Subject: Re: bug#23263: cat: missingfile: No such file or directory
From: Paul Eggert <[email-masked]>
To: Jonny Grant <[email-masked]>, [email-masked]
Date: Sun, 10 Apr 2016 12:01:09 -0700
List-Id: <debbugs-submit.debbugs.gnu.org>

Jonny Grant wrote:
> Hello
>
> I noticed that cat doesn't have an accurate message in the following use-case:
>
> $ cat missingfile
> cat: missingfile: No such file or directory
> $ mkdir testdir
> $ cat testdir
> cat: testdir: Is a directory

The "No such file or directory" message occurs because the operating system does 
not have a separate error code for missing directory versus missing file. In the 
example you gave, perhaps the working directory is missing (this can happen on 
some systems), or perhaps there is no file named "missingfile" in the working 
directory; the same code is returned for both situations.

This is not a coreutils issue, but is instead a kernel and C library issue. It's 
not something that coreutils can "fix", even assuming it was agreed that it was 
a bug. If it really bothers you, I suggest writing the POSIX standardization 
committee, but I should warn you that you'll need a strong argument to change 
something that has been standardized for decades.