Help making a port for a (somewhat) restricted program

[Vitaly Magerya]

>       Look at how java/jdk-* does it.

java/jdk* uses ${PRINTF} (/usr/bin/printf) to display a message about
you having to go and download some of the restricted files, and then exits.
Once you've downloaded the files (and that implies that you've accepted
the license), the message no longer appears, and you can proceed with
installation.
(This seems to be the common way of treating restricted ports).

The difference with Petite Chez is that you do not need to accept anything
to download sources (no restriction on redistribution), so this part can be
automated; but you do have to read and accept the license before
installing it. ${PRINTF} won't help too much, as you can't display a
file with it;
and license is too big to fit on one screen anyway (that's why I'd use a pager).