Exit with error code in go?

Question

What's the idiomatic way to exit a program with some error code?

The documentation for Exit says "The program terminates immediately; deferred functions are not run.", and log.Fatal just calls Exit. For things that aren't heinous errors, terminating the program without running deferred functions seems extreme.

Am I supposed to pass around some state that indicate that there's been an error, and then call Exit(1) at some point where I know that I can exit safely, with all deferred functions having been run?

Answer 1

I do something along these lines in most of my real main packages, so that the return err convention is adopted as soon as possible, and has a proper termination:

func main() {     if err := run(); err != nil {         fmt.Fprintf(os.Stderr, "error: %v\n", err)         os.Exit(1)     } }  func run() error {     err := something()     if err != nil {         return err     }     // etc } 

Answer 2

In python I commonly use pattern which converted to go looks like this:

func run() int {     // here goes     // the code      return 1 }  func main() {     os.Exit(run()) }