Re: Regexp to match IP address

[dsb]

in reply to Regexp to match IP address

Where's japhy when you need 'em. :)

I guess it kind of depends on how concerned you are with the validity of your data. Testing for 4 1-3 digit numbers seperated by dots is easy:

m/^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}\$/;

If you are interested making sure IP's are valid, you could do a couple of things.

One, using the above regex, you could grab the digits and test them individually.

use strict;
my @nums;
my $IP = "127.0.0.1"
(@nums) = $IP =~ m/^(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})$/;

# test each for <= 255 here.
# also make sure its not 0.0.0.0

Or you could use a more complicated regex to test for validity during the pattern matching. From O'Reilly's Mastering Regular Expressions:

m/^([01]?\d\d?|2[0-4]\d|25[0-5])\.([01]?\d\d?|2[0-4]\d|25[0-5])\.
   ([01]?\d\d?|2[0-4]\d|25[0-5])\.([01]?\d\d?|2[0-4]\d|25[0-5])$/;

UPDATE: I just realized this was my 150th post. Yay for me. :)