Portupgrade is a tool to upgrade installed packages via the port.

It upgrades ports without reinstalling dependent packages by directly
modifying the package info recorded in the files under /var/db/pkg.

The procedures it takes is shown as follows:

    1.  Build the corresponding port of the given installed package
    2.  Fix the dependency info of the ones which depends on the given
        package
    3.  Save the +REQUIRED_BY list of the given package
    4.  Uninstall the given package forcibly if -u is specified
    5.  Install the new version via the port (built in <1>)
    6.  Restore the +REQUIRED_BY list (saved in <3>)

The usage can be shown by running it without arguments or with a -h.

Author:	Akinori MUSHA <knu@FreeBSD.org>
