# DB_File.pm -- Perl 5 interface to Berkeley DB
#
-# written by Paul Marquess (Paul.Marquess@btinternet.com)
-# last modified 16th January 2000
-# version 1.72
+# written by Paul Marquess (pmqs@cpan.org)
+# last modified 12th March 2005
+# version 1.811
#
-# Copyright (c) 1995-2000 Paul Marquess. All rights reserved.
+# Copyright (c) 1995-2005 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.
package DB_File::HASHINFO ;
-require 5.003 ;
+require 5.00404;
+use warnings;
use strict;
use Carp;
require Tie::Hash;
{
my $pkg = shift ;
- bless { VALID => { map {$_, 1}
- qw( bsize ffactor nelem cachesize hash lorder)
+ bless { VALID => {
+ bsize => 1,
+ ffactor => 1,
+ nelem => 1,
+ cachesize => 1,
+ hash => 2,
+ lorder => 1,
},
GOT => {}
}, $pkg ;
my $key = shift ;
my $value = shift ;
- if ( exists $self->{VALID}{$key} )
+ my $type = $self->{VALID}{$key};
+
+ if ( $type )
{
+ croak "Key '$key' not associated with a code reference"
+ if $type == 2 && !ref $value && ref $value ne 'CODE';
$self->{GOT}{$key} = $value ;
return ;
}
package DB_File::RECNOINFO ;
+use warnings;
use strict ;
@DB_File::RECNOINFO::ISA = qw(DB_File::HASHINFO) ;
package DB_File::BTREEINFO ;
+use warnings;
use strict ;
@DB_File::BTREEINFO::ISA = qw(DB_File::HASHINFO) ;
{
my $pkg = shift ;
- bless { VALID => { map {$_, 1}
- qw( flags cachesize maxkeypage minkeypage psize
- compare prefix lorder )
+ bless { VALID => {
+ flags => 1,
+ cachesize => 1,
+ maxkeypage => 1,
+ minkeypage => 1,
+ psize => 1,
+ compare => 2,
+ prefix => 2,
+ lorder => 1,
},
GOT => {},
}, $pkg ;
package DB_File ;
+use warnings;
use strict;
-use vars qw($VERSION @ISA @EXPORT $AUTOLOAD $DB_BTREE $DB_HASH $DB_RECNO
- $db_version $use_XSLoader
- ) ;
+our ($VERSION, @ISA, @EXPORT, $AUTOLOAD, $DB_BTREE, $DB_HASH, $DB_RECNO);
+our ($db_version, $use_XSLoader, $splice_end_array);
use Carp;
-$VERSION = "1.72" ;
+$VERSION = "1.811" ;
+
+{
+ local $SIG{__WARN__} = sub {$splice_end_array = "@_";};
+ my @a =(1); splice(@a, 3);
+ $splice_end_array =
+ ($splice_end_array =~ /^splice\(\) offset past end of array at /);
+}
#typedef enum { DB_BTREE, DB_HASH, DB_RECNO } DBTYPE;
$DB_BTREE = new DB_File::BTREEINFO ;
use AutoLoader;
BEGIN {
$use_XSLoader = 1 ;
- eval { require XSLoader } ;
+ { local $SIG{__DIE__} ; eval { require XSLoader } ; }
if ($@) {
$use_XSLoader = 0 ;
sub AUTOLOAD {
my($constname);
($constname = $AUTOLOAD) =~ s/.*:://;
- my $val = constant($constname, @_ ? $_[0] : 0);
- if ($! != 0) {
- if ($! =~ /Invalid/ || $!{EINVAL}) {
- $AutoLoader::AUTOLOAD = $AUTOLOAD;
- goto &AutoLoader::AUTOLOAD;
- }
- else {
- my($pack,$file,$line) = caller;
- croak "Your vendor has not defined DB macro $constname, used at $file line $line.
-";
- }
- }
- eval "sub $AUTOLOAD { $val }";
- goto &$AUTOLOAD;
-}
+ my ($error, $val) = constant($constname);
+ Carp::croak $error if $error;
+ no strict 'refs';
+ *{$AUTOLOAD} = sub { $val };
+ goto &{$AUTOLOAD};
+}
eval {
$arg[4] = tied %{ $arg[4] }
if @arg >= 5 && ref $arg[4] && $arg[4] =~ /=HASH/ && tied %{ $arg[4] } ;
- # make recno in Berkeley DB version 2 work like recno in version 1.
+ $arg[2] = O_CREAT()|O_RDWR() if @arg >=3 && ! defined $arg[2];
+ $arg[3] = 0666 if @arg >=4 && ! defined $arg[3];
+
+ # make recno in Berkeley DB version 2 (or better) work like
+ # recno in version 1.
if ($db_version > 1 and defined $arg[4] and $arg[4] =~ /RECNO/ and
$arg[1] and ! -e $arg[1]) {
open(FH, ">$arg[1]") or return undef ;
sub CLEAR
{
my $self = shift;
- my $key = "" ;
+ my $key = 0 ;
my $value = "" ;
my $status = $self->seq($key, $value, R_FIRST());
my @keys;
}
}
+
+sub SPLICE
+{
+ my $self = shift;
+ my $offset = shift;
+ if (not defined $offset) {
+ warnings::warnif('uninitialized', 'Use of uninitialized value in splice');
+ $offset = 0;
+ }
+
+ my $length = @_ ? shift : 0;
+ # Carping about definedness comes _after_ the OFFSET sanity check.
+ # This is so we get the same error messages as Perl's splice().
+ #
+
+ my @list = @_;
+
+ my $size = $self->FETCHSIZE();
+
+ # 'If OFFSET is negative then it start that far from the end of
+ # the array.'
+ #
+ if ($offset < 0) {
+ my $new_offset = $size + $offset;
+ if ($new_offset < 0) {
+ die "Modification of non-creatable array value attempted, "
+ . "subscript $offset";
+ }
+ $offset = $new_offset;
+ }
+
+ if (not defined $length) {
+ warnings::warnif('uninitialized', 'Use of uninitialized value in splice');
+ $length = 0;
+ }
+
+ if ($offset > $size) {
+ $offset = $size;
+ warnings::warnif('misc', 'splice() offset past end of array')
+ if $splice_end_array;
+ }
+
+ # 'If LENGTH is omitted, removes everything from OFFSET onward.'
+ if (not defined $length) {
+ $length = $size - $offset;
+ }
+
+ # 'If LENGTH is negative, leave that many elements off the end of
+ # the array.'
+ #
+ if ($length < 0) {
+ $length = $size - $offset + $length;
+
+ if ($length < 0) {
+ # The user must have specified a length bigger than the
+ # length of the array passed in. But perl's splice()
+ # doesn't catch this, it just behaves as for length=0.
+ #
+ $length = 0;
+ }
+ }
+
+ if ($length > $size - $offset) {
+ $length = $size - $offset;
+ }
+
+ # $num_elems holds the current number of elements in the database.
+ my $num_elems = $size;
+
+ # 'Removes the elements designated by OFFSET and LENGTH from an
+ # array,'...
+ #
+ my @removed = ();
+ foreach (0 .. $length - 1) {
+ my $old;
+ my $status = $self->get($offset, $old);
+ if ($status != 0) {
+ my $msg = "error from Berkeley DB on get($offset, \$old)";
+ if ($status == 1) {
+ $msg .= ' (no such element?)';
+ }
+ else {
+ $msg .= ": error status $status";
+ if (defined $! and $! ne '') {
+ $msg .= ", message $!";
+ }
+ }
+ die $msg;
+ }
+ push @removed, $old;
+
+ $status = $self->del($offset);
+ if ($status != 0) {
+ my $msg = "error from Berkeley DB on del($offset)";
+ if ($status == 1) {
+ $msg .= ' (no such element?)';
+ }
+ else {
+ $msg .= ": error status $status";
+ if (defined $! and $! ne '') {
+ $msg .= ", message $!";
+ }
+ }
+ die $msg;
+ }
+
+ -- $num_elems;
+ }
+
+ # ...'and replaces them with the elements of LIST, if any.'
+ my $pos = $offset;
+ while (defined (my $elem = shift @list)) {
+ my $old_pos = $pos;
+ my $status;
+ if ($pos >= $num_elems) {
+ $status = $self->put($pos, $elem);
+ }
+ else {
+ $status = $self->put($pos, $elem, $self->R_IBEFORE);
+ }
+
+ if ($status != 0) {
+ my $msg = "error from Berkeley DB on put($pos, $elem, ...)";
+ if ($status == 1) {
+ $msg .= ' (no such element?)';
+ }
+ else {
+ $msg .= ", error status $status";
+ if (defined $! and $! ne '') {
+ $msg .= ", message $!";
+ }
+ }
+ die $msg;
+ }
+
+ die "pos unexpectedly changed from $old_pos to $pos with R_IBEFORE"
+ if $old_pos != $pos;
+
+ ++ $pos;
+ ++ $num_elems;
+ }
+
+ if (wantarray) {
+ # 'In list context, returns the elements removed from the
+ # array.'
+ #
+ return @removed;
+ }
+ elsif (defined wantarray and not wantarray) {
+ # 'In scalar context, returns the last element removed, or
+ # undef if no elements are removed.'
+ #
+ if (@removed) {
+ my $last = pop @removed;
+ return "$last";
+ }
+ else {
+ return undef;
+ }
+ }
+ elsif (not defined wantarray) {
+ # Void context
+ }
+ else { die }
+}
+sub ::DB_File::splice { &SPLICE }
+
sub find_dup
{
croak "Usage: \$db->find_dup(key,value)\n"
=head1 SYNOPSIS
- use DB_File ;
-
+ use DB_File;
+
[$X =] tie %hash, 'DB_File', [$filename, $flags, $mode, $DB_HASH] ;
[$X =] tie %hash, 'DB_File', $filename, $flags, $mode, $DB_BTREE ;
[$X =] tie @array, 'DB_File', $filename, $flags, $mode, $DB_RECNO ;
$X->push(list);
$a = $X->shift;
$X->unshift(list);
+ @r = $X->splice(offset, length, elements);
# DBM Filters
$old_filter = $db->filter_store_key ( sub { ... } ) ;
B<DB_File> is a module which allows Perl programs to make use of the
facilities provided by Berkeley DB version 1.x (if you have a newer
-version of DB, see L<Using DB_File with Berkeley DB version 2 or 3>).
+version of DB, see L<Using DB_File with Berkeley DB version 2 or greater>).
It is assumed that you have a copy of the Berkeley DB manual pages at
hand when reading this documentation. The interface defined here
mirrors the Berkeley DB interface closely.
=back
-=head2 Using DB_File with Berkeley DB version 2 or 3
+=head2 Using DB_File with Berkeley DB version 2 or greater
Although B<DB_File> is intended to be used with Berkeley DB version 1,
-it can also be used with version 2.or 3 In this case the interface is
+it can also be used with version 2, 3 or 4. In this case the interface is
limited to the functionality provided by Berkeley DB 1.x. Anywhere the
-version 2 or 3 interface differs, B<DB_File> arranges for it to work
+version 2 or greater interface differs, B<DB_File> arranges for it to work
like version 1. This feature allows B<DB_File> scripts that were built
-with version 1 to be migrated to version 2 or 3 without any changes.
+with version 1 to be migrated to version 2 or greater without any changes.
If you want to make use of the new features available in Berkeley DB
2.x or greater, use the Perl module B<BerkeleyDB> instead.
-B<Note:> The database file format has changed in both Berkeley DB
-version 2 and 3. If you cannot recreate your databases, you must dump
-any existing databases with the C<db_dump185> utility that comes with
-Berkeley DB.
-Once you have rebuilt DB_File to use Berkeley DB version 2 or 3, your
-databases can be recreated using C<db_load>. Refer to the Berkeley DB
+B<Note:> The database file format has changed multiple times in Berkeley
+DB version 2, 3 and 4. If you cannot recreate your databases, you
+must dump any existing databases with either the C<db_dump> or the
+C<db_dump185> utility that comes with Berkeley DB.
+Once you have rebuilt DB_File to use Berkeley DB version 2 or greater,
+your databases can be recreated using C<db_load>. Refer to the Berkeley DB
documentation for further details.
-Please read L<"COPYRIGHT"> before using version 2.x or 3.x of Berkeley
+Please read L<"COPYRIGHT"> before using version 2.x or greater of Berkeley
DB with DB_File.
=head2 Interface to Berkeley DB
database, delete keys/value pairs and finally how to enumerate the
contents of the database.
+ use warnings ;
use strict ;
use DB_File ;
- use vars qw( %h $k $v ) ;
+ our (%h, $k, $v) ;
unlink "fruit" ;
- tie %h, "DB_File", "fruit", O_RDWR|O_CREAT, 0640, $DB_HASH
+ tie %h, "DB_File", "fruit", O_RDWR|O_CREAT, 0666, $DB_HASH
or die "Cannot open file 'fruit': $!\n";
# Add a few key/value pairs to the file
here is the output:
Banana Exists
-
+
orange -> orange
tomato -> red
banana -> yellow
BTREE uses. Instead of using the normal lexical ordering, a case
insensitive compare function will be used.
+ use warnings ;
use strict ;
use DB_File ;
$DB_BTREE->{'compare'} = \&Compare ;
unlink "tree" ;
- tie %h, "DB_File", "tree", O_RDWR|O_CREAT, 0640, $DB_BTREE
+ tie %h, "DB_File", "tree", O_RDWR|O_CREAT, 0666, $DB_BTREE
or die "Cannot open file 'tree': $!\n" ;
# Add a key/value pair to the file
you must use the same compare function every time you access the
database.
+=item 3
+
+Duplicate keys are entirely defined by the comparison function.
+In the case-insensitive example above, the keys: 'KEY' and 'key'
+would be considered duplicates, and assigning to the second one
+would overwrite the first. If duplicates are allowed for (with the
+R_DUP flag discussed below), only a single copy of duplicate keys
+is stored in the database --- so (again with example above) assigning
+three values to the keys: 'KEY', 'Key', and 'key' would leave just
+the first key: 'KEY' in the database with three values. For some
+situations this results in information loss, so care should be taken
+to provide fully qualified comparison functions when necessary.
+For example, the above comparison routine could be modified to
+additionally compare case-sensitively if two keys are equal in the
+case insensitive comparison:
+
+ sub compare {
+ my($key1, $key2) = @_;
+ lc $key1 cmp lc $key2 ||
+ $key1 cmp $key2;
+ }
+
+And now you will only have duplicates when the keys themselves
+are truly the same. (note: in versions of the db library prior to
+about November 1996, such duplicate keys were retained so it was
+possible to recover the original keys in sets of keys that
+compared as equal).
+
+
=back
=head2 Handling Duplicate Keys
want to manipulate a BTREE database with duplicate keys. Consider this
code:
+ use warnings ;
use strict ;
use DB_File ;
- use vars qw($filename %h ) ;
+ my ($filename, %h) ;
$filename = "tree" ;
unlink $filename ;
-
+
# Enable duplicate records
$DB_BTREE->{'flags'} = R_DUP ;
-
- tie %h, "DB_File", $filename, O_RDWR|O_CREAT, 0640, $DB_BTREE
+
+ tie %h, "DB_File", $filename, O_RDWR|O_CREAT, 0666, $DB_BTREE
or die "Cannot open $filename: $!\n";
-
+
# Add some key/value pairs to the file
$h{'Wall'} = 'Larry' ;
$h{'Wall'} = 'Brick' ; # Note the duplicate key
Here is the script above rewritten using the C<seq> API method.
+ use warnings ;
use strict ;
use DB_File ;
-
- use vars qw($filename $x %h $status $key $value) ;
+
+ my ($filename, $x, %h, $status, $key, $value) ;
$filename = "tree" ;
unlink $filename ;
-
+
# Enable duplicate records
$DB_BTREE->{'flags'} = R_DUP ;
-
- $x = tie %h, "DB_File", $filename, O_RDWR|O_CREAT, 0640, $DB_BTREE
+
+ $x = tie %h, "DB_File", $filename, O_RDWR|O_CREAT, 0666, $DB_BTREE
or die "Cannot open $filename: $!\n";
-
+
# Add some key/value pairs to the file
$h{'Wall'} = 'Larry' ;
$h{'Wall'} = 'Brick' ; # Note the duplicate key
$h{'Wall'} = 'Brick' ; # Note the duplicate key and value
$h{'Smith'} = 'John' ;
$h{'mouse'} = 'mickey' ;
-
+
# iterate through the btree using seq
# and print each key/value pair.
$key = $value = 0 ;
$status == 0 ;
$status = $x->seq($key, $value, R_NEXT) )
{ print "$key -> $value\n" }
-
+
undef $x ;
untie %h ;
So assuming the database created above, we can use C<get_dup> like
this:
+ use warnings ;
use strict ;
use DB_File ;
-
- use vars qw($filename $x %h ) ;
+
+ my ($filename, $x, %h) ;
$filename = "tree" ;
-
+
# Enable duplicate records
$DB_BTREE->{'flags'} = R_DUP ;
-
- $x = tie %h, "DB_File", $filename, O_RDWR|O_CREAT, 0640, $DB_BTREE
+
+ $x = tie %h, "DB_File", $filename, O_RDWR|O_CREAT, 0666, $DB_BTREE
or die "Cannot open $filename: $!\n";
my $cnt = $x->get_dup("Wall") ;
@list = $x->get_dup("Smith") ;
print "Smith => [@list]\n" ;
-
+
@list = $x->get_dup("Dog") ;
print "Dog => [@list]\n" ;
Assuming the database from the previous example:
+ use warnings ;
use strict ;
use DB_File ;
-
- use vars qw($filename $x %h $found) ;
- my $filename = "tree" ;
-
+ my ($filename, $x, %h, $found) ;
+
+ $filename = "tree" ;
+
# Enable duplicate records
$DB_BTREE->{'flags'} = R_DUP ;
-
- $x = tie %h, "DB_File", $filename, O_RDWR|O_CREAT, 0640, $DB_BTREE
+
+ $x = tie %h, "DB_File", $filename, O_RDWR|O_CREAT, 0666, $DB_BTREE
or die "Cannot open $filename: $!\n";
$found = ( $x->find_dup("Wall", "Larry") == 0 ? "" : "not") ;
print "Larry Wall is $found there\n" ;
-
+
$found = ( $x->find_dup("Wall", "Harry") == 0 ? "" : "not") ;
print "Harry Wall is $found there\n" ;
-
+
undef $x ;
untie %h ;
Again assuming the existence of the C<tree> database
+ use warnings ;
use strict ;
use DB_File ;
-
- use vars qw($filename $x %h $found) ;
- my $filename = "tree" ;
-
+ my ($filename, $x, %h, $found) ;
+
+ $filename = "tree" ;
+
# Enable duplicate records
$DB_BTREE->{'flags'} = R_DUP ;
-
- $x = tie %h, "DB_File", $filename, O_RDWR|O_CREAT, 0640, $DB_BTREE
+
+ $x = tie %h, "DB_File", $filename, O_RDWR|O_CREAT, 0666, $DB_BTREE
or die "Cannot open $filename: $!\n";
$x->del_dup("Wall", "Larry") ;
$found = ( $x->find_dup("Wall", "Larry") == 0 ? "" : "not") ;
print "Larry Wall is $found there\n" ;
-
+
undef $x ;
untie %h ;
In the example script below, the C<match> sub uses this feature to find
and print the first matching key/value pair given a partial key.
+ use warnings ;
use strict ;
use DB_File ;
use Fcntl ;
- use vars qw($filename $x %h $st $key $value) ;
+ my ($filename, $x, %h, $st, $key, $value) ;
sub match
{
$filename = "tree" ;
unlink $filename ;
- $x = tie %h, "DB_File", $filename, O_RDWR|O_CREAT, 0640, $DB_BTREE
+ $x = tie %h, "DB_File", $filename, O_RDWR|O_CREAT, 0666, $DB_BTREE
or die "Cannot open $filename: $!\n";
-
+
# Add some key/value pairs to the file
$h{'mouse'} = 'mickey' ;
$h{'Wall'} = 'Larry' ;
$h{'Walls'} = 'Brick' ;
$h{'Smith'} = 'John' ;
-
+
$key = $value = 0 ;
print "IN ORDER\n" ;
for ($st = $x->seq($key, $value, R_FIRST) ;
$st == 0 ;
$st = $x->seq($key, $value, R_NEXT) )
-
+
{ print "$key -> $value\n" }
-
+
print "\nPARTIAL MATCH\n" ;
match "Wa" ;
still have bval default to C<"\n"> for variable length records, and
space for fixed length records.
+Also note that the bval option only allows you to specify a single byte
+as a delimiter.
+
=head2 A Simple Example
Here is a simple example that uses RECNO (if you are using a version
of Perl earlier than 5.004_57 this example won't work -- see
L<Extra RECNO Methods> for a workaround).
+ use warnings ;
use strict ;
use DB_File ;
unlink $filename ;
my @h ;
- tie @h, "DB_File", $filename, O_RDWR|O_CREAT, 0640, $DB_RECNO
+ tie @h, "DB_File", $filename, O_RDWR|O_CREAT, 0666, $DB_RECNO
or die "Cannot open file 'text': $!\n" ;
# Add a few key/value pairs to the file
Returns the number of elements in the array.
+=item B<$X-E<gt>splice(offset, length, elements);>
+
+Returns a splice of the array.
+
=back
=head2 Another Example
described above. It also makes use of the API interface directly (see
L<THE API INTERFACE>).
+ use warnings ;
use strict ;
- use vars qw(@h $H $file $i) ;
+ my (@h, $H, $file, $i) ;
use DB_File ;
use Fcntl ;
-
+
$file = "text" ;
unlink $file ;
- $H = tie @h, "DB_File", $file, O_RDWR|O_CREAT, 0640, $DB_RECNO
+ $H = tie @h, "DB_File", $file, O_RDWR|O_CREAT, 0666, $DB_RECNO
or die "Cannot open file $file: $!\n" ;
-
+
# first create a text file to play with
$h[0] = "zero" ;
$h[1] = "one" ;
$h[3] = "three" ;
$h[4] = "four" ;
-
+
# Print the records in order.
#
# The length method is needed here because evaluating a tied
sure you have already guessed, this is a problem that DBM Filters can
fix very easily.
+ use warnings ;
use strict ;
use DB_File ;
my %hash ;
- my $filename = "/tmp/filt" ;
+ my $filename = "filt" ;
unlink $filename ;
my $db = tie %hash, 'DB_File', $filename, O_CREAT|O_RDWR, 0666, $DB_HASH
Here is a DBM Filter that does it:
+ use warnings ;
use strict ;
use DB_File ;
my %hash ;
- my $filename = "/tmp/filt" ;
+ my $filename = "filt" ;
unlink $filename ;
The locking technique went like this.
- $db = tie(%db, 'DB_File', '/tmp/foo.db', O_CREAT|O_RDWR, 0644)
- || die "dbcreat /tmp/foo.db $!";
+ $db = tie(%db, 'DB_File', 'foo.db', O_CREAT|O_RDWR, 0644)
+ || die "dbcreat foo.db $!";
$fd = $db->fd;
open(DB_FH, "+<&=$fd") || die "dup $!";
flock (DB_FH, LOCK_EX) || die "flock: $!";
I<ggh> script (available from your nearest CPAN archive in
F<authors/id/TOMC/scripts/nshist.gz>).
+ use warnings ;
use strict ;
use DB_File ;
use Fcntl ;
- use vars qw( $dotdir $HISTORY %hist_db $href $binary_time $date ) ;
+ my ($dotdir, $HISTORY, %hist_db, $href, $binary_time, $date) ;
$dotdir = $ENV{HOME} || $ENV{LOGNAME};
$HISTORY = "$dotdir/.netscape/history.db";
C<strict 'subs'> pragma (or the full strict pragma) in your script.
Consider this script:
+ use warnings ;
use strict ;
use DB_File ;
- use vars qw(%x) ;
+ my %x ;
tie %x, DB_File, "filename" ;
Running it produces the error in question:
the directory F<ext/DB_File>. Given the amount of time between releases
of Perl the version that ships with Perl is quite likely to be out of
date, so the most recent version can always be found on CPAN (see
-L<perlmod/CPAN> for details), in the directory
+L<perlmodlib/CPAN> for details), in the directory
F<modules/by-module/DB_File>.
This version of B<DB_File> will work with either version 1.x, 2.x or
=head1 COPYRIGHT
-Copyright (c) 1995-1999 Paul Marquess. All rights reserved. This program
+Copyright (c) 1995-2005 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.
=head1 SEE ALSO
-L<perl(1)>, L<dbopen(3)>, L<hash(3)>, L<recno(3)>, L<btree(3)>,
-L<dbmfilter>
+L<perl>, L<dbopen(3)>, L<hash(3)>, L<recno(3)>, L<btree(3)>,
+L<perldbmfilter>
=head1 AUTHOR
The DB_File interface was written by Paul Marquess
-E<lt>Paul.Marquess@btinternet.comE<gt>.
+E<lt>pmqs@cpan.orgE<gt>.
Questions about the DB system itself may be addressed to
-E<lt>db@sleepycat.com<gt>.
+E<lt>db@sleepycat.comE<gt>.
=cut