Regular Expressions 101

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Regular ExpressionOpen Workspace

/
(?(DEFINE)(?'n'25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9][0-9]|[0-9]))(?P>n)\.(?P>n)\.(?P>n)\.(?P>n)
/
gm

Description
Created·2026-03-01 02:22
Type·Match
Flavor·PCRE2 (PHP)

Matches and verifies IP address. 192.168.0.1 Matches 999.999.9.9 Didn't match

Submitted by Anonymous
Open Workspace