perl解析ip的经典方法

my $e = qr/[01]?[0-9]?[0-9]|2[0-4][0-9]|25[0-5]/;

my $match_ip = qr/($e)\.($e)\.($e)\.($e)/;

if ( $str =~ /^$match_ip$/ ){

   print "$1,$2,$3,$4.\n";



}