Split huge csv vertically

split.php

<?php

$split_on_column = 150; // on which column we split

$fp = fopen('big.csv', 'r');  // input
$f1 = fopen('out1.csv', 'w'); // output1
$f2 = fopen('out2.csv', 'w'); // output2 


while ($row = fgetcsv($fp)) {
	fputcsv($f1, array_slice($row, 0, $split_on_column));
	fputcsv($f2, array_slice($row, $split_on_column));
}

fclose($fp);
fclose($f1);
fclose($f2);

// END