flush():刷新输出程序缓存for($i = 0; $i < 5; $i++){ echo str_repeat(“\n”, 5000); echo $i; sleep(1); flush();}ob_start(回调函数,限定长度,随时输出缓存=’true’):开启,前提:output_buffer = onob_clear():刷新ob_end_clear():关闭,并刷新ob_flush():输出ob_end_flush():关闭,并输出ob_get_contents:返回缓存ob_get_clean():返回缓存,并刷新ob_get_flush():