cache-init, cache-update, find-updated and portindex are a set of perl
scripts built around the common core of the FreeBSD::Portindex
modules. Their use is to generate and maintain the ports INDEX or
INDEX-5 files speedily and efficiently. Ultimately they work in a very
similar way to the standard make index command, except that the
FreeBSD::Portindex tools keep a cache of the make describe output from
each port, and can update that cached data incrementally as the ports
tree itself is updated.

WWW: http://www.infracaninophile.co.uk/portindex/