2480 techniquitously copies several consecutive characters from the sample
2481 between random choices, whereas a Markov chain would choose randomly
2482 for each word or character. This makes for more plausible sounding
2483 results, and runs faster.
2489 @cindex developediment
2491 It is a mustatement that too much use of Dissociated Press can be a
2492 developediment to your real work, sometimes to the point of outragedy.
2493 And keep dissociwords out of your documentation, if you want it to be well
2494 userenced and properbose. Have fun. Your buggestions are welcome.
2496 @node Amusements, Customization, Dissociated Press, Top
2497 @section Other Amusements
2502 @cindex tower of Hanoi
2504 If you are a little bit bored, you can try @kbd{M-x hanoi}. If you are
2505 considerably bored, give it a numeric argument. If you are very, very
2506 bored, try an argument of 9. Sit back and watch.
2509 If you want a little more personal involvement, try @kbd{M-x gomoku},
2510 which plays the game Go Moku with you.
2516 @kbd{M-x blackbox}, @kbd{M-x mpuz} and @kbd{M-x 5x5} are puzzles.
2517 @code{blackbox} challenges you to determine the location of objects
2518 inside a box by tomography. @code{mpuz} displays a multiplication
2519 puzzle with letters standing for digits in a code that you must
2520 guess---to guess a value, type a letter and then the digit you think it
2521 stands for. The aim of @code{5x5} is to fill in all the squares.
2525 @cindex cryptanalysis
2526 @kbd{M-x decipher} helps you to cryptanalyze a buffer which is encrypted
2527 in a simple monoalphabetic substitution cipher.
2530 @kbd{M-x dunnet} runs an adventure-style exploration game, which is
2531 a bigger sort of puzzle.
2534 @cindex landmark game
2535 @kbd{M-x lm} runs a relatively non-participatory game in which a robot
2536 attempts to maneuver towards a tree at the center of the window based on
2537 unique olfactory cues from each of the four directions.
2541 @kbd{M-x life} runs Conway's ``Life'' cellular automaton.
2543 @findex morse-region
2544 @findex unmorse-region
2546 @cindex --/---/.-./.../.
2547 @kbd{M-x morse-region} converts text in a region to Morse code and
2548 @kbd{M-x unmorse-region} converts it back. No cause for remorse.
2552 @kbd{M-x pong} plays a Pong-like game, bouncing the ball off opposing
2557 @kbd{M-x solitaire} plays a game of solitaire in which you jump pegs
2560 @findex studlify-region
2562 @kbd{M-x studlify-region} studlify-cases the region, producing
2566 M-x stUdlIfY-RegioN stUdlIfY-CaSeS thE region.
2573 @kbd{M-x tetris} runs an implementation of the well-known Tetris game.
2574 Likewise, @kbd{M-x snake} provides an implementation of Snake.
2576 When you are frustrated, try the famous Eliza program. Just do
2577 @kbd{M-x doctor}. End each input by typing @key{RET} twice.
2580 When you are feeling strange, type @kbd{M-x yow}.
2583 The command @kbd{M-x zone} plays games with the display when Emacs is
2591 arch-tag: 8f094220-c0d5-4e9e-af7d-3e0da8187474