PHP将列附加到CSV文件的末尾

I have a CSV file in the php server

Want to Add "h3" at the end and fill the row with data "data3"

here is the structure

  H1      H2   (h3)
  XXX     XXX   data3
  xxx     xxx   data3

I am trying with the following code for a long time, havent get any luck yet

<?php
$newCsvData = array();
if (($handle = fopen("file.csv", "r")) !== FALSE) {
    while (($data = fgetcsv($handle, 1000, ",")) !== FALSE) {
        $data[] = 'report_type';
        $newCsvData[] = $data;
    }
    fclose($handle);
}

$handle = fopen('test.csv', 'w');

foreach ($newCsvData as $line) {
    fputcsv($handle, $line);
}

fclose($handle);
?>

Please advice