Re: bug with eval, proc-subst and pipes

[Bart Schaefer <schaefer@xxxxxxxxxxxxxxxx>]

On Friday, July 19, 2013, Stephane Chazelas wrote:

> 2013-07-18 12:32:10 +0100, Peter Stephenson:
> [...]
> > Apparently working (except for the fact it doesn't fix Stephane's
> > original problem, don't know if we're any further forward with that).
> > However, I'll wait in case Bart can see something I missed.


For some reason I never received that message from Peter.  Did it perhaps
go privately to Stephen?

~$ eval 'ls -l <(echo 1) <(echo 2) <(echo 3) <(echo 4)' | cat
> ls: cannot access /proc/self/fd/11: No such file or directory
> ls: cannot access /proc/self/fd/13: No such file or directory
> lr-x------ 1 chazelas chazelas 64 Jul 19 20:52 /proc/self/fd/10 ->
> pipe:[509333]
> lr-x------ 1 chazelas chazelas 64 Jul 19 20:52 /proc/self/fd/12 ->
> pipe:[509335]


Ok, this is kinda strange, because on my Ubuntu system there is no
/proc/self/fd ... The "ls" shows /dev/fd files.  Why would that be
different?

And it's further odd that some of the descriptors are closed but not all of
them.


> [In strace]
>
> See how fd 13 is closed in the process that execs ls and fd 11
> in its parent shortly before the fork.


That's also odd.  It would almost seem to imply that those descriptors got
the close-on-exec flag set somehow.