procmail: dropprivs and variables.

Hey all,

I'm running procmail site-wide with dropprivs=yes, and I need to call
spamassassin's spamc in such a way that the argument is:

-u [current user]@arbitrary-hostname

Since I've seen in FAQs that logname is unaffected by DROPPRIVS, I
think it's safe to assume the opposite as well?

How would I construct such an argument string? I know in perl I could
just look at $>, but I don't think procmail has such a var. Also, how
would I have to quote and or join this variable? I know that's a
common "gotcha".

Thanks for any and all help on this.

-Dan Mahoney

PS, Email replies appreciated.