Duplicate WordPress Pages and Posts

duplicate_page_or_post.php

$current_user = wp_get_current_user();
	$new_post_author = $current_user->ID;

	/*
	 * if post data exists, create the post duplicate
	 */
	if (isset( $post ) && $post != null) {

		/*
		 * new post data array
		 */
		$args = array(
			'comment_status' => $post->comment_status,
			'ping_status'    => $post->ping_status,
			'post_author'    => $new_post_author,
			'post_content'   => $post->post_content,
			'post_excerpt'   => $post->post_excerpt,
			'post_name'      => $post->post_name,
			'post_parent'    => $post->post_parent,
			'post_password'  => $post->post_password,
			'post_status'    => 'draft',
			'post_title'     => $post->post_title,
			'post_type'      => $post->post_type,
			'to_ping'        => $post->to_ping,
			'menu_order'     => $post->menu_order
		);

		/*
		 * insert the post by wp_insert_post() function
		 */
		$new_post_id = wp_insert_post( $args );

		/*
		 * get all current post terms and set them to the new post draft
		 */
		$taxonomies = get_object_taxonomies($post->post_type); // returns array of taxonomy names for post type, ex array("category", "post_tag");
		foreach ($taxonomies as $taxonomy) {
			$post_terms = wp_get_object_terms($post_id, $taxonomy, array('fields' => 'slugs'));
			wp_set_object_terms($new_post_id, $post_terms, $taxonomy, false);
		}

		/*
		 * duplicate all post meta just in two SQL queries
		 */
		$post_meta_infos = $wpdb->get_results("SELECT meta_key, meta_value FROM $wpdb->postmeta WHERE post_id=$post_id");
		if (count($post_meta_infos)!=0) {
			$sql_query = "INSERT INTO $wpdb->postmeta (post_id, meta_key, meta_value) ";
			foreach ($post_meta_infos as $meta_info) {
				$meta_key = $meta_info->meta_key;
				if( $meta_key == '_wp_old_slug' ) continue;
				$meta_value = addslashes($meta_info->meta_value);
				$sql_query_sel[]= "SELECT $new_post_id, '$meta_key', '$meta_value'";
			}
			$sql_query.= implode(" UNION ALL ", $sql_query_sel);
			$wpdb->query($sql_query);
		}


		/*
		 * finally, redirect to the edit post screen for the new draft
		 */
		wp_redirect( admin_url( 'post.php?action=edit&post=' . $new_post_id ) );
		exit;
	} else {
		wp_die('Post creation failed, could not find original post: ' . $post_id);
	}
}
add_action( 'admin_action_rd_duplicate_post_as_draft', 'rd_duplicate_post_as_draft' );

/*
 * Add the duplicate link to action list for post_row_actions
 */
function rd_duplicate_post_link( $actions, $post ) {
	if (current_user_can('edit_posts')) {
		$actions['duplicate'] = '<a>ID, basename(__FILE__), 'duplicate_nonce' ) . '" title="Duplicate this item" rel="permalink">Duplicate</a>';
	}
	return $actions;
}

add_filter( 'post_row_actions', 'rd_duplicate_post_link', 10, 2 );