<?php

$randomData = function($count, $length = 8) {
	for($c = 0; $c < $count; $c++) {
		$data = '';
		for ($l = 0; $l < $length; $l++) {
			$data .= rand(0, 9);
		}
		yield $data;
}};

foreach($randomData(600, 100) as $str) {
	echo $str;
}