tags or the preview window is that included files are
searched.  In most cases this results in the right declaration to be found.
Also when the tags file is out of date.  Also when you don't have tags for the
included files.
   However, a few things must be right for "[I" to do its work.  First of all,
the 'include' option must specify how a file is included.  The default value
works for C and C++.  For other languages you will have to change it.


LOCATING INCLUDED FILES

   Vim will find included files in the places specified with the 'path'
option.  If a directory is missing, some include files will not be found.  You
can discover this with this command: >

	:checkpath

It will list the include files that could not be found.  Also files included
by the files that could be found.  An example of the output:

	--- Included files not found in path --- ~
	<io.h> ~
	vim.h --> ~
	  <functions.h> ~
	  <clib/exec_protos.h> ~

The "io.h" file is included by the current file and can't be found.  "vim.h"
can be found, thus ":checkpath" goes into this file and checks what it
includes.  The "functions.h" and "clib/exec_protos.h" files, included by
"vim.h" are not found.

	Note:
	Vim is not a compiler.  It does not recognize "#ifdef" statements.
	This means every "#include" statement is used, also when it comes
	after "#if NEVER".

To fix the files that could not be found, add a directory to the 'path'
option.  A good place to find out about this is the Makefile.  Look out for
lines that contain "-I" items, like "-I/usr/local/X11".  To add this directory
use: >

	:set path+=/usr/local/X11

When there are many subdirectories, you can use the "*" wildcard.  Example: >

	:set path+=/usr/*/include

This would find files in "/usr/local/include" as well as "/usr/X11/include".

When working on a project with a whole nested tree of included files, the "**"
items is useful.  This will search down in all subdirectories.  Example: >

	:set path+=/projects/invent/**/include

This will find files in the directories:

	/projects/invent/include ~
	/projects/invent/main/include ~
	/projects/invent/main/os/include ~
	etc.

There are even more possibilities.  Check out the 'path' option for info.
   If you want to see which included files are actually found, use this
command: >

	:checkpath!

You will get a (very long) list of included files, the files they include, and
so on.  To shorten the list a bit, Vim shows "(Already listed)" for files that
were found before and doesn't list the included files in