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



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 refer-ence. reference.
       ence.

       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(3pm)