As Lachesis said, the HandleError attribute is probably what you are looking for. I use it in most of the cases where I need to report something back to the screen in a cgi. There are other methods, but this is one of the cleanest, and easiest to use.

my $dbh = DBI->connect("DBI:mysql:test:localhost", "user", "pass",
                { RaiseError => 0, PrintError => 0 } );

$dbh->{HandleError} = sub {
   print "Error received: $DBI::errstr\n";
   exit;
 };

my $sth = $dbh->prepare("SELECT wibble FROM flubble");
$sth->execute();
[download]