Show contents while PHP script is running

print2.php

<?php

/**
 * Show contents while PHP script is running
 * I found someday this script with MIT license but I lost the reference.
 * It's mean I am not the author of this script, I just adapted for my own usage.
 *
 * PHP Version 7.4
 *
 * @category  Function
 * @package   Print2
 * @author    Nhu-Hoai Robert Vo <nhuhoai.vo@nhuvo.ch>
 * @copyright 2021 Nhu-Hoai Robert Vo
 * @license   https://spdx.org/licenses/MIT.html MIT License
 * @version   0.1.0
 * @link      https://www.nhuvo.ch/
 * @since     0.1.0
 */

/**
 * Fush data and display contents
 *
 * @return void
 */
function doFlush() : void
{
  if (!headers_sent()) {
		// Disable gzip in PHP
		ini_set("zlib.output_compression", 0);

		// Force disable compression in a header
		header("Content-Encoding: none");
	}

	// Fill-up 4 kB buffer, if you have a lot of conntents to display
  // Please increase the buffer size
	echo str_pad("", 4096);

	// Flush all buffers
	do {
		$flushed = @ob_end_flush();
	} while ($flushed);

	@ob_flush();
	flush();
}

/**
 * Show your text
 *
 * @param mixed $contents Contents to print
 *
 * @return void
 */
function print2($contents) : void
{
  print $contents;
  doFlush();
}

print2_example.php

<?php

/**
 * Show contents while PHP script is running (example)
 *
 * PHP Version 7.4
 *
 * @category  Function
 * @package   Print2
 * @author    Nhu-Hoai Robert Vo <nhuhoai.vo@nhuvo.ch>
 * @copyright 2021 Nhu-Hoai Robert Vo
 * @license   https://spdx.org/licenses/MIT.html MIT License
 * @version   0.1.0
 * @link      https://www.nhuvo.ch/
 * @since     0.1.0
 */

require_once __DIR__ . DIRECTORY_SEPARATOR . "print2.php";

$br = "<br />";
if (php_sapi_name() == "cli") {
  $br = "\n";
}

print2("Waiting 5 seconds...{$br}");
sleep(1);
print2("4{$br}");
sleep(1);
print2("3{$br}");
sleep(1);
print2("2{$br}");
sleep(1);
print2("1{$br}");
sleep(1);
print2("Tadaaaa");