I am trying to read variable: However normally this variable size is bigger than 256 bit how can I read more than 256
Have you tried using POST instead of GET? Be sure to change your script as well as the method of the form that is sending the information to the script.
Then there's not much you can do... GET has limits I'm afraid and unfortunately, each browser and server seems to have a different limit
I don't know any links off the top of my head, but you'd do better Googling 'http get limitations' or something like that than looking on php.net. It's an HTTP thing, not a PHP thing...
ottodo see here : http://ir.php.net/manual/en/ini.core.php i think admin can limit memory usage by scripts . and see here : http://ir.php.net/manual/en/function.memory-get-usage.php