cmd/revid-cli: using closure for readPin func so that we don't have to have global revid

cmd/revid-cli/main.go

@@ -75,8 +75,6 @@ var canProfile = true
 // The logger that will be used throughout
 var log *logger.Logger
 
-var rv *revid.Revid
-
 const (
 	metaPreambleKey  = "copyright"
 	metaPreambleData = "ausocean.org/license/content2019"
@@ -89,9 +87,8 @@ func main() {
 	runDurationPtr := flag.Duration("runDuration", defaultRunDuration, "How long do you want revid to run for?")
 
 	cfg := handleFlags()
-	var err error
 	if !*useNetsender {
-		rv, err = revid.New(cfg, nil)
+		rv, err := revid.New(cfg, nil)
 		if err != nil {
 			cfg.Logger.Log(logger.Fatal, pkg+"failed to initialiase revid", "error", err.Error())
 		}
@@ -268,21 +265,34 @@ func run(cfg revid.Config) error {
 	log.Log(logger.Info, pkg+"running in NetSender mode")
 
 	var vars map[string]string
+	var rv *revid.Revid
 
 	// initialize NetSender and use NetSender's logger
+	readPin := func(pin *netsender.Pin) error {
+		switch {
+		case pin.Name == "X23":
+			pin.Value = rv.Bitrate()
+		case pin.Name[0] == 'X':
+			return sds.ReadSystem(pin)
+		default:
+			pin.Value = -1
+		}
+		return nil // Return error only if we want NetSender to generate an error
+	}
+
 	ns, err := netsender.New(log, nil, readPin, nil)
 	if err != nil {
 		return err
 	}
 
-	vars, _ = ns.Vars()
-	vs := ns.VarSum()
-
 	rv, err = revid.New(cfg, ns)
 	if err != nil {
 		log.Log(logger.Fatal, pkg+"could not initialise revid", "error", err.Error())
 	}
 
+	vars, _ = ns.Vars()
+	vs := ns.VarSum()
+
 	// Update revid to get latest config settings from netreceiver.
 	err = rv.Update(vars)
 	if err != nil {
@@ -357,20 +367,6 @@ func run(cfg revid.Config) error {
 	}
 }
 
-// readPin is callback func for netsender so that pins can be appropriately set
-// for this circumstance.
-func readPin(pin *netsender.Pin) error {
-	switch {
-	case pin.Name == "X23":
-		pin.Value = rv.Bitrate()
-	case pin.Name[0] == 'X':
-		return sds.ReadSystem(pin)
-	default:
-		pin.Value = -1
-	}
-	return nil // Return error only if we want NetSender to generate an error
-}
-
 // flagStrings implements an appending string set flag.
 type flagStrings []string