Re: opendir(/dev/fd/n) should fail

[Helmut Karlowski <helmut dot karlowski at ish dot de>]

--------------------------------------------------
Eric Blake <eblake@redhat.com> wrote:
(23/01/2015 15:04)

> On 01/23/2015 03:00 AM, Helmut Karlowski wrote:
> > 
> > --------------------------------------------------
> > Helmut Karlowski <helmut.karlowski@ish.de> wrote:
> > (23/01/2015 10:54)
> >>
> >> It's not just bash. The same happens in my home-grown shell. Starting 
> >> with /dev/fd/3 opendir succeeds giving (only the opendir-entries):
> > 
> > Maybe it's because:
> > 
> > 3 -> /proc/3008/fd/
> > 
> > which recurses into /dev/fd again?
> 
> Yep. You'd get similar behavior for:
> 
> ln -s . dot
> 
> then trying to do a recursive listing of ./dot/**
> 
> Without some form of symlink recursion detection (aka "have we seen the
> inode of this directory higher up in the tree?"), this will affect any
> symlink-to-directory hierarchy loop.  Might be worth reporting it
> upstream to see if bash is willing to add an inode hash table to prevent
> infinite recursion on ** expansions across symlink loops, but as it is

I think ksh93 just does not follow synlinks when doing globstar. At 
least not the cygwin-version. Guess that's what I'll do as well.

-Helmut

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