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From: ho@fergvax.unl.edu (Tiny Bubbles...)
Newsgroups: comp.sys.ibm.pc
Subject: Re: What files MUST be in the root directory?
Message-ID: <1477@unocss.UUCP>
Date: 17 Aug 89 15:18:52 GMT
References: <2120@infmx.UUCP>
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From article <2120@infmx.UUCP>, by aland@infmx.UUCP (Dr. Scump):
> In article <16741@ut-emx.UUCP> nather@ut-emx.UUCP (Ed Nather) writes:
> |I keep command.com in a directory I call "systm", and have the following
> |line in my config.sys file:
> |
> |shell=c:\systm\command.com  c:\systm /P /E:32
> |
> 
> Where is that second parameter (c:\systm) documented?  It sure isn't
> in the PC-DOS 3.3 manual (see pp. 4-42)  does it apply to earlier 
> versions of DOS only?  Is it undocumented?  Is it necessary?

Does it apply to earlier versions of DOS only?  No.  It's required for all.
COMMAND can't check argv[0], because argv[0] is stored after the end of the
environment (kludge!).  By definition, the top-level COMMAND knows that it
is the top dog by making sure its environment is NULL.  As such, no argv[0]
(starting path, for non 'C' hackers) can be stored or retrieved, unlike all
other programs under DOS 3.0+ which /can/ find their environments.

Is it undocumented?  As far as I'm concerned, everything in an IBM manual
is undocumented. :-)  As for whether it's in the manual, I'm not sure.  I
never read it if I want to know something important.  I may have read about
it on the net.

Is it necessary?  Yes.  Without it, your COMSPEC will be set wrong (it will
point to the root directory, as COMSPEC=C:\COMMAND.COM) and you won't be
able to remove COMMAND from the root directory.
---
	... Michael Ho, University of Nebraska
Internet: ho@fergvax.unl.edu		USnail:  115 Nebraska Union
UUCP:	  !Im!not!sure!how...			 Lincoln, NE 68588-0461