signals/signals.go
func Parse(s string) (os.Signal, error) {
	sig, ok := SignalLookup[strings.ToUpper(s)]
	if !ok {
		return nil, fmt.Errorf("invalid signal %q - valid signals are %q",
			s, ValidSignals)
	}
	return sig, nil
}
func Parse(s string) (os.Signal, error) {
	sig, ok := SignalLookup[strings.ToUpper(s)]
	if !ok {
		return nil, fmt.Errorf("invalid signal %q - valid signals are %q",
			s, ValidSignals)
	}
	return sig, nil
}
// Parse parses the given string as a signal. If the signal is not found,
// an error is returned.