diff --git a/bin/hawkgo.go b/bin/hawkgo.go
index d3a97eac..d68332a7 100644
--- a/bin/hawkgo.go
+++ b/bin/hawkgo.go
@@ -1,18 +1,66 @@
 package main
 
 import "hawk"
+import "flag"
 import "fmt"
+import "io"
 import "os"
 import "runtime"
 import "runtime/debug"
 //import "sync"
 import "time"
 
+type Config struct {
+	assign string
+	call string
+	fs string
+	srcstr string
+	srcfile string
+
+	files []string
+}
+
 func exit_with_error(msg string, err error) {
 	fmt.Printf("ERROR: %s - %s\n", msg, err.Error())
 	os.Exit(1)
 }
 
+func parse_args_to_config(cfg *Config) bool {
+	var flgs *flag.FlagSet
+	var err error
+
+	flgs = flag.NewFlagSet("", flag.ContinueOnError)
+	flgs.Func("assign", "set a global variable with a value", func(v string) error {
+		cfg.assign = v
+		return nil
+	})
+	flgs.Func("call", "call a function instead of the pattern-action block)", func(v string) error {
+		cfg.call = v
+		return nil
+	})
+	flgs.Func("field-separator", "set the field separator(FS)", func(v string) error {
+		cfg.fs = v
+		return nil
+	})
+
+	flgs.SetOutput(io.Discard) // prevent usage output
+	err = flgs.Parse(os.Args[1:])
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "ERROR: %s\n", err.Error())
+		goto wrong_usage
+	}
+
+	if flgs.NArg() == 0 { goto wrong_usage}
+	cfg.files = flgs.Args()
+
+	return true
+
+wrong_usage:
+	fmt.Fprintf(os.Stderr, "USAGE: %s [options] sourcestring [datafile]*\n", os.Args[0])
+	fmt.Fprintf(os.Stderr, "       %s [options] -f sourcefile [datafile]*\n", os.Args[0])
+	return false
+}
+
 func make_hawk(script string) (*hawk.Hawk, error) {
 	var h *hawk.Hawk
 	var err error
@@ -32,11 +80,13 @@ func make_hawk(script string) (*hawk.Hawk, error) {
 func main() {
 	var h *hawk.Hawk
 	var rtx *hawk.Rtx
+	var cfg Config
 	var err error
 
 	debug.SetGCPercent(100) // enable normal GC
 
-	fmt.Printf ("BEGINNING OF TEST3\n")
+	if parse_args_to_config(&cfg) == false { os.Exit(99) }
+fmt.Printf("config [%+v]\n", cfg)
 
 	h, err = make_hawk(`function main(s) {
 print enbase64(s, "hello", 1.289);
@@ -50,13 +100,12 @@ return x
 
 	rtx, err = h.NewRtx("test3")
 	if err != nil {
-		//
+		fmt.Printf("ERROR: failed to make rtx - %s\n", err.Error())
 	} else  {
 		var v *hawk.Val
-
 		v, err = rtx.Call("main", hawk.Must(rtx.NewValFromStr("this is a test3 string")))
 		if err != nil {
-			//
+			fmt.Printf("ERROR: failed to make rtx - %s\n", err.Error())
 		} else {
 			fmt.Printf("V=>[%v]\n", v.String())
 		}