lucene version: 3.5.0
tar zxvf lucene-3.5.0.tgz
export CLASSPATH=~/repo/charsyam/lucene-3.5.0/lucene-core-3.5.0.jar:~/repo/charsyam/lucene-3.5.0/contrib/demo/lucene-demo-3.5.0.jar
time java org.apache.lucene.demo.IndexFiles -docs docs/
java org.apache.lucene.demo.SearchFiles