1Net::hostent(3pm)      Perl Programmers Reference Guide      Net::hostent(3pm)
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NAME

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

10        use Net::hostent;
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DESCRIPTION

13       This module's default exports override the core gethostbyname() and
14       gethostbyaddr() functions, replacing them with versions that return
15       "Net::hostent" objects.  This object has methods that return the
16       similarly named structure field name from the C's hostent structure
17       from netdb.h; namely name, aliases, addrtype, length, and addr_list.
18       The aliases and addr_list methods return array reference, the rest
19       scalars.  The addr method is equivalent to the zeroth element in the
20       addr_list array reference.
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22       You may also import all the structure fields directly into your
23       namespace as regular variables using the :FIELDS import tag.  (Note
24       that this still overrides your core functions.)  Access these fields as
25       variables named with a preceding "h_".  Thus, "$host_obj->name()"
26       corresponds to $h_name if you import the fields.  Array references are
27       available as regular array variables, so for example "@{
28       $host_obj->aliases() }" would be simply @h_aliases.
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30       The gethost() function is a simple front-end that forwards a numeric
31       argument to gethostbyaddr() by way of Socket::inet_aton, and the rest
32       to gethostbyname().
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34       To access this functionality without the core overrides, pass the "use"
35       an empty import list, and then access function functions with their
36       full qualified names.  On the other hand, the built-ins are still
37       available via the "CORE::" pseudo-package.
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EXAMPLES

40        use Net::hostent;
41        use Socket;
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43        @ARGV = ('netscape.com') unless @ARGV;
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45        for $host ( @ARGV ) {
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47           unless ($h = gethost($host)) {
48               warn "$0: no such host: $host\n";
49               next;
50           }
51
52           printf "\n%s is %s%s\n",
53                   $host,
54                   lc($h->name) eq lc($host) ? "" : "*really* ",
55                   $h->name;
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57           print "\taliases are ", join(", ", @{$h->aliases}), "\n"
58                       if @{$h->aliases};
59
60           if ( @{$h->addr_list} > 1 ) {
61               my $i;
62               for $addr ( @{$h->addr_list} ) {
63                   printf "\taddr #%d is [%s]\n", $i++, inet_ntoa($addr);
64               }
65           } else {
66               printf "\taddress is [%s]\n", inet_ntoa($h->addr);
67           }
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69           if ($h = gethostbyaddr($h->addr)) {
70               if (lc($h->name) ne lc($host)) {
71                   printf "\tThat addr reverses to host %s!\n", $h->name;
72                   $host = $h->name;
73                   redo;
74               }
75           }
76        }
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NOTE

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

83       Tom Christiansen
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87perl v5.34.1                      2022-03-15                 Net::hostent(3pm)
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