// Remove "Select options" button from (variable) products on the main WooCommerce shop page.
add_filter( 'woocommerce_loop_add_to_cart_link', function( $product ) {
	global $product;

	if ( is_shop() && 'variable' === $product->product_type ) {
		return '';
	} else {
		return sprintf( '<a rel="nofollow" href="%s" data-quantity="%s" data-product_id="%s" data-product_sku="%s" class="%s">%s</a>',
			esc_url( $product->add_to_cart_url() ),
			esc_attr( isset( $quantity ) ? $quantity : 1 ),
			esc_attr( $product->id ),
			esc_attr( $product->get_sku() ),
			esc_attr( isset( $class ) ? $class : 'button' ),
			esc_html( $product->add_to_cart_text() )
		);
	}
} );