Package “main” and func “main”

The entry point for the application is the main function in the main package as described in the specification:

A complete program is created by linking a single, unimported package called the main package with all the packages it imports, transitively. The main package must have package name main and declare a function main that takes no arguments and returns no value.

func main() { … }

Program execution begins by initializing the main package and then invoking the function main. When that function invocation returns, the program exits. It does not wait for other (non-main) goroutines to complete.

The language specification does not give special meaning to the name main outside of this context. The name main is not a reserved name.

It’s OK to declare a main function in non-main packages. In such cases, it’s just a function named main.