Add dry-run and verbose flags

cmd.go

@@ -9,8 +9,19 @@ import (
 	"github.com/go-redis/redis/v8"
 )
 
+type logger bool
+
+func (l logger) stdout(f string, a ...interface{}) {
+	if !l {
+		return
+	}
+	fmt.Fprintf(os.Stderr, f+"\n", a...)
+}
+
 func main() {
 	ctx := context.Background()
+	paramDryRun := flag.Bool("dryrun", false, "Only attempt a no-op PING command")
+	paramVerbose := flag.Bool("verbose", false, "Output more text")
 	paramFlushAll := flag.Bool("all", false, "Use FLUSHALL instead of FLUSHDB")
 	paramHost := flag.String("host", "localhost", "Hostname of primary Redis endpoint")
 	paramPort := flag.Int("port", 6379, "Port of Redis cluster")
@@ -19,6 +30,7 @@ func main() {
 	paramDB := flag.Int("db", 0, "Index of database to flush (use -all to flush all)")
 	flag.Parse()
 
+	log := logger(*paramVerbose)
 	if *paramFlushAll && *paramDB != 0 {
 		fmt.Fprintf(os.Stderr, "Use -all to target all databases, or -db to specify a specific database other than 0.")
 		return
@@ -30,17 +42,29 @@ func main() {
 		Password: *paramPassword,
 		DB:       *paramDB,
 	})
+	log.stdout("Will connect to: %s", c.Options().Addr)
+	if *paramPassword != "" {
+		log.stdout("Using password for connection.")
+	}
 	switch {
+	case *paramDryRun:
+		log.stdout("Sending PING")
+		res = c.Ping(ctx)
 	case *paramFlushAll && *paramASync:
+		log.stdout("Sending FLUSHALL ASYNC")
 		res = c.FlushAllAsync(ctx)
 	case !*paramFlushAll && *paramASync:
+		log.stdout("Sending FLUSHDB ASYNC (database %d)", *paramDB)
 		res = c.FlushDBAsync(ctx)
 	case *paramFlushAll && !*paramASync:
+		log.stdout("Sending FLUSHALL")
 		res = c.FlushAll(ctx)
 	case !*paramFlushAll && !*paramASync:
+		log.stdout("Sending FLUSHDB (database %d)", *paramDB)
 		res = c.FlushDB(ctx)
 	}
 	if res.Err() != nil {
 		panic(res.Err())
 	}
+	log.stdout("Command result: %+v", res)
 }