......
sub DB{
	$env=new BerkeleyDB::Env
		-Home=>$db_home,
		-Flags=>DB_CREATE|DB_INIT_MPOOL
	|| die;
	$db=tie(%hash,"BerkeleyDB::Btree",
		-Filename=>$db_name,
		-Flags=>DB_CREATE,
		-Env=>$env)
	|| die;
}
......

##</code><code>##

$|=1;
use BerkeleyDB;
my $env=new BerkeleyDB::Env
    -Home=>'/home/root/URL/DB'
    #-Flags=>DB_CREATE#|DB_INIT_MPOOL
|| die;
my %hash;
my $db=tie(%hash,"BerkeleyDB::Btree",
	   -Filename=>'URL.db',
	  # -Flags=>DB_CREATE,
	   -Env=>$env)
|| die;
while(my ($k,$v)=each %hash){
	print "$k\t$v\n";
}
untie $db;