Regular Expressions 101

^start of line

Group 1(10(\.(1?\d\d?|2([0-4]\d?|5[0-5])))(?2)|172\.(1[6-9]|2\d|3[0-2])(?2)|192\.168(?2))

1st Alternative10(\.(1?\d\d?|2([0-4]\d?|5[0-5])))(?2)

10the literal text 10

Group 2(\.(1?\d\d?|2([0-4]\d?|5[0-5])))

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

Group 3(1?\d\d?|2([0-4]\d?|5[0-5]))

1st Alternative1?\d\d?

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

\da digit

\d?optionally matches a digit

2nd Alternative2([0-4]\d?|5[0-5])

2the literal 2 (50₁₀ / 62₈ / 32₁₆)

Group 4([0-4]\d?|5[0-5])

1st Alternative[0-4]\d?

Character Class[0-4]

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

\d?optionally matches a digit

2nd Alternative5[0-5]

5the literal 5 (53₁₀ / 65₈ / 35₁₆)

Character Class[0-5]

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

(?2)calls group 2 as a subroutine

2nd Alternative172\.(1[6-9]|2\d|3[0-2])(?2)

172the literal text 172

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

Group 5(1[6-9]|2\d|3[0-2])

1st Alternative1[6-9]

1the literal 1 (49₁₀ / 61₈ / 31₁₆)

Character Class[6-9]

6-9one character from 6 (54₁₀) to 9 (57₁₀)

2nd Alternative2\d

2the literal 2 (50₁₀ / 62₈ / 32₁₆)

\da digit

3rd Alternative3[0-2]

3the literal 3 (51₁₀ / 63₈ / 33₁₆)

Character Class[0-2]

0-2one character from 0 (48₁₀) to 2 (50₁₀)

(?2)calls group 2 as a subroutine

3rd Alternative192\.168(?2)

192the literal text 192

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

168the literal text 168

(?2)calls group 2 as a subroutine

$end of line

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.

25 tokens

Regular Expression

^(10(\.(1?\d\d?|2([0-4]\d?|5[0-5])))(?2)|172\.(1[6-9]|2\d|3[0-2])(?2)|192\.168(?2))(?2)$

New

10.17.0.1

Extraction

10.17.0.1