info-stnd.texi

gcc-2.95.3 Linux下最常用的C编译器

@cindex scrolling through node structure
The @code{scroll-forward} and @code{scroll-backward} commands can also
move forward and backward through the node structure of the file.  If
you press @key{SPC} while viewing the end of a node, or @key{DEL} while
viewing the beginning of a node, what happens is controlled by the
variable @code{scroll-behavior}.  @xref{Variables,
@code{scroll-behavior}}, for more information.

@table @asis
@item @code{C-l} (@code{redraw-display})
@kindex C-l
@findex redraw-display
Redraw the display from scratch, or shift the line containing the cursor
to a specified location.  With no numeric argument, @samp{C-l} clears
the screen, and then redraws its entire contents.  Given a numeric
argument of @var{n}, the line containing the cursor is shifted so that
it is on the @var{n}th line of the window.

@item @code{C-x w} (@code{toggle-wrap})
@kindex C-w
@findex toggle-wrap
Toggles the state of line wrapping in the current window.  Normally,
lines which are longer than the screen width @dfn{wrap}, i.e., they are
continued on the next line.  Lines which wrap have a @samp{\} appearing
in the rightmost column of the screen.  You can cause such lines to be
terminated at the rightmost column by changing the state of line
wrapping in the window with @code{C-x w}.  When a line which needs more
space than one screen width to display is displayed, a @samp{$} appears
in the rightmost column of the screen, and the remainder of the line is
invisible.
@end table

@node Node Commands, Searching Commands, Scrolling Commands, Top
@chapter Selecting a New Node
@cindex nodes, selection of

This section details the numerous Info commands which select a new node
to view in the current window.

The most basic node commands are @samp{n}, @samp{p}, @samp{u}, and
@samp{l}.

When you are viewing a node, the top line of the node contains some Info
@dfn{pointers} which describe where the next, previous, and up nodes
are.  Info uses this line to move about the node structure of the file
when you use the following commands:

@table @asis
@item @code{n} (@code{next-node})
@kindex n
@findex next-node
Select the `Next' node.  

@item @code{p} (@code{prev-node})
@kindex p
@findex prev-node
Select the `Prev' node.

@item @code{u} (@code{up-node})
@kindex u
@findex up-node
Select the `Up' node.
@end table

You can easily select a node that you have already viewed in this window
by using the @samp{l} command -- this name stands for "last", and
actually moves through the list of already visited nodes for this
window.  @samp{l} with a negative numeric argument moves forward through
the history of nodes for this window, so you can quickly step between
two adjacent (in viewing history) nodes.

@table @asis
@item @code{l} (@code{history-node})
@kindex l
@findex history-node
Select the most recently selected node in this window.
@end table

Two additional commands make it easy to select the most commonly
selected nodes; they are @samp{t} and @samp{d}.

@table @asis
@item @code{t} (@code{top-node})
@kindex t
@findex top-node
Select the node @samp{Top} in the current Info file.

@item @code{d} (@code{dir-node})
@kindex d
@findex dir-node
Select the directory node (i.e., the node @samp{(dir)}).
@end table

Here are some other commands which immediately result in the selection
of a different node in the current window:

@table @asis
@item @code{<} (@code{first-node})
@kindex <
@findex first-node
Selects the first node which appears in this file.  This node is most
often @samp{Top}, but it does not have to be.

@item @code{>} (@code{last-node})
@kindex >
@findex last-node
Select the last node which appears in this file.

@item @code{]} (@code{global-next-node})
@kindex ]
@findex global-next-node
Move forward or down through node structure.  If the node that you are
currently viewing has a @samp{Next} pointer, that node is selected.
Otherwise, if this node has a menu, the first menu item is selected.  If
there is no @samp{Next} and no menu, the same process is tried with the
@samp{Up} node of this node.

@item @code{[} (@code{global-prev-node})
@kindex [
@findex global-prev-node
Move backward or up through node structure.  If the node that you are
currently viewing has a @samp{Prev} pointer, that node is selected.
Otherwise, if the node has an @samp{Up} pointer, that node is selected,
and if it has a menu, the last item in the menu is selected.
@end table

You can get the same behavior as @code{global-next-node} and
@code{global-prev-node} while simply scrolling through the file with
@key{SPC} and @key{DEL}; @xref{Variables, @code{scroll-behavior}}, for
more information.

@table @asis
@item @code{g} (@code{goto-node})
@kindex g
@findex goto-node
Read the name of a node and select it.  No completion is done while
reading the node name, since the desired node may reside in a separate
file.  The node must be typed exactly as it appears in the Info file.  A
file name may be included as with any node specification, for example

@example
@code{g(emacs)Buffers}
@end example

finds the node @samp{Buffers} in the Info file @file{emacs}.

@item @code{C-x k} (@code{kill-node})
@kindex C-x k
@findex kill-node
Kill a node.  The node name is prompted for in the echo area, with a
default of the current node.  @dfn{Killing} a node means that Info tries
hard to forget about it, removing it from the list of history nodes kept
for the window where that node is found.  Another node is selected in
the window which contained the killed node.

@item @code{C-x C-f} (@code{view-file})
@kindex C-x C-f
@findex view-file
Read the name of a file and selects the entire file.  The command
@example
@code{C-x C-f @var{filename}}
@end example
is equivalent to typing
@example
@code{g(@var{filename})*}
@end example

@item @code{C-x C-b} (@code{list-visited-nodes})
@kindex C-x C-b
@findex list-visited-nodes
Make a window containing a menu of all of the currently visited nodes.
This window becomes the selected window, and you may use the standard
Info commands within it.

@item @code{C-x b} (@code{select-visited-node})
@kindex C-x b
@findex select-visited-node
Select a node which has been previously visited in a visible window.
This is similar to @samp{C-x C-b} followed by @samp{m}, but no window is
created.
@end table

@node Searching Commands, Xref Commands, Node Commands, Top
@chapter Searching an Info File
@cindex searching

GNU Info allows you to search for a sequence of characters throughout an
entire Info file, search through the indices of an Info file, or find
areas within an Info file which discuss a particular topic.

@table @asis
@item @code{s} (@code{search})
@kindex s
@findex search
Read a string in the echo area and search for it.

@item @code{C-s} (@code{isearch-forward})
@kindex C-s
@findex isearch-forward
Interactively search forward through the Info file for a string as you
type it.

@item @code{C-r} (@code{isearch-backward})
@kindex C-r
@findex isearch-backward
Interactively search backward through the Info file for a string as
you type it.

@item @code{i} (@code{index-search})
@kindex i
@findex index-search
Look up a string in the indices for this Info file, and select a node
where the found index entry points to.

@item @code{,} (@code{next-index-match})
@kindex ,
@findex next-index-match
Move to the node containing the next matching index item from the last
@samp{i} command.
@end table

The most basic searching command is @samp{s} (@code{search}).  The
@samp{s} command prompts you for a string in the echo area, and then
searches the remainder of the Info file for an occurrence of that string.
If the string is found, the node containing it is selected, and the
cursor is left positioned at the start of the found string.  Subsequent
@samp{s} commands show you the default search string within @samp{[} and
@samp{]}; pressing @key{RET} instead of typing a new string will use the
default search string.

@dfn{Incremental searching} is similar to basic searching, but the
string is looked up while you are typing it, instead of waiting until
the entire search string has been specified.

@node Xref Commands, Window Commands, Searching Commands, Top
@chapter Selecting Cross References

We have already discussed the @samp{Next}, @samp{Prev}, and @samp{Up}
pointers which appear at the top of a node.  In addition to these
pointers, a node may contain other pointers which refer you to a
different node, perhaps in another Info file.  Such pointers are called
@dfn{cross references}, or @dfn{xrefs} for short.

@menu
* Parts of an Xref::            What a cross reference is made of.
* Selecting Xrefs::             Commands for selecting menu or note items.
@end menu

@node Parts of an Xref, Selecting Xrefs,  , Xref Commands
@section Parts of an Xref

Cross references have two major parts: the first part is called the
@dfn{label}; it is the name that you can use to refer to the cross
reference, and the second is the @dfn{target}; it is the full name of
the node that the cross reference points to.

The target is separated from the label by a colon @samp{:}; first the
label appears, and then the target.  For example, in the sample menu
cross reference below, the single colon separates the label from the
target.

@example
* Foo Label: Foo Target.        More information about Foo.
@end example

Note the @samp{.} which ends the name of the target.  The @samp{.} is
not part of the target; it serves only to let Info know where the target
name ends.

A shorthand way of specifying references allows two adjacent colons to
stand for a target name which is the same as the label name:

@example
* Foo Commands::                Commands pertaining to Foo.
@end example

In the above example, the name of the target is the same as the name of
the label, in this case @code{Foo Commands}.

You will normally see two types of cross reference while viewing nodes:
@dfn{menu} references, and @dfn{note} references.  Menu references
appear within a node's menu; they begin with a @samp{*} at the beginning
of a line, and continue with a label, a target, and a comment which
describes what the contents of the node pointed to contains.

Note references appear within the body of the node text; they begin with
@code{*Note}, and continue with a label and a target.

Like @samp{Next}, @samp{Prev}, and @samp{Up} pointers, cross references
can point to any valid node.  They are used to refer you to a place
where more detailed information can be found on a particular subject.
Here is a cross reference which points to a node within the Texinfo
documentation:  @xref{xref, , Writing an Xref, texinfo, the Texinfo
Manual}, for more information on creating your own texinfo cross
references.

@node Selecting Xrefs,  , Parts of an Xref, Xref Commands
@section Selecting Xrefs

The following table lists the Info commands which operate on menu items.

@table @asis
@item @code{1} (@code{menu-digit})
@itemx @code{2} @dots{} @code{9}
@cindex 1 @dots{} 9, in Info windows
@kindex 1 @dots{} 9, in Info windows
@findex menu-digit
Within an Info window, pressing a single digit, (such as @samp{1}),
selects that menu item, and places its node in the current window.
For convenience, there is one exception; pressing @samp{0} selects the
@emph{last} item in the node's menu.

@item @code{0} (@code{last-menu-item})
@kindex 0, in Info windows
@findex last-menu-item
Select the last item in the current node's menu.

@item @code{m} (@code{menu-item})
@kindex m
@findex menu-item
Reads the name of a menu item in the echo area and selects its node.
Completion is available while reading the menu label.

@item @code{M-x find-menu}
@findex find-menu
Move the cursor to the start of this node's menu.
@end table

This table lists the Info commands which operate on note cross references.

@table @asis
@item @code{f} (@code{xref-item})
@itemx @code{r}
@kindex f
@kindex r
@findex xref-item
Reads the name of a note cross reference in the echo area and selects
its node.  Completion is available while reading the cross reference
label.
@end table

Finally, the next few commands operate on menu or note references alike: