X-Authentication-Warning: delorie.com: mailnull set sender to opendos-bounces using -f
Message-ID: <000001c193fc$3b6c9ce0$c03dfea9@atlantis>
From: "Matthias Paul" <Matthias DOT Paul AT post DOT rwth-aachen DOT de>
To: <opendos AT delorie DOT com>
References: <Pine DOT GSO DOT 4 DOT 33 DOT 0201022147220 DOT 1001-100000 AT jedi DOT apana DOT org DOT au>
Subject: Re: on a related note
Date: Thu, 3 Jan 2002 03:08:02 +0100
Organization: University of Technology, RWTH Aachen, Germany
MIME-Version: 1.0
Content-Type: text/plain;
	charset="iso-8859-1"
X-Priority: 3
X-MSMail-Priority: Normal
X-Mailer: Microsoft Outlook Express 5.50.4522.1200
X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4522.1200
Content-Transfer-Encoding: 8bit
X-MIME-Autoconverted: from quoted-printable to 8bit by delorie.com id g032Cmd17118
Reply-To: opendos AT delorie DOT com

On 2002-01-02, DONALD PEDDER" <jims_son AT jedi DOT apana DOT org DOT au> wrote:

>    I wrote a batch file to call several programs (this is with MS-DOS, as
> that is what is on the computer I'm using it on - I don't have DR-DOS on
> it yet). For some reason the batch-file ceases to execute after the first
> program has run, which kinda defeats the purpose of it. :-)

I assume you just called the external program by specifying its
name without extension and forgot to prepend the call with "CALL".
If this would be the case, the batch will be returned control unless
you (at any time later) used a batch file to call the original
external in a different place. Example:

...
myextprg params...
REM Batch execution will come back here if myextprg is a .COM
REM or .EXE file, but not if it is a .BAT file. Check %PATH%!
...

To be replaced by this:

...
CALL myextprg params...
REM Batch execution will come back here even if myextprg
REM is actually a batch file.
...

or even better:

...
@CALL myextprg params...
REM Batch execution will come back here even if myextprg
REM is actually a batch file.
...
    
Remember that the same applies to any recursive external
references in the myextprg.bat file.
As a general rule of thumb, you should keep the good habit
to always pre-pend references to externals with CALL, no
matter, if this is required at the time you write the
batch job. These are difficult to find mistakes when you
have to maintain a large set of interwoven batchjobs later.

If you cannot guarantee this for all the files involved,
an alternative that will also work with pre-DOS 3 issues
is to use "COMMAND.COM /C" or better "%COMSPEC% /C" instead
of the "CALL". This will always return, but is slower and
will temporarily consume some 5 - 10 Kb for a secondary
instance of the command interpreter, while CALL is handled
internally in the original copy of COMMAND.COM.

Hope it helps,

 Matthias

-- 

 <mailto:Matthias DOT Paul AT post DOT rwth-aachen DOT de>; <mailto:mpaul AT drdos DOT org>
 http://www.uni-bonn.de/~uzs180/mpdokeng.html; http://mpaul.drdos.org