sub test_fixed_block_read($)
{
    my $block_size=$_[0];
    open TIN,"<$test_file";
    binmode TIN;
    my ($data, $n);
    my $newlinecount=0;
    my $block_ends_with_eol=0;
    while ((read TIN, $data, $_[0]) != 0)
    {
        $block_ends_with_eol=1 if (substr $data,-1,1) eq "\n";
        $newlinecount+=($data =~ tr/\012//);
    }
    close(TIN);
    $newlinecount++ if (!$block_ends_with_eol);
    print ">>>test_fixed_block_read: $newlinecount\n";
}

sub test_fixed_block_sysread($)
{
    my $block_size=$_[0];
    open TIN,"<$test_file";
    my ($data, $n);
    my $newlinecount=0;
    my $block_ends_with_eol=0;
    while ((sysread TIN, $data, $_[0]) != 0)
    {
        $block_ends_with_eol=1 if (substr $data,-1,1) eq "\n";
        $newlinecount+=($data =~ tr/\012//);
    }
    close(TIN);
    $newlinecount++ if (!$block_ends_with_eol);
    print ">>>test_fixed_block_sysread: $newlinecount\n";
}