Please enable JavaScript to use regex101
/
^
r
e
g
e
x
[
\
-
_
]
?
1
0
1
$
/
i
Reg
ular
Ex
pressions
101
Upgrade to Pro
Enterprise
Regular Expression
r"
(?:\s|^) # Start of string or word boundary ( # Capture Group (?: # Non-Capture Group for X. (?: # Nested NCG for 0..255 (?:\d){1,2}| # Allow any single digit or any pair of digits or (?:1\d{2})| # 3 Digits starting with 1 or (?:2[0-4]\d)| # 3 Digists starting with 20..24 or (?:25[0-5]) # 250..255 ) # this should allow X=0..255 in the NCG \. # Must be followed by a literal . ){3} # X. Must repeat exactly 3 times (?: # NCG for final 0..255 (?:\d{1,2})| # Allow any single digit or any pair of digits or (?:1\d{2})| # 3 Digits starting with 1 or (?:2[0-4]\d)| # 3 digits starting 20..24 or (?:25[0-5]) # 250.255 ) # End of final 0.255 ) # End of capture group (?:\s|$) # Must be followed by EOS or wspace
"
gx
Input 1
1
New
123.123.123.145 is an IP4 so is 1.2.3.4 and 1.22.33.44 but 256.1.2.3 isn't 254.1.2.3 is but 260.1.1.1 isn't nor 2.5.256.1 and 1.2.3.4:222 IP6 1.2.3.4.5.6
Substitution
123.123.123.145 is an IP4 so is 1.2.3.4 and 1.22.33.44 but 256.1.2.3 isn't 254.1.2.3 is but 260.1.1.1 isn't nor 2.5.256.1 and 1.2.3.4:222 IP6 1.2.3.4.5.6