runner

type Error interface {
	Script() *script.Script
	Command() string
	ExitCode() int // -1 when runner error without completing script
	Error() string
	Unwrap() error
}

type Runner interface {
	SetStdoutWriter(io.Writer)
	SetStderrWriter(io.Writer)
	StdoutPipe() (io.Reader, error) // use in combination with Start() & Wait(), don't use in combination with Run()
	StderrPipe() (io.Reader, error) // use in combination with Start() & Wait(), don't use in combination with Run()

	Run() error
	Start() error
	Wait() error
	Close() error

	ExitCode() int // -1 when runner error without completing script
}