package AnyDBM_File;
-use vars qw(@ISA);
+use warnings;
+use strict;
-@ISA = qw(NDBM_File DB_File GDBM_File SDBM_File ODBM_File) unless @ISA;
+use 5.006_001;
+our $VERSION = '1.01';
+our @ISA = qw(NDBM_File DB_File GDBM_File SDBM_File ODBM_File) unless @ISA;
my $mod;
for $mod (@ISA) {
- return 1 if eval "require $mod"
+ if (eval "require $mod") {
+ @ISA = ($mod); # if we leave @ISA alone, warnings abound
+ return 1;
+ }
}
die "No DBM package was successfully found or installed";
-#return 0;
+
+__END__
=head1 NAME
AnyDBM_File - provide framework for multiple DBMs
-NDBM_File, ODBM_File, SDBM_File, GDBM_File - various DBM implementations
+NDBM_File, DB_File, GDBM_File, SDBM_File, ODBM_File - various DBM implementations
=head1 SYNOPSIS
finally ODBM. This way old programs that used to use NDBM via dbmopen()
can still do so, but new ones can reorder @ISA:
- @AnyDBM_File::ISA = qw(DB_File GDBM_File NDBM_File);
-
-Note, however, that an explicit use overrides the specified order:
-
- use GDBM_File;
- @AnyDBM_File::ISA = qw(DB_File GDBM_File NDBM_File);
-
-will only find GDBM_File.
+ BEGIN { @AnyDBM_File::ISA = qw(DB_File GDBM_File NDBM_File) }
+ use AnyDBM_File;
Having multiple DBM implementations makes it trivial to copy database formats:
- use POSIX; use NDBM_File; use DB_File;
+ use Fcntl; use NDBM_File; use DB_File;
tie %newhash, 'DB_File', $new_filename, O_CREAT|O_RDWR;
tie %oldhash, 'NDBM_File', $old_filename, 1, 0;
%newhash = %oldhash;
=head1 SEE ALSO
-dbm(3), ndbm(3), DB_File(3)
+dbm(3), ndbm(3), DB_File(3), L<perldbmfilter>
=cut