Decode protoc -o files

decode.go

package main

import (
	"fmt"
	"github.com/golang/protobuf/proto"
	google_protobuf "github.com/golang/protobuf/protoc-gen-go/descriptor"
	"io/ioutil"
	"os"
)

func main() {
	d, err := ioutil.ReadFile(os.Args[1]) // protoc -o output.pb.bin *.proto
	if err != nil {
		panic(err)
	}

	var fs google_protobuf.FileDescriptorSet
	if err := proto.Unmarshal(d, &fs); err != nil {
		panic(err)
	}

	for _, f := range fs.File {
		fmt.Println(*f.Name)
		fmt.Println(*f.Package)

		fmt.Println("messages:")
		for _, m := range f.MessageType {
			fmt.Printf("\t%s\n", *m.Name)
			for _, field := range m.Field {
				fmt.Printf("\t\t%v %v = %v\n", field.Type.String(), *field.Name, *field.Number)
			}
		}
		fmt.Println("services:")
		for _, s := range f.Service {
			fmt.Printf("rpc %s {\n", *s.Name)
			for _, m := range s.Method {
				fmt.Printf("\trpc %s(%s) returns (%s);\n", *m.Name, *m.InputType, *m.OutputType)
			}
			fmt.Println("}")
		}
	}
}