Re^2: Validate Ip address Regexp

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Re^3: Validate Ip address Regexp by AnomalousMonk (Archbishop) on Nov 28, 2015 at 13:52 UTC
Now, and without using or looking at Regexp::Common::net or other such modules or Super Search, write, as an exercise (for it may be better in practice to use multiple regexes and separate tests), a single regex that will accept `'255.1.12.123'` and reject `'256.1.12.123'` or `'300.1.12.123'`. (Think of the alternate ranges (hint) of numbers involved: 0-9, 00-99, 000-199, 200-249, 250-255.) Then write a regex that will extract (or parse) valid IPv4 decimal octet addresses from an arbitrary string: `'foo255.1.12.123bar1.2.3.4 x 11.2.33.44 y 300.123.12.1z000123.3.2.11111'` Now you've got something. See perlre, perlretut, and perlrequick. Give a man a fish: `<%-{-{-{-<`	[reply] [d/l] [select]

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Re^3: Validate Ip address Regexp
by AnomalousMonk (Archbishop) on Nov 28, 2015 at 13:52 UTC

Now, and without using or looking at Regexp::Common::net or other such modules or Super Search, write, as an exercise (for it may be better in practice to use multiple regexes and separate tests), a single regex that will accept '255.1.12.123' and reject '256.1.12.123' or '300.1.12.123'. (Think of the alternate ranges (hint) of numbers involved: 0-9, 00-99, 000-199, 200-249, 250-255.) Then write a regex that will extract (or parse) valid IPv4 decimal octet addresses from an arbitrary string:
'foo255.1.12.123bar1.2.3.4 x 11.2.33.44 y 300.123.12.1z000123.3.2.11111'
Now you've got something.

See perlre, perlretut, and perlrequick.

Give a man a fish: <%-{-{-{-<

[reply]
[d/l]
[select]