Shell Programming and Scripting

#!/usr/bin/perl
use strict;
use warnings;

use Net::DNS::Resolver;

my $hostname = 'perlmonks.org';
my $res = Net::DNS::Resolver->new(
  nameservers => [qw(8.8.8.8)],
);

my $query = $res->search($hostname);

if ($query) {
  foreach my $rr ($query->answer) {
    next unless $rr->type eq "A";
    print "Found an A record for $hostname: ".$rr->address;
    print "\n";
  }
}

Found an A record for perlmonks.org: 66.39.54.27
Found an A record for perlmonks.org: 216.92.34.251
Found an A record for perlmonks.org: 209.197.123.153

#!/usr/bin/perl
use strict;
use warnings;

use Net::DNS::Resolver;

open FILE, "<hostname_check.txt" || die $!;
while (<FILE>) {
my $res = Net::DNS::Resolver->new(
  nameservers => [qw(8.8.8.8)],
);
my $query = $res->search($_);

if ($query) {
  foreach my $rr ($query->answer) {
    next unless $rr->type eq "A";
    print "Found an A record for $_: ".$rr->address;
    print "\n";
  }
}
}
close FILE;

#!/usr/bin/perl
use strict;
use warnings;

use Net::DNS::Resolver;

my $res = Net::DNS::Resolver->new(
  nameservers => [qw(8.8.8.8)],
);

open FILE, "<hostname_check.txt" || die $!;
while (<FILE>) {
chomp;
my $hostname = $_;
my $query = $res->search($hostname);

if ($query) {
  foreach my $rr ($query->answer) {
    next unless $rr->type eq "A";
    print "Found an A record for $_: ".$rr->address;
    print "\n";
  }
}
}
close FILE;

open (FILE, "<hostname_check.txt") || die $!;

open FILE, "<hostname_check.txt" or die $!;