From: Austin Ziegler <halostatue@...>
Date: 2005-01-05T00:05:41+09:00
Subject: Re: Error handling in file related methods?

On Sat, 11 Dec 2004 01:21:50 +0900, Johan Holmberg <holmberg@iar.se> wrote:
> I wonder what the "philosophy" is regarding error handling in file
> related methods in Ruby. Let me give an example. It is the method
> Kernel.test(?-, ...), i.e. a test to see if two files are hard links
> to the same file:
> 
>      $ mkdir subdir
>      $ touch subdir/aaa
>      $ ln subdir/aaa subdir/bbb
>      $
>      $ chmod 0755 subdir
>      $ ruby -e 'p test(?-, *ARGV)' subdir/aaa subdir/bbb
>      true
>      $
>      $ chmod 0 subdir
>      $ ruby -e 'p test(?-, *ARGV)' subdir/aaa subdir/bbb
>      false                    <--- NOTE THIS !!!
>      $
> 
> The "problem" with this behaviour is that the files *are* hard links
> but the permissions prevents us from finding that out. I think it
> would be better to get an exception indicating that, instead of
> "lying" to the script.
> 
> I suspect that Ruby behaves in this way in several similar situations.
> 
> Should this be changed?
> If so, what would be the preferred action?

I don't know what the preferred action would be on this, Johan -- I
don't actually use Kernel#test. However, ?- is doing the same as
bash's -ef test:

  [ subdir/aaa -ef subdir/bbb ] && echo true || echo false

-austin
-- 
Austin Ziegler * halostatue@gmail.com
               * Alternate: austin@halostatue.ca