added netstat support for darwin/macOS

mod/network/netstat/netstat.go

@@ -111,6 +111,37 @@ func GetNetworkInterfaceStats() (int64, int64, error) {
 
 		//Return value as bits
 		return rxSum * 8, txSum * 8, nil
+
+	} else if runtime.GOOS == "darwin" {
+		cmd := exec.Command("netstat", "-ib") //get data from netstat -ib
+		out, err := cmd.Output()
+		if err != nil {
+			return 0, 0, err
+		}
+
+		outStrs := string(out[:])                                                       //byte array to multi-line string
+		for _, outStr := range strings.Split(strings.TrimSuffix(outStrs, "\n"), "\n") { //foreach multi-line string
+			if strings.HasPrefix(outStr, "en") { //search for ethernet interface
+				if strings.Contains(outStr, "<Link#") { //search for the link with <Link#?>
+					outStrSplit := strings.Fields(outStr) //split by white-space
+
+					rxSum, errRX := strconv.Atoi(outStrSplit[6]) //received bytes sum
+					if errRX != nil {
+						return 0, 0, errRX
+					}
+
+					txSum, errTX := strconv.Atoi(outStrSplit[9]) //transmitted bytes sum
+					if errTX != nil {
+						return 0, 0, errTX
+					}
+
+					return int64(rxSum), int64(txSum), nil //return results
+				}
+			}
+		}
+		outStrs = ""
+
+		return 0, 0, nil //no ethernet adapters with en*/<Link#*>
 	}
 
 	return 0, 0, errors.New("Platform not supported")