a brief tutorial on sendmail rules

[Chris Torek]

One rather vague point in all the sendmail documentation I have
read is that the `subroutine call' RHS macro $>n works by finishing
the expansion of the RHS, then taking the entire result and handing
it to ruleset n.  It might seem that there is a way to hand it just
part of an address, which I happen to feel would be extremely
useful, but there is none.  Also note that the $>n must be the
first part of the string on the RHS after $:, $@, or $# (if present).
This is not true of the host name canonicalization feature in 4.3
sendmail, $[; that may appear anywhere.

While I am running off at the keyboard here, here are some of the
other things I would also like to see in sendmail.  Remember that
this is supposed to be an address rewriting programming language.
(What else can you call it?)

	- Long variable names.  32 characters is an absolute minimum;
	  flexnames preferred.  Small name spaces are bad.  Remember
	  the *big* 8K (core of course) computers you worked on?

	- Real control structures, not just `do this once per
	  match' vs. `do this every match'.

	- Table lookups with return values, tables usually
	  being files of some kind, hopefully fast (e.g., hashed).

You might think this is overkill; and maybe it is.  But then I am
the guy who is recommending 64-bit address spaces on new hardware.
-- 
In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 4251)
UUCP:	seismo!umcp-cs!chris
CSNet:	chris at umcp-cs		ARPA:	chris at mimsy.umd.edu