Re: [PATCH] be paranoid about closed stdin/stdout/stderr

Nick Andrew wrote:

On Wed, Aug 27, 2008 at 02:22:39PM -0400, Avery Pennarun wrote:

quoted

I'm just feeling protective of the future sanity of other developers
here, hoping they don't have to go through what I did on a multi-week

You're not alone. I've been having trouble with a combination of
fetchmail, procmail and ssmtp, in which situation the ssmtp program
_somehow_ sometimes opens /dev/urandom as file descriptor 0 (while

in controlled circumstances. It's possible that fetchmail or procmail
is doing something stupid - but a little more defensive programming
in ssmtp could avoid the total disaster area of sending an endless
binary stream to an SMTP server.

Procmail I can vouch for, it basically assumes your OS is broken and
fights it's way back to sanity (it can be setuid root, so it has to
be rather careful).
Nonetheless, I still maintain that hiding problems doesn't help, it
only makes the bugs even rarer and more difficult to find.

The filedescriptor problem is a programmer-error, not a user-error,
which is why not hiding it should be preferred.  If it were a
user-error, thing would be different, assisting the user is a Good
Thing.
-- 
Sincerely,
           Stephen R. van den Berg.

"Listen carefully, I shall say this only wence."