regex to match an ip

echo 254.003.032.3 | grep -P '^((25[0-4]|2[0-4]\d|[01]?[\d]?[1-9])\.){3}(25[0-4]|2[0-4]\d|[01]?[\d]?[1-9])$'
This obey that you don't match any broadcast or network addresses and stay between 1.1.1.1 - 254.254.254.254

0
By: foob4r
2009-09-17 12:59:44

3 Alternatives + Submit Alt

What Others Think

Doesn't handle 127.0.0.1, which is a valid address.
arcege · 461 weeks and 1 day ago
How do you know what the network and broadcast addresses are without knowing the network mask? If you're on 10.0.0.0/8, then 10.0.0.255 and 10.0.1.0 are both valid addresses.
andrew112358 · 461 weeks and 1 day ago
The combo of the leading ^ and the trailing $ will force the regex to match an IP address on a line all by itself, so this will not match IPs embedded in text.
bwoodacre · 461 weeks and 1 day ago
ok u'r right @andrew112358 i only thought about /24
foob4r · 461 weeks ago

What do you think?

Any thoughts on this command? Does it work on your machine? Can you do the same thing with only 14 characters?

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