$ npm install [-g] core-validate-commit

# for a single commit
$ core-validate-commit <sha>
# validate since <sha>
$ git rev-list <sha>..HEAD | xargs core-validate-commit
# list all rules
$ core-validate-commit --list
         fixes-url enforce format of Fixes URLs
  line-after-title enforce a blank newline after the commit title
       line-length enforce max length of lines in commit body
      metadata-end enforce that metadata is at the end of commit messages
            pr-url enforce PR-URL
         reviewers enforce having reviewers
         subsystem enforce subsystem validity
      title-format enforce commit title format
      title-length enforce max length of commit title

$ core-validate-commit --list-subsystem

$ npm test