Perl Socket::inet_aton和inet_ntoa

云中漫步

　　得到DNS地址的两个主要函数是Socket模块中的inet_aton()函数，用来保存DNS地址，然后使用inet_ntoa()函数把保存的地址转换成IP地址。
 
　　l  inet_aton HOSTNAME
　　Takes a string giving the name of a host, and translates that to an opaque string (if programming in C, struct in_addr). Takes arguments of both the 'rtfm.mit.edu' type and '18.181.0.24'. If the host name cannot be resolved, returns undef. For multi-homed hosts (hosts with more than one address), the first address found is returned.
　　For portability do not assume that the result of inet_aton() is 32 bits wide, in other words, that it would contain only the IPv4 address in network order.
　　l  inet_ntoa IP_ADDRESS
　　Takes a string (an opaque string as returned by inet_aton(), or a v-string representing the four octets of the IPv4 address in network order) and translates it into a string of the form 'd.d.d.d' where the 'd's are numbers less than 256 (the normal human-readable four dotted number notation for Internet addresses).

#!/usr/bin/perl -w
use strict;
use Socket;
my $ipdotted    = 'www.wtgame.com';
my $ipnetwork   = inet_aton($ipdotted);
my $revipdotted = inet_ntoa($ipnetwork);
print $ipnetwork,"\n";
print "$ipdotted\n$revipdotted \n";
exit 0;