foreach my $upload ($r->upload()) {
        my $upload_fh = $upload->fh;
        my $contents;

        while(<$upload_fh>) {
                $contents .= $_;
        }
        close($upload_fh);

        # write $contents to the file here...
}

##</code><code>##

Can't locate object method "fh" via package "form_field_name (perhaps you forgot to load "form_field_name"?)