highlight differences between 2 strings

[diridam]

Hello,

I want to compare new thread titles with titles that i already have in dbase and if the new thread title has 4-6 simmilar words with one from the dbase it should show me both titles for comparison.

To take as a basic example: "this is a string" and "this is a big string bicaboo".

What`s the best way to compare the two strings ?

I`ve tried methods with strstr, str_pos, etc and no success