


Net::hostent(3p) Perl Programmers Reference GuideNet::hostent(3p)


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

SYNOPSIS
        use Net::hostent;

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() function 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* ",



perl v5.10.1                2003-12-02                          1





Net::hostent(3p) Perl Programmers Reference GuideNet::hostent(3p)


                   $h->name;

           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



























perl v5.10.1                2003-12-02                          2


