restructure command line tool

cmd/gommunityid.go

@@ -0,0 +1,60 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"log"
+	"os"
+
+	"github.com/satta/gommunityid"
+)
+
+func main() {
+
+	pcapCmd := flag.NewFlagSet("pcap", flag.ExitOnError)
+	pcapVersion := pcapCmd.Uint("version", 1, "Community ID version")
+	pcapSeed := pcapCmd.Uint("seed", 0, "seed value (default 0)")
+
+	tupleCmd := flag.NewFlagSet("tuple", flag.ExitOnError)
+	tupleVersion := tupleCmd.Uint("version", 1, "Community ID version")
+	tupleSeed := tupleCmd.Uint("seed", 0, "seed value (default 0)")
+
+	if len(os.Args) < 2 {
+		fmt.Println("expected 'pcap' or 'tuple' subcommands")
+		os.Exit(1)
+	}
+	switch os.Args[1] {
+	case "pcap":
+		pcapCmd.Parse(os.Args[2:])
+		if len(pcapCmd.Args()) == 0 {
+			log.Println("No input file given")
+			flag.PrintDefaults()
+			os.Exit(0)
+		}
+		ftChan, err := gommunityid.PcapFlowTupleSource(pcapCmd.Args()[0])
+		if err != nil {
+			log.Fatal(err)
+		}
+		cid, err := gommunityid.GetCommunityIDByVersion(*pcapVersion, uint16(*pcapSeed))
+		if err != nil {
+			log.Fatal(err)
+		}
+		for ft := range ftChan {
+			communityid := cid.CalcBase64(ft.FlowTuple)
+			fmt.Printf("%d%s | %s | %s %s %d %d %d\n",
+				ft.Metadata.Timestamp.Unix(),
+				ft.Metadata.Timestamp.Format(".000000"),
+				communityid,
+				ft.FlowTuple.Srcip, ft.FlowTuple.Dstip,
+				ft.FlowTuple.Proto,
+				ft.FlowTuple.Srcport, ft.FlowTuple.Dstport)
+		}
+	case "tuple":
+		tupleCmd.Parse(os.Args[2:])
+		fmt.Printf("not yet implemented")
+		_, _ = tupleSeed, tupleVersion
+	default:
+		fmt.Println("expected 'pcap' or 'tuple' subcommands")
+		os.Exit(1)
+	}
+}