Regex to exclude an entire line match if certain characters found

user_5516578 0
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I'm stuck on the cleanest way to accomplish two bits of regex. Every solution I've come up with so far seems clunky.

Example text 
Match:    Choose: blah blah blah 123 for 100'ish characters, this matches

NoMatch:  Choose: blah blah blah 123! for 100'ish characters?, .this potential match fails for the ! ? and .

The first regex (?:^\w+?:)(((?![.!?]).)*)$ needs to:

  • Match a line containing any word followed by a : so long as !?. are not found in the same line (the word: will always be at the beginning of a line)
  • Ideally, match every part of the line from the example EXCEPT Choose:. Matching the whole line is still a win.

The second regex ^(^\w+?:)(?:(?![.!?]).)*$ needs to:

  • Match a line containing any word followed by a : so long as !?. are not found in the same line (the word: will always be at the beginning of a line)
  • Match only Choose:

The regex is in a greasemonkey/tampermonkey script.

tampermonkey greasemonkey javascript regex
3 Answers

Does this do what you want?

(?:^\w+:)((?:(?![!?.]).)*)$

What makes you feel that this is clunky?

    (?: ... )  non-capturing group
    ^          start with
    \w+:       a series of one or more word characters followed by a :
    ( ... )$   capturing group that continues to the end
    (?: ... )* non-capturing group, repeated zero or more times, with
    (?! ... )  negative look-ahead: no following character can be
    [!?.]      either ?, ! or .
    .          followed by any character
user_19275890

Use

^\w+:(?:(?!.*[.!?])(.*))?

See proof.

EXPLANATION

NODE                     EXPLANATION
--------------------------------------------------------------------------------
  ^                        the beginning of the string
--------------------------------------------------------------------------------
  \w+                      word characters (a-z, A-Z, 0-9, _) (1 or
                           more times (matching the most amount
                           possible))
--------------------------------------------------------------------------------
  :                        ':'
--------------------------------------------------------------------------------
  (?:                      group, but do not capture (optional
                           (matching the most amount possible)):
--------------------------------------------------------------------------------
    (?!                      look ahead to see if there is not:
--------------------------------------------------------------------------------
      .*                       any character except \n (0 or more
                               times (matching the most amount
                               possible))
--------------------------------------------------------------------------------
      [.!?]                    any character of: '.', '!', '?'
--------------------------------------------------------------------------------
    )                        end of look-ahead
--------------------------------------------------------------------------------
    (                        group and capture to \1:
--------------------------------------------------------------------------------
      .*                       any character except \n (0 or more
                               times (matching the most amount
                               possible))
--------------------------------------------------------------------------------
    )                        end of \1
--------------------------------------------------------------------------------
  )?                       end of grouping
user_113298900

For the first pattern, you could first check that there is no ! ? or . present using a negative lookahead. Then capture in the first group 1+ word chars and : and the rest of the line in group 2.

^(?![^!?.\n\r]*[!?.])(\w+:)(.*)$
  • ^ Start of string
  • (?! Negative lookahead, assert what is on the right is not
    • [^!?.\n\r]*[!?.] Match 0+ times any char except the listed using contrast, then match either ! ? .
  • ) Close lookahead
  • (\w+:) Capture group 1, match 1+ word chars and a colon
  • (.*) Capture group 2, match any char except a newline 0+ times
  • $ End of string

Regex demo

For the second part, if you want a match only for Choose:, you could use the negative lookahead only without a capturing group.

^(?![^!?.\n\r]*[!?.])\w+:

Regex demo

user_54249880
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