exec

type Cmd interface {
	// CombinedOutput runs the command and returns its combined standard output
	// and standard error.  This follows the pattern of package os/exec.
	CombinedOutput() ([]byte, error)
	// Output runs the command and returns standard output, but not standard err
	Output() ([]byte, error)
	SetDir(dir string)
	SetStdin(in io.Reader)
	SetStdout(out io.Writer)
}

type CodeExitError struct {
	Err  error
	Code int
}

type ExitError interface {
	String() string
	Error() string
	Exited() bool
	ExitStatus() int
}

type ExitErrorWrapper struct {
	*osexec.ExitError
}

type Interface interface {
	// Command returns a Cmd instance which can be used to run a single command.
	// This follows the pattern of package os/exec.
	Command(cmd string, args ...string) Cmd
	CommandContext(ctx context.Context, cmd string, args ...string) Cmd

	// LookPath wraps os/exec.LookPath
	LookPath(file string) (string, error)
}