I can’t for the life of me get the PHP flush function to work properly, using WAMP. Here is some sample code, commented out are all of the different things I’ve tried:
//apache_setenv('no-gzip', 1); // returns error that apache_setenv does not exist
//ini_set('zlib.output_compression',0);
//ini_set('implicit_flush',1);
//ob_end_clean();
//for ($i = 0; $i < ob_get_level(); $i++) { ob_end_flush(); }
//ob_implicit_flush(1);
set_time_limit(0);
echo "<pre>";
for ($i = 0; $i < 100; ++$i) {
echo $i.' '.time().str_repeat(' ',256)."\n";
//ob_flush(); // returns error without output buffering enabled
flush();
usleep(100000);
}
It seems no matter what I do, I always get the results all together in one giant chunk.
Edit:
I’ve uploaded the same exact code to a server running on cPanel/linux, and it works perfect in all browsers. Why can’t I get it to work properly on a localhost WAMP server??
flush() may not be able to override the buffering scheme of your web server and it has no effect on any client-side buffering in the browser. It also doesn’t affect PHP’s userspace output buffering mechanism. This means you will have to call both ob_flush() and flush() to flush the ob output buffers if you are using those.
Several servers, especially on Win32, will still buffer the output from your script until it terminates before transmitting the results to the browser.
Server modules for Apache like mod_gzip may do buffering of their own that will cause flush() to not result in data being sent immediately to the client.
Even the browser may buffer its input before displaying it. Netscape, for example, buffers text until it receives an end-of-line or the beginning of a tag, and it won’t render tables until the tag of the outermost table is seen.
Some versions of Microsoft Internet Explorer will only start to display the page after they have received 256 bytes of output, so you may need to send extra whitespace before flushing to get those browsers to display the page.