Store subset of opennames data in gob format and use that to restore index.

cmd/save-gob/main.go

@@ -0,0 +1,18 @@
+package main
+
+import (
+	"log"
+	"os"
+
+	"github.com/ray1729/gpx-utils/pkg/openname"
+)
+
+func main() {
+	log.SetFlags(0)
+	if len(os.Args) != 3 {
+		log.Fatal("Usage: %s INFILE OUTFILE", os.Args[0])
+	}
+	if err := openname.Save(os.Args[1], os.Args[2]); err != nil {
+		log.Fatal(err)
+	}
+}