How to Write a Valid C Program Without a main() Function

The tutorial “Writing a (valid) C program without main()” shows how to bypass the standard entry point. It explains that alternative entry points can be defined using compiler extensions. The guide walks through creating a program that starts execution at a custom function. It covers linking options and required attributes for the replacement entry point. Sample code illustrates a minimal program that prints a message without main(). The article discusses portability concerns across different platforms. It notes that such techniques are generally used for low‑level or embedded development. The tutorial also warns about potential undefined behavior in standard C environments. Readers learn how to compile the example with specific flags to enable the custom entry. The piece concludes with suggestions for further experimentation and debugging.