How to delete all lines except lines which have a colon in the 4th column in Notepad++?

  • Ctrl+H
  • Find what: ^[^:]{4,}.*\R?
  • Replace with: LEAVE EMPTY
  • CHECK Wrap around
  • CHECK Regular expression
  • UNCHECK . matches newline
  • Replace all

Explanation:

^           # beginning of line
[^:]{4,}    # 4 or more any character that is not colon
.*          # 0 or more any character 
\R?         # any kind of llinebreak, optional

Screenshot (before):

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Screenshot (after):

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