How do I remove duplicates AND the originals from a list in Sublime Text 3?

Question

Edit > Permute Lines > Unique is great for removing duplicate from a list in Sublime Text. But what if I wanted to remove all matching results instead? For example:

james
james
bobby
mary
ann
ann

The above list of names would become:

bobby
mary

Because bobby and mary are the only names that only appear once.

Answer 1

If you don't mind your lines being sorted, you could do it like this:

1. Edit > Sort Lines
2. Find > Replace...
3. Ensure RegEx mode is on
4. Find What: (^.*$\n)\1+
5. Replace With: (blank)

Although, sorting wouldn't be necessary if all the duplicates are next to each other, as per your example. e.g. it would even work with the following:

james
james
bobby
mary
ann
ann
james
james
james

Note that this regex requires the last line to have a trailing newline character, if it is a duplicate, otherwise it won't find it.