uPHP has several special arrays that are populated automatically before the script is run:

$_SERVER - Information about the server and script

$_GET - Parameters passed to the script - this is only applicable for scripts run from the web interface, not from telnet or cron. The maximum number of GET parameters is 7, and the maximum length of each parameter is 32 bytes.

$_POST - Variables submitted to the HTTP script. This can be used to save multiple parameters from a web form.

$_GLOBALS - System-wide global variables that can be used as a shared memory area between scripts. This is only cleared upon a reboot.

Note: This is different from the PHP $GLOBALS - this is truly global and accessible across scripts. $GLOBALS does not exist in uPHP - instead use $_GLOBALS['key_name'] to reference a global script variable.

Tip: If you wish to view the global variables in the system you can execute /scripts/tests/globals.cgi. This simple script shows the entire contents of the $_GLOBALS array, which is useful for learning about the Wattmon system for customizing, programming and debugging purposes.

$_SESSION - Variables defined here are persistent for any web session using a SESSID cookie

$_COOKIES - Cookie data defined to be accessed or passed back to the browser