使用输出处理程序

When invoked, output handlers are passed the contents of the buffer and a bitmask indicating the status of output buffering.

handler ( string $buffer , int $phase = ?): string
buffer
Contents of the output buffer.
phase
Bitmask of PHP_OUTPUT_HANDLER_* constants .

<div class="callout callout-danger mb-3">**警告** Calling any of the following functions from within an output handler will result in a fatal error: ob_clean(), ob_end_clean(), ob_end_flush(), ob_flush(), ob_get_clean(), ob_get_flush(), ob_start().</div>

<div class="callout callout-info mb-3">注意: If the PHP_OUTPUT_HANDLER_DISABLED of a handler is set, the handler will not be invoked by calling ob_end_clean(), ob_end_flush(), ob_get_clean(), ob_get_flush() or during PHP's shutdown process. This flag has no effect on when calling ob_clean() or ob_flush().</div>

<div class="callout callout-info">注意: The working directory of the script can change inside the shutdown function under some web servers, e.g. Apache or the built-in web server.</div>