Programmatic access to read the Princeton University Host Database is available via the hostExtDB library.
The hostExtDB library is a perl5 library which programmers may use to extract information from the Host Database.
The library is made available via the /usr/hostdatabase NFS filesystem exported by OIT; the filesystem may be mounted by NFS clients at Princeton University.
Detailed documentation for using the library is available in the hostExtDB manual page.
The hostExtDB has been available for many years via the /usr/princeton NFS filesystem exported by OIT.
While it is still available via that filesystem, use of the library via that filesystem is no longer practical for most clients. That version relied upon a version of perl located in that filesystem, built for certain operating systems that were popular years ago. OIT no longer maintains the /usr/princeton filesystem (and most hosts rely on a locally-installed copy of perl).
To provide continued access to the hostExtDB library, we have made it available via a new OIT NFS filesystem called /usr/hostdatabase. Most any NFS client at Princeton University that can run perl should be able to use the library from the /usr/hostdatabase filesystem.