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From: fisher@sc2a.unige.ch (Markus Fischer)
Newsgroups: comp.os.msdos.apps
Subject: Re: DBASE refuses to send CHR(0) to printer.
Message-ID: <271@sc2a.unige.ch>
Date: 18 Oct 90 13:40:17 GMT
References: <2292@wn1.sci.kun.nl>
Distribution: comp
Organization: University of Geneva, Switzerland
Lines: 54

In article <2292@wn1.sci.kun.nl>, vlsi3@erato.cs.kun.nl (vlsi cursus) writes:
> Hi readers,
> 
> I'm writing a small database program using Dbase, which uses the printer.
> Therefore I need to send the null character, because it is part of a
> printer control code. It is used in the following context:
> SET PRINT ON
> ?? ....+CHR(0)+..
> |
> SET PRINT OFF
> 
> The problem is, the printer doesn't receive the null character (I checked
> it with a hex-dump). Does anyone know what how to do it in another way??
> 
> BTW: it is dbase 3+.
> 

I just tried it myself, and it really doesn't work!

One way around this would be to use an external program to send the null
character, or even better, any control code to the printer.  Example (TC):

#include <stdio.h>
main()
{
   FILE *prn = fopen("PRN","wb");  /* open DOS' PRN */
   fprintf(prn, "\0");             /* send the code */
}

something more technical like

#include <io.h>
main()
{
   _write(4, "\0", 1);   /* (binary) write one byte to file handle 4 (prn?) */
}

works also.

In dBASE, you call the external program with
 run <prog> [parameters]

If your dBASE program uses the external very often, you could try to convert
it to a "binary" (a *.BIN produced by EXE2BIN, same format as a *.COM), and
use it as:
 load <prog>
 call <prog> [with <param>]
but to tell the truth, I couldn't get it to work, even with the mose elementary
program like "printf("Hello dBASE!\n")".  I guess I'm missing some point, and
as I don't have any technical docs...

Sorry for the sketchy information, hope it helps some.

Markus Fischer, Dpt. of Anthropology.