Commonly used environment system variables in php_PHP tutorial

In any development language, there will be some variables of its own. These are called system variables or environment variables. Friends in need can refer to them.

PHP environment variables mainly include $GLOBALS[], $_SERVER[], $_GET[], $_POST[], $_COOKIE[], $_FILES[], $_ENV[], $_REQUEST[], $_SESSION []. $_GET and $_POST are mainly for data submitted by FORM forms, $_COOKIE and $_SESSION are mainly for client browser and server-side session data. $_FILES mainly targets the data submitted when uploading files. $_REQUEST mainly targets all request arrays in the submission form, including all contents in $_GET, $_POST, and $_COOKIE. You can output $_REQUEST or $_COOKIE respectively through the print_r function. Compare.

$_SERVER variable
It is a PHP global environment variable that contains server-side related information. $HTTP_SERVER_VARS is used in versions before PHP4.1.0.

$_SERVER['PHP_SELF']

#The file name of the currently executing script, related to document root. In the FORM form, if the executable file is itself, you can use

in ACTION

$_SERVER['QUERY_STRING']

#Get the query statement, that is, get the value after '?' in the url string

$_SERVER['DOCUMENT_ROOT']

#The document root directory where the currently running script is located. Defined in the server configuration file.

$_SERVER['HTTP_ACCEPT']

#Contents of the Accept: header of the current request.

$_SERVER['HTTP_ACCEPT_CHARSET']

#Contents of the Accept-Charset: header of the current request. For example: "iso-8859-1,*,utf-8".

$_SERVER['HTTP_ACCEPT_ENCODING']

#Contents of the Accept-Encoding: header of the current request. For example: "gzip".

$_SERVER['HTTP_ACCEPT_LANGUAGE']

#Contents of the Accept-Language: header of the current request. For example: "en".

$_SERVER['HTTP_CONNECTION']

#Contents 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']

#Contents of the User_Agent: header of the current request.

$_SERVER['SERVER_NAME']

         #The name of the server host where the currently running PHP program is located.

$_SERVER['REQUEST_METHOD']

#Request method when accessing the page, namely GET, HEAD, POST, PUT.

$_SERVER['DOCUMENT_ROOT']

#The document root directory where the currently running PHP program is located. That is the definition in the PHP.INI file.

$_SERVER['HTTP_REFERER']

#The URL address of the previous page linked to the current page. Very useful in page jump function.

$_SERVER['REMOTE_ADDR']

#The IP address of the visitor 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 the browsing user to connect to the server.

$_SERVER['SCRIPT_FILENAME']

#The absolute path name of the currently executing script.

$_SERVER['SERVER_PORT']

#Port used by the server

$_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. Such as "/index.html".

$_SERVER['PHP_AUTH_USER']

# Applied in the HTTP user login authentication function, this variable is the user name entered by the user.

$_SERVER['PHP_AUTH_PW']

# Applied in the HTTP user login authentication function, this variable is the password entered by the user.

$_SERVER['AUTH_TYPE']

#Apply to the HTTP user login authentication function, this variable is the authentication type.

$_SERVER['SERVER_SOFTWARE']
#The string identifying the server, given in the header when responding to the request.

System constants
__FILE__ The absolute path and file name of the current PHP program script

__LINE__ The line number where the constant is stored

__FUNCTION__ is the name of the function where the constant is stored

__CLASS__ is the name of the class where the constant is stored

PHP_VERSION stores the current PHP version number, which can also be obtained through the PHPVERSION() function.

PHP_OS stores the operating system of the current server

http://www.bkjia.com/PHPjc/629263.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/629263.htmlTechArticleIn any development language, there will be some variables of its own. These are called system variables or environment variables. Friends in need can refer to them. one time. PHP environment variables mainly include $GLOBALS[], $_SERVER[], $_GE...