Removing duplicate rows in vi?

Question

I have a text file that contains a long list of entries (one on each line). Some of these are duplicates, and I would like to know if it is possible (and if so, how) to remove

Answer 1

An alternative method that does not use vi/vim (for very large files), is from the Linux command line use sort and uniq:

sort {file-name} | uniq -u