nul detection

Gentlefolk,

I have been trying to formulate a recipe which catches a nul, and have
not been successful. I can catch bel, but similar tests fail for nul.

In particular, if xx is a procmail rc file with the following:

 SHELL=/bin/sh
 NUL=`/usr/5bin/echo "\000"`
 BEL=`/usr/5bin/echo "\007"`
 LF="
"
 :0HB
 * $ $\NUL
 { LOG="Caught <NUL>$LF" }
 :0HB
 * $ $\BEL
 { LOG="Caught <BEL>$LF" }
 :0
 /dev/null

I get the following result:

 $ /usr/5bin/echo "ab\000\007" | procmail ./xx
 Caught <NUL>
 Caught <BEL>

 $ /usr/5bin/echo "ab\007" | procmail ./xx
 Caught <NUL>
 Caught <BEL>

 $ /usr/5bin/echo "ab\000" | procmail ./xx
 Caught <NUL>

 $ /usr/5bin/echo "ab" | procmail ./xx
 Caught <NUL>


This all started with a spam which ends:

0002200    l   y  sp   r   e   q   u   e   s   t  sp   i   t   .  nl  nl
0002220    % nul  nl  nl
0002224

Has anyone come across this before (and solved it)? This happens with
3.11pre4 and pre7

For extra credit, does anyone know what mailer might be creating this?
I've seen it on a couple of spams recently.


-- 
Rik Kabel          Old enough to be an adult              
rik(_at_)netcom(_dot_)com