Obtain revision information from pj-file without server communication

The pj-file in every PTC Integrity subproject stores some information about the contained members, also the current working revision checked out for a member. Is ther an si command to access this information without server communication?

When the information stored in the pj-file could be accessed without server communication, then it would be independent if the current directory is within a registered sandbox. (see Get associated sandbox from a subproject within a SUBSTituted drive)