# same as chunk_size => 1 in MCE
$n_lines = mce_read $fh, \@lines, 1;

# read max 500 lines
$n_lines = mce_read $fh, \@lines, 500;

# read 1m, including till the end of line
$n_lines = mce_read $fh, \@lines, '1m';

# read 16k, ditto regarding till the end of line
$n_lines = mce_read $fh, \@lines, '16k';

# same thing as above, but slurp into $buf
$n_chars = mce_read $fh, $buf, 500;
$n_chars = mce_read $fh, $buf, '1m';
$n_chars = mce_read $fh, $buf, '16k';

$. gives chunk_id