Regular Expressions 101

Group 1(25[0-5]|2[0-4]\d|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 digit

3rd Alternative1?\d\d?

1?optionally matches the literal 1 (49₁₀ / 61₈ / 31₁₆)

\da digit

\d?optionally matches a digit

Group 2(\.\g<-2>){3}

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

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

\g<-2>calls group 1 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

Detailed match information will be displayed here automatically.

Search reference

Regular Expression

(25[0-5]|2[0-4]\d|1?\d\d?)(\.\g<-2>){3}

New

123 hahab  abcde 123
//192.168.10.254/10.4.32.21 / 1.2.3 /125.258.33.22/ 432.2.3.475