Re: [nmh-workers] closefds() _before_ fork?

[Ken Hornstein]

>I agree with the general principle that if we open it, we track it, and
>then close it so it doesn't reach the child, typically with O_CLOEXEC or
>FD_CLOEXEC.  Calling close(2) lots of times based on getdtablesize(3)
>can take a while.  screen(1) had a bug recently where it was taking ages
>trying to close almost 512 Ki of them.
>https://lists.archlinux.org/pipermail/arch-general/2019-March/046214.html

I was curious what they did, so I looked ... it looks like they actually
didn't really "solve" the issue.   They use a function fdwalk() on Solaris
but made sure they called getdtablesize() on Linux, which it seems returns a
smaller number than getrlimit().

--Ken