PHP: How to Break a URL

How do I get URL elements and any associated parameters?

Two cases may appear: either the URL is in the character string and you want to find its elements, or this is a web script launched to process form data using the POST method, from which you want to extract data.

1) Using the parse_url function

When parsing a URL in a string, two functions come in handy: parse_url and parse_str. The first splits the URL into elements such as Location in JavaScript, the second splits the parameter string into variables and values .

Comparison with JavaScript

The function parse_url to the JavaScript equivalent of a Location object. Associative table keys are replaced by the properties of the Location object.

The complete URL is obtained with the __ constant FILE __ which is global and does not belong to the table created by the parse_url.

Other differences:

• If you add both an internal anchor and parameters, which is incorrect, the set will be associated with a hash in JavaScript and a query in PHP.
In
• The JavaScript protocol includes both points, as in http: but not in PHP.

Using the parse_url Feature

Example:

$url = "https://www.iqlevsha.ru/comment/parser-url.php#content";
$arr = parse_url($url)
print_r($arr);

The result is an associative table, where the keys are described in detail in the previous table.

array(
"scheme" => http,
"host" => www.iqlevsha.ru,
"path" => /comment/parser-url.php,
"fragment" => content
)

Using the parse_str Feature

Example:

$parameters = $arr["query"];

parse_str($parameters, $data);
print_r($data);

$ data is an associative array, where the keys are the variables passed to the parameters, and the values, the contents of these variables.

Exempli gratia:

fichier.php?nom=untel&numero=50

The generated table will be:

array(
"nom" => untel,
"numero" => 50
)

Sources and loading

• Online script source code.
• Local script source code.
• Archive containing sources and demo page.

2) Using the $ _ SERVER variable

The second part shows how to get the same information using the $ _ SERVER preset variable and, in particular, get the form data to switch to PHP script.

Comparison with parse_url

Information about the PHP script or page is obtained using the $ _ SERVER preset variable and a list of keys corresponding to the found information, which are shown in the table below.

Let's clarify that the domain name is assigned directly by the user. Using our example, this is www.example.com.

Differences:

The
• parse_url function provides the common name of the protocol, and the system variable provides the version, for example, in the form of a HTTP/1.1.

Using a preset variable

Example:

$protocol = $_SERVER[SERVER_PROTOCOL];

The list of keys is presented in the PHP guide in the section: "Predefined variables."

Retrieving data from an HTML form

Example:

$parameters = $_SERVER[QUERY_STRING];

parse_str($parameters, $data);
print_r($data);

$ data is an associative array, where the keys are the variables passed to the parameters, and the values, the contents of these variables.

For details, see the first part of the article.

Sources and loading

• Script source code displaying $ _ SERVER values
.
• Archive containing code for both parts.