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*() func‐
7       tions
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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 simi‐
16       larly named structure field name from the C's hostent structure from
17       netdb.h; namely name, aliases, addrtype, length, and addr_list.  The
18       aliases and addr_list methods return array reference, the rest scalars.
19       The addr method is equivalent to the zeroth element in the addr_list
20       array reference.
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22       You may also import all the structure fields directly into your names‐
23       pace as regular variables using the :FIELDS import tag.  (Note that
24       this still overrides your core functions.)  Access these fields as
25       variables named with a preceding "h_".  Thus, "$host_obj->name()" cor‐
26       responds 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 mod‐
80       ule 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 v5.8.8                       2001-09-21                 Net::hostent(3pm)
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