PHP

Redirect image attachment pages in Wordpress

function myprefix_redirect_attachment_page() {
	if ( is_attachment() ) {
		global $post;
		if ( $post && $post->post_parent ) {
			wp_redirect( esc_url( get_permalink( $post->post_parent ) ), 301 );
			exit;
		} else {
			wp_redirect( esc_url( home_url( '/' ) ), 301 );
			exit;
		}
	}
}
add_action( 'template_redirect', 'myprefix_redirect_attachment_page' );

wordpress redirect attachment page to file

function redirectAttachmentsToAssociatedFile()
{
    if (is_attachment()) {
        global $post;

        if ($post && $post->post_parent) {
            wp_redirect(esc_url(home_url(wp_get_attachment_url($post->ID))), 301);
            exit;
        } else {
            wp_redirect(esc_url(home_url('/')), 301);
            exit;
        }
    }
}

add_action('template_redirect', 'redirectAttachmentsToAssociatedFile');