esfstats is a Scala program wrapped in a shell script that runs with Ammonite*. It extracts some statistics re. field coverage in the documents.
*) i.e. you need to install Ammonite at your machine (and maybe Scala and Ivy as well)
esfstats --
-host hostname or IP of the elasticsearch instance
-port port of the native Elasticsearch transport protocol API
-index index name
-type document type
-help print this help
note: --
is required to delegate the parameters to the Scala script (otherwise they will be interpreted as Ammonite parameters)