(err error) – ordinary exec • func ForkExec(argv0 string, argv []string, a[r *ProcA[r)(pid int, err error) – combinaJon of fork and exec, careful be thread safe • StartProcess(argv0 atring, argv []string, a[r * ProcA[r)(pid int, handle uintptr, err error) – Start Process wraps ForkExec for package os – この返り値がos.Processの構成要素になってる