ref: 使ってないポートを取得する
#!/usr/bin/env perl
use strict;
use warnings;
use v5.14;
use IO::Socket::INET;
sub empty_port () {
my $sock = IO::Socket::INET->new(
Prot => 'tcp',
Listen => 1,
(($^O eq 'MSWin32') ? () : (ReuseAddr => 1)),
);
my $port = $sock->sockport;
$sock->close;
$port;
}
say empty_port;