Find duplicates and delete all in notepad++

Question

I have multiple email addresses. I need to find and delete all (including found one). Is this possible in notepad++?

example:[email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected],

I need results back like

[email protected], [email protected], [email protected], [email protected], [email protected], [email protected],

How to do in notepad++?

Answer 1

If it is possible to change the sequence of the lines you could do:

1. sort line with Edit -> Line Operations -> Sort Lines Lexicographically ascending
2. do a Find / Replace:
   • Find What: ^(.*\r?\n)\1+
   • Replace with: (Nothing, leave empty)
   • Check Regular Expression in the lower left
   • Click Replace All

How it works: The sorting puts the duplicates behind each other. The find matches a line ^(.*\r?\n) and captures the line in \1 then it continues and tries to find \1 one or more times (+) behind the first match. Such a block of duplicates (if it exists) is replaced with nothing.

The \r?\n should deal nicely with Windows and Unix lineendings.