Matthew Miller mattdm at
Wed Jan 5 15:16:54 UTC 2005

On Wed, Jan 05, 2005 at 07:57:36AM -0600, Les Mikesell wrote:
> The traditional in-band delimiter has worked for 20+ years with
> correctly written tools that do not mangle the messages.

Sadly, not so. What character to you see at the the front of this next line?

>From is used as the delimiter in mbox.

And it can't tell the difference between From to start a new message and
>From because I happened to start a line that way. And worse, this mangling
is irreversible -- it's very possible that a quoted line in the body
contains >From just naturally.

The alternative -- using "Content-Length", is even more dangerous, because
it can't be trusted.

> Unix provides file locking mechanisms that allow different programs
> to access mailboxes without corrupting them.  As usual, if you
> want to shoot yourself in the foot, it will happily hand you
> the gun....  Over the years at least 3 different locking

And all my users a gun of their own. All I know is: have a bunch of people
on a system running pine, and every now and then you'll be fixing corrupt
mbox mailboxes. You can argue all you want that these people aren't doing it
right -- but I guess that's the _point_.

> mechanisms have been used and no one is going to force you
> to use the same one on all of your tools.  However, it works
> when done right and there is no reason to arbitrarily break
> programs that have worked for years by changing the delivery
> format.



Matthew Miller           mattdm at        <>
Boston University Linux      ------>                <>

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