How to find Subnet of the given IP using perl cgi? - perl

Question

I need to find the subnet of any IP that user entered. I am executing the "ypcat -k netmasks.byaddr" unix command in perl to find netmasks. It is working fine in command line execution. But it is not working while executing in webserver.
The below is the code.
use strict;
use CGI;
my $page=new CGI;
print $page->header;
my $ipaddress=$page->param("ip");
my #splitted=split(/\./,$ipaddress);
my $part1=$splitted[0].".".$splitted[1].".".$splitted[2];
my $part2=$splitted[3];
my $comma1="ypcat -k netmasks.byaddr|grep -w $part1|awk '{print \$1}'|awk -F. '{print \$4}'|sort -g";
my $comm2="ypcat -k netmasks.byaddr|grep -w $part1|sort";
my #out=`$comm1`;
my #out2=`$comm2`;
my $match;my $sub;my $found;
foreach my $i(#out){
chomp($i);
if($part2 > $i){
$sub=$i;
$found=$part1.".".$sub;
}
}
my (#matched) = grep $_=~m/$found/, #out2;
chomp(#matched);
print "#matched\n";
The above is the code I am using to find subnet of the given IP. In that the execution of "$comm1" and "$comm2" is failing.
Is any other way to find subnet of the user entered IP using Perl script?
Thanks,
Madhan

Answer 1

You can use NetAddr::IP module for this job as given below:
#!/usr/local/bin/perl
use strict;
use warnings;
use CGI;
use NetAddr::IP;
my $page = new CGI;
print $page->header;
my $ipaddress = $page->param("ip");
my $ip = NetAddr::IP->new($ipaddress);
print "The address is ", $ip->addr, " with mask ", $ip->mask, "\n" ;