From:	"Matthias Paul" <MPAUL AT ibh DOT rwth-aachen DOT de>
Organization:	IBH, RWTH-Aachen
To:	opendos AT mail DOT tacoma DOT net
Date:	Thu, 6 Mar 1997 15:08:42 GMT+0100
Subject:	Re: [opendos] OD case sensitivity
Reply-to:	Matthias DOT Paul AT post DOT rwth-aachen DOT de
Message-ID:	<2D00DB059D5@ibh.rwth-aachen.de>
Sender:	owner-opendos AT mail DOT tacoma DOT net

Hi!


[Environment is case-sensitive?]

> > OpenDOS is internally case-sensitive in environment operations.
> > 
> > When I've changed the 'set path=c:\opendos' to 'set PATH=c:\opendos' in 
> > dconfig.sys - everything went just OK.
> >
> > Conclusion: OpenDOS internally pays attention to the env. variable's case and 
> > programs that do 'getenv("PATH")' receive NULL. Or... what else could it be?

There is a great difference between the CONFIG.SYS pre-environment 
and its related SET= directive, and the later environment, to be used
in batchjobs...

The normal environment functions (batchjobs) are not case-sensitive, 
that is, if you set new environment variables, they will be upstringed
before they appear in the environment.  If you test on environment 
variables e.g. using IF "%var1%"=="%var2%" ..., both sides are 
upstringed.

However, the CONFIG.SYS SET= directive works very different:

- It does *not* upstring variables before putting them into the 
  pre-environment.
  
- It does not clear or overwrite already existing entries. 
  In fact, if you do:
  
   SET test=Hello
   SET test=World!
   SET test=
   SET path=c:\opendos
   
  the pre-environment will actually contain:
  
   test=Hello
   test=World!
   test=
   path=c:\opendos

  Some may call this a bug, but it's also a feature, if it's known...
  (Mind, that a pre-environment was introduced with DR DOS 6.0, long
  before MS-DOS 6.0 did it rather differently).
  
  Normally, when loading COMMAND.COM via SHELL = /P, it will parse 
  the pre-environment and create a master-environment from it,
  stripping out those doubled definitions, and so forth... 
  
  It will *not* upstring these strings!  When using these variables 
  in batchjobs, there won't be problems, since the variables will be
  upstringed before the test.  If you use your compilers runtime
  library functions, depending on your compiler, you need to test 
  for both, upcase and lowcase variants, which, of course, is not 
  very convenient.  You may patch your RTL (if I remember well, 
  Borland/Turbo Pascal libraries upstring the environment 
  internally).  However, you always need to upstring the resulting 
  string (and always had to do this in the past).
  
  4DOS & NDOS do not evaluate the pre-environment, when they build
  the master-environment from it.  They just take it over.  
  So, strange side effects appear with these command processors, 
  if you don't upstring all your CONFIG.SYS SET= directives.
  
  To avoid some of the problems, 4DOS & NDOS have with DR DOS style
  pre-environments, you should insert:
  
   IF "4"=="%@Eval[2+2]%" c:\opendos\command.com /C EXIT
   
  at the beginning of your AUTOEXEC.BAT file.  This lets COMMAND.COM
  do some changes in the kernel structures, that 4DOS/NDOS won't 
  do, but that are required for optimal stability, e.g. closing 
  the pre-environment.  Of course, these are items, that should be
  added to 4DOS, but since we don't have the sources, JP has to do 
  it themselfs.
   
  For more details refer to Caldera's OpenDOS mailing list archive, 
  or my comprehensive tips & tricks document NWDOSTIP.TXT (from 
  MPDOSTIP.ZIP).


[Spaces in environment variables]
 
> In addition, the SET command has something wierd about it.
> 
> My SET BLASTER line used to read thus:
> 
>     SET BLASTER = A220 I7 D1 T4
> 
> But numerous programs fell over and said that the soundcard was gone.
> A lot of fiddling and recompiling later, I discovered that it would only
> work if it read:
> 
>     SET BLASTER=A220 I7 D1 T4
> 
> If you put spaces in it, getenv("BLASTER=") returned NULL.
> 
> This never happened with DRDOS.
> 
Yes, there were some fixes with the Novell DOS updates, that 
apparently cannot yet be found in OpenDOS.  Install the latest 
Novell DOS update on your OpenDOS system, or don't use spaces 
before and directly after the equal sign.  Also, don't use 
spaces at the end of the value, for example, if you would do:

 SET test=Hello World! > \dev\nul
                      ^---- don't set spaces here!!!
               ^---- this space should (and will) remain!!!
        ^^^--- spaces may be stripped of or not, depending on 
               your implementation
               
Novell DOS/OpenDOS (and MS-DOS before 7) won't have problems 
with these, since they strip off pending spaces, but MS-DOS 7 
does not!!!

Bye,

 Matthias
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