Correct very old exit code logic?

[plutonium-239]

Hello, I was just passing by and noticed that in the acknowledgements of the readme you write

Strangely, Go doesn't just provide this, it requires magic like exiterr.Sys().(syscall.WaitStatus) and more.

However, this doesn't seem to be true, as cmd.ProcessState.ExitCode() returns the exit code and was introduced in go1.12 released > 6 years ago.

It works correctly, I've been using it in my project rbcp which calls robocopy on windows and parses it's streaming output (I did not know of this library at that time 😅).

[plutonium-239]

Relevant lines:

cmd/cmd.go

Lines 519 to 539 in 7e4872c

	exitCode := 0
	signaled := false
	if err != nil && fmt.Sprintf("%T", err) == "*exec.ExitError" {
	// This is the normal case which is not really an error. It's string
	// representation is only "*exec.ExitError". It only means the cmd
	// did not exit zero and caller should see ExitError.Stderr, which
	// we already have. So first we'll have this as the real/underlying
	// type, then discard err so status.Error doesn't contain a useless
	// "*exec.ExitError". With the real type we can get the non-zero
	// exit code and determine if the process was signaled, which yields
	// a more specific error message, so we set err again in that case.
	exiterr := err.(*exec.ExitError)
	err = nil
	if waitStatus, ok := exiterr.Sys().(syscall.WaitStatus); ok {
	exitCode = waitStatus.ExitStatus() // -1 if signaled
	if waitStatus.Signaled() {
	signaled = true
	err = errors.New(exiterr.Error()) // "signal: terminated"
	}
	}
	}

[daniel-nichter]

Thanks for reporting this. This is very likely the case--a lot has changed since this pkg was created ~8 years ago! I'll look into it and update things as needed.