regular expressions issue

[Amichai Teumim]

I created a file called data.txt which contains a bunch of junk, including
some IPs. I want $line to be  stored in
$ip<http://www.tek-tips.com/viewthread.cfm?qid=1382614&page=1#>
.

It works, except for the regular expressions which should find only IPs. If
I use the regular expression with the grep command in terminal I get only
the IPs. Here in Perl I don't get any output.

#!/usr/bin/perl

@input = `cat ~/ip.txt`;

foreach $line (@input){
 if($line =~
/[[:digit:]]\{1,3\}\.[[:digit:]]\{1,3\}\.[[:digit:]]\{1,3\}\.[[:digit:]]\{1,3\}/){
 $ip = $line;
 print $ip;
 }
}

Any ideas? It's breaking my head.

Amichai