1 files changed, 21 insertions, 2 deletions
diff --git a/main.go b/main.go
index 26a7798..f4480f6 100644
--- a/main.go
+++ b/main.go
@@ -2,6 +2,8 @@ package main
 
 import (
 	"bufio"
+	"errors"
+	"flag"
 	"fmt"
 	"io"
 	"log"
@@ -11,8 +13,13 @@ import (
 	"time"
 )
 
-
 func main() {
+	if len(os.Args) != 2 {
+		printUsage()
+	}
+	luaExe := os.Args[1]
+	mustExist(luaExe)
+
 	httpClient := &http.Client{}
 
 	// queue for http messages for workers to handle
@@ -132,7 +139,7 @@ func main() {
 		wrk := NewWorker()
 		wrks = append(wrks, wrk)
 		go func () {
-			err := wrk.Start("init.lua", module)
+			err := wrk.Start(luaExe, module)
 			if err != nil {
 				log.Fatal(err)
 			}
@@ -160,3 +167,15 @@ func main() {
 	fmt.Println("luna is running at 127.0.0.1:3002...")
 	log.Fatal(http.ListenAndServe("127.0.0.1:3002", mux))
 }
+
+func printUsage() {
+	fmt.Printf("usage: %s [luafile]\n", os.Args[0])
+	flag.PrintDefaults()
+	os.Exit(2)
+}
+
+func mustExist(file string) {
+	if _, err := os.Stat(file); errors.Is(err, os.ErrNotExist) {
+		log.Fatalf("file \"%s\" does not exist", file)
+	}
+}