use DBI;
use DBD::mysql; #although not used in this example
##</code><code>##

my @installed_databases = DBI->data_sources('mysql');

##</code><code>##

my $drh=DBI->install_driver('mysql');
my @installed_databases= $drh->func($HOST,'_ListDBs');

##</code><code>##

my @installed_databases = `mysqlshow --user=$USERNAME --password=$PASSWORD`;

##</code><code>##

my $dbh=DBI->connect("DBI:mysql:host=$HOST",$USER,$PASSWORD);
my @installed_databases= $dbh->func('_ListDBs');