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Net::hostent(3perl) Perl Programmers Reference Guide Net::hostent(3perl)
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 v5.20.2 2014-12-27 Net::hostent(3perl)
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