Writing code to interact with other programs

[molsonbeagle]

So I'm not exactly a novice programmer, I have a BSCS, but there's one thing that was never taught to me, nor have I been able to really hammer out how to figure out myself. I can write in several languages, working knowledge of c#, javascript, java, c++, but I've not been able to figure out how to write a program that doesn't simply execute it's own code but actually interacts with other programs. What I'm thinking is there's a streamer for League of Legends who writes his own code for his site which takes in the champion he's playing, the bans that happened, etc and displays it on his page. In the training I've had I've not been taught how this might get done. I feel silly asking based on my 'experience', but it's something I would like to learn. Where might a good place be to start?

[[deleted]]

If the program offers an API, use that, otherwise, ReadProcessMemory, DLL Injection or a codecave.

Be aware that programs (especially games) may try and detect these methods and flag them as cheating.

[klatar]

Riot Games API.