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From: Ken Hagan (k.hagan_at_[hidden])
Date: 2002-01-25 11:41:39


----- Original Message -----
From: "George A. Heintzelman" <georgeh_at_[hidden]>
To: <boost_at_[hidden]>
Sent: Friday, January 25, 2002 3:40 PM
Subject: Re: [boost] Re: the first version of abstract path manipulation
class (interface)

> VMS is definitely really weird. A typical fully-specified VMS filename
> might look something like this:
>
> DISK$SCRATCH:[GEORGE.PROJECT1.DAT]BIG_DATA_FILE.NTP;5
>
> The general format is:
>
> Device:[directories.dot.separated]filename.extension;version_number

Thanks. My memory certainly didn't extend to that.

> I have always thought that handling VMS, without losing the ability to
> use a significant VMS-specific feature, would be a real challenge to
> any pathname utility. Most of the ports of Unix programs that I have
> seen ignore version numbers completely, and are rather clumsy around
> extensive use of logical devices and logical names.

Even MS-DOS has logical devices (mapped and subst-ed drive letters).
However, they wouldn't affect parsing. The point of creating a logical
device name is to abstract away the physical device details.

WinNT also has named streams, such as "MyFile.txt:stream". Most
programs don't support them. (The command prompt used to, but
I've just tried it and it no longer recognises it.) These were
introduced to support the Mac's resource and data forks. I suppose
that means the Mac also has its little twists.

Mainframe OSes have yet more ways of naming files, not all of which
have any concept of a directory. Someone must maintain a list of
file system syntaxes. I expect a question on comp.lang.c.moderated
would elicit a few pointers. (C rather than C++ to maximise the
number of people still using older architectures.)


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