External calls in C require an underscore (e.g., "_printf") to be easily trackable as possibly unsafe. Also, at some point in the code (e.g., after you include

External calls in C require an underscore (e.g., "_printf") to be easily trackable as possibly unsafe. Also, at some point in the code (e.g., after you include your libraries), one can disable these calls with a directive. But typically, one will use bindings for asynchronous libraries, such as libuv (https://github.com/fsantanna/ceu-libuv https://github.com/fsantanna/ceu-libuv).