Hi all,

Below is a copy of the printer class that I am using to send output to the
printer. I have have one major problem with this code, if the printer is not
on-line then the program bombs and MS-Dos responds by saying that the printer
is not ready.

So I am looking for some c/c++ code to add to this code below that will help
me determine if the printer is on-line or not. Please tell me is there a
header file and function that I can use to check for the i/o status of the
printer.

This program has been designed to run on an Ms-Dos machine but I want to be
able to port it to Unix or any other platform, so I would like to take out
the machine specific code below.

The printer used is an Epson LX-400
The compiler is borland C++ 3.1

Any help in sorting out this problem would be greatly appreciated.

Thank you.


>------------<

#include <iostream.h>
#include <fstream.h>

#define TRUE  1
#define FALSE 0

class Printer {
     int counter;
     fstream prnts;
  public:
     Printer ();
     virtual ~Printer();
     virtual char Ok();
     virtual char Print( char *);
     virtual char Print( char  );
};

Printer::Printer()
{
 counter = 0;
 prnts.open("prns",ios::binary|ios::out);
}

Printer::~Printer()
{
 prnts.close();
}

char Printer::Ok ()
{
 unsigned char retval = 0;

// The code below is specific for the ms-dos machine.
 asm {
 mov ah,02;
 mov dx,0000;
 int 0x17;
 mov retval, ah;
 }
 retval = retval << 4;
 retval = retval >> 7;
 return !retval;
}

char Printer::Print(char *temp)
{
 char retval = TRUE;
 if (!Ok())
 retval = FALSE;
 else {
 char tmp = strlen(temp);
 prnts << temp;
 prnts.flush();
 counter += tmp;
      }
 return retval;
}

char Printer::Print(char test)
{
 char retval = TRUE;
 if (!Ok())
 retval = FALSE;
 else {
 prnts.put (test);
     if (Ok() )
 prnts.flush();
 counter++;
      }
 return retval;
}

>---
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| Louis Rogers                 Internet: lrogers@cs.uct.ac.za         |
| Fidonet:     5:7102/116.13             rgrlou02@uctvax.uct.ac.za    |
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