                                     DB_File

                                  Version 1.62

                                  2nd Dec 1998  

 	Copyright (c) 1995/6/7/8 Paul Marquess. All rights reserved. This
	program is free software; you can redistribute it and/or modify
	it under the same terms as Perl itself.


DESCRIPTION
-----------

DB_File is a module which allows Perl programs to make use of the
facilities provided by Berkeley DB version 1. (DB_File can be built
version 2 of Berkeley DB, but it will only support the 1.x features),

If you want to make use of the new features available in Berkeley DB
2.x, use the Perl module BerkeleyDB instead.
 
Berkeley DB is a C library which provides a consistent interface to a
number of database formats. DB_File provides an interface to all three
of the database types (hash, btree and recno) currently supported by
Berkeley DB.

For further details see the documentation included at the end of the
file DB_File.pm.

PREREQUISITES
-------------

Before you can build DB_File you need to have the following installed
on your system:

    * Perl 5.004 or greater.

    * Berkeley DB. 

      For version 1 of Berkeley DB either 1.85 or 1.86 are best.
      For version 2 of Berkeley DB you must have 2.0.5 or greater.

      The official web site for Berkeley DB is
      http://www.sleepycat.com/db. The ftp equivalent is
      ftp.sleepycat.com:/pub. Both versions 1 and 2 of Berkeley DB are
      available there.

      Alternatively, Berkeley DB version 1 is available at your nearest
      CPAN archive (see the section on CPAN in the perlmod manpage for
      a list) in src/misc/db.1.85.tar.gz

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


BUILDING THE MODULE
-------------------

Assuming you have met all the prerequisites, building the module should
be relatively straightforward. If you are running either Solaris 2.5 or
HP-UX 10 and want to use Berkeley DB version 2, read the Solaris Notes
or HP-UX Notes sections below.

The first step is to edit the file config.in to suit you local
installation. Instructions are given in the file.

The module can now be built and tested using this sequence of
commands:

    perl Makefile.PL
    make
    make test


  NOTE:
      If you have a very old version of Berkeley DB, three of the tests
      in the recno test hasness may fail (tests 51, 53 and 55). You can
      safely ignore the errors if you're never going to use the broken
      functionality (recno databases with a modified bval).
      Otherwise you'll have to upgrade your DB library.

INSTALLATION
------------

    make install

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 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.


FEEDBACK
--------

How to report a problem with DB_File.

To help me help you, I need of the following information:

 1. The version of Perl and the operating system name and version you
    are running. If you are running a newish version of Perl, the
    output from running "perl -V" will tell me all I need to know. 
    If your perl doesn't understand the -V flag, then not only do you
    have quite an old version of Perl, you very likely have an old
    version of DB_File.  You should consider upgrading. The problem you
    have might already be fixed.

 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 "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 have installed. The most recent
    recommended versions are 1.85, 1.86 and 2.1.14. Again, if you have
    an older version, think about upgrading. One point to note if you
    are considering upgrading Berkeley DB - the file formats for 1.85,
    1.86 and 2.0 are all different.

 4. If you are having problems building DB_File, send me a complete log
    of what happened.

 5. 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 <pmarquess@bfsec.bt.co.uk>
