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Net::hostent(3)        Perl Programmers Reference Guide        Net::hostent(3)



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* ",
                   $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 v5.8.8                       2001-09-21                   Net::hostent(3)