Php predefines $ _ SERVER instances. all instances starting with $ _ SERVER are predefines service variables.

: This article mainly introduces php pre-defined $ _ SERVER instances. all instances starting with $ _ SERVER are pre-defined service variables ., If you are interested in the PHP Tutorial, refer.

 ". Error_reporting (E_ALL )."
"; Echo" PHP_SELF => ". $ _ SERVER ['php _ SELF ']."
"; # File name of the script being executed, which is related to document root. Echo "argv =>". $ _ SERVER ['argv']."
"; # Parameters passed to the script. Echo "argc =>". $ _ SERVER ['argc ']."
"; # Contains the number of command line parameters passed to the program (if running in command line mode ). Echo "GATEWAY_INTERFACE =>". $ _ SERVER ['gateway _ interface']."
"; # The CGI standard version used by the server. For example, "CGI/1.1 ". Echo "SERVER_NAME =>". $ _ SERVER ['server _ name']."
"; # Name of the server host where the script is currently running. Echo "SERVER_SOFTWARE =>". $ _ SERVER ['server _ soft']."
"; # The string identified by the server, which is provided in the header of the response request. Echo "SERVER_PROTOCOL =>". $ _ SERVER ['server _ protocol']."
"; # Name and version of the communication protocol on the request page. For example, "HTTP/1.0 ". Echo "REQUEST_METHOD =>". $ _ SERVER ['request _ method']."
"; # Request method for accessing the page. For example, "GET", "HEAD", "POST", and "PUT ". Echo "REQUEST_TIME =>". date ("Y-m-d H: s: I", $ _ SERVER ['request _ time'])."
"; # Request start timestamp echo" QUERY_STRING => ". $ _ SERVER ['query _ string']."
"; # Query string. Echo "DOCUMENT_ROOT =>". $ _ SERVER ['document _ root']."
"; # The root directory of the document where the script is currently running. Defined in the server configuration file. Echo "HTTP_ACCEPT =>". $ _ SERVER ['http _ ACCEPT ']."
"; # Accept of the current request: content in the header. Echo "HTTP_ACCEPT_CHARSET =>". $ _ SERVER ['http _ ACCEPT_CHARSET ']."
"; # Accept-Charset of the current request: content in the header. Example: "ISO-8859-1, *, UTF-8 ". Echo "HTTP_ACCEPT_ENCODING =>". $ _ SERVER ['http _ ACCEPT_ENCODING ']."
"; # Accept-Encoding of the current request: content in the header. For example, "gzip ". Echo "HTTP_ACCEPT_LANGUAGE =>". $ _ SERVER ['http _ ACCEPT_LANGUAGE ']."
"; # Accept-Language of the current request: content in the header. For example, "en ". Echo "HTTP_C> $ _ SERVER ['http _ connection']."
"; # Connection of the current request: content in the header. For example, "Keep-Alive ". Echo "HTTP_HOST =>". $ _ SERVER ['http _ host']."
"; # Host of the current request: content in the header. Echo "HTTP_REFERER =>". $ _ SERVER ['http _ referer']."
"; # The URL of the previous page to which the tag is redirected. Echo "HTTP_USER_AGENT =>". $ _ SERVER ['http _ USER_AGENT ']."
"; # User-Agent of the current request: content in the header. Echo "HTTPS =>". $ _ SERVER ['https']."
"; # If you access through https, it is set to a non-null value (on); otherwise, offecho" REMOTE_ADDR => "is returned ". $ _ SERVER ['remote _ ADDR ']."
"; # Browsing the IP address of the user on the current page. Echo "REMOTE_HOST =>". $ _ SERVER ['remote _ host']."
"; # The host name of the user browsing the current page. Echo "REMOTE_PORT =>". $ _ SERVER ['remote _ port']."
"; # The port used by the user to connect to the server. Echo "SCRIPT_FILENAME =>". $ _ SERVER ['script _ filename']."
"; # The absolute path name of the currently executed script. Echo "SERVER_ADMIN =>". $ _ SERVER ['server _ admin']."
"; # Administrator information echo" SERVER_PORT => ". $ _ SERVER ['server _ port']."
"; # Echo" SERVER_SIGNATURE => ". $ _ SERVER ['server _ SIGNATURE ']."
"; # A string containing the server version and virtual host name. Echo "PATH_TRANSLATED =>". $ _ SERVER ['path _ TRANSLATED ']."
"; # 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']."
"; # Contains the path of the current script. This is useful when the page needs to point to itself. Echo "REQUEST_RUI =>". $ _ SERVER ['request _ URI ']."
"; # URI required to access this page. For example, "/index.html ". Echo "_ FILE __=>". _ FILE __."
";

The preceding section describes the php predefined $ _ SERVER instance. all instances starting with $ _ SERVER are predefined service variables ., Including some content, hope to be helpful to friends who are interested in PHP tutorials.