search in pdf files for strings matching a regular expression

 Pdfgrep is a tool to search text in PDF files. It works similar to
 `grep'.
 .
 Features:
  - search for regular expressions.
  - support for some important grep options, including:
    + filename output.
    + page number output.
    + optional case insensitivity.
    + count occurrences.
  - and the most important feature: color output!