Hyper-Global variables in PHP
The super global variable in PHP starts with PHP 4.2.0, the default value of Register_globals is off, so many variables that can be used directly, such as $PHP _self or the session variable you set, cannot be accessed in the form of "$ variable name". This may give you a lot of the same, but it can help improve safety. To access these variables, you need to use a PHP super global variable, as follows:
$_server
Variables are set by the WEB server or directly associated with the execution environment of the current script. An array $HTTP _server_vars similar to the old array. The previous $php_self corresponds to $_server[' php_self ', and you can use Phpinfo to view your $_server variables.
$_get
A variable that is submitted to the script via the HTTP GET method. An array $HTTP _get_vars similar to the old array.
$_post
A variable that is submitted to the script via the HTTP POST method. An array $HTTP _post_vars similar to the old array.
$_cookie
A variable that is submitted to the script via the HTTP cookie method. An array $HTTP _cookie_vars similar to the old array.
$_session
The variable currently registered to the script session. An array $HTTP _session_vars similar to the old array.
$_files
A variable that is submitted to the script via an HTTP POST file upload. An array $HTTP _post_files similar to the old array.
$_env
Executes the variables that the environment submits to the script. An array $HTTP _env_vars similar to the old array.
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For $_files variables: (The File Field field is "MyFile")
$_files[' myfile ' [' Name ']
The original name of the client machine file (including the path).
$_files[' myfile ' [' type ']
The MIME type of the file requires the browser to provide support for that information, such as "Image/gif".
$_files[' myfile ' [' Size ']
The size of the uploaded file, in bytes.
$_files[' myfile ' [' Tmp_name ']
Temporary file names (including paths) stored on the server after the files have been uploaded.
$_files[' myfile ' [' Error ']
The error code associated with the file upload. [' ERROR '] was added in version PHP 4.2.0.
When register_globals in PHP.ini is set to ON, the $myfile _name is equivalent to $_files[' myfile ' [' name '], $myfile _type equivalent to $_files[' myfile ' [' Type '] and so on.
Hyper-Global variables in PHP