<?php
for($i=0;$i<20;$i++)
{
echo 'printing...<br />';
ob_flush();
flush();
usleep(300000);
}
?>
Url that contains the code: http://domainsoutlook.com/sandbox/delayed.php
I have a dedicated server so I can make the changes. I am running apache and nginx as the proxy server.
So if anyone ever stumbles on this forum because they are having the same issue let me explain what and why it went wrong.
If you include a function not in your directory(e.g c:// or file://) but instead include using http. The include can only return what was echoed in the file, but something like a variable or function will not be shown. So always include functions and variables through a directory
Documentation for flush() says:
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.
In your case you can replace flush() with ob_flush() as I don't think you are looking to flush the system output buffers.
As a little extra this code:
$content = ob_get_contents();
ob_end_clean();
Can be condensed into one function call that is an alias for both of the previous commands combined:
$content = ob_get_clean();
Documentation for ob_get_clean()
FINAL SOLUTION
So that's what I found out:
Flush would not work under Apache's mod_gzip or Nginx's gzip because, logically, it is gzipping the content, and to do that it must buffer content to gzip it. Any sort of web server gzipping would affect this. In short, at the server side, we need to disable gzip and decrease the fastcgi buffer size. So:
In php.ini:
. output_buffering = Off
. zlib.output_compression = Off
In nginx.conf:
. gzip off;
. proxy_buffering off;
Also have this lines at hand, specially if you don't have acces to php.ini:
@ini_set('zlib.output_compression',0);
@ini_set('implicit_flush',1);
@ob_end_clean();
set_time_limit(0);
Last, if you have it, coment the code bellow:
ob_start('ob_gzhandler');
ob_flush();
PHP test code:
ob_implicit_flush(1);
for($i=0; $i<10; $i++){
echo $i;
//this is for the buffer achieve the minimum size in order to flush data
echo str_repeat(' ',1024*64);
sleep(1);
}
Related:
php flush not working
How to flush output after each `echo` call?
PHP flushing output as soon as you call echo
From PHP Manual:
flush() may not be able to override the buffering scheme of your web server and it has no effect on any client-side buffering in the browser. It also doesn't affect PHP's userspace output buffering mechanism. This means you will have to call both ob_flush() and flush() to flush the ob output buffers if you are using those.
echo "Hello!";
flush();
ob_flush();
for($i = 0; $i < 10; $i ++) {
echo $i;
//5-10 sec execution time
flush();
ob_flush();
}
-or- you can flush and turn off Buffering
<?php
//Flush (send) the output buffer and turn off output buffering
while (ob_get_level() > 0)
ob_end_flush();
echo "Hello!";
for($i = 0; $i < 10; $i ++) {
echo $i . "rn";
}
?>
You're using
ob_flushwithoutob_start, so there is nothing to flush for it.It also depends on the webserver and proxy and its settings.
You should disable buffering for Nginx (add
proxy_buffering off;to the config file and restart Nginx)Also, check if your php.ini contains
output_buffering = Offandzlib.output_compression = Off.