it was forbidden before?

You can use a DNS challenge to show you are in control of the domain without having anything exposed to the net. Essentially LE gives you a special value you have to add as a TXT DNS entry. LE will check if this record exists for your domain, and gives you a certificate, no public IP involved. This even allows you to create wildcard certificates.

fun situations can arise when you write , instead of ; For those not in the know, in c++ the comma operator evaluates the left expression, discards the value, then evaluates the right expression and returns the value. if you now have a a situation like this

int i = 0,
printf("some message");

i has a completely different value, since it actually uses the return value of printf instead

Did you set the modem to bridge mode/DMZ, or alternatively set it to port forward to the router. The router should then port forward to the server.

Are you sure the IP address in duckdns is correct? Do you have a static or dynamic public IP, and if dynamic, how are you updating it?

proposal to rename exit() to oh_shit_oh_shit_oh_shit()

Witcher 3. Just huge walls of text, teaching you the most intricate details of some mechanics, and not enough for others.

Even paradoxically, AI needs ever improving artists to generate new training data and improve itself. You can’t really train an AI on AI-generated works. (see: AI collapse)