visualise port tree freebsd code example

Example: visualise port tree freebsd

$ pkg_depends.pl ruby18-bdb-0.6.5_1
Package ruby18-bdb-0.6.5_1 depends on:
    db41-4.1.25_4
    ruby-1.8.7.248_5,1
Package ruby18-bdb-0.6.5_1 is required by:
    portupgrade-2.4.7,2