Re: procfs difference between NetBSD and Linux

[Sad Clouds <cryintothebluesky%gmail.com@localhost>]

On Thu, 3 Jun 2021 10:02:20 +1200
Mark Davies <mark%ecs.vuw.ac.nz@localhost> wrote:

> 
> 
> On 2/06/21 5:49 am, Robert Elz wrote:
> > And while doing that, ask them what they're possibly trying to achieve
> > with the O_CREAT flag - if /proc/$$/fd/N doesn't exist, how is creating
> > (what would be a normal file, if procfs allowed it) going to possibly
> > do anything useful?   It is hard to believe that they're intending that
> > creating a file there will magically cause the fd to open (open to
> > what underlying object?)   If they know the fd is open (which they
> > seem to do here) then they know that /proc/$$/fd/N already exists, in
> > which case O_CREAT is useless (in the best of cases).
> 
> I think that is because after they set the path to /proc/self/fd/N they 
> pass it back to their generic open routines to do the actual open.
> see reopen_from_procfd() in source3/smbd/open.c
> 
> cheers
> mark

And why rely on procfs to open file descriptors? Shell scripts do it,
but a C program should know better.