Date   : Tue, 20 Apr 2010 13:50:31 +0100
From   : mike@... (Michael Howard)
Subject: Unzipping metadata

Rick Murray wrote:
> On 20/04/2010 07:06, P. Van Ek wrote:
>
>   
>> I did look and as Rick says I am using a pc to unzip the files....
>> Where does it say you must use a bbc unzip program to extract them !!!
>>     
>
> Common sense! :-)
>
> Ever got a generic Windows zip program to understand the difference 
> between public and owner file permissions? Ever got a generic Windows 
> zip program to understand RISC OS filetypes or BBC load/exec addresses? 
> Heck, it's enough to a trial to get WinZip to put stuff in relative 
> paths (it likes either no paths at all, or everything relative to root!).
>   

Never has a problem with WinZip myself.

> I guess getting a generic Windows zip program to understand such 
> extended features is akin to getting Windows to read an ADFS floppy. Or 
> an ext# one, for that matter.
>
>
> Interestingly enough, the RISC OS filetype (BBC load/exec) does not seem 
> to be part of the official Zip specification. Was this an omission on 
> the part of Acorn/RISC OS coders, or has it been forgotten?
>     http://www.pkware.com/documents/casestudies/APPNOTE.TXT
>
> Thanks to Kevin Bracey, this information is a documented part of the 
> gzip format:
>     http://www.gzip.org/format.txt
> but, of course, this doesn't mean that:
>     a. A PC gzip program will support Acorn extensions
> &  b. It would know what to do with them even if it did...
>
>
> Therefore, if you wish to extract metadata (load/exec/etc) with files in 
> a zip file, it makes sense to use a system that is actually capable of 
> handling such - namely a BBC itself or, for most cases, RISC OS (but 
> note that RISC OS can't do load/exec *AND* datestamp, not that the 
> datestamp matters in 99% of cases)...
>   
Or you could just ask someone who knows ....... :)

-- 
Michael Howard        mike at dewberryfields dot co dot uk
Lancashire
England