Using standard printing from windows

Using standard printing from windows

There are many applications where I don't really want to use the usual windows page print. Instead I want output to go directly to the printer using standard print i/o. It's actually a topic that is hard to find in any of the books on Windows, at least I've never found anything on it. But to my surprise I recently learned that standard (DOS/UNIX) printing is alive and well underneath windows. All we need to do is open a printer port and print to it.

If the printer is directly attached to the computer it's trivial. The method for obtaining a printer port when the printer is on the network isn't hard either.

The example below shows how I use the Windows NET USE command to re-direct LPT1 to a shared printer on an NT Server. The same technique applies for Novell networks with a slightly different syntax.

Try this out by creating a new MFC Form-based project. Put a button on the form and attach this code to it. You can actually print with only 3 lines of code:

FILE *fp = fopen("LPT1", "w");

fprintf(fp,"What's up, Doc?\n");

fclose(fp);

Instant print gratification!!

While the program is open it hogs the printer port. In my shop that isn't a problem but be aware of the effect on your windows spooled output.

*********************************************************

THE CODE

*********************************************************

// the headers for the conventional i/o routines

#include

#include

#include

using namespace std; // makes string and ofstream

// work without std:: qualifier

void CLineprtView::OnButton1()

{

// I could have used a CString instead of the buff[]

// but I wanted to show how this is used with lightweight

// ATL code and STD library

char buff[MAX_BUFF_SIZE];

// My printer is located on another server so I must re-direct the

// printer port. If the printer is directly attached this extra step

// is not needed.

// on my network the printer is published as \\GREEN\hp5annex

// All those back-slashes escape the backslash in the path name

if (PRINTER_IS_REMOTE)

{

system("NET USE LPT1 /d"); // free up the port

system("net use lpt1 \\\\green\\hp5annex");

}

// old fashioned file handle with

// old fashioned open of the printer port

FILE *ptr = fopen("LPT1","w");

// laser printer setup string

sprintf(buff,"\033E\033(s0p4102t1b16.66H\033&l1O");

fprintf(ptr,buff);

// old fashioned print

fprintf(ptr,"Who of late doth make a thimble.\n");

fprintf(ptr,"Is a lower bunk a status symbol??\n");

// old fashioned close

fclose(ptr);

// now the same thing with stream io

ofstream optr("LPT1", ios::out);

string str_text = "Hey Doc, Ain't this a print test from windows\n";

str_text += "with more lines to follow?\n";

optr << str_text << endl;

optr << "Quiet, wabbit. I'm conversing with my muse!!\n";

optr << "That's all folks." << "\f" << flush; // add a formfeed

// the printer connection is still open so close it

optr.close();

// drop the network link

if (PRINTER_IS_REMOTE)

{

system("net use lpt1 /d");

}

}

In practice I get printer path information from the registry on each machine, so the real live code is a little busier than this example, but not much.