use strict;
use warnings;

use Socket;

my @handles;
for (0..9) {
    open($handles[$_], '<', $0) or die;
    print("$_: ", fileno($handles[$_]), "\n");
}

print("--\n");

close($handles[5]);

socket(my $mysocket, PF_INET, SOCK_STREAM, getprotobyname('tcp')) or die;
print(fileno($mysocket), "\n");