PDFTK outputs a corrupt pdf to the browser

Question

I am using PHP to fill a PDF form, which I would like to output to the browser. I am using the function found here: http://koivi.com/fill-pdf-form-fields to create an xfdf file. I then use the following code to fill the form and output the resulting file to the browser:

header('Content-type: application/pdf');
header('Content-Disposition: inline; filename="filename.pdf"');
passthru("/usr/local/bin/pdftk forms/pdf_form.pdf fill_form filename.xfdf output - ");

When I open the PDF created from the browser, I get an error from adobe pdf reader that says "Adobe Reader could not open 'filename.pdf' because it is either not a supported file type or because the file has been damaged (for example, it was sent as an email attachment and wasn't correctly decoded)." Opening the same PDF in another reader does not give the error, but my users will be using acrobat.

By way of contrast, if I change my code to the following:

header('Content-type: application/pdf');
header('Content-Disposition: inline; filename="filename.pdf"');
passthru("/usr/local/bin/pdftk forms/pdf_form.pdf fill_form filename.xfdf output filename.pdf ");

I can open, read and edit the resulting PDF from the tmp folder. It seems that the 'output - ' option is somehow corrupting the PDF.

My question is this: Am I doing something wrong? Is there some piece of code that I am missing or a better way to accomplish this?

• PHP version: 5.3.19; Server OS: Mac OS 10.7.5; Client OS: Mac OS 10.7.5; Browsers tested: Chrome, FireFox; Readers tested: Adobe PDF Reader, Preview; PDFTK version: 1.4.5

Answer 1

Use <?php ... for instance without final ?> so you are sure no final whitespace, especially newline is written after the PDF output.