userdoc.texi

gcc-2.95.3 Linux下最常用的C编译器

environment variable @code{INFO_PRINT_COMMAND}.  If the variable doesn't
exist, the node is simply piped to @code{lpr}.
@end table

@node Miscellaneous Commands
@chapter Miscellaneous Commands

GNU Info contains several commands which self-document GNU Info:

@table @asis
@item @code{M-x describe-command}
@cindex functions, describing
@cindex commands, describing
@findex describe-command
Reads the name of an Info command in the echo area and then displays a
brief description of what that command does.

@item @code{M-x describe-key}
@cindex keys, describing
@findex describe-key
Reads a key sequence in the echo area, and then displays the name and
documentation of the Info command that the key sequence invokes.

@item @code{M-x describe-variable}
Reads the name of a variable in the echo area and then displays a brief
description of what the variable affects.

@item @code{M-x where-is}
@findex where-is
Reads the name of an Info command in the echo area, and then displays
a key sequence which can be typed in order to invoke that command.

@item @code{C-h} (@code{get-help-window})
@itemx @code{?}
@kindex C-h
@kindex ?, in Info windows
@findex get-help-window
Creates (or moves into) the window displaying @code{*Help*}, and places
a node containing a quick reference card into it.  This window displays
the most concise information about GNU Info available.

@item @code{h} (@code{get-info-help-node})
@kindex h
@findex get-info-help-node
Tries hard to visit the node @code{(info)Help}.  The info file
@file{info.texi} distributed with GNU Info contains this node.  Of
course, the file must first be processed with @code{makeinfo}, and then
placed into the location of your info directory.
@end table

Here are the commands for creating a numeric argument:

@table @asis
@item @code{C-u} (@code{universal-argument})
@cindex numeric arguments
@kindex C-u
@findex universal-argument
Starts (or multiplies by 4) the current numeric argument.  @samp{C-u} is
a good way to give a small numeric argument to cursor movement or
scrolling commands; @samp{C-u C-v} scrolls the screen 4 lines, while
@samp{C-u C-u C-n} moves the cursor down 16 lines.

@item @code{M-1} (@code{add-digit-to-numeric-arg})
@itemx @code{M-2} @dots{} @code{M-9}
@kindex M-1 @dots{} M-9
@findex add-digit-to-numeric-arg
Adds the digit value of the invoking key to the current numeric
argument.  Once Info is reading a numeric argument, you may just type
the digits of the argument, without the Meta prefix.  For example, you
might give @samp{C-l} a numeric argument of 32 by typing:

@example
@kbd{C-u 3 2 C-l}
@end example
or
@example
@kbd{M-3 2 C-l}
@end example
@end table

@samp{C-g} is used to abort the reading of a multi-character key
sequence, to cancel lengthy operations (such as multi-file searches) and
to cancel reading input in the echo area.

@table @asis
@item @code{C-g} (@code{abort-key})
@cindex cancelling typeahead
@cindex cancelling the current operation
@kindex C-g, in Info windows
@findex abort-key
Cancels current operation.
@end table

The @samp{q} command of Info simply quits running Info.

@table @asis
@item @code{q} (@code{quit})
@cindex quitting
@kindex q
@findex quit
Exits GNU Info.
@end table

If the operating system tells GNU Info that the screen is 60 lines tall,
and it is actually only 40 lines tall, here is a way to tell Info that
the operating system is correct.

@table @asis
@item @code{M-x set-screen-height}
@findex set-screen-height
@cindex screen, changing the height of
Reads a height value in the echo area and sets the height of the
displayed screen to that value.
@end table

Finally, Info provides a convenient way to display footnotes which might
be associated with the current node that you are viewing:

@table @asis
@item @code{ESC C-f} (@code{show-footnotes})
@kindex ESC C-f
@findex show-footnotes
@cindex footnotes, displaying
Shows the footnotes (if any) associated with the current node in another
window.  You can have Info automatically display the footnotes
associated with a node when the node is selected by setting the variable
@code{automatic-footnotes}.  @xref{Variables, , @code{automatic-footnotes}}.
@end table

@node Variables
@chapter Manipulating Variables

GNU Info contains several @dfn{variables} whose values are looked at by various
Info commands.  You can change the values of these variables, and thus
change the behaviour of Info to more closely match your environment and
info file reading manner.

@table @asis
@item @code{M-x set-variable}
@cindex variables, setting
@findex set-variable
Reads the name of a variable, and the value for it, in the echo area and
then sets the variable to that value.  Completion is available when
reading the variable name; often, completion is available when reading
the value to give to the variable, but that depends on the variable
itself.  If a variable does @emph{not} supply multiple choices to
complete over, it expects a numeric value.

@item @code{M-x describe-variable}
@cindex variables, describing
@findex describe-variable
Reads the name of a variable in the echo area and then displays a brief
description of what the variable affects.
@end table

Here is a list of the variables that you can set in Info.

@table @code
@item automatic-footnotes
@vindex automatic-footnotes
When set to @code{On}, footnotes appear and disappear automatically.
This variable is @code{On} by default.  When a node is selected, a
window containing the footnotes which appear in that node is created,
and the footnotes are displayed within the new window.  The window that
Info creates to contain the footnotes is called @samp{*Footnotes*}.  If
a node is selected which contains no footnotes, and a @samp{*Footnotes*}
window is on the screen, the @samp{*Footnotes*} window is deleted.
Footnote windows created in this fashion are not automatically tiled so
that they can use as little of the display as is possible.

@item automatic-tiling
@vindex automatic-tiling
When set to @code{On}, creating or deleting a window resizes other
windows.  This variable is @code{Off} by default.  Normally, typing
@samp{C-x 2} divides the current window into two equal parts.  When
@code{automatic-tiling} is set to @code{On}, all of the windows are
resized automatically, keeping an equal number of lines visible in each
window.  There are exceptions to the automatic tiling; specifically, the
windows @samp{*Completions*} and @samp{*Footnotes*} are @emph{not}
resized through automatic tiling; they remain their original size.

@item visible-bell
@vindex visible-bell
When set to @code{On}, GNU Info attempts to flash the screen instead of
ringing the bell.  This variable is @code{Off} by default.  Of course,
Info can only flash the screen if the terminal allows it; in the case
that the terminal does not allow it, the setting of this variable has no
effect.  However, you can make Info perform quietly by setting the
@code{errors-ring-bell} variable to @code{Off}.

@item errors-ring-bell
@vindex errors-ring-bell
When set to @code{On}, errors cause the bell to ring.  The default
setting of this variable is @code{On}.

@item gc-compressed-files
@vindex gc-compressed-files
When set to @code{On}, Info garbage collects files which had to be
uncompressed.  The default value of this variable is @code{Off}.
Whenever a node is visited in Info, the info file containing that node
is read into core, and Info reads information about the tags and nodes
contained in that file.  Once the tags information is read by Info, it
is never forgotten.  However, the actual text of the nodes does not need
to remain in core unless a particular info window needs it.  For
non-compressed files, the text of the nodes does not remain in core when
it is no longer in use.  But de-compressing a file can be a time
consuming operation, and so Info tries hard not to do it twice.
@code{gc-compressed-files} tells Info it is okay to garbage collect the
text of the nodes of a file which was compressed on disk.

@item show-index-match
@vindex show-index-match
When set to @code{On}, the portion of the matched search string is
highlighted in the message which explains where the matched search
string was found.  The default value of this variable is @code{On}.
When Info displays the location where an index match was found,
(@pxref{Searching Commands, , @code{next-index-match}}), the portion of the
string that you had typed is highlighted by displaying it in the inverse
case from its surrounding characters.

@item scroll-behaviour
@vindex scroll-behaviour
Controls what happens when forward scrolling is requested at the end of
a node, or when backward scrolling is requested at the beginning of a
node.  The default value for this variable is @code{Continuous}.  There
are three possible values for this variable:

@table @code
@item Continuous
Tries to get the first item in this node's menu, or failing that, the
@samp{Next} node, or failing that, the @samp{Next} of the @samp{Up}.
This behaviour is identical to using the @samp{]}
(@code{global-next-node}) and @samp{[} (@code{global-prev-node})
commands.

@item Next Only
Only tries to get the @samp{Next} node.

@item Page Only
Simply gives up, changing nothing.  If @code{scroll-behaviour} is
@code{Page Only}, no scrolling command can change the node that is being
viewed.
@end table

@item scroll-step
@vindex scroll-step
The number of lines to scroll when the cursor moves out of the window.
Scrolling happens automatically if the cursor has moved out of the
visible portion of the node text when it is time to display.  Usually
the scrolling is done so as to put the cursor on the center line of the
current window.  However, if the variable @code{scroll-step} has a
nonzero value, Info attempts to scroll the node text by that many lines;
if that is enough to bring the cursor back into the window, that is what
is done.  The default value of this variable is 0, thus placing the
cursor (and the text it is attached to) in the center of the window.
Setting this variable to 1 causes a kind of "smooth scrolling" which
some people prefer.

@item ISO-Latin
@cindex ISO Latin characters
@vindex ISO-Latin
When set to @code{On}, Info accepts and displays ISO Latin characters.
By default, Info assumes an ASCII character set.  @code{ISO-Latin} tells
Info that it is running in an environment where the European standard
character set is in use, and allows you to input such characters to
Info, as well as display them.
@end table

@c The following node and its children are currently unfinished.  Please feel
@c free to finish it!

@ifset NOTSET
@node Info for Sys Admins
@chapter Info for System Administrators

This text describes some common ways of setting up an Info heierarchy
from scratch, and details the various options that are available when
installing Info.  This text is designed for the person who is installing
GNU Info on the system; although users may find the information present
in this section interesting, none of it is vital to understanding how to
use GNU Info.

@menu
* Setting the INFOPATH::	Where are my Info files kept?
* Editing the DIR node::	What goes in `DIR', and why?
* Storing Info files::		Alternate formats allow flexibilty in setups.
* Using `localdir'::		Building DIR on the fly.
* Example setups::		Some common ways to origanize Info files.
@end menu

@node Setting the INFOPATH
@section Setting the INFOPATH
Where are my Info files kept?

@node Editing the DIR node
@section Editing the DIR node
What goes in `DIR', and why?

@node Storing Info files
@section Storing Info files
Alternate formats allow flexibilty in setups.

@node Using `localdir'
@section Using `localdir'
Building DIR on the fly.

@node Example setups
@section Example setups
Some common ways to origanize Info files.
@end ifset

@ifset STANDALONE
@node GNU Info Global Index
@appendix Global Index
@printindex cp
@end ifset