uke 是查询LUCENE索引文件的工具， 而且用 Luke 的Search可以做查询 Luke is a handy development and diagnostic tool, which accesses already existing Lucene indexes and allows you to display and modify their contents in several ways.

Luke是用来查看lucene格式索引的工具。而nutch的索引采用的就是lucene格式，所以，luke就成为查看nutch索引的利器。