How to program a text search and replace in PDF files

Question

How would I be able to programmatically search and replace some text in a large number of PDF files? I would like to remove a URL that has been added to a set of files. I

Answer 1

The question is for a programmatic solution, but I will still share this free online tool which helped me mass replace text in some PDF files:

http://www.pdfdu.com/pdf-replace-text.aspx

I did not notice any ads or other modifications in the resulting PDF files after replacing the text.

I was not able to make the changes locally with the software I tried. I think the main problem was that I was missing the font used in the PDF and it did not work properly, even with Acrobat Pro. The online tool did not complain and produced a great result.