Variables and some applicable methods in php_PHP tutorial

Variable: $_SERVER, used in PHP 4.1.0 and later versions. In previous versions, use $HTTP_SERVER_VARS
Variable: $_ENV, used in PHP 4.1.0 and later versions. In previous versions, use $HTTP_ENV_VARS
Variable: $_COOKIE, used in PHP 4.1.0 and later versions. In previous versions, use $HTTP_COOKIE_VARS
Variable: $_GET, used in PHP 4.1.0 and later versions. In previous versions, use $HTTP_GET_VARS
Variable: $_POST, used in PHP 4.1.0 and later versions. In previous versions, use $HTTP_POST_VARS
Variable: $_FILES, used in PHP 4.1.0 and later versions. In previous versions, use $HTTP_POST_FILES
variable: $_REQUEST, used in PHP 4.1.0 and later versions. In previous versions, there was no equivalent array
variable: $_SESSION, used in PHP 4.1.0 and later versions. Previous versions, use $HTTP_SESSION_VARS
Variables: $GLOBALS $GLOBALS Applicable in PHP 3.0.0 and later versions


Detailed usage of $_SERVER in PHP:
$_SERVER[' PHP_SELF'] #The file name of the currently executing script, related to document root.
$_SERVER['argv'] #The parameters passed to the script.
$_SERVER['argc'] #Contains the number of command line arguments passed to the program (if running in command line mode).
$_SERVER['GATEWAY_INTERFACE'] #The version of the CGI specification used by the server. For example, "CGI/1.1".
$_SERVER['SERVER_NAME'] #The name of the server host where the script is currently running.
$_SERVER['SERVER_SOFTWARE'] #The string of server identification, given in the header when responding to the request.
$_SERVER['SERVER_PROTOCOL'] #The name and version of the communication protocol when requesting the page. For example, "HTTP/1.0".
$_SERVER['REQUEST_METHOD'] #Request method when accessing the page. For example: "GET", "HEAD", "POST", "PUT".
$_SERVER['QUERY_STRING'] #Query string.
$_SERVER['DOCUMENT_ROOT'] #The document root directory where the currently running script is located. Defined in the server configuration file.
$_SERVER['HTTP_ACCEPT'] #The content of the Accept: header of the current request.
$_SERVER['HTTP_ACCEPT_CHARSET'] #The content of the Accept-Charset: header of the current request. For example: "iso-8859-1,*,utf-8".
$_SERVER['HTTP_ACCEPT_ENCODING'] #The content of the Accept-Encoding: header of the current request. For example: "gzip".
$_SERVER['HTTP_ACCEPT_LANGUAGE']#The content of the Accept-Language: header of the current request. For example: "en".
$_SERVER['HTTP_CONNECTION'] #The content of the Connection: header of the current request. For example: "Keep-Alive".
$_SERVER['HTTP_HOST'] #The content of the Host: header of the current request.
$_SERVER['HTTP_REFERER'] #The URL address of the previous page linked to the current page.
$_SERVER['HTTP_USER_AGENT'] #The content of the User_Agent: header of the current request.
$_SERVER['REMOTE_ADDR'] #The IP address of the user who is browsing the current page.
$_SERVER['REMOTE_HOST'] #The host name of the user who is browsing the current page.
$_SERVER['REMOTE_PORT'] #The port used by users to connect to the server.
$_SERVER['SCRIPT_FILENAME'] #The absolute path name of the currently executing script.
$_SERVER['SERVER_ADMIN'] #Administrator information
$_SERVER['SERVER_PORT'] #Port used by the server
$_SERVER['SERVER_SIGNATURE'] #Contains characters for the server version and virtual host name string.
$_SERVER['PATH_TRANSLATED'] #The base path of the file system (not the document root directory) where the current script is located.
$_SERVER['SCRIPT_NAME'] #Contains the path of the current script. This is useful when the page needs to point to itself.
$_SERVER['REQUEST_URI'] #The URI required to access this page. For example, "/index.html".
$_SERVER['PHP_AUTH_USER'] #When PHP is running in Apache module mode and is using the HTTP authentication function, this variable is the username entered by the user.
$_SERVER['PHP_AUTH_PW'] #When PHP is running in Apache module mode and is using the HTTP authentication function, this variable is the password entered by the user.
$_SERVER['AUTH_TYPE'] #When PHP is running in Apache module mode and is using the HTTP authentication function, this variable is the authentication type.