regex101: PCRE (Legacy) Match Workspace

^start of string

Negative Lookahead(?!(?>(?1)"?(?>\\\[ -~]|[^"])"?(?1)){255,})

Atomic Group(?>(?1)"?(?>\\\[ -~]|[^"])"?(?1)){255,}

{255,}repeats the group contents below at least 255 times:

(?1)calls group 1 as a subroutine

"?optionally matches the literal " (34₁₀ / 42₈ / 22₁₆)

Atomic Group(?>\\\[ -~]|[^"])

1st Alternative\\\[ -~]

\\the literal \ (92₁₀ / 134₈ / 5C₁₆)

\[the literal [ (91₁₀ / 133₈ / 5B₁₆)

-~]the literal text -~]

2nd Alternative[^"]

Negated Character Class[^"]

"the literal " (34₁₀ / 42₈ / 22₁₆)

"?optionally matches the literal " (34₁₀ / 42₈ / 22₁₆)

(?1)calls group 1 as a subroutine

Negative Lookahead(?!(?>(?1)"?(?>\\\[ -~]|[^"])"?(?1)){65,}@)

Atomic Group(?>(?1)"?(?>\\\[ -~]|[^"])"?(?1)){65,}

{65,}repeats the group contents below at least 65 times:

(?1)calls group 1 as a subroutine

"?optionally matches the literal " (34₁₀ / 42₈ / 22₁₆)

Atomic Group(?>\\\[ -~]|[^"])

1st Alternative\\\[ -~]

\\the literal \ (92₁₀ / 134₈ / 5C₁₆)

\[the literal [ (91₁₀ / 133₈ / 5B₁₆)

-~]the literal text -~]

2nd Alternative[^"]

Negated Character Class[^"]

"the literal " (34₁₀ / 42₈ / 22₁₆)

"?optionally matches the literal " (34₁₀ / 42₈ / 22₁₆)

(?1)calls group 1 as a subroutine

@the literal @ (64₁₀ / 100₈ / 40₁₆)

Group 1((?>(?>(?>((?>(?>(?>\x0D\x0A)?[\t ])+|(?>[\t ]*\x0D\x0A)?[\t ]+)?)($(?>(?2)(?>[\x01-\x08\x0B\x0C\x0E-\'*-\[\]-\x7F]|\\\[\x00-\x7F]|(?3)))*(?2)$))+(?2))|(?2))?)

Atomic Group(?>(?>(?>((?>(?>(?>\x0D\x0A)?[\t ])+|(?>[\t ]*\x0D\x0A)?[\t ]+)?)($(?>(?2)(?>[\x01-\x08\x0B\x0C\x0E-\'*-\[\]-\x7F]|\\\[\x00-\x7F]|(?3)))*(?2)$))+(?2))|(?2))?

?repeats the group contents below at most once:

1st Alternative(?>(?>((?>(?>(?>\x0D\x0A)?[\t ])+|(?>[\t ]*\x0D\x0A)?[\t ]+)?)($(?>(?2)(?>[\x01-\x08\x0B\x0C\x0E-\'*-\[\]-\x7F]|\\\[\x00-\x7F]|(?3)))*(?2)$))+(?2))

Atomic Group(?>(?>((?>(?>(?>\x0D\x0A)?[\t ])+|(?>[\t ]*\x0D\x0A)?[\t ]+)?)($(?>(?2)(?>[\x01-\x08\x0B\x0C\x0E-\'*-\[\]-\x7F]|\\\[\x00-\x7F]|(?3)))*(?2)$))+(?2))

Atomic Group(?>((?>(?>(?>\x0D\x0A)?[\t ])+|(?>[\t ]*\x0D\x0A)?[\t ]+)?)($(?>(?2)(?>[\x01-\x08\x0B\x0C\x0E-\'*-\[\]-\x7F]|\\\[\x00-\x7F]|(?3)))*(?2)$))+

+repeats the group contents below at least once:

Group 2((?>(?>(?>\x0D\x0A)?[\t ])+|(?>[\t ]*\x0D\x0A)?[\t ]+)?)

Atomic Group(?>(?>(?>\x0D\x0A)?[\t ])+|(?>[\t ]*\x0D\x0A)?[\t ]+)?

?repeats the group contents below at most once:

1st Alternative(?>(?>\x0D\x0A)?[\t ])+

Atomic Group(?>(?>\x0D\x0A)?[\t ])+

+repeats the group contents below at least once:

Atomic Group(?>\x0D\x0A)?

?repeats the group contents below at most once:

\x0Dthe literal ↵ (D₁₆ / 15₈ / 13₁₀)

\x0Athe literal ↵ (A₁₆ / 12₈ / 10₁₀)

Character Class[\t ]

\ta tab character (ASCII 9)

the literal (32₁₀ / 40₈ / 20₁₆)

2nd Alternative(?>[\t ]*\x0D\x0A)?[\t ]+

Atomic Group(?>[\t ]*\x0D\x0A)?

?repeats the group contents below at most once:

Character Class[\t ]*

\x0Dthe literal ↵ (D₁₆ / 15₈ / 13₁₀)

\x0Athe literal ↵ (A₁₆ / 12₈ / 10₁₀)

Character Class[\t ]+

Group 3($(?>(?2)(?>[\x01-\x08\x0B\x0C\x0E-\'*-\[\]-\x7F]|\\\[\x00-\x7F]|(?3)))*(?2)$)

(?2)calls group 2 as a subroutine

2nd Alternative(?2)

Group 4([!#-\'*+\/-9=?^-~-]+|"(?>(?2)(?>[\x01-\x08\x0B\x0C\x0E-!#-\[\]-\x7F]|\\\[\x00-\x7F]))*(?2)")

Atomic Group(?>(?1)\.(?1)(?4))*

(?1)calls group 1 as a subroutine

@the literal @ (64₁₀ / 100₈ / 40₁₆)

Negative Lookahead(?!(?1)[a-z0-9-]{64,})

(?1)calls group 1 as a subroutine

Atomic Group(?>([a-z0-9](?>[a-z0-9-]*[a-z0-9])?)(?>(?1)\.(?!(?1)[a-z0-9-]{64,})(?1)(?5)){0,126}|\[(?:(?>IPv6:(?>([a-f0-9]{1,4})(?>:(?6)){7}|(?!(?:.*[a-f0-9][:\]]){8,})((?6)(?>:(?6)){0,6})?::(?7)?))|(?>(?>IPv6:(?>(?6)(?>:(?6)){5}:|(?!(?:.*[a-f0-9]:){6,})(?8)?::(?>((?6)(?>:(?6)){0,4}):)?))?(25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9]?[0-9])(?>\.(?9)){3}))\])

(?1)calls group 1 as a subroutine

$end of string, or before its final line terminator

Global pattern flags

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

i modifier: insensitive. Matches without distinguishing uppercase and lowercase letters

Search reference

Regular Expression

^(?!(?>(?1)"?(?>\\\[ -~]|[^"])"?(?1)){255,})(?!(?>(?1)"?(?>\\\[ -~]|[^"])"?(?1)){65,}@)((?>(?>(?>((?>(?>(?>\x0D\x0A)?[\t ])+|(?>[\t ]*\x0D\x0A)?[\t ]+)?)(\((?>(?2)(?>[\x01-\x08\x0B\x0C\x0E-\'*-\[\]-\x7F]|\\\[\x00-\x7F]|(?3)))*(?2)\)))+(?2))|(?2))?)([!#-\'*+\/-9=?^-~-]+|"(?>(?2)(?>[\x01-\x08\x0B\x0C\x0E-!#-\[\]-\x7F]|\\\[\x00-\x7F]))*(?2)")(?>(?1)\.(?1)(?4))*(?1)@(?!(?1)[a-z0-9-]{64,})(?1)(?>([a-z0-9](?>[a-z0-9-]*[a-z0-9])?)(?>(?1)\.(?!(?1)[a-z0-9-]{64,})(?1)(?5)){0,126}|\[(?:(?>IPv6:(?>([a-f0-9]{1,4})(?>:(?6)){7}|(?!(?:.*[a-f0-9][:\]]){8,})((?6)(?>:(?6)){0,6})?::(?7)?))|(?>(?>IPv6:(?>(?6)(?>:(?6)){5}:|(?!(?:.*[a-f0-9]:){6,})(?8)?::(?>((?6)(?>:(?6)){0,4}):)?))?(25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9]?[0-9])(?>\.(?9)){3}))\])(?1)$

Unit Tests

There are no unit tests, click to add some.