regex101: PCRE (Legacy) Match Workspace

1st Alternative#IPv4 (?<IPv4> (?!0+\.) (?<byte>2(?:[0-4]\d|5[0-5])|1?\d{1,2}) (?:\.(?&byte)){3} ) #IPv6 from http://vernon.mauery.com/content/projects/linux/ipv6_regex

Comment:IPv4

Group IPv4(?<IPv4> (?!0+\.) (?<byte>2(?:[0-4]\d|5[0-5])|1?\d{1,2}) (?:\.(?&byte)){3} )

Negative Lookahead(?!0+\.)

0+the literal 0 (48₁₀ / 60₈ / 30₁₆) , repeated at least once

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

Group byte(?<byte>2(?:[0-4]\d|5[0-5])|1?\d{1,2})

1st Alternative2(?:[0-4]\d|5[0-5])

2the literal 2 (50₁₀ / 62₈ / 32₁₆)

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

1st Alternative[0-4]\d

Character Class[0-4]

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

\da digit

2nd Alternative5[0-5]

5the literal 5 (53₁₀ / 65₈ / 35₁₆)

Character Class[0-5]

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

2nd Alternative1?\d{1,2}

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

\d{1,2}a digit, repeated between 1 and 2 times

Non-Capturing Group(?:\.(?&byte)){3}

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

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

(?&byte)calls group byte as a subroutine

Comment:IPv6 from http://vernon.mauery.com/content/projects/linux/ipv6_regex

2nd Alternative (?<smb>[0-9a-f]{1,4}:){1,1} (?<sme>:[0-9a-f]{1,4}){1,6}

Group smb(?<smb>[0-9a-f]{1,4}:){1,1}

{1,1}repeats the group contents below exactly 1 time:

Character Class[0-9a-f]{1,4}

{1,4}matches between 1 and 4 characters from the set below:

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

a-fone character from a (97₁₀) to f (102₁₀) (case sensitive)

:the literal : (58₁₀ / 72₈ / 3A₁₆)

Group sme(?<sme>:[0-9a-f]{1,4}){1,6}

{1,6}repeats the group contents below between 1 and 6 times:

:the literal : (58₁₀ / 72₈ / 3A₁₆)

Character Class[0-9a-f]{1,4}

{1,4}matches between 1 and 4 characters from the set below:

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

a-fone character from a (97₁₀) to f (102₁₀) (case sensitive)

3rd Alternative (?&smb){1,2} (?&sme){1,5}

(?&smb){1,2}calls group smb as a subroutine, repeated between 1 and 2 times

(?&sme){1,5}calls group sme as a subroutine, repeated between 1 and 5 times

4th Alternative (?&smb){1,3} (?&sme){1,4}

(?&smb){1,3}calls group smb as a subroutine, repeated between 1 and 3 times

(?&sme){1,4}calls group sme as a subroutine, repeated between 1 and 4 times

5th Alternative (?&smb){1,4} (?&sme){1,3}

(?&smb){1,4}calls group smb as a subroutine, repeated between 1 and 4 times

(?&sme){1,3}calls group sme as a subroutine, repeated between 1 and 3 times

6th Alternative (?&smb){1,5} (?&sme){1,2}

(?&smb){1,5}calls group smb as a subroutine, repeated between 1 and 5 times

(?&sme){1,2}calls group sme as a subroutine, repeated between 1 and 2 times

7th Alternative (?&smb){1,6} (?&sme){1,1}

(?&smb){1,6}calls group smb as a subroutine, repeated between 1 and 6 times

(?&sme){1,1}calls group sme as a subroutine, repeated exactly 1 time

8th Alternative ((?&smb){1,7}|:):

Group 5((?&smb){1,7}|:)

1st Alternative(?&smb){1,7}

(?&smb){1,7}calls group smb as a subroutine, repeated between 1 and 7 times

2nd Alternative:

: the literal text :

9th Alternative :(?&sme){1,7}

10th Alternative (?&smb){6} (?&IPv4)

11th Alternative (?&smb){5} :?+ [0-9a-f]{1,4} :(?&IPv4)

12th Alternative (?&smb){1,1} (?&sme){1,4} :(?&IPv4)

13th Alternative (?&smb){1,2} (?&sme){1,3} :(?&IPv4)

14th Alternative (?&smb){1,3} (?&sme){1,2} :(?&IPv4)

15th Alternative (?&smb){1,4} (?&sme){1,1} :(?&IPv4)

16th Alternative ((?&smb){1,5}|:) :(?&IPv4)

17th Alternative :(?&sme){1,5} :(?&IPv4)

Global pattern flags

s modifier: single line. Allows a dot to match line terminators

x modifier: extended. Ignores unescaped whitespace and comments outside character classes

X modifier: eXtra. A \ followed by a letter with no special meaning causes an error

g modifier: global. Finds all matches instead of stopping after the first

Search reference

Regular Expression

#IPv4
(?<IPv4>
  (?!0+\.)
  (?<byte>2(?:[0-4]\d|5[0-5])|1?\d{1,2})
  (?:\.(?&byte)){3}
)

#IPv6 from http://vernon.mauery.com/content/projects/linux/ipv6_regex
| (?<smb>[0-9a-f]{1,4}:){1,1} (?<sme>:[0-9a-f]{1,4}){1,6}
| (?&smb){1,2} (?&sme){1,5}
| (?&smb){1,3} (?&sme){1,4}
| (?&smb){1,4} (?&sme){1,3}
| (?&smb){1,5} (?&sme){1,2}
| (?&smb){1,6} (?&sme){1,1}
| ((?&smb){1,7}|:):
| :(?&sme){1,7}
| (?&smb){6} (?&IPv4)
| (?&smb){5} :?+ [0-9a-f]{1,4} :(?&IPv4)
| (?&smb){1,1} (?&sme){1,4} :(?&IPv4)
| (?&smb){1,2} (?&sme){1,3} :(?&IPv4)
| (?&smb){1,3} (?&sme){1,2} :(?&IPv4)
| (?&smb){1,4} (?&sme){1,1} :(?&IPv4)
| ((?&smb){1,5}|:) :(?&IPv4)
| :(?&sme){1,5} :(?&IPv4)

Test String
New

Valid
192.168.1.1
192.168.255.255

Invalid
0.0.0.0
0.0.0.1
0.0.0.255
1.0.0.255

Regular Expressions 101

Regular Expression

Test String
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Substitution
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Regular Expression

Test StringNew

SubstitutionProcessing...

Test String
New

Substitution
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