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.
