How to delete all lines found in another txt document

[CookieXD]

I have one document called “source.txt” and one called “delete.txt”.
I would like to delete every line that is in “delete.txt” from “source.txt”.
That process should be easily repeatable, because I will have to do that many times…

Thanks a lot for your help!

[guy038]

Hello, @cookiexd and All,

Here is an easy work-around :

• Open your source.txt file, in Notepad++

• At the end of source.txt file, add a new line beginning with, at least, three = equal symbols

• Then, append the contents of the delete.txt file, after the line =====...

• To end, add an empty line, at the very end of the file ( IMPORTANT )

• Now, open the Replace dialog

• SEARCH (?s-i)^((?-s).+\R)(?=.*^====+\R.*^\1)|^=+\R.+

• REPLACE Leave EMPTY

• Tick the Wrap around option

• Select the Regular expression search mode

• Click, once, on the Replace All button

• Save the modifications of your Source.txt file

---

Notes :

• First, the in-line modifiers (?s-i) forces, by default, the regex engine :

  • To acts in a sensitive case way (?-i)

  • To consider the regex symbol . as standing for any single character, even an EOL one (?s)

• Now, this search regex contains two alternatives, separated with the alternation symbol | :

  • In the first alternative ^((?-s).+\R)(?=.*^====+\R.*^\1) :

    • The part ((?-s).+\R) matches any non-null range of standard characters, due to the (?-s) modifier, followed with its line-break \R ( so, a complete line ! ) and stores it as group1 due the outer parentheses

    • But… ONLY IF  followed with the same line \1, somewhere, further on, after the separator line ===== ..., due to the look-ahead construction (?=.*^====+\R.*^\1)

  • In the second alternative ^=+\R.+, when all initial lines of Source.txt file are processed :

    • The part ^=+\R matches the complete separator line ===..., with its like-break

    • Then, the part .+ selects all the subsequent characters, even EOL ones, after this separator line, till the very end of file

• Whatever the alternative selected, the matched contents are simply deleted as the Replace zone is empty

Best Regards,

guy038