That won't work for www.some.domain.com. Use a loop. 

my $QNAME= "www.google.com"; 
 
my $QNAME_packed = '';
for my $part ( split( /\./, $QNAME ) ) {
   $QNAME_packed .= pack( 'C', length($part) ) . $part;
}
$QNAME_packed .= pack('C', 0)

[download]

Or 

my $QNAME= "www.google.com"; 
 
my $QNAME_packed = '';
for my $part ( split( /\./, $QNAME ) ) {
   $QNAME_packed .= pack( 'C/a*', $part );
}
$QNAME_packed .= pack('C', 0)

[download]

Or 

my $QNAME= "www.google.com"; 
 
my $QNAME_packed = '';
for my $part ( split( /\./, $QNAME ), '' ) {
   $QNAME_packed .= pack( 'C/a*', $part );
}

[download]

Or if requiring Perl 5.8 is acceptable 

my $QNAME= "www.google.com"; 
 
my $QNAME_packed = pack( '(C/a*)*', split( /\./, $QNAME ), '' ) );

[download]

In reply to Re^5: How to create a DNS message in perl? by ikegami
in thread How to create a DNS message in perl? by sanjay nayak

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