> How can I get the same behaviour as $RANDOM in a portable way?

I saw another example in pkgsrc that just uses $$.

Here are some ideas:

http://home.comcast.net/~j.p.h/cus-faq.html#2

http://linuxgazette.net/issue55/tag/4.html

http://www.shelldorado.com/scripts/cmds/rand

Also jot -r does random but that is not portable.

And our NetBSD ksh has $RANDOM also.