perl 利用函数将获取主机名转换为ip

  inet_aton()    转换，转换压缩为二进制形式，也可以将主机名转换为压缩的ip地址

  gethostbyname     将符号型主机名转换为压缩的ip地址

  gethostbyaddr     作相反的转换

  inet_ntoa     转换为可阅读的“圆点四元组”

[root@jzlfs perl]# cat gethostbyname.pl 

#!/usr/bin/perl -w 

use Socket;

while(<>){

chomp;

my $packed_address = gethostbyname($_);

unless ($packed_address){

print "$_ => ?\n";

next

}

  my $dotted_quad = inet_ntoa($packed_address);

  print "$_ => $dotted_quad \n";

} 

测试：

perl gethostbyname.pl < hostname.txt 

=> 192.168.1.222 

2.将ip转换为主机名

#!/usr/bin/perl -w 

use Socket;

my $ADDR_PAT = '^/d \. \d \. \d \.\d $';

while (<>){

chomp;

die "$_: not a valid address" unless /$ADDR_PAT/o;

my $name = gethostbyaddr(inet_aton($_),AF_INET);

$name ||= '?';

print "$_ => $name \n";

}