Re: inconsistent recipie failure

> From [email protected]  Mon Jan 24 07:51:40 2011
> Date: Mon, 24 Jan 2011 05:42:22 -0800
> To: [email protected]
> From: [email protected] (Professional Software Engineering)
> Subject: Re: inconsistent recipie failure
>
> At 02:38 2011-01-24, Robert Bonomi wrote:
>
> >Relevant ~/.procmailrc fragments
>
> You might be surprised at how much of the irrelevant fragments play a 
> role <g>

Yeah, well.  My .procmailrc is close to a thousand lines long, with *LOTS*
of variable usage.  I wasn't going to inflict _that_ on the list. <grn>

I've been using procmail for _decades_, literally, and this is the first 
time I've failed to understand what it was talking about.

> >   MAILDOMAIN="r-bonomi[.]com"
>
> More typically, one escapes a dot when one wants it treated as a literal:
>          MAILDOMAIN=r-bonomi\.com
>
> Yes, you character class will evaluate the same in the end, but it's not 
> the more commonly used method.

I know.  It's a matter of personal preference.

> >     * $ ^Received: from [^ ]* \( *[^[].*${MAILHOST}
> >     DELIVERABLE=|/bin/echo /home/bonomi/{{filename}}
>
> Would you mind explaining what you THINK this is accomplishing?

I -know- exactly what it's doing.  and it does the job just fine.  <grin>

I'm examining the Received line added by _my_ external-facing mailserver, and
ensuring that there _was_ a rDNS entry for the IP address that connected to
it.  The Received line is formatted as:
    Received: from {heloname} ({rDNSname, if any}[{IP address]) by {server}...

Aside: occasionally, a rDNS name comes back with leading whitespace (it 
*shouldn't* but _does_)

The " [^ ]* " matches the white-space-bounded heloname,
the "\( *[^[]" matches the start of the parenthetical information (with or
without the 'incorrect' whitespace),  *IF* a rDNS name is present, (i.e.
it does *not* match "([", "( [", or similar variations)
and ".*${MAILHOST}" ensures that I only look at the received line that
my $MAILHOST added.

The action sets a variable specifying where the message should be filed.

I have a collection of actions that I take _only_ on 'deliverable' mail, 
and not on spam.  By coding this way, and using 'else' chains in the match 
recipies, I can code that collection of actions _once_, as a block action
on a recipie that checks for a common characteristic in what  ${DELIVERABLE}
is set to.

> >Every once-in-a-while, for no reason that I can ascertain, and with no 
> >apparent commonality in the messages involved, the following happens:
>
> The ones you don't have problems with are all small messages, and the 
> ones you do, are larger - they exceed a certain buffer size, and procmail 
> detects that echo isn't reading all of the message procmail is putting on 
> the pipe for it, and therefore expects the app choked.

> It should be consistently reproduceable if you sandbox with one of the 
> messages which has failed.  Are they eventually delivered to a mailbox?  

Yeah, _everything_ incoming gets delivered 'somewhere'.  I run statistical
analyses every once-in-a-while on the incoming spam.

> Check the delivery summary lines in the procmail log - the number that 
> trails the subject line text is the size of the message.  The pattern 
> should be quite evident.

I'll have go go check logfiles, but that sounds very reasonable, and likely.
Practically all the legitimate mail I get is relatively small stuff.  Except
for one mailing list that goes through _this_ rule.

> >   procmail: Error while writing to "/bin/echo" procmail: Rescue of 
> >   unfiltered data succeeded
>
> >Does _anybody_ have any idea what might be going on, and how to fix it??
>
> Quick solution: add an 'i' to the flags.

I thought of that, but it just covers up the problem, rather than fixing
it.

Given the way I'm doing things,
  
  "echo {foo}; cat >/dev/null" 

should do the trick.
>
> And/or rethink how you're setting your variable.  Why are you using echo?

"As opposed to?"  <grin>

The only other way I know of to do it is along the lines of:

    : 0
    * <<condition>>
    {
      VARIABLE=value
    }