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6bf7aab6 | 1 | @c This is part of the Emacs manual. |
b65d8176 TTN |
2 | @c Copyright (C) 1985, 1986, 1987, 1993, 1994, 1995, 1997, 2000, 2001, |
3 | @c 2002, 2003, 2004, 2005 Free Software Foundation, Inc. | |
6bf7aab6 DL |
4 | @c See file emacs.texi for copying conditions. |
5 | @node Help, Mark, M-x, Top | |
6 | @chapter Help | |
7 | @kindex Help | |
8 | @cindex help | |
9 | @cindex self-documentation | |
10 | @findex help-command | |
11 | @kindex C-h | |
12 | @kindex F1 | |
13 | ||
14 | Emacs provides extensive help features accessible through a single | |
c8cdfe6a | 15 | character, @kbd{C-h}. @kbd{C-h} is a prefix key that is used for |
58fa012d | 16 | commands that display documentation. The characters that you can type after |
6bf7aab6 DL |
17 | @kbd{C-h} are called @dfn{help options}. One help option is @kbd{C-h}; |
18 | that is how you ask for help about using @kbd{C-h}. To cancel, type | |
19 | @kbd{C-g}. The function key @key{F1} is equivalent to @kbd{C-h}. | |
20 | ||
21 | @kindex C-h C-h | |
22 | @findex help-for-help | |
23 | @kbd{C-h C-h} (@code{help-for-help}) displays a list of the possible | |
24 | help options, each with a brief description. Before you type a help | |
25 | option, you can use @key{SPC} or @key{DEL} to scroll through the list. | |
26 | ||
27 | @kbd{C-h} or @key{F1} means ``help'' in various other contexts as | |
0bbb35f9 RS |
28 | well. After a prefix key, it displays a list of the alternatives that |
29 | can follow the prefix key. (A few prefix keys don't support | |
30 | @kbd{C-h}, because they define other meanings for it, but they all | |
31 | support @key{F1}.) | |
6bf7aab6 DL |
32 | |
33 | Most help buffers use a special major mode, Help mode, which lets you | |
7d291226 | 34 | scroll conveniently with @key{SPC} and @key{DEL}. It also offers |
22e388cd BW |
35 | hyperlinks to URLs and further help regarding cross-referenced names, Info |
36 | nodes, customization buffers and the like. @xref{Help Mode}. | |
6bf7aab6 | 37 | |
576c1dcb EZ |
38 | @cindex searching documentation efficiently |
39 | @cindex looking for a subject in documentation | |
ab6620fa | 40 | If you are looking for a certain feature, but don't know where |
0ec1f115 | 41 | exactly it is documented, and aren't sure of the name of a |
19b2c4ca | 42 | related command or variable, we recommend trying these methods. Usually |
ab6620fa RS |
43 | it is best to start with an apropos command, then try searching the |
44 | manual index, then finally look in the FAQ and the package keywords. | |
576c1dcb EZ |
45 | |
46 | @table @kbd | |
de22da59 RS |
47 | @item C-h a @var{topics} @key{RET} |
48 | This searches for commands whose names match @var{topics}, which | |
49 | should be a keyword, a list of keywords, or a regular expression | |
7a32e81f | 50 | (@pxref{Regexps}). This command displays all the matches in a new |
de22da59 | 51 | buffer. @xref{Apropos}. |
57f49913 | 52 | |
dc941693 | 53 | @item C-h i d m emacs @key{RET} i @var{topic} @key{RET} |
a83e8765 | 54 | This looks up @var{topic} in the indices of the Emacs on-line manual. |
dcd5ecef | 55 | If there are several matches, Emacs displays the first one. You can then |
97db3e8a | 56 | press @kbd{,} to move to other matches, until you find what you are |
a83e8765 RS |
57 | looking for. |
58 | ||
dc941693 | 59 | @item C-h i d m emacs @key{RET} s @var{topic} @key{RET} |
a83e8765 RS |
60 | Similar, but searches for @var{topic} (which can be a regular |
61 | expression) in the @emph{text} of the manual rather than in its | |
62 | indices. | |
63 | ||
1dcc8951 | 64 | @item C-h C-f |
0bbb35f9 RS |
65 | This brings up the Emacs FAQ. You can use the Info commands |
66 | to browse it. | |
576c1dcb | 67 | |
3085f862 | 68 | @item C-h p |
576c1dcb | 69 | Finally, you can try looking up a suitable package using keywords |
3085f862 | 70 | pertinent to the feature you need. @xref{Library Keywords}. |
576c1dcb EZ |
71 | @end table |
72 | ||
4e9d1a58 | 73 | To find the documentation of a key sequence or a menu item, type |
00b5a712 | 74 | @kbd{C-h K} and then type that key sequence or select the menu |
4e9d1a58 EZ |
75 | item. This looks up the description of the command invoked by the key |
76 | or the menu in the appropriate manual (not necessarily the Emacs | |
00b5a712 | 77 | manual). Likewise, use @kbd{C-h F} for reading documentation of a |
4e9d1a58 EZ |
78 | command. |
79 | ||
6bf7aab6 DL |
80 | @menu |
81 | * Help Summary:: Brief list of all Help commands. | |
82 | * Key Help:: Asking what a key does in Emacs. | |
83 | * Name Help:: Asking about a command, variable or function name. | |
84 | * Apropos:: Asking what pertains to a given topic. | |
85 | * Library Keywords:: Finding Lisp libraries by keywords (topics). | |
86 | * Language Help:: Help relating to international language support. | |
87 | * Help Mode:: Special features of Help mode and Help buffers. | |
88 | * Misc Help:: Other help commands. | |
00b5a712 | 89 | * Help Files:: Commands to display pre-written help files. |
7d291226 | 90 | * Help Echo:: Help on active text and tooltips (`balloon help') |
6bf7aab6 DL |
91 | @end menu |
92 | ||
93 | @iftex | |
94 | @node Help Summary | |
95 | @end iftex | |
49e71458 | 96 | @ifnottex |
6bf7aab6 DL |
97 | @node Help Summary |
98 | @section Help Summary | |
49e71458 | 99 | @end ifnottex |
6bf7aab6 | 100 | |
00b5a712 RS |
101 | Here is a summary of the Emacs interactive help commands. |
102 | @xref{Help Files}, for other help commands that just display a | |
103 | pre-written file of information. | |
6bf7aab6 DL |
104 | |
105 | @table @kbd | |
de22da59 RS |
106 | @item C-h a @var{topics} @key{RET} |
107 | Display a list of commands whose names match @var{topics} | |
108 | (@code{apropos-command}; @pxref{Apropos}). | |
6bf7aab6 DL |
109 | @item C-h b |
110 | Display a table of all key bindings in effect now, in this order: minor | |
111 | mode bindings, major mode bindings, and global bindings | |
112 | (@code{describe-bindings}). | |
113 | @item C-h c @var{key} | |
c8cdfe6a | 114 | Show the name of the command that @var{key} runs |
2684ed46 RS |
115 | (@code{describe-key-briefly}). Here @kbd{c} stands for ``character.'' |
116 | For more extensive information on @var{key}, use @kbd{C-h k}. | |
de22da59 RS |
117 | @item C-h d @var{topics} @key{RET} |
118 | Display a list of commands and variables whose documentation matches | |
119 | @var{topics} (@code{apropos-documentation}). | |
b7bfc840 KS |
120 | @item C-h e |
121 | Display the @code{*Messages*} buffer | |
122 | (@code{view-echo-area-messages}). | |
6bf7aab6 DL |
123 | @item C-h f @var{function} @key{RET} |
124 | Display documentation on the Lisp function named @var{function} | |
125 | (@code{describe-function}). Since commands are Lisp functions, | |
126 | a command name may be used. | |
127 | @item C-h h | |
dc941693 | 128 | Display the @file{HELLO} file, which shows examples of various character |
6bf7aab6 DL |
129 | sets. |
130 | @item C-h i | |
131 | Run Info, the program for browsing documentation files (@code{info}). | |
132 | The complete Emacs manual is available on-line in Info. | |
133 | @item C-h k @var{key} | |
134 | Display the name and documentation of the command that @var{key} runs | |
135 | (@code{describe-key}). | |
136 | @item C-h l | |
137 | Display a description of the last 100 characters you typed | |
138 | (@code{view-lossage}). | |
139 | @item C-h m | |
140 | Display documentation of the current major mode (@code{describe-mode}). | |
6bf7aab6 DL |
141 | @item C-h p |
142 | Find packages by topic keyword (@code{finder-by-keyword}). | |
143 | @item C-h s | |
58fa012d | 144 | Display the current contents of the syntax table, plus an explanation of |
6bf7aab6 DL |
145 | what they mean (@code{describe-syntax}). @xref{Syntax}. |
146 | @item C-h t | |
147 | Enter the Emacs interactive tutorial (@code{help-with-tutorial}). | |
148 | @item C-h v @var{var} @key{RET} | |
c8cdfe6a | 149 | Display the documentation of the Lisp variable @var{var} |
6bf7aab6 DL |
150 | (@code{describe-variable}). |
151 | @item C-h w @var{command} @key{RET} | |
c8cdfe6a | 152 | Show which keys run the command named @var{command} (@code{where-is}). |
6bf7aab6 | 153 | @item C-h C @var{coding} @key{RET} |
c8cdfe6a | 154 | Describe coding system @var{coding} |
6bf7aab6 DL |
155 | (@code{describe-coding-system}). |
156 | @item C-h C @key{RET} | |
157 | Describe the coding systems currently in use. | |
158 | @item C-h I @var{method} @key{RET} | |
159 | Describe an input method (@code{describe-input-method}). | |
160 | @item C-h L @var{language-env} @key{RET} | |
0ec1f115 | 161 | Display information on the character sets, coding systems, and input |
c8cdfe6a | 162 | methods used for language environment @var{language-env} |
6bf7aab6 | 163 | (@code{describe-language-environment}). |
00b5a712 | 164 | @item C-h F @var{function} @key{RET} |
6bf7aab6 DL |
165 | Enter Info and go to the node documenting the Emacs function @var{function} |
166 | (@code{Info-goto-emacs-command-node}). | |
00b5a712 | 167 | @item C-h K @var{key} |
6bf7aab6 DL |
168 | Enter Info and go to the node where the key sequence @var{key} is |
169 | documented (@code{Info-goto-emacs-key-command-node}). | |
00b5a712 | 170 | @item C-h S @var{symbol} @key{RET} |
6bf7aab6 DL |
171 | Display the Info documentation on symbol @var{symbol} according to the |
172 | programming language you are editing (@code{info-lookup-symbol}). | |
8f4fc840 RS |
173 | @item C-h . |
174 | Display a help message associated with special text areas, such as | |
846d7db2 | 175 | links in @samp{*Help*} buffers (@code{display-local-help}). |
6bf7aab6 DL |
176 | @end table |
177 | ||
178 | @node Key Help | |
179 | @section Documentation for a Key | |
180 | ||
181 | @kindex C-h c | |
182 | @findex describe-key-briefly | |
183 | The most basic @kbd{C-h} options are @kbd{C-h c} | |
184 | (@code{describe-key-briefly}) and @w{@kbd{C-h k}} (@code{describe-key}). | |
1ba2ce68 RS |
185 | @kbd{C-h c @var{key}} displays in the echo area the name of the command |
186 | that @var{key} is bound to. For example, @kbd{C-h c C-f} displays | |
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187 | @samp{forward-char}. Since command names are chosen to describe what |
188 | the commands do, this is a good way to get a very brief description of | |
189 | what @var{key} does. | |
190 | ||
191 | @kindex C-h k | |
192 | @findex describe-key | |
193 | @kbd{C-h k @var{key}} is similar but gives more information: it | |
194 | displays the documentation string of the command as well as its name. | |
195 | This is too big for the echo area, so a window is used for the display. | |
196 | ||
197 | @kbd{C-h c} and @kbd{C-h k} work for any sort of key sequences, | |
198 | including function keys and mouse events. | |
199 | ||
0bbb35f9 RS |
200 | @kindex C-h w |
201 | @findex where-is | |
202 | @kbd{C-h w @var{command} @key{RET}} tells you what keys are bound to | |
203 | @var{command}. It displays a list of the keys in the echo area. If it | |
204 | says the command is not on any key, you must use @kbd{M-x} to run it. | |
205 | @kbd{C-h w} runs the command @code{where-is}. | |
206 | ||
6bf7aab6 DL |
207 | @node Name Help |
208 | @section Help by Command or Variable Name | |
209 | ||
210 | @kindex C-h f | |
211 | @findex describe-function | |
212 | @kbd{C-h f} (@code{describe-function}) reads the name of a Lisp function | |
213 | using the minibuffer, then displays that function's documentation string | |
214 | in a window. Since commands are Lisp functions, you can use this to get | |
215 | the documentation of a command that you know by name. For example, | |
216 | ||
217 | @example | |
218 | C-h f auto-fill-mode @key{RET} | |
219 | @end example | |
220 | ||
221 | @noindent | |
222 | displays the documentation of @code{auto-fill-mode}. This is the only | |
223 | way to get the documentation of a command that is not bound to any key | |
224 | (one which you would normally run using @kbd{M-x}). | |
225 | ||
0bbb35f9 RS |
226 | @kbd{C-h f} is also useful for Lisp functions that you are planning |
227 | to use in a Lisp program. For example, if you have just written the | |
228 | expression @code{(make-vector len)} and want to check that you are | |
229 | using @code{make-vector} properly, type @kbd{C-h f make-vector | |
230 | @key{RET}}. Because @kbd{C-h f} allows all function names, not just | |
231 | command names, you may find that some of your favorite completion | |
232 | abbreviations that work in @kbd{M-x} don't work in @kbd{C-h f}. An | |
233 | abbreviation may be unique among command names, yet fail to be unique | |
234 | when other function names are allowed. | |
6bf7aab6 | 235 | |
c8cdfe6a EZ |
236 | The default function name for @kbd{C-h f} to describe, if you type |
237 | just @key{RET}, is the name of the function called by the innermost Lisp | |
238 | expression in the buffer around point, @emph{provided} that is a valid, | |
239 | defined Lisp function name. For example, if point is located following | |
240 | the text @samp{(make-vector (car x)}, the innermost list containing | |
241 | point is the one that starts with @samp{(make-vector}, so the default is | |
242 | to describe the function @code{make-vector}. | |
6bf7aab6 DL |
243 | |
244 | @kbd{C-h f} is often useful just to verify that you have the right | |
245 | spelling for the function name. If @kbd{C-h f} mentions a name from the | |
246 | buffer as the default, that name must be defined as a Lisp function. If | |
247 | that is all you want to know, just type @kbd{C-g} to cancel the @kbd{C-h | |
248 | f} command, then go on editing. | |
249 | ||
6bf7aab6 DL |
250 | @kbd{C-h v} (@code{describe-variable}) is like @kbd{C-h f} but describes |
251 | Lisp variables instead of Lisp functions. Its default is the Lisp symbol | |
252 | around or before point, but only if that is the name of a known Lisp | |
a8ec80f1 RS |
253 | variable. @xref{Variables}. |
254 | ||
255 | Help buffers describing Emacs variables and functions normally have | |
256 | hyperlinks to the definition, if you have the source files installed. | |
257 | (@xref{Hyperlinking}.) If you know Lisp (or C), this provides the | |
258 | ultimate documentation. If you don't know Lisp, you should learn it. | |
259 | If you are just @emph{using} Emacs, treating Emacs as an object | |
260 | (file), then you don't really love it. For true intimacy with your | |
261 | editor, you need to read the source code. | |
a83e8765 | 262 | |
6bf7aab6 DL |
263 | @node Apropos |
264 | @section Apropos | |
265 | ||
de22da59 RS |
266 | A more sophisticated sort of question to ask is, ``What are the |
267 | commands for working with files?'' The @dfn{apropos} commands ask | |
268 | such questions---they look for things whose names match an | |
269 | @dfn{apropos pattern}, which means either a word, a list of words, or | |
270 | a regular expression. Each apropos command displays a list of | |
271 | matching items in a special buffer. | |
272 | ||
273 | @table @kbd | |
274 | @item C-h a @var{pattern} @key{RET} | |
275 | Search for commands whose names match @var{pattern}. | |
276 | ||
277 | @item M-x apropos @key{RET} @var{pattern} @key{RET} | |
278 | Similar, but it searches for noninteractive functions and for | |
279 | variables, as well as commands. | |
280 | ||
281 | @item M-x apropos-variable @key{RET} @var{pattern} @key{RET} | |
282 | Similar, but it searches for variables only. | |
283 | ||
284 | @item M-x apropos-value @key{RET} @var{pattern} @key{RET} | |
285 | Similar, but it searches for variables based on their values, or | |
286 | functions based on their definitions. | |
287 | ||
288 | @item C-h d @var{pattern} @key{RET} | |
289 | Search the @emph{documentation strings} (the built-in short | |
290 | descriptions) of all variables and functions (not their names) for a | |
291 | match for @var{pattern}. | |
292 | @end table | |
293 | ||
6bf7aab6 DL |
294 | @kindex C-h a |
295 | @findex apropos-command | |
296 | @cindex apropos | |
de22da59 RS |
297 | To find the commands that work on files, type @kbd{C-h a file |
298 | @key{RET}}. This displays a list of all command names that contain | |
299 | @samp{file}, including @code{copy-file}, @code{find-file}, and so on. | |
300 | With each command name appears a brief description of how to use the | |
301 | command, and what keys you can currently invoke it with. For example, | |
302 | it would say that you can invoke @code{find-file} by typing @kbd{C-x | |
303 | C-f}. The @kbd{a} in @kbd{C-h a} stands for ``Apropos''; @kbd{C-h a} | |
304 | runs the command @code{apropos-command}. This command normally checks | |
305 | only commands (interactive functions); if you specify a prefix | |
306 | argument, it checks noninteractive functions as well. | |
307 | ||
308 | If you want more information about a function definition, variable or | |
309 | symbol property listed in the Apropos buffer, you can click on it with | |
310 | @kbd{Mouse-1} or @kbd{Mouse-2}, or move there and type @key{RET}. | |
311 | ||
312 | @kbd{C-h a} with a single word can find too many matches. Don't | |
313 | just give up; you can give Apropos a list of words to search for. | |
314 | When you specify more than one word in the apropos pattern, a name | |
315 | must contain at least two of the words in order to match. Thus, if | |
316 | you are looking for commands to kill a chunk of text before point, you | |
317 | could try @kbd{C-h a kill back backward behind before @key{RET}}. | |
318 | ||
319 | For even greater flexibility, you can specify a regular expression | |
320 | (@pxref{Regexps}). An apropos pattern is interpreted as a regular | |
321 | expression if it contains any of the regular expression special | |
322 | characters, @samp{^$*+?.\[}. | |
6bf7aab6 DL |
323 | |
324 | Here is a set of arguments to give to @kbd{C-h a} that covers many | |
de22da59 RS |
325 | classes of Emacs commands, since there are strong conventions for |
326 | naming the standard Emacs commands. By giving you a feel for the | |
327 | naming conventions, this set should also serve to aid you in | |
328 | developing a technique for picking Apropos keywords. | |
6bf7aab6 DL |
329 | |
330 | @quotation | |
331 | char, line, word, sentence, paragraph, region, page, sexp, list, defun, | |
332 | rect, buffer, frame, window, face, file, dir, register, mode, beginning, end, | |
333 | forward, backward, next, previous, up, down, search, goto, kill, delete, | |
334 | mark, insert, yank, fill, indent, case, change, set, what, list, find, | |
335 | view, describe, default. | |
336 | @end quotation | |
337 | ||
de22da59 | 338 | @findex apropos |
7a32e81f | 339 | To list all Lisp symbols that contain a match for an Apropos pattern, |
de22da59 RS |
340 | not just the ones that are defined as commands, use the command |
341 | @kbd{M-x apropos} instead of @kbd{C-h a}. This command does not check | |
342 | key bindings by default; specify a numeric argument if you want it to | |
343 | check them. | |
344 | ||
6bf7aab6 | 345 | @findex apropos-variable |
de22da59 RS |
346 | To list user-customizable variables that match an apropos pattern, |
347 | use the command @kbd{M-x apropos-variable}. If you specify a prefix | |
19b2c4ca | 348 | argument, it checks all variables. |
6bf7aab6 | 349 | |
b7bfc840 | 350 | @kindex C-h d |
6bf7aab6 | 351 | @findex apropos-documentation |
de22da59 RS |
352 | The @code{apropos-documentation} command is like @code{apropos} |
353 | except that it searches documentation strings instead of symbol names | |
354 | for matches for the specified Apropos pattern. | |
6bf7aab6 DL |
355 | |
356 | @findex apropos-value | |
de22da59 RS |
357 | The @code{apropos-value} command is like @code{apropos} except that |
358 | it searches variables' values for matches for the pattern. With a | |
359 | prefix argument, it also checks symbols' function definitions and | |
360 | property lists. | |
6bf7aab6 DL |
361 | |
362 | @vindex apropos-do-all | |
363 | If the variable @code{apropos-do-all} is non-@code{nil}, the commands | |
364 | above all behave as if they had been given a prefix argument. | |
365 | ||
8f4fc840 | 366 | @vindex apropos-sort-by-scores |
846d7db2 | 367 | @cindex apropos search results, order by score |
8f4fc840 RS |
368 | By default, Apropos lists the search results in alphabetical order. |
369 | If the variable @code{apropos-sort-by-scores} is non-@code{nil}, | |
370 | Apropos tries to guess the relevance of each result, and displays the | |
371 | most relevant ones first. | |
372 | ||
b7bfc840 KS |
373 | @vindex apropos-documentation-sort-by-scores |
374 | By default, Apropos lists the search results for | |
de22da59 RS |
375 | @code{apropos-documentation} in order of relevance of the match. If |
376 | the variable @code{apropos-documentation-sort-by-scores} is | |
7a32e81f | 377 | @code{nil}, Apropos lists the symbols found in alphabetical order. |
6bf7aab6 DL |
378 | |
379 | @node Library Keywords | |
380 | @section Keyword Search for Lisp Libraries | |
381 | ||
382 | @kindex C-h p | |
383 | @findex finder-by-keyword | |
384 | The @kbd{C-h p} command lets you search the standard Emacs Lisp | |
385 | libraries by topic keywords. Here is a partial list of keywords you can | |
386 | use: | |
387 | ||
a70a412f RS |
388 | @multitable {emulations} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa} |
389 | @item abbrev@tab abbreviation handling, typing shortcuts, macros. | |
1dcc8951 JL |
390 | @item bib@tab code related to the @code{bib} bibliography processor. |
391 | @item c@tab support for the C language and related languages. | |
a70a412f RS |
392 | @item calendar@tab calendar and time management support. |
393 | @item comm@tab communications, networking, remote access to files. | |
1dcc8951 | 394 | @item convenience@tab convenience features for faster editing. |
a70a412f RS |
395 | @item data@tab support for editing files of data. |
396 | @item docs@tab support for Emacs documentation. | |
397 | @item emulations@tab emulations of other editors. | |
398 | @item extensions@tab Emacs Lisp language extensions. | |
1dcc8951 JL |
399 | @item faces@tab support for multiple fonts. |
400 | @item files@tab support for editing and manipulating files. | |
a70a412f RS |
401 | @item frames@tab support for Emacs frames and window systems. |
402 | @item games@tab games, jokes and amusements. | |
403 | @item hardware@tab support for interfacing with exotic hardware. | |
404 | @item help@tab support for on-line help systems. | |
1dcc8951 | 405 | @item hypermedia@tab support for links between text or other media types. |
a70a412f RS |
406 | @item i18n@tab internationalization and alternate character-set support. |
407 | @item internal@tab code for Emacs internals, build process, defaults. | |
408 | @item languages@tab specialized modes for editing programming languages. | |
1dcc8951 JL |
409 | @item lisp@tab Lisp support, including Emacs Lisp. |
410 | @item local@tab code local to your site. | |
a70a412f RS |
411 | @item maint@tab maintenance aids for the Emacs development group. |
412 | @item mail@tab modes for electronic-mail handling. | |
1dcc8951 JL |
413 | @item matching@tab various sorts of searching and matching. |
414 | @item mouse@tab mouse support. | |
415 | @item multimedia@tab images and sound support. | |
a70a412f | 416 | @item news@tab support for netnews reading and posting. |
a70a412f | 417 | @item oop@tab support for object-oriented programming. |
1dcc8951 | 418 | @item outlines@tab support for hierarchical outlining. |
a70a412f RS |
419 | @item processes@tab process, subshell, compilation, and job control support. |
420 | @item terminals@tab support for terminal types. | |
1dcc8951 | 421 | @item tex@tab supporting code for the @TeX{} formatter. |
a70a412f | 422 | @item tools@tab programming tools. |
1dcc8951 | 423 | @item unix@tab front-ends/assistants for, or emulators of, UNIX-like features. |
a70a412f RS |
424 | @item wp@tab word processing. |
425 | @end multitable | |
6bf7aab6 DL |
426 | |
427 | @node Language Help | |
428 | @section Help for International Language Support | |
429 | ||
430 | You can use the command @kbd{C-h L} | |
58fa012d EZ |
431 | (@code{describe-language-environment}) to find out information about |
432 | the support for a specific language environment. @xref{Language | |
433 | Environments}. This tells you which languages this language | |
434 | environment is useful for, and lists the character sets, coding | |
435 | systems, and input methods that go with it. It also shows some sample | |
436 | text to illustrate scripts. | |
6bf7aab6 DL |
437 | |
438 | The command @kbd{C-h h} (@code{view-hello-file}) displays the file | |
439 | @file{etc/HELLO}, which shows how to say ``hello'' in many languages. | |
440 | ||
441 | The command @kbd{C-h I} (@code{describe-input-method}) describes | |
442 | information about input methods---either a specified input method, or by | |
443 | default the input method in use. @xref{Input Methods}. | |
444 | ||
445 | The command @kbd{C-h C} (@code{describe-coding-system}) describes | |
446 | information about coding systems---either a specified coding system, or | |
447 | the ones currently in use. @xref{Coding Systems}. | |
448 | ||
449 | @node Help Mode | |
450 | @section Help Mode Commands | |
451 | ||
c8cdfe6a EZ |
452 | Help buffers provide the same commands as View mode (@pxref{Misc File |
453 | Ops}), plus a few special commands of their own. | |
6bf7aab6 DL |
454 | |
455 | @table @kbd | |
456 | @item @key{SPC} | |
457 | Scroll forward. | |
458 | @item @key{DEL} | |
7d794ffb EZ |
459 | @itemx @key{BS} |
460 | Scroll backward. On some keyboards, this key is known as @key{BS} or | |
461 | @key{backspace}. | |
6bf7aab6 DL |
462 | @item @key{RET} |
463 | Follow a cross reference at point. | |
464 | @item @key{TAB} | |
465 | Move point forward to the next cross reference. | |
466 | @item S-@key{TAB} | |
467 | Move point back to the previous cross reference. | |
0bbb35f9 RS |
468 | @item Mouse-1 |
469 | @itemx Mouse-2 | |
6bf7aab6 DL |
470 | Follow a cross reference that you click on. |
471 | @end table | |
472 | ||
0bbb35f9 | 473 | When a function name (@pxref{M-x,, Running Commands by Name}) or |
6bf7aab6 | 474 | variable name (@pxref{Variables}) appears in the documentation, it |
0bbb35f9 RS |
475 | normally appears inside paired single-quotes. You can click on the |
476 | name with @kbd{Mouse-1} or @kbd{Mouse-2}, or move point there and type | |
477 | @key{RET}, to view the documentation of that command or variable. Use | |
478 | @kbd{C-c C-b} to retrace your steps. | |
6bf7aab6 | 479 | |
7145db42 BW |
480 | @cindex URL, viewing in help |
481 | @cindex help, viewing web pages | |
482 | @cindex viewing web pages in help | |
483 | @cindex web pages, viewing in help | |
484 | @findex browse-url | |
c9acf4f7 | 485 | You can follow cross references to URLs (web pages) as well. When |
7145db42 BW |
486 | you follow a cross reference that is a URL, the @code{browse-url} |
487 | command is used to view the web page in a browser of your choosing. | |
488 | @xref{Browse-URL}. | |
489 | ||
6bf7aab6 DL |
490 | @kindex @key{TAB} @r{(Help mode)} |
491 | @findex help-next-ref | |
492 | @kindex S-@key{TAB} @r{(Help mode)} | |
493 | @findex help-previous-ref | |
494 | There are convenient commands for moving point to cross references in | |
495 | the help text. @key{TAB} (@code{help-next-ref}) moves point down to the | |
496 | next cross reference. Use @kbd{S-@key{TAB}} to move point up to the | |
497 | previous cross reference (@code{help-previous-ref}). | |
498 | ||
499 | @node Misc Help | |
500 | @section Other Help Commands | |
501 | ||
502 | @kindex C-h i | |
503 | @findex info | |
504 | @cindex Info | |
505 | @cindex manuals, on-line | |
506 | @cindex on-line manuals | |
507 | @kbd{C-h i} (@code{info}) runs the Info program, which is used for | |
508 | browsing through structured documentation files. The entire Emacs manual | |
c8cdfe6a | 509 | is available within Info. Eventually all the documentation of the GNU |
6bf7aab6 DL |
510 | system will be available. Type @kbd{h} after entering Info to run |
511 | a tutorial on using Info. | |
512 | ||
ba86d34d | 513 | @cindex find Info manual by its file name |
c882ba2e RS |
514 | With a numeric argument, @kbd{C-h i} selects an Info buffer with the |
515 | number appended to the default @samp{*info*} buffer name | |
516 | (e.g. @samp{*info*<2>}). This is useful if you want to browse | |
517 | multiple Info manuals simultaneously. If you specify just @kbd{C-u} | |
518 | as the prefix argument, @kbd{C-h i} prompts for the name of a | |
519 | documentation file. This way, you can browse a file which doesn't | |
6bf7aab6 | 520 | have an entry in the top-level Info menu. It is also handy when you |
c882ba2e RS |
521 | need to get to the documentation quickly, and you know the exact name |
522 | of the file. | |
6bf7aab6 | 523 | |
00b5a712 RS |
524 | @kindex C-h F |
525 | @kindex C-h K | |
6bf7aab6 DL |
526 | @findex Info-goto-emacs-key-command-node |
527 | @findex Info-goto-emacs-command-node | |
00b5a712 RS |
528 | There are two special help commands for accessing Emacs |
529 | documentation through Info. @kbd{C-h F @var{function} @key{RET}} | |
530 | enters Info and goes straight to the documentation of the Emacs | |
531 | function @var{function}. @kbd{C-h K @var{key}} enters Info and goes | |
532 | straight to the documentation of the key @var{key}. These two keys | |
533 | run the commands @code{Info-goto-emacs-command-node} and | |
534 | @code{Info-goto-emacs-key-command-node}. You can use @kbd{C-h K} to | |
4e9d1a58 | 535 | find the documentation of a menu item: just select that menu item when |
00b5a712 | 536 | @kbd{C-h K} prompts for a key. |
4e9d1a58 | 537 | |
00b5a712 RS |
538 | @kbd{C-h F} and @kbd{C-h K} know about commands and keys described |
539 | in manuals other than the Emacs manual. Thus, they make it easier to | |
540 | find the documentation of commands and keys when you are not sure | |
541 | which manual describes them, like when using some specialized mode. | |
6bf7aab6 | 542 | |
00b5a712 RS |
543 | @kindex C-h S |
544 | @findex info-lookup-symbol | |
545 | When editing a program, if you have an Info version of the manual | |
546 | for the programming language, you can use the command @kbd{C-h S} | |
547 | (@code{info-lookup-symbol}) to refer to the manual documentation for a | |
548 | symbol (keyword, function or variable). The details of how this | |
549 | command works depend on the major mode. | |
6bf7aab6 DL |
550 | |
551 | @kindex C-h l | |
552 | @findex view-lossage | |
553 | If something surprising happens, and you are not sure what commands you | |
1ba2ce68 | 554 | typed, use @kbd{C-h l} (@code{view-lossage}). @kbd{C-h l} displays the last |
6bf7aab6 DL |
555 | 100 command characters you typed in. If you see commands that you don't |
556 | know, you can use @kbd{C-h c} to find out what they do. | |
557 | ||
00b5a712 RS |
558 | @kindex C-h e |
559 | @findex view-echo-area-messages | |
560 | To review messages that recently appeared in the echo area, use | |
561 | @kbd{C-h e} (@code{view-echo-area-messages}). This displays the | |
562 | buffer @code{*Messages*}, where those messages are kept. | |
563 | ||
6bf7aab6 DL |
564 | @kindex C-h m |
565 | @findex describe-mode | |
566 | Emacs has numerous major modes, each of which redefines a few keys and | |
567 | makes a few other changes in how editing works. @kbd{C-h m} | |
1ba2ce68 | 568 | (@code{describe-mode}) displays documentation on the current major mode, |
6bf7aab6 DL |
569 | which normally describes all the commands that are changed in this |
570 | mode. | |
571 | ||
572 | @kindex C-h b | |
573 | @findex describe-bindings | |
574 | @kbd{C-h b} (@code{describe-bindings}) and @kbd{C-h s} | |
575 | (@code{describe-syntax}) present other information about the current | |
576 | Emacs mode. @kbd{C-h b} displays a list of all the key bindings now in | |
58fa012d | 577 | effect, showing the local bindings defined by the current minor modes first, |
6bf7aab6 DL |
578 | then the local bindings defined by the current major mode, and finally |
579 | the global bindings (@pxref{Key Bindings}). @kbd{C-h s} displays the | |
580 | contents of the syntax table, with explanations of each character's | |
581 | syntax (@pxref{Syntax}). | |
582 | ||
583 | You can get a similar list for a particular prefix key by typing | |
584 | @kbd{C-h} after the prefix key. (There are a few prefix keys for which | |
585 | this does not work---those that provide their own bindings for | |
586 | @kbd{C-h}. One of these is @key{ESC}, because @kbd{@key{ESC} C-h} is | |
587 | actually @kbd{C-M-h}, which marks a defun.) | |
588 | ||
00b5a712 RS |
589 | @node Help Files |
590 | @section Help Files | |
591 | ||
592 | The Emacs help commands described above display the state of data | |
593 | bases within Emacs. Emacs has a few other help commands that display | |
594 | pre-written help files. These commands all have the form @kbd{C-h | |
595 | C-@var{char}}; that is, @kbd{C-h} followed by a control character. | |
596 | ||
6bf7aab6 DL |
597 | @kindex C-h C-c |
598 | @findex describe-copying | |
599 | @kindex C-h C-d | |
600 | @findex describe-distribution | |
00b5a712 RS |
601 | @kindex C-h C-e |
602 | @findex view-emacs-problems | |
603 | @kindex C-h C-f | |
604 | @findex view-emacs-FAQ | |
605 | @kindex C-h C-n | |
606 | @findex view-emacs-news | |
6bf7aab6 DL |
607 | @kindex C-h C-p |
608 | @findex describe-project | |
00b5a712 RS |
609 | @kindex C-h C-t |
610 | @findex view-emacs-todo | |
611 | @kindex C-h C-w | |
612 | @findex describe-no-warranty | |
58fa012d | 613 | The other @kbd{C-h} options display various files containing useful |
00b5a712 RS |
614 | information. |
615 | ||
616 | @table @kbd | |
617 | @item C-h C-c | |
618 | Displays the Emacs copying conditions (@code{describe-copying}). | |
619 | These are the rules under which you can copy and redistribute Emacs. | |
620 | @item C-h C-d | |
621 | Displays information on how to download or order the latest version of | |
622 | Emacs and other GNU software (@code{describe-distribution}). | |
623 | @item C-h C-e | |
624 | Displays the list of known Emacs problems, sometimes with suggested | |
625 | workarounds (@code{view-emacs-problems}). | |
626 | @item C-h C-f | |
627 | Displays the Emacs frequently-answered-questions list (@code{view-emacs-FAQ}). | |
628 | @item C-h C-n | |
629 | Displays the Emacs ``news'' file, which lists new Emacs features, most | |
630 | recent first (@code{view-emacs-news}). | |
631 | @item C-h C-p | |
632 | Displays general information about the GNU Project | |
633 | (@code{describe-project}). | |
634 | @item C-h C-t | |
635 | Displays the Emacs to-do list (@code{view-todo}). | |
636 | @item C-h C-w | |
637 | Displays the full details on the complete absence of warranty for GNU | |
638 | Emacs (@code{describe-no-warranty}). | |
639 | @end table | |
7d291226 DL |
640 | |
641 | @node Help Echo | |
642 | @section Help on Active Text and Tooltips | |
643 | ||
644 | @cindex tooltips | |
58fa012d | 645 | @cindex balloon help |
0ec1f115 | 646 | When a region of text is ``active,'' so that you can select it with |
2684ed46 | 647 | the mouse or a key like @kbd{RET}, it often has associated help text. |
8f4fc840 RS |
648 | Areas of the mode line are examples. On most window systems, the help |
649 | text is displayed as a ``tooltip'' (sometimes known as ``balloon | |
43d0ed81 LT |
650 | help''), when you move the mouse over the active text. @xref{Tooltips}. |
651 | On some systems, it is shown in the echo area. On text-only | |
652 | terminals, Emacs may not be able to follow the mouse and hence will | |
653 | not show the help text on mouse-over. | |
8f4fc840 RS |
654 | |
655 | @kindex C-h . | |
656 | @findex display-local-help | |
657 | @vindex help-at-pt-display-when-idle | |
658 | You can also access text region help info using the keyboard. The | |
659 | command @kbd{C-h .} (@code{display-local-help}) displays any help text | |
660 | associated with the text at point, using the echo area. If you want | |
661 | help text to be displayed automatically whenever it is available at | |
662 | point, set the variable @code{help-at-pt-display-when-idle} to | |
663 | @code{t}. | |
ab5796a9 MB |
664 | |
665 | @ignore | |
666 | arch-tag: 6f33ab62-bc75-4367-8057-fd67cc15c3a1 | |
667 | @end ignore |