Solution to the problem that php ob_flush cannot output every second

$i = 3;
ob_start();
while ($i--) {
 echo $i, "";
 ob_flush();
 flush ();
 sleep(1);
}
ob_end_clean();
?>

Question: Can’t this code be output every second? Cause Analysis: Apache operating principle: After accessing an address (sending a request), PHP is started in the apache server. PHP execution is at the page level. If there is executable code: After it is all executed, it is thrown to apache, and apache is thrown to the browser to display the results.

Solution: If the cli displays results in a different way, what's the difference? linux cmd: php5test.php It can be implemented directly by php without going through apache or web service:

$i = 3;
while ($i--) {
 echo $i, "n";
 sleep(1);
}
ob_end_clean();
?> ;