Xtykutl

Is it possible to write a regex which is matching to "findme" but doesn't match if the line contains "black" or "red" or "yellow" words?

Possible regex: (?!black|red|yellow)findme

excluded words: yellow , black , red

Test lines:

findme     (OK)

xyz        (NOT!)

XYZfindmeXYZ     (OK)

somethingelseFINDMEsome_thingelse     (OK)

BLACK_ findme       (NOT !)

BLACK findme       (NOT !)

XyBlacK findme xyz_xy       (NOT !)

xy findme RED           (NOT !)

yellow__ findme _xy        (NOT !)

_xy_ findme _something    (OK)

You can use the following regex:

^(?!.*(?:black|red|yellow)).*(findme)

Demo: https://regexr.com/42r4q

Details:

• 
  ^ - matches start of the string


• 
  (?!) - negative lookahead


• 
  .* - Match any character (except newlines) 0+ times


• 
  (?:) - non-capturing group


• 
  black|red|yellow - matches 'black', 'red' or 'yellow'


• 
  findme - matches 'findme' string

Flags:

• 
  g - global


• 
  i - case-insensitive


• 
  m - multiline

Use a negative look ahead, anchored to start, for the unwanted terms:

^(?i)(?!.*(black|red|yellow)).*findme

See live demo passing all your tests.

(?i) means “ignore case"
(?!...) is a negative look ahead (asserts without consuming that the expression is not found)