diff --git a/main.go b/main.go
index 647f8f7..e82c9ee 100644
--- a/main.go
+++ b/main.go
@@ -37,7 +37,7 @@ const (
 )
 
 func usage() {
-	fmt.Fprintf(os.Stderr, "Usage: %s file_format input_file output_file\n\n", path.Base(os.Args[0]))
+	fmt.Fprintf(os.Stderr, "Usage: %s format input output\n\n", path.Base(os.Args[0]))
 	fmt.Fprintf(os.Stderr, "Parameters:\n")
 	flag.PrintDefaults()
 }
@@ -65,7 +65,7 @@ func outputJson(fileFormat, inputPath, outputDir string, flags int) error {
 }
 
 func main() {
-	prettyJson := flag.Bool("prettyJson", false, "output prettified json")
+	prettyJson := flag.Bool("pretty", false, "output prettified json")
 
 	flag.Usage = usage
 	flag.Parse()
diff --git a/termmeta.go b/termmeta.go
index 0e85527..56712f5 100644
--- a/termmeta.go
+++ b/termmeta.go
@@ -75,12 +75,12 @@ func newTermMetaIndex(entries []termMetaEntry, entities map[string]string) termM
 	}
 }
 
-func (index *termMetaDb) output(dir string, pretty bool) error {
+func (db *termMetaDb) output(dir string, pretty bool) error {
 	if err := os.MkdirAll(dir, 0755); err != nil {
 		return err
 	}
 
-	bytes, err := marshalJson(index, pretty)
+	bytes, err := marshalJson(db, pretty)
 	if err != nil {
 		return err
 	}
@@ -96,7 +96,7 @@ func (index *termMetaDb) output(dir string, pretty bool) error {
 	}
 
 	var entries [][]string
-	for _, e := range index.entries {
+	for _, e := range db.entries {
 		entries = append(
 			entries,
 			[]string{
@@ -212,6 +212,6 @@ func outputTermMetaJson(dir string, reader io.Reader, flags int) error {
 		entries = append(entries, extractEdictTermMeta(jmdictEntry)...)
 	}
 
-	index := newTermMetaIndex(entries, entities)
-	return index.output(dir, flags&flagPrettyJson == flagPrettyJson)
+	db := newTermMetaIndex(entries, entities)
+	return db.output(dir, flags&flagPrettyJson == flagPrettyJson)
 }