RegEx/ANSI/Underline.regex.txt

# Matches ANSI Underline/DoubleUnderline Start or Underline End
\e # An Escape
\[ # Followed by a bracket
(?>
  (?<UnderlineStart>4m) # 4m starts underline
  |
  (?<DoubleUnderlineStart>21m) # 21m start a double underline
  |
  (?<UnderlineEnd>24m) # 24m stops underline
)