regex101: PCRE (Legacy) Match Workspace

(?imx)applies the following effective flags to the remainder of the pattern: gmix

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

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

x modifier: extended. Ignores unescaped whitespace and comments outside character classes

Atomic Group(?> [\|\/] | ^ )

1st Alternative [\|\/]

Character Class[\|\/]

\|the literal | (124₁₀ / 174₈ / 7C₁₆)

\/the literal / (47₁₀ / 57₈ / 2F₁₆)

2nd Alternative ^

^start of line

Comment: was darf vor der gesamten Domain stehen? - hier |, / und der Zeilenanfang

Branch Reset Group(?| # entweder eine Domain: (?>[a-z\d-]{1,63}\.)*\K # Subdomains größer als Level 2 [a-z\d-]{1,63}\.[a-z]{1,23} # die eigentliche TLD + eine SubDomain | # oder eine IPv4-Adresse: (?>(?>25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(?(?=\.?\d)\.)){4} # IPv4-Adresse )

1st Alternative # entweder eine Domain: (?>[a-z\d-]{1,63}\.)*\K # Subdomains größer als Level 2 [a-z\d-]{1,63}\.[a-z]{1,23} # die eigentliche TLD + eine SubDomain

Comment: entweder eine Domain:

Atomic Group(?>[a-z\d-]{1,63}\.)*

*repeats the group contents below any number of times:

Character Class[a-z\d-]{1,63}

{1,63}matches between 1 and 63 characters from the set below:

a-zone character from a (97₁₀) to z (122₁₀) (case insensitive)

\da digit

-the literal - (45₁₀ / 55₈ / 2D₁₆)

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

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

Comment: Subdomains größer als Level 2

Character Class[a-z\d-]{1,63}

{1,63}matches between 1 and 63 characters from the set below:

a-zone character from a (97₁₀) to z (122₁₀) (case insensitive)

\da digit

-the literal - (45₁₀ / 55₈ / 2D₁₆)

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

Character Class[a-z]{1,23}

{1,23}matches between 1 and 23 characters from the set below:

a-zone character from a (97₁₀) to z (122₁₀) (case insensitive)

Comment: die eigentliche TLD + eine SubDomain

2nd Alternative # oder eine IPv4-Adresse: (?>(?>25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(?(?=\.?\d)\.)){4} # IPv4-Adresse

Comment: oder eine IPv4-Adresse:

Atomic Group(?>(?>25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(?(?=\.?\d)\.)){4}

{4}repeats the group contents below exactly 4 times:

Atomic Group(?>25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)

1st Alternative25[0-5]

25the literal text 25

Character Class[0-5]

0-5one character from 0 (48₁₀) to 5 (53₁₀)

2nd Alternative2[0-4]\d

2the literal 2 (50₁₀ / 62₈ / 32₁₆)

Character Class[0-4]

0-4one character from 0 (48₁₀) to 4 (52₁₀)

\da digit

3rd Alternative1\d\d

1the literal 1 (49₁₀ / 61₈ / 31₁₆)

\da digit

4th Alternative[1-9]?\d

Character Class[1-9]?

?matches at most one character from the set below:

1-9one character from 1 (49₁₀) to 9 (57₁₀)

\da digit

Condition(?(?=\.?\d)\.)

Uses the first branch if the lookaround matches

Positive Lookahead(?=\.?\d)

\.?optionally matches the literal . (46₁₀ / 56₈ / 2E₁₆)

\da digit

If the condition is true, match this branch:\.

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

Comment: IPv4-Adresse

Positive Lookahead(?= [\/#^\r\n] | $)

1st Alternative [\/#^\r\n]

2nd Alternative $

Comment: was darf alles nach der Domain kommen? - hier die Zeichen #, / und ^ sowie Zeilenende

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

(?imx)
(?> [\|\/] | ^ ) # was darf vor der gesamten Domain stehen? - hier |, / und der Zeilenanfang
(?| # entweder eine Domain:
   (?>[a-z\d-]{1,63}\.)*\K # Subdomains größer als Level 2
   [a-z\d-]{1,63}\.[a-z]{1,23} # die eigentliche TLD + eine SubDomain
|  # oder eine IPv4-Adresse:
   (?>(?>25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(?(?=\.?\d)\.)){4} # IPv4-Adresse
)
(?= [\/#^\r\n] | $) # was darf alles nach der Domain kommen? - hier die Zeichen #, / und ^ sowie Zeilenende

Unit Tests

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