How to find lines that contain 3 specific characters?

Question

Is there a way to remove lines that contain three specific characters?

For example the characters should be U S E

So for these lines, it should just remove USER AND UDES:

USER
USAD
UDES

Thanks

Answer 1

• Ctrl+H
• Find what: ^(?=.*U)(?=.*S)(?=.*E).+\R?
• Replace with: LEAVE EMPTY
• TICK Match case
• TICK Wrap around
• SELECT Regular expression
• UNTICK . matches newline
• Replace all

Explanation:

^           # beginning of line
(?=         # positive lookahead, make sure we have after:
    .*          # 0 or more any character but newline
    U           # letter uppercase U
)           # end lookahead
(?=.*S)     # same as above for letter S
(?=.*E)     # same as above for letter E
.+          # 1 or more any character but newline
\R?         # any kind of linebreak, optional

Screenshot (before):

Screenshot (after):