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.

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