Manual Pages for Linux CentOS command on man Net::hostent
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Manual Pages for Linux CentOS command on man Net::hostent

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 addrlist. The aliases and addrlist methods return array reference, the rest scalars. The addr method is equivalent to the zeroth element in the addrlist 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, "$hostobj->name()"

corresponds to $hname if you import the fields. Array references are available as regular array variables, so for example "@{

$hostobj->aliases() }" would be simply @haliases.

The gethost() function is a simple front-end that forwards a numeric argument to gethostbyaddr() by way of Socket::inetaton, 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->addrlist} > 1 ) {

my $i;

for $addr ( @{$h->addrlist} ) {

printf "\taddr #%d is [%s]\n", $i++, inetntoa($addr); } } else {

printf "\taddress is [%s]\n", inetntoa($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 v5.16.3 2013-02-26 Net::hostent(3pm)




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