Regular Expressions 101

Explanation

Pro

^start of line

Group 1((10|127)(\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?))|169\.254|192\.168|172\.(2[0-9]|1[6-9]|3[0-1]))

1st Alternative(10|127)(\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?))

Group 2(10|127)

1st Alternative10

10the literal text 10

2nd Alternative127

127the literal text 127

Group 3(\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?))

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

Group 4(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)

2nd Alternative169\.254

169the literal text 169

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

254the literal text 254

3rd Alternative192\.168

192the literal text 192

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

168the literal text 168

4th Alternative172\.(2[0-9]|1[6-9]|3[0-1])

172the literal text 172

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

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

1st Alternative2[0-9]

2the literal 2 (50₁₀ / 62₈ / 32₁₆)

Character Class[0-9]

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

2nd Alternative1[6-9]

1the literal 1 (49₁₀ / 61₈ / 31₁₆)

Character Class[6-9]

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

3rd Alternative3[0-1]

3the literal 3 (51₁₀ / 63₈ / 33₁₆)

Character Class[0-1]

Group 6(\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)){2}

$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

Match Information

Detailed match information will be displayed here automatically.

Quick Reference

25 tokens

Regular Expression

^((10|127)(\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?))|169\.254|192\.168|172\.(2[0-9]|1[6-9]|3[0-1]))(\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)){2}$

New

Private ranges
10.0.0.0-10.255.255.255
127.0.0.0-127.255.255.255
169.254.0.0-169.254.255.255
172.16.0.0-172.31.255.255
192.168.0.0-192.168.255.255


-----OK-----
10.0.0.0
10.255.255.255
127.0.0.0
127.255.255.255
169.254.0.255
169.254.255.255
172.16.0.0
172.31.255.255
192.168.0.0
192.168.255.255
------NOT OK------
1.1.1.1
9.255.255.255
11.0.0.0
126.255.255.255
128.0.0.0
169.253.255.255
169.255.0.0
172.15.255.255
172.32.0.0
192.167.255.255
192.169.0.0

Substitution

Private ranges
10.0.0.0-10.255.255.255
127.0.0.0-127.255.255.255
169.254.0.0-169.254.255.255
172.16.0.0-172.31.255.255
192.168.0.0-192.168.255.255


-----OK-----
10.0.0.0
10.255.255.255
127.0.0.0
127.255.255.255
169.254.0.255
169.254.255.255
172.16.0.0
172.31.255.255
192.168.0.0
192.168.255.255
------NOT OK------
1.1.1.1
9.255.255.255
11.0.0.0
126.255.255.255
128.0.0.0
169.253.255.255
169.255.0.0
172.15.255.255
172.32.0.0
192.167.255.255
192.169.0.0