sub choose_host {
    my $chosen_host;
    while ( !defined $chosen_host ) {
        printchoices();
        $chosen_host = hostname_by_num( getchoice() );
    }

    return $chosen_host;
}

# for loop can now be:
sub printchoices {
    print join "\n",
        "\n",
        "ssh hosts",
        "-"x8;

    foreach my $host_num ( 1..num_hosts() ) {
        print "[$host_num] ", hostname_by_num($host_num), "\n" ;
    }
}