Added command line argument to extract payload

cmd/sdb/main.go

@@ -5,29 +5,52 @@ import (
 	"fmt"
 	"io/ioutil"
 	"os"
+	"flag"
 )
 
 func main() {
-	if len(os.Args) < 2 {
-		fmt.Fprintf(os.Stderr,
-			"required argument missing\n")
+	flags := flag.NewFlagSet("sdb", flag.ExitOnError)
+	flags.SetOutput(os.Stdout)
+	flags.Usage = func() {
+		fmt.Fprintf(flags.Output(),
+			"Usage: %s [OPTION] <files> ...\nOptions:\n",
+			os.Args[0])
+		flags.PrintDefaults()
+	}
+
+	plonly := flags.Bool("payload", false, "only return the payload")
+
+	flags.Parse(os.Args[1:])
+
+	if flags.NArg() < 1 {
+		fmt.Fprintf(os.Stderr, "files parameter cannot be empty\n")
 		os.Exit(1)
 	}
 
-	raw, err := ioutil.ReadFile(os.Args[1])
+	for _, fn := range flags.Args() {
+		raw, err := ioutil.ReadFile(fn)
 		if err != nil {
 			fmt.Fprintf(os.Stderr,
 				"error reading \"%s\": %s\n",
-			os.Args[1], err.Error())
+				fn, err.Error())
+			continue
 		}
 
 		data, err := sdb.ParseSDB(raw)
 		if err != nil {
 			fmt.Fprintf(os.Stderr,
 				"%s\n", err.Error())
-		os.Exit(1)
+			continue
 		}
 
+		if *plonly {
+			for _, i := range data.Elements {
+				switch v := i.(type) {
+					case sdb.MOPayload:
+						os.Stdout.Write(v.Payload)
+				}
+			}
+		} else {
 			fmt.Printf("Protocol Revision: %d\n",
 				data.ProtocolRevision)
 			fmt.Printf("Message Length: %d\n",
@@ -71,3 +94,5 @@ func main() {
 				}
 			}
 		}
+	}
+}