• PHP 7+

• Simply clone repository

git clone https://github.com/nucleargen/shorturl.git

• choose folder, where shortened urls must be stored

defaults is u/ folder in root folder

if choose another - change it in index.php at line 4:

define('SHORTS_PATH',ROOT.'u'.DIRECTORY_SEPARATOR);

• configure web-server to proxy any requests to non-existent locations to index.php

i.e. for nginx:

location / { 
	try_files $uri $uri/ /index.php?$query_string; 
}

• configure web-server to deny all requests to u/ folder if it is left defaults

i.e. for nginx:

location ~ ^/u/ { deny all; }

• Used readonly input instead span for best user experience. Result in input autoselects after request by programmatically clicking its label.
• Original task text moved from html to task.md file