regex101: PCRE (Legacy) Match Workspace

^start of line

(?3)*calls group 3 as a subroutine, repeated any number of times

\)*the literal ) (41₁₀ / 51₈ / 29₁₆) , repeated any number of times

$end of line

Group 1(()((?(2)|\)*)($(?1)*($|$)|0|"[^\n"]*.?|(1|(2|(3|4(?3))(?3))(?3))(?3))))?

?repeats the group contents below at most once:

Group 2() — does not consume characters

Group 3((?(2)|\)*)($(?1)*($|$)|0|"[^\n"]*.?|(1|(2|(3|4(?3))(?3))(?3))(?3)))

Condition(?(2)|\)*)

Uses the first branch if group 2 matched

If the condition is true, match this branch: — matches an empty string

Otherwise, match this branch:\)*

\)*the literal ) (41₁₀ / 51₈ / 29₁₆) , repeated any number of times

Group 4($(?1)*($|$)|0|"[^\n"]*.?|(1|(2|(3|4(?3))(?3))(?3))(?3))

1st Alternative$(?1)*($|$)

\(the literal ( (40₁₀ / 50₈ / 28₁₆)

(?1)*calls group 1 as a subroutine, repeated any number of times

Group 5(\)|$)

1st Alternative\)

\)the literal ) (41₁₀ / 51₈ / 29₁₆)

2nd Alternative$

$end of line

2nd Alternative0

0the literal 0 (48₁₀ / 60₈ / 30₁₆)

3rd Alternative"[^\n"]*.?

"the literal " (34₁₀ / 42₈ / 22₁₆)

Negated Character Class[^\n"]*

*matches any number of characters outside the set below:

\na line-feed (newline) character (ASCII 10)

"the literal " (34₁₀ / 42₈ / 22₁₆)

.?optionally matches any character (except for line terminators)

4th Alternative(1|(2|(3|4(?3))(?3))(?3))(?3)

Group 6(1|(2|(3|4(?3))(?3))(?3))

1st Alternative1

1the literal 1 (49₁₀ / 61₈ / 31₁₆)

2nd Alternative(2|(3|4(?3))(?3))(?3)

Group 7(2|(3|4(?3))(?3))

1st Alternative2

2the literal 2 (50₁₀ / 62₈ / 32₁₆)

2nd Alternative(3|4(?3))(?3)

Group 8(3|4(?3))

1st Alternative3

3the literal 3 (51₁₀ / 63₈ / 33₁₆)

2nd Alternative4(?3)

4the literal 4 (52₁₀ / 64₈ / 34₁₆)

(?3)calls group 3 as a subroutine

Global pattern flags

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

m modifier: multiline. Causes ^ and $ to match the start and end of each line, not only the start and end of the string

Search reference

Regular Expression

^(?3)*\)*$(()((?(2)|\)*)(\((?1)*(\)|$)|0|"[^\n"]*.?|(1|(2|(3|4(?3))(?3))(?3))(?3))))?

New

Truthy:

0
)
(
"
()
""
10
400010
210010
("")00
3"""""
2(2(2(0)0)0)0
2"010""44)()4"
)31(0)0(20102010
())2)1))0"3())"))
3("4321("301(0)21100"4")"123"00)40"121"31000""01010

Falsy:

1
1(310
12(010
4"00010"
3120102100
20(2((0)(0)))
2(2(2(0)0)0)01)
4(0102)00)00000
2"00"("00"2(""))

Regular Expressions 101

Regular Expression

Substitution