diff --git a/zero-epwing/main.go b/zero-epwing/main.go
index c44531e..0101a58 100644
--- a/zero-epwing/main.go
+++ b/zero-epwing/main.go
@@ -1,25 +1,90 @@
 package main
 
 import (
+	"encoding/json"
+	"flag"
+	"fmt"
+	"io/ioutil"
 	"log"
 	"os"
+	"path"
 
 	zig "github.com/FooSoft/zero-epwing-go"
 )
 
+type Entry struct {
+	Heading string `json:"heading"`
+	Text    string `json:"text"`
+}
+
+type Subbook struct {
+	Title     string  `json:"title"`
+	Copyright string  `json:"copyrignt"`
+	Entries   []Entry `json:"entries"`
+}
+
+type Book struct {
+	DiscCode string    `json:"discCode"`
+	CharCode string    `json:"charCode"`
+	Subbooks []Subbook `json:"subbooks"`
+}
+
+func outputBook(bookSrc *zig.Book, path string, pretty bool) error {
+	bookDst := Book{DiscCode: bookSrc.DiscCode, CharCode: bookSrc.CharCode}
+	for _, subbookSrc := range bookSrc.Subbooks {
+		subbookDst := Subbook{Title: subbookSrc.Title, Copyright: subbookSrc.Copyright}
+		for _, entrySrc := range subbookSrc.Entries {
+			entryDst := Entry{entrySrc.Heading, entrySrc.Text}
+			subbookDst.Entries = append(subbookDst.Entries, entryDst)
+		}
+
+		bookDst.Subbooks = append(bookDst.Subbooks, subbookDst)
+	}
+
+	var (
+		data []byte
+		err  error
+	)
+
+	if pretty {
+		data, err = json.MarshalIndent(bookDst, "", "\t")
+	} else {
+		data, err = json.Marshal(bookDst)
+	}
+
+	if err != nil {
+		return err
+	}
+
+	return ioutil.WriteFile(path, data, 0644)
+}
+
 func main() {
-	book, err := zig.Load(os.Args[1])
+	var (
+		entriesPath   = flag.String("entries-path", "", "output path for dictionary entries")
+		entriesPretty = flag.Bool("entries-pretty", false, "pretty-print dictionary entries")
+	)
+
+	flag.Usage = func() {
+		fmt.Fprintf(os.Stderr, "Usage: %s [options] path\n", path.Base(os.Args[0]))
+		fmt.Fprintf(os.Stderr, "Parameters:\n")
+		flag.PrintDefaults()
+	}
+
+	flag.Parse()
+
+	args := flag.Args()
+	if len(args) != 1 {
+		flag.Usage()
+		os.Exit(2)
+	}
+
+	book, err := zig.Load(args[0])
 	if err != nil {
 		log.Fatal(err)
 	}
 
-	fp, err := os.Create(os.Args[2])
-	defer fp.Close()
-
-	for _, subbook := range book.Subbooks {
-		for _, entry := range subbook.Entries {
-			fp.WriteString(entry.Heading)
-			fp.WriteString("\n")
-		}
+	if err := outputBook(book, *entriesPath, *entriesPretty); err != nil {
+		log.Fatal(err)
 	}
 }