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described in the "Incompatible versions of db.h and libdb" section of
this file.

To make matters worse, prior to Perl 5.6.1, the perl binary itself
*always* included the Berkeley DB library.

If you want to use a newer version of Berkeley DB with this module, the
easiest solution is to use Perl 5.6.1 (or better) and Berkeley DB 3.x
(or better).

There are two approaches you can use to get older versions of Perl to
work with specific versions of Berkeley DB. Both have their advantages
and disadvantages.

The first approach will only work when you want to build a version of
Perl older than 5.6.1 along with Berkeley DB 3.x. If you want to use
Berkeley DB 2.x, you must use the next approach. This approach involves
rebuilding your existing version of Perl after applying an unofficial
patch. The "patches" directory in the this module's source distribution
contains a number of patch files. There is one patch file for every
stable version of Perl since 5.004. Apply the appropriate patch to your
Perl source tree before re-building and installing Perl from scratch.
For example, assuming you are in the top-level source directory for
Perl 5.6.0, the command below will apply the necessary patch. Remember
to replace the path shown below with one that points to this module's
patches directory.

    patch -p1 -N </path/to/DB_File/patches/5.6.0

Now rebuild & install perl. You should now have a perl binary that can
be used to build this module. Follow the instructions in "BUILDING THE
MODULE", remembering to set the INCLUDE and LIB variables in config.in.


The second approach will work with both Berkeley DB 2.x and 3.x.
Start by building Berkeley DB as a shared library. This is from
the Berkeley DB build instructions:

    Building Shared Libraries for the GNU GCC compiler

    If you're using gcc and there's no better shared library example for
    your architecture, the following shared library build procedure will
    probably work.

    Add the -fpic option to the CFLAGS value in the Makefile.

    Rebuild all of your .o files. This will create a Berkeley DB library
    that contains .o files with PIC code. To build the shared library,
    then take the following steps in the library build directory:

    % mkdir tmp
    % cd tmp
    % ar xv ../libdb.a
    % gcc -shared -o libdb.so *.o
    % mv libdb.so ..
    % cd ..
    % rm -rf tmp

    Note, you may have to change the gcc line depending on the
    requirements of your system.

    The file libdb.so is your shared library

Once you have built libdb.so, you will need to store it somewhere safe.

    cp libdb.so /usr/local/BerkeleyDB/lib

If you now set the LD_PRELOAD environment variable to point to this
shared library, Perl will use it instead of the version of Berkeley DB
that shipped with your Linux distribution.

    export LD_PRELOAD=/usr/local/BerkeleyDB/lib/libdb.so

Finally follow the instructions in "BUILDING THE MODULE" to build,
test and install this module. Don't forget to set the INCLUDE and LIB
variables in config.in.

Remember, you will need to have the LD_PRELOAD variable set anytime you
want to use Perl with Berkeley DB. Also note that if you have LD_PRELOAD
permanently set it will affect ALL commands you execute. This may be a
problem if you run any commands that access a database created by the
version of Berkeley DB that shipped with your Linux distribution.


Solaris Notes
-------------

If you are running Solaris 2.5, and you get this error when you run the
DB_File test harness:

    libc internal error: _rmutex_unlock: rmutex not held.

you probably need to install a Sun patch. It has been reported that
Sun patch 103187-25 (or later revisions) fixes this problem.

To find out if you have the patch installed, the command "showrev -p"
will display the patches that are currently installed on your system.


HP-UX 10 Notes
--------------

Some people running HP-UX 10 have reported getting an error like this
when building DB_File with the native HP-UX compiler.

    ld: (Warning) At least one PA 2.0 object file (DB_File.o) was detected.
    The linked output may not run on a PA 1.x system.
    ld: Invalid loader fixup for symbol "$000000A5".

If this is the case for you, Berkeley DB needs to be recompiled with
the +z or +Z option and the resulting library placed in a .sl file. The
following steps should do the trick:

  1: Configure the Berkeley DB distribution with the +z or +Z C compiler
     flag:

        env "CFLAGS=+z" ../dist/configure ...

  2: Edit the Berkeley DB Makefile and change:

        "libdb= libdb.a" to "libdb= libdb.sl".


  3: Build and install the Berkeley DB distribution as usual.

HP-UX 11 Notes
--------------

Some people running the combination of HP-UX 11 and Berkeley DB 2.7.7 have
reported getting this error when the run the test harness for DB_File

    ...
    lib/db-btree.........Can't call method "DELETE" on an undefined value at lib/db-btree.t line 216.
    FAILED at test 26
    lib/db-hash..........Can't call method "DELETE" on an undefined value at lib/db-hash.t line 183.
    FAILED at test 22
    ...

The fix for this is to rebuild and install Berkeley DB with the bigfile
option disabled.


IRIX NOTES
----------

If you are running IRIX, and want to use Berkeley DB version 1, you can
get it from http://reality.sgi.com/ariel. It has the patches necessary
to compile properly on IRIX 5.3.


FEEDBACK
========

How to report a problem with DB_File.

When reporting any problem, I need the information requested below. 

 1. The *complete* output from running this

        perl -V

    Do not edit the output in any way. 
    Note, I want you to run "perl -V" and NOT "perl -v".

    If your perl does not understand the "-V" option it is too
    old. DB_File needs Perl version 5.00405 or better.

 2. The version of DB_File you have.
    If you have successfully installed DB_File, this one-liner will
    tell you:

       perl -e 'use DB_File; print qq{DB_File ver $DB_File::VERSION\n}'

    If you haven't installed DB_File then search DB_File.pm for a line
    like this:

      $VERSION = "1.20" ;

 3. The version of Berkeley DB you are using.
    If you are using a version older than 1.85, think about upgrading. One
    point to note if you are considering upgrading Berkeley DB - the
    file formats for 1.85, 1.86, 2.0, 3.0 & 3.1 are all different.

    If you have successfully installed DB_File, this command will display
    the version of Berkeley DB it was built with:

       perl -e 'use DB_File; print qq{Berkeley DB ver $DB_File::db_ver\n}'

 4. A copy the file config.in from the DB_File main source directory.

 5. A listing of directories where Berkeley DB is installed.
    For example, if Berkeley DB is installed in /usr/BerkeleDB/lib and
    /usr/BerkeleyDB/include, I need the output from running this

        ls -l /usr/BerkeleyDB/lib
        ls -l /usr/BerkeleyDB/include

 6. If you are having problems building DB_File, send me a complete log
    of what happened. Start by unpacking the DB_File module into a fresh
    directory and keep a log of all the steps

        [edit config.in, if necessary]
        perl Makefile.PL
        make 
        make test TEST_VERBOSE=1

 7. Now the difficult one. If you think you have found a bug in DB_File
    and you want me to fix it, you will *greatly* enhance the chances
    of me being able to track it down by sending me a small
    self-contained Perl script that illustrates the problem you are
    encountering. Include a summary of what you think the problem is
    and a log of what happens when you run the script, in case I can't
    reproduce your problem on my system. If possible, don't have the
    script dependent on an existing 20Meg database. If the script you
    send me can create the database itself then that is preferred.

    I realise that in some cases this is easier said than done, so if
    you can only reproduce the problem in your existing script, then
    you can post me that if you want. Just don't expect me to find your
    problem in a hurry, or at all. :-)


CHANGES
-------

See the Changes file.

Paul Marquess <[e-mail]>