[PHP]Delete Duplicates in .txt

programming
1

Is there a quick and relatively easy way to go through a .txt file and delete lines that are duplicate? The structure is pretty much:


http://blog.digitalcarnival.com/
http://blog.digitalcarnival.com/
http://blog.digitalcarnival.com/about/
http://blog.digitalcarnival.com/about-the-library/
http://blog.digitalcarnival.com/current-functions/
http://blog.digitalcarnival.com/2007/02/25/new-writer/
http://blog.digitalcarnival.com/category/random/
http://blog.digitalcarnival.com/2007/02/25/new-writer/

Of course as you can see I threw in two duplicate as an example.