gistfile1.php

<?php

// Headings and rows
$headings = array('ID', 'Name', 'Colour');
$array = array(
  array(1, 'Apple', 'Green'),
  array(2, 'Banana', 'Yellow'),
  array(3, 'Orange', 'Orange'),
);

// Open the output stream
$fh = fopen('php://output', 'w');
        
// Start output buffering (to capture stream contents)
ob_start();
        
fputcsv($fh, $headings);
        
// Loop over the * to export
if (! empty($array)) {
  foreach ($array as $item) {
    fputcsv($fh, $item);
  }
}
        
// Get the contents of the output buffer
$string = ob_get_clean();
        
$filename = 'csv_' . date('Ymd') .'_' . date('His');
        
// Output CSV-specific headers
header("Pragma: public");
header("Expires: 0");
header("Cache-Control: must-revalidate, post-check=0, pre-check=0");
header("Cache-Control: private",false);
header("Content-Type: application/octet-stream");
header("Content-Disposition: attachment; filename=\"$filename.csv\";" );
header("Content-Transfer-Encoding: binary");

exit($string);