A hint for PHP beginners like me:
The buffered output which is write by fflush() has nothing to do with the output buffer which is initiated by the ob_start() function.
(PHP 4 >= 4.0.1, PHP 5, PHP 7, PHP 8)
fflush — Força a liberação do buffer para um arquivo
Esta função força a escrita de toda saída cacheada para o recurso
apontado fluxo de arquivo stream.
streamO ponteiro de arquivo deve ser válido e deve apontar para um arquivo aberto com sucesso por fopen() ou fsockopen() (e ainda não fechado por fclose()).
Exemplo #1 File write example using fflush()
<?php
$filename = 'bar.txt';
$file = fopen($filename, 'r+');
rewind($file);
fwrite($file, 'Foo');
fflush($file);
ftruncate($file, ftell($file));
fclose($file);
?>
A hint for PHP beginners like me:
The buffered output which is write by fflush() has nothing to do with the output buffer which is initiated by the ob_start() function.