Colin's git trees - cmccabe-bin/blob - msgpack-translate.go

   1 package main
   2
   3 import (
   4         "bytes"
   5         "encoding/hex"
   6         "fmt"
   7         "github.com/ugorji/go/codec"
   8         "io/ioutil"
   9         "os"
  10         "strings"
  11 )
  12
  13 func usage(retval int) {
  14         fmt.Printf("%s: converts msgpack data structures to JSON.\n",
  15                 os.Args[0])
  16         fmt.Printf("usage: %s [input-file]\n", os.Args[0])
  17         fmt.Printf("\n")
  18         fmt.Printf("The input file should contain hex digits with no spaces or linebreaks.\n")
  19         os.Exit(retval)
  20 }
  21
  22 func main() {
  23         i := 1
  24         if len(os.Args) < 2 {
  25                 usage(1)
  26         }
  27         if (os.Args[i] == "-h") || (os.Args[i] == "--help") {
  28                 usage(0)
  29         }
  30         if i >= len(os.Args) {
  31                 usage(1)
  32         }
  33         path := os.Args[i]
  34         buf, err := ioutil.ReadFile(path)
  35         if err != nil {
  36                 fmt.Fprintf(os.Stderr, "Got error reading from %s: %s\n",
  37                         path, err.Error())
  38                 os.Exit(1)
  39         }
  40         str := strings.ToLower(strings.TrimSpace(string(buf)))
  41         if len(str)%2 != 0 {
  42                 fmt.Fprintf(os.Stderr, "The number of hex digits is not even.\n")
  43                 os.Exit(1)
  44         }
  45         var bin []byte
  46         bin, err = hex.DecodeString(str)
  47         if err != nil {
  48                 fmt.Fprintf(os.Stderr, "Failed to decode hex string '%s': %s\n",
  49                         str, err.Error())
  50                 os.Exit(1)
  51         }
  52         fmt.Fprintf(os.Stdout, "input=\n"+hex.Dump(bin)+"\n")
  53
  54         // Decode msgpack
  55         mh := new(codec.MsgpackHandle)
  56         mh.WriteExt = true
  57         mh.RawToString = true
  58         dec := codec.NewDecoderBytes(bin, mh)
  59         var body interface{}
  60         err = dec.Decode(&body)
  61
  62         //fmt.Fprintf(os.Stdout, "body=%v\n", body);
  63
  64         // Encode JSON
  65         jh := new(codec.JsonHandle)
  66         var out bytes.Buffer
  67         enc := codec.NewEncoder(&out, jh)
  68         err = enc.Encode(body)
  69         if err != nil {
  70                 fmt.Fprintf(os.Stderr, "Error re-encoding message as JSON: %s\n",
  71                         err.Error())
  72                 os.Exit(1)
  73         }
  74         fmt.Fprintf(os.Stdout, "output=\n%s\n", out.String())
  75         os.Exit(0)
  76 }