Question

Is it possible to have print_r() displayed live. By live I mean while the script is executed. I do not want to wait the end of the script to have it displayed. Hope I am clear. Thank you in advance for your replies. Cheers. Marc

Answer 1

Likely you are using PHP through a webserver like Apache.

Webservers have caching implemented, they tend to send their data out in larger blocks.
Browsers also have caching implemented, they only refresh the data from time to time and at the end when they finished loading the website.
Finally PHP also has caching built in.

HTTP was not made for “live” display it’s more like a static page, that’s why people invented “AJAX” and Javascript to poll for changed/live events after a page was loaded.

What you can do:

1. To make sure the data from PHP is sent to the webserver you can use the command flush()
   There is also a php setting called implicit_flush you might want to look up.
2. The webserver is likely using gzip/mod_gzip to compress output. You need to disable that behaviour.
   Maybe that will do it: @apache_setenv('no-gzip', 1);
3. Add some more content than just pure text, if you put the data inside a simple “table” including </table> it’s more likely browsers will display it during load.
4. Look in php ini for this:
   output_buffering = Off
zlib.output_compression = Off
   You can do this at runtime too (@ini_set('zlib.output_compression', 0);)
5. Some browsers will only display data if they receive a certain amount of bytes.
   If I recall right 256 byte might help.
   str_repeat(" ", 256); (or anything else)

I’d like to add that these steps can help solve the issue but from my experience the results are not perfect.
Every new browser and browser version might act different.