Museum

Net::hostent(3)                                                Net::hostent(3)



NAME
     Net::hostent - by-name interface to Perl's built-in gethost*() functions

SYNOPSIS
      use Net::hostnet;


DESCRIPTION
     This module's default exports override the core gethostbyname() and
     gethostbyaddr() functions, replacing them with versions that return
     "Net::hostent" objects.  This object has methods that return the
     similarly named structure field name from the C's hostent structure from
     netdb.h; namely name, aliases, addrtype, length, and addr_list.  The
     aliases and addr_list methods return array reference, the rest scalars.
     The addr method is equivalent to the zeroth element in the addr_list
     array reference.

     You may also import all the structure fields directly into your namespace
     as regular variables using the :FIELDS import tag.  (Note that this still
     overrides your core functions.)  Access these fields as variables named
     with a preceding h_.  Thus, $host_obj->name() corresponds to $h_name if
     you import the fields.  Array references are available as regular array
     variables, so for example @{ $host_obj->aliases() } would be simply
     @h_aliases.

     The gethost() funtion is a simple front-end that forwards a numeric
     argument to gethostbyaddr() by way of Socket::inet_aton, and the rest to
     gethostbyname().

     To access this functionality without the core overrides, pass the use an
     empty import list, and then access function functions with their full
     qualified names.  On the other hand, the built-ins are still available
     via the CORE:: pseudo-package.

EXAMPLES
      use Net::hostent;
      use Socket;

      @ARGV = ('netscape.com') unless @ARGV;

      for $host ( @ARGV ) {

         unless ($h = gethost($host)) {
             warn "$0: no such host: $host\n";
             next;
         }

         printf "\n%s is %s%s\n",
                 $host,
                 lc($h->name) eq lc($host) ? "" : "*really* ",
                 $h->name;




                                                                        Page 1

Net::hostent(3)                                                Net::hostent(3)



         print "\taliases are ", join(", ", @{$h->aliases}), "\n"
                     if @{$h->aliases};

         if ( @{$h->addr_list} > 1 ) {
             my $i;
             for $addr ( @{$h->addr_list} ) {
                 printf "\taddr #%d is [%s]\n", $i++, inet_ntoa($addr);
             }
         } else {
             printf "\taddress is [%s]\n", inet_ntoa($h->addr);
         }

         if ($h = gethostbyaddr($h->addr)) {
             if (lc($h->name) ne lc($host)) {
                 printf "\tThat addr reverses to host %s!\n", $h->name;
                 $host = $h->name;
                 redo;
             }
         }
      }


NOTE
     While this class is currently implemented using the Class::Struct module
     to build a struct-like class, you shouldn't rely upon this.

AUTHOR
     Tom Christiansen



























                                                                        Page 2