Thread: Print pdf to network printer

Hi guys,

Looking for some help again... I've searched the forums and I've come as far as this:

Code:

#include <stdio.h>
#include <conio.h>
#include <stdafx.h>

int main(void)
{
  char ih;
  FILE *fp=fopen("lpt4", "w"), *fpin=fopen("test.pdf", "rb");
  char flin[256];

  if ( fp == NULL )
  {
    perror( "No printer" );
    getch();
    exit( 1 );
  }
	
  while((ih=fgetc(fpin))!=EOF)
  {
    fputc(ih,fp);
    putch(ih);
  }
  getch();
  return 0;
}

with the examples I've found. This bit of code doesnt print anything though. It works fine for a text file (because the fputc bit sends every single character to the printer) but it doesnt work for a pdf or other non-text file...
Does anyone have an idea of what to do to make this work?

I've also tried

Code:

fprintf(fp, "test.pdf");

But that results in a nice A4 paper with the text string "test.pdf" on it


Hope you can help, thanks a lot in advance!

René

- Alternatively, is it possible to execute a batch-like line:

type test.pdf >lpt4

from a C program?


- Second alternative: I could create a batch file with that line and use

Code:

system("tralala.bat");

But the filename to print should be variable.... is there a possibility to pass a variable to a batch file?




EDIT: I could of course create a batch file like this:

Code:

*fp=fopen("tralala.bat", "w");
fprintf(fp,"type %s >lpt4", pdf_file);

and then execute it with the system line above... this would be a solution, but of course the best would be if I needn't use a batch file!

Thanks for any help

Originally Posted by SKeane

Have you tried opening the printer as a binary file, like you open your PDF file?

Hadn't tried that before no. Just did it, and it doesn't work either It prints some weird characters on the screen and the printer just doesnt respond.

> but it doesnt work for a pdf or other non-text file...
I'm assuming you do get a whole bunch of gibberish which begins with "%PDF".

Printers have many different control languages in addition to understanding plain text. PDF isn't one of them.

Postscript on the other hand is.

So at the very least you need to read the PDF file, figure out what all those bits and bytes mean, create some kind of page "layout" of each page in the PDF document, then send the result to the printer.

>> but it doesnt work for a pdf or other non-text file...
>I'm assuming you do get a whole bunch of gibberish which begins with "%PDF".
yep

>So at the very least you need to read the PDF file, figure out what all those bits and bytes mean, create some kind of page "layout" of each page in the PDF document, then send the result to the printer.
Hmm.. how about: "no thanks"? :P

I've implemented the batch "strategy" and that works perfectly! Thanks for your help though!

The batch actually works? I'm astonished.

Err, but I'm sure you implementation is too complicated. This would suffice:

Code:

#define CMD_TEMPLATE "type %s > lpt4"
char *cmd = malloc(strlen(CMD_TEMPLATE) + strlen(pdf_file) + 1);
sprintf(cmd, CMD_TEMPLATE, pdf_file);
system(cmd);
free(cmd);

Originally Posted by CornedBee

The batch actually works? I'm astonished.

Err, but I'm sure you implementation is too complicated. This would suffice:

Code:

#define CMD_TEMPLATE "type %s > lpt4"
char *cmd = malloc(strlen(CMD_TEMPLATE) + strlen(pdf_file) + 1);
sprintf(cmd, CMD_TEMPLATE, pdf_file);
system(cmd);
free(cmd);

Nice idea, the template defining..! I actually didn't even know %s was allowed and working in defines! What about the free(cmd); by the way? Does system(); automatically request memory?

I actually didn't even know %s was allowed and working in defines!

It's just a string. It doesn't "work" in defines. It's the *printf family of functions that make it work.

The free() is to counter the malloc() I have earlier.

Originally Posted by CornedBee

It's just a string. It doesn't "work" in defines. It's the *printf family of functions that make it work.

Yeah, that I understood

Originally Posted by CornedBee

The free() is to counter the malloc() I have earlier.

D'oh, missed that malloc then!


Thanks