I'm trying to make a log viewer that updates in real time; while the game is running.
The game logs chat and system text to separate text files.
These log files can get very big. The system log is about 5MB at the moment.

What is the best way to grab new lines of text from a text file? (Note: New lines are added to the end of the file.)
Or
What is the best way to grab the last 30 lines of text from a text file? (I can just go through and do a quick line comparison using this method.)