[Oberon] Email and file names in ETH Oberon.

[peter at easthope.ca]

From:	peter at easthope.ca
Date:	Mon, 19 Dec 2022 18:48:37 -0800
> Mail.UIDLFile creates a file name such as 
> "UIDL.172.23.5.1.peterXeasthope.ca".
>
> That's 33 characters.  Mail.UIDLFile attempts to open or create a file 
> with that name but fails with any name longer than 27 characters.  Ie. 
> name + .Bak + 0x is limited to 32 characters.

What limits length of a file name?

OFS declares.
CONST ... LocalLength = 128;

OFSAosFiles restricts further.
CONST ... FnLength = 32;	(* includes 0X *)

For programming instruction in 1990 I imagine that limit sufficed.

Originally, a mail user id might have not included a domain name.  So 
a hypothetical file name in Mail would have been UIDL.172.23.5.1.peter
rather UIDL.172.23.5.1.peterXeasthope.ca.  So the 32 character limit 
worked for Mail.  =8~)  Now for many current mail user identities the 
attempted file name fails.  =8~(

Expedient solution: change OFSAosFiles to allow a longer file name.
CONST ... FnLength = 40;

Tolerable?  Objectionable?

More sophisticated solution: store the mail service information 
elsewhere from the file name.  Hypothetical possibility.

Current Mail
File name UIDL.172.23.5.1.peterXeasthope.ca containing this line.
UID16252-1329772258 UID77894-1329772258 UID98661-1329772258 

And file name UIDL.172.23.6.1.joXdoe.ca containing this line.
UID25216-2258132977 UID89477-2258132977 

etc.

Additional detail: in some cultures a human name can begin with X.
Replacement of @ with X can yield a failure.  =8~/

Hypothetical Simplification
File name UIDL containing these lines.
172.23.5.1.peter at easthope.ca UID16252-1329772258 UID77894-1329772258 UID98661-1329772258 
172.23.6.1.jo at doe.ca UID25216-2258132977 UID89477-2258132977 
etc.

Additional detail: replacement of @ with X is abolished.  =8~)

At least I should avoid documenting a broken MUA. =8~)

Thanks,                           ... P.L.


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