Lucene Core&160; is an open-source search software, provides Java-based indexing and search technology, as well as spellchecking, hit highlighting and advanced analysis/tokenization capabilities. Luke is a handy development and diagnostic tool, which accesses already existing Lucene indexes and allows you to display and modify their content.

Luke is awesome, but often times it is not feasible to inspect an index on a remote machine using a GUI. That's where Clue comes in. You can SSH into your production box and inspect your index using your favorite shell

Another important feature for Clue is the ability to interact with other Unix commands via piping, e.g. grep, more etc.

Interactive Mode:

./bin/ my-idx

Non-interactive Mode:

./bin/ my-idx command args

Command list:

./bin/ my-idx help
using configuration file found at: /Users/johnwang/github/clue/config/clue.conf
Analyzer:       class org.apache.lucene.analysis.standard.StandardAnalyzer
Query Builder:      class com.senseidb.clue.api.DefaultQueryBuilder
Directory Builder:  class com.senseidb.clue.api.DefaultDirectoryBuilder
IndexReader Factory:    class com.senseidb.clue.api.DefaultIndexReaderFactory
delete - deletes a list of documents from searching via a query, input: query
directory - prints directory information
docval - gets doc value for a given doc, <field> <docid>, if <docid> not specified, all docs are shown
exit - exits program
explain - shows score explanation of a doc
export - export index to readable text files
help - displays help
info - displays information about the index, <segment number> to get information on the segment
merge - force merges segments into given N segments, input: number of max segments
norm - displays norm values for a field for a list of documents
postings - iterating postings given a term, e.g. <fieldname:fieldvalue>
readonly - puts clue in readonly mode
reconstruct - reconstructs an indexed field for a document
search - executes a query against the index, input: <query string>
stored - displays stored data for a given field
terms - gets terms from the index, <field:term>, term can be a prefix
trim - trims the index, <TRIM PERCENTAGE> <OPTIONS>, options are: head, tail, random
tv - shows term vector of a field for a doc

See for more details

Thanks javasoze for this wonderful tool, it is now part of my standard toolbox.