(PHP 4 >= 4.2.0, PHP 5, PHP 7, PHP 8)
ob_flush — Flush (send) the return value of the active output handler
This function calls the output handler
(with the PHP_OUTPUT_HANDLER_FLUSH
flag),
flushes (sends) it's return value
and discards the contents of the active output buffer.
This function does not turn off the active output buffer like ob_end_flush() or ob_get_flush() does.
ob_flush() will fail
without an active output buffer started with the
PHP_OUTPUT_HANDLER_FLUSHABLE
flag.
This function has no parameters.
If the function fails it generates an E_NOTICE
.