[Drako]

Gift card generators a not real unless they had insider access to the companies internal infrastructure that would on fly instantly generate a valid code BUT you can make a gift card cracker quite easy.

I agree. You would be able to generate a string based on rules you have seen on expired cards then use a library like requests to send them to the server after using the inspection window in a browser to see which form is being submitted. I imagine they will have some sort of cap on the number of requests you will be able to send in a given time though or they might blacklist your IP so you should probably get some proxies and send x requests before switching or something.

Good luck

I'm attempting to write the program in C and using Curl for networking. It seems to be more effective for this use case.

I've already taken into account that I'll need to use proxies, which will be difficult to implement. But it's necessary.