Links in shortcode

Hey,

I’m using the following code to grab the gallery images from a page except the feature image. It’s working great except I do not want it to link to the image or any other link for that matter.

<?php echo do_shortcode('[gallery size="portfolio-main" exclude="' . get_post_thumbnail_id( $post->ID ) . '" ]'); ?>

I’ve seen a few posts online to include link=”file” but had no luck.

I’m sure it’s something small but just cannot get it to work.