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Mail Archives: djgpp/1996/12/28/20:45:09

From: slstewart AT infocom DOT net
Newsgroups: comp.os.msdos.djgpp
Subject: Re: File utils are crap?
Date: Sat, 28 Dec 1996 14:52:17 -0600
Organization: InfoCom Networks, Houston, Tx
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To: djgpp AT delorie DOT com
DJ-Gateway: from newsgroup comp.os.msdos.djgpp

Eli Zaretskii wrote:
> Anyway, the /dev directory is special in both Unix and DOS as the place
> where the devices reside.  However, DOS handles it rather half-heartedly:
> it reserves it for the above function (since most DOS machines won't
> actually have it), but also lets you create a directory by that name.  For
> instance, assuming there is no \DEV directory on your disk C:, try these
> commands from the DOS prompt (DOS response is to the right of the arrow):
> 
>         truename c:\dev\con   ==> C:/CON
>         truename c:\dos\con   ==> C:\DOS\CON
>         dir c:\dev\con        ==> File not found
>         truename c:\dev\xyzzy ==> C:\DEV\XYZZY
> 
> See?  First, DOS knows that \dev\con is different from \dos\con.  Second,
> some (most) DOS commands and functions will fail for "\dev\con" (or
> "\dev\nul", or any other device name).  Third, DOS knows that "con" is a
> device name, but "xyzzy" is not.

Interesting...  What exactly is "truename"?  "truename /?" returned "Reserved command name"
I assume its really for subst's & such, though it does not appear in any DOS manual I own.
Are there other undocumented commands?

Also, DOS knows about devices regardless of what directory you put them in:
truename c:\heeba\jeeba\con  ==> C:/CON

Jim
[insert witty sig here]

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