regex101: ipv4 and ipv6 with mask in CIDR

Pro

1st Alternative\b((?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)+(?:\/{1}((?:[0-9])|(?:[1-2][0-9])|(?:3[0-2]))\b)?)

\ban ASCII word boundary

Group 1((?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)+(?:\/{1}((?:[0-9])|(?:[1-2][0-9])|(?:3[0-2]))\b)?)

Non-Capturing Group(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}

{3}repeats the group contents below exactly 3 times:

Non-Capturing Group(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)

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][0-9]

2the literal 2 (50₁₀ / 62₈ / 32₁₆)

Character Class[0-4]

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

Character Class[0-9]

0-9one character from 0 (48₁₀) to 9 (57₁₀)

3rd Alternative[01]?[0-9][0-9]?

Character Class[01]?

?matches at most one character from the set below:

0the literal 0 (48₁₀ / 60₈ / 30₁₆)

1the literal 1 (49₁₀ / 61₈ / 31₁₆)

Character Class[0-9]

0-9one character from 0 (48₁₀) to 9 (57₁₀)

Character Class[0-9]?

?matches at most one character from the set below:

0-9one character from 0 (48₁₀) to 9 (57₁₀)

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

Non-Capturing Group(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)+

+repeats the group contents below at least once:

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][0-9]

2the literal 2 (50₁₀ / 62₈ / 32₁₆)

Character Class[0-4]

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

Character Class[0-9]

0-9one character from 0 (48₁₀) to 9 (57₁₀)

3rd Alternative[01]?[0-9][0-9]?

Character Class[01]?

?matches at most one character from the set below:

0the literal 0 (48₁₀ / 60₈ / 30₁₆)

1the literal 1 (49₁₀ / 61₈ / 31₁₆)

Character Class[0-9]

0-9one character from 0 (48₁₀) to 9 (57₁₀)

Character Class[0-9]?

?matches at most one character from the set below:

0-9one character from 0 (48₁₀) to 9 (57₁₀)

Non-Capturing Group(?:\/{1}((?:[0-9])|(?:[1-2][0-9])|(?:3[0-2]))\b)?

?repeats the group contents below at most once:

\/{1}the literal / (47₁₀ / 57₈ / 2F₁₆) , repeated exactly 1 time

Group 2((?:[0-9])|(?:[1-2][0-9])|(?:3[0-2]))

1st Alternative(?:[0-9])

2nd Alternative(?:[1-2][0-9])

3rd Alternative(?:3[0-2])

\ban ASCII word boundary

2nd Alternative((?:[a-f0-9:]+:+)+(?:[a-f0-9])+(?:\/{1}((?:(?:3[0-2]|[12]?\d)))\b)?)

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

25 tokens

Regular Expression

\b((?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)+(?:\/{1}((?:[0-9])|(?:[1-2][0-9])|(?:3[0-2]))\b)?)|((?:[a-f0-9:]+:+)+(?:[a-f0-9])+(?:\/{1}((?:(?:3[0-2]|[12]?\d)))\b)?)

Unit Tests

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