print ip address from string using regex

flyganji has asked for the wisdom of the Perl Monks concerning the following question:

Hi all, First time writing perl question here. Thank you all for help. I have an assignment to write a few lines of code that would match an IP address from $string and store it in a variable called $ip. $string = "My IP is 10.0.0.2" and the result should be $ip = "10.0.0.2" My trial code was

#!/usr/bin/perl
$string = "My IP is 10.0.0.2";
if($string =~/\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}/{
$ip = $string;
}
print "$ip\n";
[download]

I know this will print out "My IP is 10.0.0.2" but I can't seem to make find a solution to print just IP = 10.0.0.2. thank you all again for any solution.

Comment on print ip address from string using regex Download Code

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Re: print ip address from string using regex by roboticus (Chancellor) on Oct 04, 2011 at 15:28 UTC
flyganji: You need to use a group in your regex to capture the match value, as described in `perldoc perlre`. For example: `use strict; use warnings; my $string='foo bar baz bow'; if ($string =~ /bar(.)bow/) { print "between bar and bow is '$1'\n"; }` [download] gives me: `$ perl x.pl between bar and bow is ' baz '` [download] ...roboticus When your only tool is a hammer, all problems look like your thumb.* Update: Added quotes in print statement to show that the whitespace is also captured.	[reply] [d/l] [select]
Re^2: print ip address from string using regex by flyganji (Initiate) on Oct 04, 2011 at 20:47 UTC
Thank you all for help.	[reply]
Re: print ip address from string using regex by AR (Friar) on Oct 04, 2011 at 15:23 UTC
You need to capture: `if($string =~/(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})/{ $ip = $1; }` [download] See Capture Groups.	[reply] [d/l]
Re^2: print ip address from string using regex by Anonymous Monk on Aug 14, 2013 at 07:40 UTC
i wanna print ip address class also pls tel me the code like 10.10.10.1 is class a 172.30.2.2 is class b like that	[reply]