Regular Expressions are super powerful, and are included in most programming languages.
Regardless of what programming language you use, regular expressions will make certain text processing tasks a breeze.
If you have ever looped through every character in a string of text searching for specific characters just stop and learn regular expressions.
You will be so glad you did.

Perl

http://perldoc.perl.org/perlrequick.html

First a really quick Perl tutorial.

What is Perl?

Perl is a great language for almost anything. The syntax is consice and Perl makes simple things simple and makes hard things possible or so the motto goes.
Perl is one of the best languages there is for manipulating text and also makes an excellent glue language because Perl allows you to choose your quote opperater, supports here documents, and has built in regular expressions.  Perl also has a bad reputation for looking like line noise for the same reasons listed above.

This is just a simple perl script that makes it easy to do svn diffs in kompare. Basically, just put it in your bin dir and then from your svn working dir you can just say svndiffr filename or svndiffr path/filename. The script will print out the svn log for the file and ask you for a revision. Enter the revision number you want to diff you working copy with and hit enter. Kompare will launch with the revision on the left and the working copy on the right so that changes are saved to the working copy.