My last PR introduced a bug that does not allow new URLs to be created because q is empty before that logic is processed. My next PR will fix this behavior.

I always get this error when open my website

My .htaccess:
RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ index.php?q=$1 [QSA,L]

config.php is finished too

When doing:
mysql -u root -p new_database < database.sql
I see the error:
ERROR 1071 (42000) at line 4: Specified key was too long; max key length is 767 bytes
using MariaDB.

This seems to be a limitation of the database itself, according to:

https://answers.launchpad.net/maria/+question/241612

Would there be any way to work around this?

I followed the guide, added database and htdocs.
But I still get this error.

Notice: Undefined index: q in C:\xampp\htdocs\shorty\shorty.php on line 314
404 Not Found

this is my project path : C:\xampp\htdocs\shorty
this is my htdocs path : C:\xampp\htdocs\shorty.htdocs

this is my config file.

<?php
// Hostname for your URL shortener
$hostname = 'http://localhost.com';
// PDO connection to the database
$connection = new PDO('mysql:dbname=shorty_temp;host=localhost', 'root', '');
$chars = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';
$salt = '';
$padding = 3;
?>

how can I fix this?

The home page does not show a 404 message because $_GET['url'] is unset at the time of checking. The page is blank, and an error is logged:

2018/04/04 21:51:30 [error] 2990#2990: *21 FastCGI sent in stderr: "PHP message: PHP Notice:  Undefined index: url in /usr/share/nginx/html/v.craftblock.me/shorty.php on line 315
PHP message: PHP Notice:  Undefined index: format in /usr/share/nginx/html/v.craftblock.me/shorty.php on line 316" while reading response header from upstream, client: 172.69.142.45, server: v.craftblock.me, request: "GET / HTTP/1.1", upstream: "fastcgi://unix:/var/run/php/php7.2-fpm.sock:", host: "v.craftblock.me"

Set everything up following the guide, .htaccess, confs for the domain etc all done, database sorted. When I try to add a URL it generates, but when I click on the URL it doesn't work, instead giving a 404 message.

I'm not sure if you maintain this anymore or if you would even be willing to help me with my issue. Regardless I'll ask.

I'm using PHP 7.4 on Ubuntu 20.04.4 using nginx to server my site.
To my knowledge I have configured everything correctly.
Upon testing it does display the shortened url page however it does not finish its execution, therefore the shortened url isn't actually attached to anything.
Checking my error log (/var/log/nginx/error.log) I see it has produced the following exception.

2022/06/27 23:57:33 [error] 739740#739740: *1953 FastCGI sent in stderr: "PHP message: PHP Notice:  Undefined index: q in /var/www/mysite.com/shorty.php on line 314" while reading response header from upstream, client: 172.69.68.17, server: mysite.com, request: "GET /index.php?url=http://www.google.com HTTP/1.1", upstream: "fastcgi://unix:/var/run/php/php7.4-fpm.sock:", host: "mysite.com"

The issue stems from this line

While I do not think this is the cause of my issues it might be relevant.
The mysql user that shorty is using only has INSERT, SELECT, and UPDATE permissions within the scope of shorty.urls

For example, always generate 6-chars key for id 1 to 1,000,000?

I think homepage in index.php and making custom link can be awesome for your script like https://bit.do

It works fine, I think.

But where are the IDs / the shorted URLs stored?

In the database is only an ID and the long URL but no shorted URL...