This is probably a pretty newbie-ish question, but I've tried everything I can think of so far for this problem, and I've decided to beg for the help of the great monks. ;)

Basically what I'm doing is, I want to have a function that will take two strings and compare them, returning a percentage of differences between string A and string B. This is pretty easy if you assume they will be the same length and simply want to compare character by character, but I'll be working with strings of varying lengths.

For example, if string A is "this is a really annoying piece of text" and string B is "a really annoying piece of text" a character-by-character comparison would work very poorly for indicating how similar the strings are for the most part.

Anyway, I was wondering what might be good approaches for doing this sort of comparison, so that I can get fairly accurate ideas of how one string relates to another in this project I'm working on.

Thanks in advance for any help