FitNesse. UserGuide.
CommandLineTestRunner [add child]

Reasons for running FitNesse tests from the command line.

Using the TestRunner

usage: java fitnesse.runner.TestRunner [options] host port page-name
-v verbose: prints test progress to stdout
-xml <file> Sends xml test results to the file. If file is 'stdout' sends xml to standard out.
-suiteFilter <filter> runs only those tests of a suite which have been marked with the respective filter

There are three required arguments: host port page-name. The command to run the FitNesse test suite on your local instance of FitNesse is:
java -cp fitnesse.jar fitnesse.runner.TestRunner localhost 80 FitNesse.SuiteAcceptanceTests

The TestRunner, regardless of options, exits with the number of pages with failures + exceptions that occurred during execution. An exit value of 0 means all the tests passed. Adding the -v prints a summary of the test results on standard out. The page designated by page-name may be either a suite or test page.

For the XML format see RestfulTests

More details about suite filters can be found here.