Regular Expressions 101

(?s)applies the following effective flags to the remainder of the pattern: gs

s modifier: single line. Allows a dot to match line terminators

Positive Lookahead(?=\()

\(the literal ( (40₁₀ / 50₈ / 28₁₆)

Non-Capturing Group(?:(?=.*?$(?!.*?\1)(.*$(?!.*\2).*))(?=.*?\)(?!.*?\2)(.*)).)+?

+?repeats the group contents below at least once:

Positive Lookahead(?=.*?$(?!.*?\1)(.*$(?!.*\2).*))

.*?any character, repeated any number of times

\(the literal ( (40₁₀ / 50₈ / 28₁₆)

Negative Lookahead(?!.*?\1)

.*?any character, repeated any number of times

\1the text saved by group 1

Group 1(.*\)(?!.*\2).*)

.*any character, repeated any number of times

\)the literal ) (41₁₀ / 51₈ / 29₁₆)

Negative Lookahead(?!.*\2)

.*any character, repeated any number of times

\2the text saved by group 2

.*any character, repeated any number of times

Positive Lookahead(?=.*?\)(?!.*?\2)(.*))

.*?any character, repeated any number of times

\)the literal ) (41₁₀ / 51₈ / 29₁₆)

Negative Lookahead(?!.*?\2)

.*?any character, repeated any number of times

\2the text saved by group 2

Group 2(.*)

.*any character, repeated any number of times

.any character

.*?any character, repeated any number of times

Positive Lookahead(?=\1)

\1the text saved by group 1

Negated Character Class[^(]*

*matches any number of characters outside the set below:

(the literal ( (40₁₀ / 50₈ / 28₁₆)

Positive Lookahead(?=\2$)

\2the text saved by group 2

$end of string, or before its final line terminator

Global pattern flags

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

Detailed match information will be displayed here automatically.

Search reference

Regular Expression

(?s)(?=\()(?:(?=.*?\((?!.*?\1)(.*\)(?!.*\2).*))(?=.*?\)(?!.*?\2)(.*)).)+?.*?(?=\1)[^(]*(?=\2$)

New

Hey! ( (Look,) (ma!) ( (no) r(e(c(u(r)s)i)o)n!! ) ) Woooo
( Matches (can (even
span ) multiple ) 
lines! ) yeah buddy!!
(((((((()(((((()(((((( NO LIMITS!!! ))))))())))))()))))))))))))

Regular Expression

Extraction