[ -w filename ] returns true when permissions are -r--r--r--

Larry Hall (Cygwin) reply-to-list-only-lh@cygwin.com
Thu Jul 21 18:52:00 GMT 2011


On 7/21/2011 9:31 AM, Corinna Vinschen wrote:
> On Jul 21 07:43, Nellis, Kenneth wrote:
>>> From: Eric Blake
>>> On 07/20/2011 12:05 PM, Reid Thompson wrote:
>>>> Is this broken?  Or a known windows/cygwin discrepancy?  Or am I
>>> missing
>>>> something with my posix/windows file permissions settings
>>>
>>> If you are running as an administrator, that might explain it.  Admins
>>> can alter any file regardless of permissions, in which case [ -w is
>>> telling you the truth that under your current uid, you can indeed write
>>> to the file.
>>>
>>> This is a feature of access(file,W_OK), and not a bug.
>>
>> FWIW, I'm not running as administrator and I'm running 1.7.9, and I'm
>> seeing the same thing:
>>
>> $ touch afile
>> $ chmod 444 afile
>> $ ls -l
>> total 0
>> -r--r--r-- 1 knellis knellis 0 Jul 21 08:36 afile
>> $ [ -w afile ]&&  echo writable || echo not writable
>> writable
>> $ echo abc>>  afile
>> $ cat afile
>> abc
>> $ ls -l
>> total 1
>> -r--r--r-- 1 knellis knellis 4 Jul 21 08:37 afile
>> $
>
> What system?  XP, Vista?  7?
> What's the output of `id'?

Or even <http://cygwin.com/snapshots/>. ;-)


-- 
Larry

_____________________________________________________________________

A: Yes.
 > Q: Are you sure?
 >> A: Because it reverses the logical flow of conversation.
 >>> Q: Why is top posting annoying in email?

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