title: How to find and replace text in a existing PDF file with PDFTK (or other command line application)
body: <p>I have on each page of my PDF document a line with this string:</p>
  
  <p><code>%REPLACE%</code></p>
  
  <p>Which I'd like to find and replace with another string.</p>
  
  <p>Does anyone know how to do this with some command line application such as PDFTK?</p>
  
  <p>This <a href="https://stackoverflow.com/questions/7746687/pdf-insert-a-line-of-text-into-an-existing-pdf-file">folk</a> gave me an important clue however I'd like something more direct.</p>
  
  <p>Thanks.</p>