I humbly ask the Monks for their sage advice.

Well, I have a project that requires me to: parse a PDF file, add some content inside the file, then out put the file for viewing on a browser that has Adobe Acrobat reader installed. I searched the net. I found the great pdflib library but found out that it would cost me $1000 to get a licence for their PDI library that would allow me to parse the PDF then manipluate it. So, I searched some more. I found Panda PDF project that seemed to fit the bill. I downloaded the source then compiled into a Windows DLL since that is the system that I am using. I was going to use ActivePerl's Win32::API to call into the dll to access the functions and allow me to complete this project.

At first, it seemed to work. I needed to call a function that takes two char *. I read the manual for Win32::API. I found out that you need to pack the variables to pass into the function if they are pointers. Here is some sample code to show you what I mean:

use Win32::API;

$panda_init = Win32::API->new("c:\\temp\\panda",
               "panda_init",
               [],
               V);

$panda_init->Call();

$panda_open = Win32::API->new("c:\\temp\\panda",
                  "panda_open",
                  [P, P],
                  P);

$filename = pack("p", "dd.pdf");
$mode = pack("p", "w");

$panda_open->Call($filename, $mode);

[download]

When I did this it returned "Unknown file mode handed to panda." Now I looked in the docs and the source. The only supported file mode right now is "w". Although, it always returns this error no matter what character I pack.

Does anyone have experience with Win32::API enough to give me some clues? It is probably my pack but I cannot be sure. I am about to go hack the code to see what the function thinks it is receiving but I wanted to know if anyone has encountered this before I start.

Many many thanks in advance!

In reply to Pack and Win32::API by cyocum

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