Re: file as a directory

[Peter Foldiak]

On Tue, 2004-12-14 at 17:21, Jan Engelhardt wrote:
> Recently I discovered that calling "joe /etc" on FreeBSD opens the directory 
> itself (rather than erroring out with EISDIR). The byte string looked like a 
> number of "struct dirent"s. Did it break apps in BSD? I donot think so.

I don't imagine anyone would miss that behaviour, we can probably have
something more useful than a
cat: /etc: Is a directory
message.

> >(I am not sure whether the access method, e.g. read() vs. readdir() is
> >sufficient to distinguish the meaning. Another way may be putting a "/"
> >after the objectname to indicate that you want it as a directory.)
> 
> I would not rely on that. Many apps strip a trailing slash (just to add it 
> later again) or vice versa!

ok, I don't really care about the trailing slash. The reading method
(read() vs. readdir()) may be enough to distinguish the uses. The
trailing / is still a useful (and logical) visual notation though for
the different meanings, so something like ls could give both versions.

> What will ls do? 

list both /etc/passwd and /etc/passwd/ perhaps?

> Consider this on a "normal" filesystem:
> 
> ls -l /etc/passwd
> -rw-r--r--  1 root root 1614 Dec 12 23:57 /etc/passwd
> ls -l /etc
> [lots of files]
> 
> 
> What will happen on v4 then?
> ls -l /etc
> -rw-r--r-- 1 root root 123456 Dec 01 23:45 /etc
> ls -l /etc/passwd
> -rw-r--r-- 1 root root 1234 Dec 01 23:45 root
> -rw-r--r-- 1 root root 1234 Dec 01 23:45 jengelh
> -rw-r--r-- 1 root root 1234 Dec 01 23:45 daemon
> -rw-r--r-- 1 root root 1234 Dec 01 23:45 sys
> -rw-r--r-- 1 root root 1234 Dec 01 23:45 stduser
> 
> It's because "ls" checks the type of the argument to decide what to do (unless
> you add -d).
> 
> 
> Jan Engelhardt

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