Save CSV directly in the browser with PHP

/**
 * Saves CSV directly in the browser.
 *
 * @see https://wpcodebook.com/php-save-csv-directly-browser/
 * @see https://www.php.net/manual/en/function.header.php
 */
function wpcodebook_save_csv_in_browser( $csv, $filename = 'output.csv' ) {

	// Headers
	header( 'Content-Description: File Transfer' );
	header( 'Content-Type: application/octet-stream' );
	header( 'Content-Disposition: attachment; filename=' . $filename );
	header( 'Content-Transfer-Encoding: binary' );
	header( 'Expires: 0' );
	header( 'Cache-Control: must-revalidate, post-check=0, pre-check=0' );
	header( 'Pragma: public' );
	header( 'Content-Length: ' . strlen( $csv ) );

	// Content
	echo $csv;

	// Exit
	die();

}

// Data (array)
$head = array( 'Name', 'Height', 'Weight' );
$data = array(
	array( 'Leia', '150', '49' ),
	array( 'Luke', '172', '77' ),
	array( 'Han',  '180', '80' ),
);
array_unshift( $data, $head );

// Convert array to csv
$sep = ',';
foreach ( $data as &$row ) {
	$row = implode( $sep, $row );
}
$csv = implode( PHP_EOL, $data );

// Save CSV in browser
wpcodebook_save_csv_in_browser( $csv );