Regular Expressions 101

^start of line

Non-Capturing Group(?:.*?\b((?:25[0-5]|2[0-4]\d|[0-1]?\d?\d)(?:\.(?:25[0-5]|2[0-4]\d|[0-1]?\d?\d)){3}(?:/\d+)?)){2}

{2}repeats the group contents below exactly 2 times:

.*?any Unicode character (except for line terminators), repeated any number of times

\ba Unicode word boundary

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

Non-Capturing Group(?:25[0-5]|2[0-4]\d|[0-1]?\d?\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 Unicode decimal digit

3rd Alternative[0-1]?\d?\d

Character Class[0-1]?

?matches at most one character from the set below:

0-1one character from 0 (48₁₀) to 1 (49₁₀)

\d?optionally matches a Unicode decimal digit

\da Unicode decimal digit

Non-Capturing Group(?:\.(?:25[0-5]|2[0-4]\d|[0-1]?\d?\d)){3}

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

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

Non-Capturing Group(?:25[0-5]|2[0-4]\d|[0-1]?\d?\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 Unicode decimal digit

3rd Alternative[0-1]?\d?\d

Character Class[0-1]?

?matches at most one character from the set below:

0-1one character from 0 (48₁₀) to 1 (49₁₀)

\d?optionally matches a Unicode decimal digit

\da Unicode decimal digit

Non-Capturing Group(?:/\d+)?

?repeats the group contents below at most once:

/the literal / (47₁₀ / 57₈ / 2F₁₆)

\d+a Unicode decimal digit, repeated at least once

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

No unit tests · Add a test to get started

Search reference

Regular Expression

^(?:.*?\b((?:25[0-5]|2[0-4]\d|[0-1]?\d?\d)(?:\.(?:25[0-5]|2[0-4]\d|[0-1]?\d?\d)){3}(?:/\d+)?)){2}

Unit Tests

There are no unit tests, click to add some.