use warnings; no warnings 'uninitialized';
use strict;
use CGI qw(:standard);
use DBI;

my $data_source = 'whatever';
my $username = 'whoever';
my $auth = 'whichever';
my %attr = ();

print
    header(),
    start_html(-title => "Search poems"),
    start_form(),
    textfield(-name => 'q');

eval {
    my $dbh = DBI->connect($data_source, $username, $auth, \%attr);

    if ( param('q') ) {
        my $sth = $dbh->prepare(<<"");
        SELECT * FROM whatever WHERE this MATCHES ?

        $sth->execute( param('q') );

        while ( my $row = $sth->fetchrow_hashref ) {
            # format and print the results
        }
        # OR mention you couldn't find anything
    }
};

print h3("Couldn't execute querry! $@") if $@;

print
    end_form(),
    end_html();