Mailing List Archive

On 23 Apr 1999, Preston Landers wrote:


> I've looked at the mailbox.UnixMailbox package. I am able to write a
> script that retrieves each message in /var/spool/mail/myuser and
> displays the sender, recipient, and subject. I am able to generate a
> reply using /usr/bin/mail. But for the life of me, I cannot look at
> the body of the incoming message. Silly me. Where in the
> documentation is this describe? 10 points to anyone who can point out
> the specific place to me.


Yeah -- mailbox and rfc822 aren't the prettiest modules in the Python
libraries! Here's where the class browser in the Mac Python IDE comes
in handy, along with some interactive snooping.


>>> mb = mailbox.UnixMailbox( open( 'OneGig:Python+11', 'r' ))
>>> mb
<mailbox.UnixMailbox instance at 2735700>

## mb is a mailbox

>>> dir(mb)
['fp', 'seekp']
>>> a = mb.next()
>>> a
<rfc822.Message instance at 2749760>

## a is a message.

>>> dir(a)
['dict', 'fp', 'headers', 'seekable', 'startofbody', 'startofheaders',
'status', 'unixfrom']
>>> a
<rfc822.Message instance at 2749760>
>>> a.fp
<mailbox._Subfile instance at 27496a0>
>>> a.fp.fp
<open file 'OneGig:Python+11', mode 'r' at 27353c0>

# a's _Subfile is what you want, speficially, for the message body:

>>> print a.fp.read()



> Periodically, I want my daemon to check a standard Unix mail spool
> file for new messages. Under certain conditions, I want the script to
> act on those messages (ie, do its thang on the contents of the message
> and mail the results back to the sender.)


However, the typical way to do this sort of thing on unix is to
redirect all messages with a .forward file to dispatcher program
that gets each message one at a time on it's standard input.
Thus you don't have to check the spool periodically -- the program
gets triggered as part of the mail delivery. There are unix programs
like procmail & filter that already do this. ( and procmail has
a companion program, formail, which among other things can split
a mailbox up into separate messages, pipeing each one to a new
procmail process, thus simulating the delivery process in batch
mode. )

You can use a python script in place of procmail -- in which case,
it doesn't have to split a mailbox into separate messages -- it gets
a single message on it's standard input.

Or, you can use procmail to selectively send particular messages to
another script.

Or, you can select a subset of messages and redirect them into a
different file, which can be the input for your batch processing.


You might also want to look a Mailman -- which is a mailing list
manager written in Python. It may already have most of the tools
you need for your responder.



---| Steven D. Majewski (804-982-0831) <sdm7g@Virginia.EDU> |---
---| Department of Molecular Physiology and Biological Physics |---
---| University of Virginia Health Sciences Center |---
---| P.O. Box 10011 Charlottesville, VA 22906-0011 |---

Caldera Open Linux: "Powerful and easy to use!" -- Microsoft(*)
(*) <http://www.pathfinder.com/fortune/1999/03/01/mic.html>

"Steven D. Majewski" <sdm7g@Virginia.EDU> writes:

> Yeah -- mailbox and rfc822 aren't the prettiest modules in the Python
> libraries! Here's where the class browser in the Mac Python IDE comes
> in handy, along with some interactive snooping.

Thank you! Your message was most helpful. Unlike a snotty reply I
recieved in email that just said "You didn't read the docs."

> Thus you don't have to check the spool periodically -- the program
> gets triggered as part of the mail delivery. There are unix programs
> like procmail & filter that already do this. ( and procmail has

Yeah, I considered this. I actually use fetchmail & procmail for my
day to day email. It does have advantages, particularly like you
describe ... the script isn't running continuously but is invoked for
each message.

> Or, you can use procmail to selectively send particular messages to
> another script.

Right, right. I'd want some kind of validation on who's allowed to
send messages to this script.

> You might also want to look a Mailman -- which is a mailing list
> manager written in Python. It may already have most of the tools
> you need for your responder.

I only glanced briefly at that package but I may go back and look at
it again more carefully. At the time, it seemed like overkill. In
fact, since my needs aren't very complicated, and I already know a bit
about procmail, I may just go with that.

Once again, your message was quite helpful and pointed me in the right
direction. Thanks a lot!!!!

--Preston