[OT] File type on UNIX

"Jérôme M. Berger" jeberger at free.fr
Fri Sep 17 13:24:36 PDT 2010


KennyTM~ wrote:
> On Sep 17, 10 02:26, "Jérôme M. Berger" wrote:
>> Jérôme M. Berger wrote:
>>> KennyTM~ wrote:
>>>> On Sep 16, 10 04:35, "Jérôme M. Berger" wrote:
>>>>> Nick Sabalausky wrote:
>>>>>> I didn't think unix file systems had a concept of mime type.
>>>>>>
>>>>>      It doesn't, but Unix tools use the file contents to determine the
>>>>> mime type and then choose the app associated to the mime type.
>>>>>
>>>>>          Jerome
>>>> Please don't confuse Unix with a distro.
>>>
>>>     Which distro? I used the terms "Unix tools" because it transcends
>>> distributions and Unices. It is as true on Ubuntu as on *BSD or
>>> Solaris...
>>>
>>>         Jerome
>> BTW: http://www.darwinsys.com/file/
>> <quote>
>> Unlike most GUI systems, command-line UNIX systems - with this
>> program leading the charge - don't rely on filename extentions to
>> tell you the type of a file, but look at the file's actual contents.
>> </quote>
>>
>>     They say "UNIX systems", they don't say "Ubuntu" (which I don't use
>> anyway).
>>
>>         Jerome
> 
> This describes the file(1) command, which the job is to inspect the file
> content and conclude what kind of file it actually is.
> 
	I suggest you re-read the paragraph I posted. Although it was taken
from the "file" web site, it states clearly that other apps look at
the file contents instead of the extension. Of course, some apps
don't care about the file type but some do. And most of those that
do care don't use the extension.

> But this is just one particular UNIX command. The command line interface
> in general does not care about the type of a regular file. This is
> needed in the GUI, but it is outside of the common parts of UNIX. There
> is no rule saying that a file manager must use file(1) or MIME type or
> extensions to determine the file type.
> 
	True, but then, there is no rule that says that on windows a file
manager must use the extension. However, on Windows, all the file
managers I've tried have used the extension (actually, most of the
time they don't use the extension themselves, they simply ask
Windows to open the file and Windows uses the extension), whereas on
UNIX most file managers use the file contents (usually, they don't
use the file command, but instead rely on libmagic directly) and
most applications will ignore the extension when asked to open a
file (OK, some Windows applications do that too but on *NIX most of
them do).

		Jerome
-- 
mailto:jeberger at free.fr
http://jeberger.free.fr
Jabber: jeberger at jabber.fr

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 198 bytes
Desc: OpenPGP digital signature
URL: <http://lists.puremagic.com/pipermail/digitalmars-d/attachments/20100917/aaadcfc7/attachment.pgp>


More information about the Digitalmars-d mailing list