Universal Resource Locator (URL)¶
Universal Resource Locator is a string that represents a resource, where to find it, how to access it.
The full URL include the following information :
protocol : for example, http, https, mongodb, zip
user : the username for authentication purposes
pass : the password associated with the username
server : the name or the address of the server where the resource reside
path : the location of the resource on the server
query : extra parameters to reach the resource
fragment : the location of the resource inside the previous address (server + path)
PHP has several functions dedicated to processing URL, such as parse_url() and http_build_query().
PHP also makes use of URL as a generalisation for file path. For example, file_get_contents() and fopen() both work on local and remote files, via URL.
PHP is able to process different protocols with its internal Protocols and Wrappers, using the file system functions.
<?php
print_r(parse_url('https://www.php.net/'));
/*
Array
(
[scheme] => https
[host] => www.php.net
[path] => /
)
*/
// fetch the PHP home page
$html = file_get_contents('https://www.php.net/');
?>