# RETURNS: ( $stdout, $stderr )  Both are refs to an array of lines.
sub OSexecute {
    my @execute = @_;

    my @stdout;
    my @stderr;

    local $, = ' ';  # for print "...@execute..."

    my $debug = 0;
    #$debug = 1;
    print("OSexecute(@execute)\n") if ($debug);

    # Here is the actual execution.
    my $pid = eval { open3($din, $dout, $derr, @execute) };
    die "OSexecute(@execute): $@" if ($@);

    my $select = IO::Select->new();
    $select->add($dout);
    $select->add($derr);

    my @ready;
    my $fh;

    # Gather the results
    while (@ready = $select->can_read()) {
       foreach $fh (@ready) {
          push(@stdout, <$fh>) if ($fh == $dout);
          push(@stderr, <$fh>) if ($fh == $derr);
       }
    }

    # Wait for process to complete and reap it.
    waitpid($pid, 0);

    # We should check the return code of the child.
    # Gotta trap SIGPIPE for that.

    return ( \@stdout, \@stderr );
}