This gives an xml output in checkstyle 5.0 format. The other options are displayed if you specify --help:
$ java -jar ../scalastyle-batch/target/scalastyle-batch_2.10.jar
Error: Unknown argument '--help'
Error: missing arguments: <directory>
scalastyle 0.3.3-SNAPSHOT
Usage: scalastyle [options] <directory>
-c <value> | --config <value>
configuration file (required)
-v <value> | --verbose <value>
verbose
-q <value> | --quiet <value>
quiet
--xmlOutput <value>
XML output (optional)
--xmlEncoding <value>
XML output encoding (optional)
--inputEncoding <value>
Source file encoding (input) (optional)
-w <value> | --warnings <value>
fail if there are warnings
<directory>
directories / files
Matthew Farwell.