-*-text-*-

    The file vgrep-patch contains a patch to GNU grep 2.0 to enable
    working on AtFS versions. 


What is does:

    This patch turns GNU grep into Vgrep -- a grep program that is
    aware of AtFS version and selection rules. With Vgrep (and Vegrep)
    you can work on AtFS version as well as on normal Files. GNU
    grep's normal capabilities are not affected by the patch -- you
    can use Vgrep exactly like GNU grep.

    For further information refer to the manual pages of vgrep(1)
    (after applying the patch and installing vgrep) and vbind(1).


How to apply the patch:

    Unpack the GNU grep 2.0 distribution. This should create a
    directory named grep-2.0. Copy the file vgrep-patch into this
    directory and change to this directory.

    Patch the source files with "patch -p0 < vgrep-patch".

    Now configure the package as described in the file INSTALL.
    Before you run "make", define an environment variable "SHAPETOOLS"
    that points to the place where ShapeTools are installed. This
    should be the directory that contains the "lib", and "include"
    subdirectories for shape. After that, you probably only need to
    type "configure ; make ; make install".  This installs vgrep and
    vegrep in /usr/local/bin and the manual page vgrep.man as
    /usr/local/man/man1/vgrep.1. 

    IMPORTANT NOTE: Some systems, such as Linux, provide functions for
    regular expression matching in their C-Libraries. In order to
    prevent multiple symbol definition errors when vgrep is loaded,
    you should apply the vgrep-Makefile-patch *after* you have
    configured the grep-2.0 distribution, *before* running "make".

    GNU grep comes with a test suite that is run automatically after
    (v)grep has been built. Some of these tests may fail (they failed
    when I ran them under Linux-1.0, and under SunOS 4.1.2).
    Nevertheless, vgrep works OK. The following tests are failing:

	 Spencer test #67 failed
	 Spencer test #68 failed
	 Spencer test #82 failed
	 Spencer test #117 failed

    If you want to apply the patch to a different version of GNU grep,
    you may have to apply the patches by hand, we haven't tried it.
    There exists an older version of the vgrep-patch that applies to
    GNU-grep 1.6. It is available on demand. We recommend upgrading to
    grep-2.0, however.
