Php predefines $ _ SERVER instances. All instances starting with $ _ SERVER are predefines service variables ., _ Server instance
<Style> body {background: # EEE ;}</style> <? Phpheader ("Content-type: text/html; charset = utf8"); echo "error_reporting => ". error_reporting (E_ALL ). "<br>"; echo "PHP_SELF => ". $ _ SERVER ['php _ SELF ']. "<br>"; # File Name of the script being executed, which is related to document root. Echo "argv =>". $ _ SERVER ['argv']. "<br>"; # parameters passed to the script. Echo "argc => ". $ _ SERVER ['argc ']. "<br>"; # contains the number of command line parameters passed to the Program (if it is in command line mode ). Echo "GATEWAY_INTERFACE =>". $ _ SERVER ['Gateway _ interface']. "<br>"; # The CGI standard version used by the SERVER. For example, "CGI/1.1 ". Echo "SERVER_NAME =>". $ _ SERVER ['server _ name']. "<br>"; # NAME of the SERVER host on which the script is currently running. Echo "SERVER_SOFTWARE =>". $ _ SERVER ['server _ soft']. "<br>"; # the string of the server id, which is provided in the header of the Response Request. Echo "SERVER_PROTOCOL =>". $ _ SERVER ['server _ Protocol']. "<br>"; # name and version of the communication PROTOCOL when requesting the page. For example, "HTTP/1.0 ". Echo "REQUEST_METHOD =>". $ _ SERVER ['request _ method']. "<br>"; # request method when accessing the page. For example, "GET", "HEAD", "POST", and "PUT ". Echo "REQUEST_TIME => ". date ("Y-m-d H: s: I", $ _ SERVER ['request _ time']). "<br>"; # The request start timestamp echo "QUERY_STRING => ". $ _ SERVER ['query _ string']. "<br>"; # query string. Echo "DOCUMENT_ROOT =>". $ _ SERVER ['document _ root']. "<br>"; # ROOT directory of the DOCUMENT where the script is currently running. Defined in the server configuration file. Echo "HTTP_ACCEPT =>". $ _ SERVER ['HTTP _ ACCEPT ']. "<br>"; # Accept of the current request: Content in the header. Echo "HTTP_ACCEPT_CHARSET =>". $ _ SERVER ['HTTP _ ACCEPT_CHARSET ']. "<br>"; # Accept-Charset of the current request: Content in the header. Example: "iso-8859-1, *, UTF-8 ". Echo "HTTP_ACCEPT_ENCODING =>". $ _ SERVER ['HTTP _ ACCEPT_ENCODING ']. "<br>"; # Accept-Encoding of the current request: Content in the header. For example, "gzip ". Echo "HTTP_ACCEPT_LANGUAGE =>". $ _ SERVER ['HTTP _ ACCEPT_LANGUAGE ']. "<br>"; # Accept-Language of the current request: Content in the header. For example, "en ". Echo "HTTP_CONNECTION =>". $ _ SERVER ['HTTP _ connection']. "<br>"; # CONNECTION of the current request: Content in the header. For example, "Keep-Alive ". Echo "HTTP_HOST =>". $ _ SERVER ['HTTP _ host']. "<br>"; # The requested HOST: the content in the header. Echo "HTTP_REFERER =>". $ _ SERVER ['HTTP _ referer']. "<br>"; # The a tag redirects to the URL of the previous page of the current page. Echo "HTTP_USER_AGENT =>". $ _ SERVER ['HTTP _ USER_AGENT ']. "<br>"; # User-Agent of the current request: Content in the header. Echo "HTTPS => ". $ _ SERVER ['https']. "<br>"; # If you access through https, it is set to a non-empty value (on); otherwise, offecho "REMOTE_ADDR =>" is returned ". $ _ SERVER ['remote _ ADDR ']. "<br>"; # browsing the IP address of the user on the current page. Echo "REMOTE_HOST =>". $ _ SERVER ['remote _ host']. "<br>"; # The HOST Name of the user on the current page is being viewed. Echo "REMOTE_PORT =>". $ _ SERVER ['remote _ port']. "<br>"; # The PORT used by the user to connect to the SERVER. Echo "SCRIPT_FILENAME =>". $ _ SERVER ['script _ filename']. "<br>"; # the absolute path name of the currently executed SCRIPT. Echo "SERVER_ADMIN => ". $ _ SERVER ['server _ admin']. "<br>"; # administrator information echo "SERVER_PORT => ". $ _ SERVER ['server _ port']. "<br>"; # The port used by the server echo "SERVER_SIGNATURE => ". $ _ SERVER ['server _ SIGNATURE ']. "<br>"; # a string containing the server version and virtual host name. Echo "PATH_TRANSLATED =>". $ _ SERVER ['path _ TRANSLATED ']. "<br>"; # The basic PATH of the file system where the current script is located (not the root directory of the document. Echo "SCRIPT_NAME =>". $ _ SERVER ['script _ name']. "<br>"; # contains the path of the current SCRIPT. This is useful when the page needs to point to itself. Echo "REQUEST_RUI =>". $ _ SERVER ['request _ URI ']. "<br>"; # URI required to access this page. For example, "/index.html ". Echo "_ FILE __=>". _ FILE _. "<br> ";