Subj : Re: Fmail Compression and Decompression
To   : Michiel van der Vlist
From : Wilfred van Velzen
Date : Mon Aug 21 2023 04:25 pm

Hi Michiel,

On 2023-08-21 14:30:53, you wrote to me:

WV>> For unpacking you need some kind of detection mechanism.

MvdV> That could be circumveneted by allowing the user to not only specify a
MvdV> compression method for outgoing mail but to als allow the user to specify a
MvdV> decompression method per node. To be used if autodetection fails.

I don't think that is a good idea...

MvdV> Or let the user specify the "fingerprint" for a custom compression
MvdV> method. From what I remember it is enough to look at the first two
MvdV> bytes of a compressed file. Fingerprint for ZIP is "PK"

The current detection mechanism in FMail uses up to 7 bytes for the detection, and an offset into the file for some archivers...

MvdV> OTOH... It may not be worth the effort this late in the game...

I don't think so either.

WV>> Which incase of FMail is left to the "General Unpack Shell". Which is
WV>> fed everything that is unknown to FMail itself...

MvdV> GUS... I never used it myself, never had a need for it. It is still under
MvdV> development or is it abandonware like so many other FTN stuff?

I can't remember using it. I don't think it's still under development. A quick google only gives me this: https://archive.org/details/GUS_170_ZIP so 1993...

Bye, Wilfred.

--- FMail-lnx64 2.2.0.0
* Origin: FMail development HQ (2:280/464)