$ _ S E R V E R F I R S T O F F, W H AT I S A S U P E R G L O B - - PowerPoint PPT Presentation

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May 27, 2023 199 likes •292 views

S U P E R _ G L O B A L S : $ _ S E R V E R F I R S T O F F, W H AT I S A S U P E R G L O B A L ? ? ? A super global is always available to the PHP code for a page. They are built-in variables. Examples: $_GET & $_POST

SLIDE 1

$ _ S E R V E R

S U P E R _ G L O B A L S :

SLIDE 2

F I R S T O F F, W H AT I S A S U P E R G L O B A L ? ? ?

A super global is always

available to the PHP code for a page.

They are built-in variables.
Examples: $_GET &

$_POST (look familiar??)

Image from http://www.php5dp.com/design-patterns-scope-globals-and-superglobals-in-php/

SLIDE 3

W H AT I S $ _ S E R V E R ?

$_SERVER is a Superglobal array that holds

headers, paths, and script locations.

In other words it holds the information that

you could find in a header, the url, and secure web server type things (https).

The information is provided by the Web

Server so sometimes you won’t get what you are looking for.

There are many elements you can find in

$_SERVER, for example the IP address, or what revision of CGI the server is using.

SLIDE 4

E X A M P L E # 1

<!DOCTYPE html> <html> <body> <?php echo $_SERVER['PHP_SELF']; echo " "; echo $_SERVER['SERVER_NAME']; echo " "; echo $_SERVER['HTTP_HOST']; echo " "; echo $_SERVER['HTTP_REFERER']; echo " "; echo $_SERVER['HTTP_USER_AGENT']; echo " "; echo $_SERVER['SCRIPT_NAME']; ?> </body> </html> /php/demo_global_server.php www.w3schools.com www.w3schools.com http://www.w3schools.com/php/ showphp.asp? filename=demo_global_server Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/42.0.2311.90 Safari/ 537.36 /php/demo_global_server.php

Result: Code:

From http://www.w3schools.com/php/showphp.asp?filename=demo_global_server

SLIDE 5

W H E N D O W E U S E I T ? W H Y ?

We can use it to gather and display needed

data about the website and server.

We can use it to check for, and then create a

secure connection.

We can use it to create better security and

fix bugs.

SLIDE 6

S Y N TA X …

To assign it to a Variable: $variable = $_SERVER [‘ELEMENT’] To use it with filter input: $variable = filter_input(INPUT_SERVER, ‘ELEMENT’);

SLIDE 7

S O M E E L E M E N T S O F $ _ S E R V E R …

Y O U C A N F I N D A L L O F T H E M O N T H E P H P. N E T W E B S I T E .

‘REQUEST_TIME’: The timestamp of

the start of the request. Available since PHP 5.1.0.

‘REQUEST_TIME_FLOAT’: The

timestamp of the start of the request, with microsecond precision. Available since PHP 5.4.0.

‘QUERY_STRING’: The query string, if

any, via which the page was accessed.

‘DOCUMENT_ROOT’: The document

root directory under which the current script is executing, as defined in the server's configuration file.

‘HTTP_ACCEPT’: Contents of the

Accept: header from the current request, if there is one.

‘HTTP_ACCEPT_CHARSET’: Contents
f the Accept-Charset: header from

the current request, if there is one. Example: 'iso-8859-1,*,utf-8'.

‘HTTP_ACCEPT_ENCODING’:

Contents of the Accept-Encoding: header from the current request, if there is one. Example: 'gzip'.

‘HTTP_ACCEPT_LANGUAGE’:

Contents of the Accept-Language: header from the current request, if there is one. Example: 'en'.

SLIDE 8

E X A M P L E # 2 - R E D I R E C T I N G T O S E C U R E C O N N E C T I O N

<?php $https = filter_input (INPUT_SERVER, ‘HTTPS’); if (!$https) { $host = filter_input (INPUT_SERVER, ‘HTTP_HOST’); $uri = filter_input (INPUT_SERVER, ‘REQUEST_URI’); $url = ‘https://' . $host . $uri; header (“Location: “ . $url); exit(); } ?>

Code:

From Murach’s PHP and MySQL 2nd Edition pg. 691

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