Variables
Server configuration and request information—including form parameters and cookies—are accessible in three different ways from your PHP scripts, as described in this section. Collectively, this information is referred to as EGPCS (environment, GET, POST, cookies, and server).
If the register_globals
option in
php.ini
is enabled, PHP creates a separate
global variable for every form
parameter, every piece of request information, and every server
configuration value. This functionality is convenient but dangerous,
as it lets the browser provide initial values for any of the
variables in your program. The (negative) effects this can have on
your program’s security are explained in Chapter 12.
Regardless of the setting of
register_globals
, PHP creates six global arrays
that contain the EGPCS information.
The global arrays are:
-
$HTTP_COOKIE_VARS
Contains any cookie values passed as part of the request, where the keys of the array are the names of the cookies
-
$HTTP_GET_VARS
Contains any parameters that are part of a GET request, where the keys of the array are the names of the form parameters
-
$HTTP_POST_VARS
Contains any parameters that are part of a POST request, where the keys of the array are the names of the form parameters
-
$HTTP_POST_FILES
Contains information about any uploaded files
-
$HTTP_SERVER_VARS
Contains useful information about the web server, as described in the next section
-
$HTTP_ENV_VARS
Contains the values of any environment variables, where ...
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