diff --git a/cmd/cmds_style.go b/cmd/cmds_style.go
index 351a382..e6aa29b 100644
--- a/cmd/cmds_style.go
+++ b/cmd/cmds_style.go
@@ -1,6 +1,7 @@
 package cmd
 
 import (
+	"github.com/sincerefly/capybara/base/log"
 	"github.com/sincerefly/capybara/cmd/border"
 	"github.com/spf13/cobra"
 )
@@ -15,5 +16,11 @@ func init() {
 var borderCmd = &cobra.Command{
 	Use:   "border",
 	Short: "To batch add borders to images.",
-	Run:   func(cmd *cobra.Command, args []string) {},
+	Run: func(cmd *cobra.Command, args []string) {
+		if len(args) > 0 {
+			log.Warnf("border style '%s' unsupported", args[0])
+		} else {
+			log.Warnf("border need subcommand, e.g., 'capybara border simple [parameter]'")
+		}
+	},
 }
diff --git a/service/border/handler.go b/service/border/handler.go
index 530046f..2f1fdd3 100644
--- a/service/border/handler.go
+++ b/service/border/handler.go
@@ -6,8 +6,7 @@ import (
 	"github.com/sincerefly/capybara/constants"
 	"github.com/sincerefly/capybara/service/border/styles"
 	"github.com/sincerefly/capybara/structure/fileitem"
-	"github.com/sincerefly/capybara/utils"
-	"github.com/spf13/afero"
+	"github.com/sincerefly/capybara/utils/fsutil"
 	"path/filepath"
 	"slices"
 	"strings"
@@ -41,11 +40,6 @@ func NewStyleProcessor(style Style, params Parameterizable) *StyleProcessor {
 
 func (s *StyleProcessor) Run() {
 
-	style := s.style
-	if !slices.Contains(s.Supports(), style) { // check
-		log.Fatal("unsupported style")
-	}
-
 	fiStore, err := s.collectInputs()
 	if err != nil {
 		log.Fatal(err)
@@ -55,7 +49,7 @@ func (s *StyleProcessor) Run() {
 		log.Fatal(err)
 	}
 
-	switch style {
+	switch s.style {
 	case StyleSimple:
 		params := s.params.(*styles.SimpleParameter)
 		err = styles.NewSimpleProcessor(params, fiStore).Run()
@@ -69,10 +63,6 @@ func (s *StyleProcessor) Run() {
 	log.Info("finished")
 }
 
-func (s *StyleProcessor) Supports() []Style {
-	return []Style{StyleSimple, StyleTextBottom}
-}
-
 func (s *StyleProcessor) SupportExtensions() []string {
 	return []string{constants.ExtJPG, constants.ExtPNG, constants.ExtJPEG}
 }
@@ -84,8 +74,7 @@ func (s *StyleProcessor) collectInputs() (*fileitem.Store, error) {
 	input := s.params.Input()
 	output := s.params.Output()
 
-	fs := afero.NewOsFs()
-	srcImagePaths, err := utils.GetAllFiles(fs, s.params.Input())
+	srcImagePaths, err := fsutil.ListFiles(s.params.Input())
 	if err != nil {
 		return nil, fmt.Errorf("load input folder failed, %v", err)
 	}
@@ -121,7 +110,7 @@ func (s *StyleProcessor) collectInputs() (*fileitem.Store, error) {
 // prepare output dirs
 func (s *StyleProcessor) prepareOutputDirs(fiStore *fileitem.Store) error {
 	for _, outputDir := range fiStore.GetTargetPaths() {
-		if err := utils.MkdirAll(outputDir); err != nil {
+		if err := fsutil.MkdirAll(outputDir); err != nil {
 			return err
 		}
 	}
diff --git a/utils/dirfile.go b/utils/fsutil/fs.go
similarity index 61%
rename from utils/dirfile.go
rename to utils/fsutil/fs.go
index 942c6b4..76d1afd 100644
--- a/utils/dirfile.go
+++ b/utils/fsutil/fs.go
@@ -1,4 +1,4 @@
-package utils
+package fsutil
 
 import (
 	"github.com/spf13/afero"
@@ -8,36 +8,35 @@ import (
 
 var appFs afero.Fs
 
-func MkdirAll(path string) error {
+func init() {
+	appFs = afero.NewOsFs()
+}
 
-	if appFs == nil {
-		appFs = afero.NewOsFs()
-	}
+func MkdirAll(path string) error {
 	fs := afero.NewOsFs()
 	return fs.MkdirAll(path, 0755)
 }
 
-// GetAllFiles all files
-func GetAllFiles(fs afero.Fs, root string) ([]string, error) {
-	var files []string
-
-	err := afero.Walk(fs, root, func(path string, info os.FileInfo, err error) error {
+func ListFiles(root string) ([]string, error) {
+	var paths []string
+	walkFn := func(path string, info os.FileInfo, err error) error {
 		if err != nil {
 			return err
 		}
 		if !info.IsDir() {
-			files = append(files, path)
+			paths = append(paths, path)
 		}
 		return nil
-	})
-
+	}
+	err := afero.Walk(appFs, root, walkFn)
 	if err != nil {
 		return nil, err
 	}
-	return files, nil
+	return paths, nil
 }
 
 func ExecutableDir() (string, error) {
+
 	executablePath, err := os.Executable()
 	if err != nil {
 		return "", err