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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 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 v5.24.0                      2015-10-14                 Net::hostent(3pm)

perl 5.24 - Generated Fri Nov 18 18:05:38 CST 2016
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