Regular Expressions 101

Non-Capturing Group(?:\G(?!\A)|:keyword_start:\s)

1st Alternative\G(?!\A)

\Gstart of current search

Negative Lookahead(?!\A)

\Astart of string

2nd Alternative:keyword_start:\s

:keyword_start:the literal text :keyword_start: (case sensitive)

\sany whitespace character

Non-Capturing Group(?:(?!:keyword_end:)\S+\s)*+

*+repeats the group contents below any number of times:

Negative Lookahead(?!:keyword_end:)

:keyword_end:the literal text :keyword_end: (case sensitive)

\S+any non-whitespace character, repeated at least once

\sany whitespace character

\Kresets the starting point of the reported match. Any previously consumed characters are no longer included in the final match

\s+any whitespace character, repeated at least once

Global pattern flags

g modifier: global. Finds all matches instead of stopping after the first

Detailed match information will be displayed here automatically.

25 tokens

Regular Expression

(?:\G(?!\A)|:keyword_start:\s)(?:(?!:keyword_end:)\S+\s)*+\K\s+

New

This is a teststring ... :keyword_start: this is    the content    with double spaces :keyword_end: more text ... :keyword_start: this is the second   content    with double spaces :keyword_end: ... more tex

Regular Expression

Substitution