How to extract IP from following string

Question

$string  > show box detail
2 boxes:
1) Box ID: 1
       IP:                  127.0.0.1*
Interface:           1/1
 Priority:            31

How to extract IP from above string withc additional check for * ?

Answer 1

Since you only have one thing that looks like an ip, you can just use this regex:

(?:([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])

This is what it looks like on Debuggex.

Answer 2

Since that looks like a file, my first assumption is that you want a one-liner:

perl -anlwe 'if ($F[0] eq "IP:") { print $F[1] }' input.txt 

Otherwise, I would suggest a soft regex such as:

if ($foo =~ /IP:\s*(\S+)/) { 
    $ip = $1;
}

Answer 3

Use Regexp::Common:

#!/usr/bin/env perl

use 5.012;
use strict;
use warnings;

use Regexp::Common qw( net );

while (my $line = <DATA>) {
    my @ips = ($line =~ /($RE{net}{IPv4})/g)
        or next;
    say @ips;
}

__DATA__
$string  > show box detail
2 boxes:
1) Box ID: 1
       IP:                  127.0.0.1*
Interface:           1/1
 Priority:            31
2) Box ID: 2
       IP:                  10.10.1.1
Interface:           1/1
 Priority:            31

Answer 4

You can use this to match (shown with optional *)

((\d{1,3}\.){3}\d{1,3}\*?)