I have a list of e-mail addresses and I would like to replace all duplicates with a single copy (\1), but I'm not sure what regex is involved to find each e-mail address. >.<
Use TextFX/Tools/Sort and select output UNIQUE.
Ah, thank you - but is it possible without using the TextFX plugin? I also don't appear to have any positive response from selecting such an option. I was using a program called replace pioneer, but a regex alternative would be greatly beneficial for personal enrichment.
If you want to remove duplicate lines, when several adjacent lines are identical, it can be done with the following regex: replace "^(.+\r?\n)\1+" by "\1". It requires better regex support than what is currently included in Notepad++, just download the binary of this recent patch https://sourceforge.net/projects/notepad-plus/forums/forum/331753/topic/4987428 .
Thank you for your help!
You could use Text Crawler's Extract and one of its Search Pad features.
Just Extract all items from the list (.* or specifiy the email address regex).
Then in the Scratch Pad choose to remove duplicate items.
Add it "Edit -> Line Operations -> Remove duplicates of lines"
You can use "Scripting.Dictionary"