fixes iawia002#1121

main.go

@@ -7,15 +7,25 @@ import (
 	"github.com/fatih/color"
 
 	"github.com/iawia002/lux/app"
+	"github.com/iawia002/lux/utils"
 )
 
 func main() {
+	errFFMPEG := utils.IsFfmpegInstalled()
+	if errFFMPEG != nil {
+		fmt.Fprintf(
+			color.Output,
+			"Dependency not found: %s\n",
+			color.RedString("%s", errFFMPEG),
+		)
+		os.Exit(1)
+	}
 	if err := app.New().Run(os.Args); err != nil {
 		fmt.Fprintf(
 			color.Output,
 			"Run %s failed: %s\n",
 			color.CyanString("%s", app.Name), color.RedString("%v", err),
 		)
-		os.Exit(1)
+		os.Exit(2)
 	}
 }

utils/ffmpeg.go

@@ -9,6 +9,14 @@ import (
 	"github.com/pkg/errors"
 )
 
+func IsFfmpegInstalled() error {
+	_, err := exec.LookPath("ffmpeg")
+	if err != nil {
+		return errors.Errorf("%s", err)
+	}
+	return nil
+}
+
 func runMergeCmd(cmd *exec.Cmd, paths []string, mergeFilePath string) error {
 	var stderr bytes.Buffer
 	cmd.Stderr = &stderr