@c This is part of the Emacs manual.
-@c Copyright (C) 1985, 86, 87, 93, 94, 95, 97, 2000, 2001, 2004
-@c Free Software Foundation, Inc.
+@c Copyright (C) 1985, 1986, 1987, 1993, 1994, 1995, 1997, 2000, 2001,
+@c 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
@c See file emacs.texi for copying conditions.
@node Help, Mark, M-x, Top
@chapter Help
Most help buffers use a special major mode, Help mode, which lets you
scroll conveniently with @key{SPC} and @key{DEL}. It also offers
-hyperlinks to further help regarding cross-referenced names, Info nodes,
-customization buffers and the like. @xref{Help Mode}.
+hyperlinks to URLs and further help regarding cross-referenced names, Info
+nodes, customization buffers and the like. @xref{Help Mode}.
@cindex searching documentation efficiently
@cindex looking for a subject in documentation
manual index, then finally look in the FAQ and the package keywords.
@table @kbd
-@item C-h a @var{topic} @key{RET}
-This searches for commands whose names match @var{topic}, which should
-be a regular expression (@pxref{Regexps}). Browse the buffer that this
-command displays to find what you are looking for. @xref{Apropos}.
-
-@item M-x apropos @key{RET} @var{topic} @key{RET}
-This works like @kbd{C-h a}, but it also searches for noninteractive
-functions and for variables. @xref{Apropos}.
-
-@item M-x apropos-documentation @key{RET} @var{topic} @key{RET}
-This searches the @emph{documentation strings} (the built-in short
-descriptions) of all variables and functions (not their names) for a
-match for @var{topic}, a regular expression. @xref{Apropos}.
+@item C-h a @var{topics} @key{RET}
+This searches for commands whose names match @var{topics}, which
+should be a keyword, a list of keywords, or a regular expression
+(@pxref{Regexps}). This command displays all the matches in a new
+buffer. @xref{Apropos}.
@item C-h i d m emacs @key{RET} i @var{topic} @key{RET}
This looks up @var{topic} in the indices of the Emacs on-line manual.
pre-written file of information.
@table @kbd
-@item C-h a @var{regexp} @key{RET}
-Display a list of commands whose names match @var{regexp}
-(@code{apropos-command}).
+@item C-h a @var{topics} @key{RET}
+Display a list of commands whose names match @var{topics}
+(@code{apropos-command}; @pxref{Apropos}).
@item C-h b
Display a table of all key bindings in effect now, in this order: minor
mode bindings, major mode bindings, and global bindings
Show the name of the command that @var{key} runs
(@code{describe-key-briefly}). Here @kbd{c} stands for ``character.''
For more extensive information on @var{key}, use @kbd{C-h k}.
+@item C-h d @var{topics} @key{RET}
+Display a list of commands and variables whose documentation matches
+@var{topics} (@code{apropos-documentation}).
+@item C-h e
+Display the @code{*Messages*} buffer
+(@code{view-echo-area-messages}).
@item C-h f @var{function} @key{RET}
Display documentation on the Lisp function named @var{function}
(@code{describe-function}). Since commands are Lisp functions,
@node Apropos
@section Apropos
+ A more sophisticated sort of question to ask is, ``What are the
+commands for working with files?'' The @dfn{apropos} commands ask
+such questions---they look for things whose names match an
+@dfn{apropos pattern}, which means either a word, a list of words, or
+a regular expression. Each apropos command displays a list of
+matching items in a special buffer.
+
+@table @kbd
+@item C-h a @var{pattern} @key{RET}
+Search for commands whose names match @var{pattern}.
+
+@item M-x apropos @key{RET} @var{pattern} @key{RET}
+Similar, but it searches for noninteractive functions and for
+variables, as well as commands.
+
+@item M-x apropos-variable @key{RET} @var{pattern} @key{RET}
+Similar, but it searches for variables only.
+
+@item M-x apropos-value @key{RET} @var{pattern} @key{RET}
+Similar, but it searches for variables based on their values, or
+functions based on their definitions.
+
+@item C-h d @var{pattern} @key{RET}
+Search the @emph{documentation strings} (the built-in short
+descriptions) of all variables and functions (not their names) for a
+match for @var{pattern}.
+@end table
+
@kindex C-h a
@findex apropos-command
@cindex apropos
- A more sophisticated sort of question to ask is, ``What are the
-commands for working with files?'' To ask this question, type @kbd{C-h
-a file @key{RET}}, which displays a list of all command names that
-contain @samp{file}, including @code{copy-file}, @code{find-file}, and
-so on. With each command name appears a brief description of how to use
-the command, and what keys you can currently invoke it with. For
-example, it would say that you can invoke @code{find-file} by typing
-@kbd{C-x C-f}. The @kbd{a} in @kbd{C-h a} stands for ``Apropos'';
-@kbd{C-h a} runs the command @code{apropos-command}. This command
-normally checks only commands (interactive functions); if you specify a
-prefix argument, it checks noninteractive functions as well.
-
- Because @kbd{C-h a} looks only for commands matching the string you
-specify, you may not find what you want on the first try. In that
-case, don't just give up. You can give Apropos a list of words to
-search for. When more than one word is specified, at least two of
-those words must be present for an item to match. If you are looking
-for commands to kill a chunk of text before point, try @kbd{C-h a kill
-back behind before @key{RET}}. For even greater flexibility, you can
-also supply a regular expression to Apropos (@pxref{Regexps}).
+ To find the commands that work on files, type @kbd{C-h a file
+@key{RET}}. This displays a list of all command names that contain
+@samp{file}, including @code{copy-file}, @code{find-file}, and so on.
+With each command name appears a brief description of how to use the
+command, and what keys you can currently invoke it with. For example,
+it would say that you can invoke @code{find-file} by typing @kbd{C-x
+C-f}. The @kbd{a} in @kbd{C-h a} stands for ``Apropos''; @kbd{C-h a}
+runs the command @code{apropos-command}. This command normally checks
+only commands (interactive functions); if you specify a prefix
+argument, it checks noninteractive functions as well.
+
+ If you want more information about a function definition, variable or
+symbol property listed in the Apropos buffer, you can click on it with
+@kbd{Mouse-1} or @kbd{Mouse-2}, or move there and type @key{RET}.
+
+ @kbd{C-h a} with a single word can find too many matches. Don't
+just give up; you can give Apropos a list of words to search for.
+When you specify more than one word in the apropos pattern, a name
+must contain at least two of the words in order to match. Thus, if
+you are looking for commands to kill a chunk of text before point, you
+could try @kbd{C-h a kill back backward behind before @key{RET}}.
+
+ For even greater flexibility, you can specify a regular expression
+(@pxref{Regexps}). An apropos pattern is interpreted as a regular
+expression if it contains any of the regular expression special
+characters, @samp{^$*+?.\[}.
Here is a set of arguments to give to @kbd{C-h a} that covers many
-classes of Emacs commands, since there are strong conventions for naming
-the standard Emacs commands. By giving you a feel for the naming
-conventions, this set should also serve to aid you in developing a
-technique for picking @code{apropos} strings.
+classes of Emacs commands, since there are strong conventions for
+naming the standard Emacs commands. By giving you a feel for the
+naming conventions, this set should also serve to aid you in
+developing a technique for picking Apropos keywords.
@quotation
char, line, word, sentence, paragraph, region, page, sexp, list, defun,
view, describe, default.
@end quotation
+@findex apropos
+ To list all Lisp symbols that contain a match for an Apropos pattern,
+not just the ones that are defined as commands, use the command
+@kbd{M-x apropos} instead of @kbd{C-h a}. This command does not check
+key bindings by default; specify a numeric argument if you want it to
+check them.
+
@findex apropos-variable
- To list all user variables that match a regexp, use the command
-@kbd{M-x apropos-variable}. By default, this command shows only
-variables meant for user customization; if you specify a prefix
+ To list user-customizable variables that match an apropos pattern,
+use the command @kbd{M-x apropos-variable}. If you specify a prefix
argument, it checks all variables.
-@findex apropos
- To list all Lisp symbols that contain a match for a regexp, not just
-the ones that are defined as commands, use the command @kbd{M-x apropos}
-instead of @kbd{C-h a}. This command does not check key bindings by
-default; specify a numeric argument if you want it to check them.
-
+@kindex C-h d
@findex apropos-documentation
- The @code{apropos-documentation} command is like @code{apropos} except
-that it searches documentation strings as well as symbol names for
-matches for the specified regular expression.
+ The @code{apropos-documentation} command is like @code{apropos}
+except that it searches documentation strings instead of symbol names
+for matches for the specified Apropos pattern.
@findex apropos-value
- The @code{apropos-value} command is like @code{apropos} except that it
-searches symbols' values for matches for the specified regular
-expression. This command does not check function definitions or
-property lists by default; specify a numeric argument if you want it to
-check them.
+ The @code{apropos-value} command is like @code{apropos} except that
+it searches variables' values for matches for the pattern. With a
+prefix argument, it also checks symbols' function definitions and
+property lists.
@vindex apropos-do-all
If the variable @code{apropos-do-all} is non-@code{nil}, the commands
Apropos tries to guess the relevance of each result, and displays the
most relevant ones first.
- If you want more information about a function definition, variable or
-symbol property listed in the Apropos buffer, you can click on it with
-@kbd{Mouse-1} or @kbd{Mouse-2}, or move there and type @key{RET}.
+@vindex apropos-documentation-sort-by-scores
+ By default, Apropos lists the search results for
+@code{apropos-documentation} in order of relevance of the match. If
+the variable @code{apropos-documentation-sort-by-scores} is
+@code{nil}, Apropos lists the symbols found in alphabetical order.
@node Library Keywords
@section Keyword Search for Lisp Libraries
@key{RET}, to view the documentation of that command or variable. Use
@kbd{C-c C-b} to retrace your steps.
+@cindex URL, viewing in help
+@cindex help, viewing web pages
+@cindex viewing web pages in help
+@cindex web pages, viewing in help
+@findex browse-url
+ You can follow cross references to URLs (web pages) as well. When
+you follow a cross reference that is a URL, the @code{browse-url}
+command is used to view the web page in a browser of your choosing.
+@xref{Browse-URL}.
+
@kindex @key{TAB} @r{(Help mode)}
@findex help-next-ref
@kindex S-@key{TAB} @r{(Help mode)}
the mouse or a key like @kbd{RET}, it often has associated help text.
Areas of the mode line are examples. On most window systems, the help
text is displayed as a ``tooltip'' (sometimes known as ``balloon
-help''). @xref{Tooltips}. Otherwise, it is shown in the echo area
-when you move point into the active text.
+help''), when you move the mouse over the active text. @xref{Tooltips}.
+On some systems, it is shown in the echo area. On text-only
+terminals, Emacs may not be able to follow the mouse and hence will
+not show the help text on mouse-over.
@kindex C-h .
@findex display-local-help