flush
(PHP 4, PHP 5, PHP 7, PHP 8)
Flush system output buffer
Description
Flushes the system write buffers of PHP and the backend used by PHP (e.g.: CGI, a web server). In a command line environment flush() will attempt to flush the contents of the buffers only whereas in a web context headers and the contents of the buffers are flushed.
flush() may not be able to override the buffering scheme of the web server and it has no effect on any client-side buffering in the browser.
This function does not have any effect on user level output handlers such as those started by ob_start() or output_add_rewrite_var().
flush() can interfere with output handlers that set and send headers in a web context (e.g. ob_gzhandler()) by sending headers before these handlers can do so.
Parameters Parameters
Return Values
Void
Changelog
| Version | Description |
|---|---|
| 8.4.0 | Flushing headers without a body will now succeed in FastCGI. |