CLue - Command Line tool for Apache Lucene


When working with Lucene, it is often useful to inspect an index.

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.


Clue is under the Apache Public License v2.0.


Please file bugs and feature requests here.


latest version: 8.5.0-1.0.0

What's new in this release?

See Release Note


mvn package

This will create the following artifact in the target directory:



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 io.dashbase.clue.api.DefaultQueryBuilder
Directory Builder:  class io.dashbase.clue.api.DefaultDirectoryBuilder
IndexReader Factory:    class io.dashbase.clue.api.DefaultIndexReaderFactory
delete - deletes a list of documents from searching via a query, input: query
directory - prints directory information
docsetinfo - doc id set info and stats
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

Build a sample index to play with:

Clue bundles with some test data (15000 car data) for you to build a sample index to play with, do:

./bin/ my-idx


  1. Getting all the terms in the field 'color_indexed':

    ./bin/ my-idx terms color_indexed

  2. Getting all the terms in the field 'color_indexed' starting with the term staring with 'r':

    ./bin/ my-idx terms color_indexed:r

    ./bin/ my-idx terms color_indexed | grep r

  3. Do a search:

    ./bin/ my-idx search myquery

  4. Get the index info:

    ./bin/ my-idx info

  5. Iterate a posting for the term color_indexed:red

    ./bin/ my-idx postings color_indexed:red

  6. List docvalues for the column-stride-field color:

    ./bin/ my-idx docval color

  7. Get docvalue for the column-stride-field category for document 4:

    ./bin/ my-idx docval category 5

  8. Get docvalue for the column-stride-field year of type numeric for document 3:

    ./bin/ my-idx docval year 3

  9. Get docvalue for the column-stride-field json of type binary for document 3:

    ./bin/ my-idx docval json 3

  10. Get docvalue for the column-stride-field tags of type sorted-set for document 3:

    ./bin/ my-idx docval tags 3