一些重要的数组

$_COOKIE[] the cookies send by clients

$_ENV[], example $_ENV["HOSTNAME"]

$_FILES[], used for upload files

error, name, size, tmp_name, type. Example $_FILES["formvalue"]["name"]

$_GET[], the values posted by HTTP GET method

$_POST[], the values posted by HTTP POST method

$_REQUEST[], combines _GET, _POST, _COOKIES, _FILES

$SERVER

$_SERVER["DOCUMENT_ROOT"] = /var/www/html

HTTP_ACCEPT = "*/*"

HTTP_ACCEPT_CHARSET

HTTP_ACCEPT_ENCODING

HTTP_ACCEPT_LANGUAGE

HTTP_CONNECTION = Keep-Alive

HTTP_HOST

HTTP_REFERER

HTTP_USER_AGENT

PHP_AUTH_PW

PHP_AUTH_TYPE

PHP_AUTH_USER

PHP_SELF

QUERY_STRING

REMOTE_ADDR

REMOTE_PORT

REQUEST_METHOD

REQUEST_URI

SERVER_ADMIN ( email address )

SERVER_NAME

SERVER_PORT

SERVER_PROTOCOL

SERVER_SIGNATURE // banner of the server

$_SESSION[]