[delphizip] Re: Span volume problems
- From: "Russell Peters" <russellpeters@xxxxxxxxxxx>
- To: <delphizip@xxxxxxxxxxxxx>
- Date: Sat, 7 Dec 2002 15:55:34 +1100
It should be possible to calculate the size of central directory and keep it
on last disk if it will fit on single disk (should not be a problem with
CDs!)
Would like to be able to split a zipfile into a number of (complete)
zipfiles of upto a given size - should not be too difficult, only rather
involved!
Russell Peters
http://www.users.bigpond.com/russellpeters/delphizip.html
----- Original Message -----
From: "James Turner" <james.d.h.turner@xxxxxxxxxxxx>
To: <delphizip@xxxxxxxxxxxxx>
Sent: Saturday, December 07, 2002 12:07 PM
Subject: [delphizip] Re: Span volume problems
> Surely, if the central directory is wholly on the last disk (this may be a
big if) only the last disk needs to be read in order to get a directory
listing. This can be established by reading the EndOfDir record and
comparing the values ThisDiskNo and CentralDiskNo (field names may vary).
The worst case scenario is that all disks between these two values need to
be read (in practice this should never be more than 2 disks).
>
> That said, the issue of extracting files across disk boundaries is an
interesting one. The most elegant way to solve this would be to create a
special stream type capable of prompting for disk changes, opening and
closing files, etc. (I have this in mind for some code of my own in the
future). However, I'm certainly not about to suggest that, given existing
code, it would be sensible to move in that direction.
>
> -- James Turner
> www.skaro.net
>
> PS
> Regarding file erasure (instead of format) on hard disks. I believe that
you should NEVER erase files on (or format) a hard disk.
>
>
>
>
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