issue #51: Add a flag to list only directories in a tree

README.md

@@ -13,6 +13,7 @@ treels                 # compact ls-style view
 treels -t              # tree view
 treels -t --depth 2    # tree view, limited to two levels
 treels -t --gitignore  # tree view, excluding .gitignore matches
+treels -t --dirs-only  # show directory structure only
 treels --no-summary    # hide the final count line
 ```
 
@@ -83,6 +84,7 @@ $ treels -t --depth 2 --no-icons service
 - Optional Nerd Font icons and file-type colors.
 - `--gitignore` support to skip generated files, dependencies, logs, and build output.
 - `--depth N` to keep tree output readable in large repositories.
+- `--dirs-only` to inspect folder structure without file-level noise.
 - `--readable` file sizes.
 - `--all` support for hidden files.
 - `--no-icons` fallback for terminals without icon fonts.
@@ -147,6 +149,12 @@ Respect `.gitignore` rules:
 treels --tree --gitignore
 ```
 
+Show directories only:
+
+```bash
+treels --tree --dirs-only
+```
+
 Show readable sizes:
 
 ```bash
@@ -171,6 +179,7 @@ treels --no-summary
 | --- | --- |
 | `-a`, `--all` | List hidden files and directories. |
 | `-t`, `--tree` | Show recursive tree view. |
+| `--dirs-only` | Show only directories. |
 | `--depth N` | Limit tree recursion depth. |
 | `--gitignore` | Respect `.gitignore` rules from the target directory. |
 | `--no-icons` | Disable file and folder icons. |

cmd/flag.go

@@ -10,6 +10,7 @@ import (
 func FlagDefinition(cmd *cobra.Command, flags *module.Flags) {
 	cmd.PersistentFlags().BoolVarP(&flags.ShowHidden, "all", "a", false, "List all files and directories")
 	cmd.PersistentFlags().BoolVarP(&flags.ShowTreeView, "tree", "t", false, "Tree view of the directory")
+	cmd.PersistentFlags().BoolVar(&flags.ShowDirsOnly, "dirs-only", false, "List directories only")
 	cmd.PersistentFlags().BoolVar(&flags.HideIcon, "no-icons", false, "Disable icons")
 	cmd.PersistentFlags().BoolVar(&flags.HideSummary, "no-summary", false, "Hide the final file and directory count")
 	cmd.PersistentFlags().BoolVar(&flags.RespectGitIgnore, "gitignore", false, "Respect .gitignore rules")

cmd/root_test.go

@@ -191,6 +191,38 @@ func TestRootCmd_NoSummaryFlag(t *testing.T) {
 	}
 }
 
+func TestRootCmd_DirsOnlyFlag(t *testing.T) {
+	dir := t.TempDir()
+	if err := os.Mkdir(filepath.Join(dir, "cmd"), 0o755); err != nil {
+		t.Fatalf("Mkdir() error = %v", err)
+	}
+	if err := os.WriteFile(filepath.Join(dir, "main.go"), []byte("package main"), 0o644); err != nil {
+		t.Fatalf("WriteFile() error = %v", err)
+	}
+
+	output := captureStdout(t, func() {
+		cmd := newRootCmd()
+		cmd.SetArgs([]string{"--dirs-only", "--no-icons", dir})
+
+		if err := cmd.Execute(); err != nil {
+			t.Fatalf("Execute() error = %v, want nil", err)
+		}
+	})
+
+	if !strings.Contains(output, "cmd") {
+		t.Fatalf("Execute() output = %q, want directory", output)
+	}
+	if strings.Contains(output, "main.go") {
+		t.Fatalf("Execute() output = %q, want file omitted", output)
+	}
+	if !strings.Contains(output, "1 directories") {
+		t.Fatalf("Execute() output = %q, want directory-only summary", output)
+	}
+	if strings.Contains(output, "0 files") {
+		t.Fatalf("Execute() output = %q, want no file count in dirs-only summary", output)
+	}
+}
+
 func TestRootCmd_GitIgnoreFlag(t *testing.T) {
 	dir := t.TempDir()
 	if err := os.WriteFile(filepath.Join(dir, ".gitignore"), []byte("ignored.txt\n"), 0o644); err != nil {

module/types.go

@@ -8,6 +8,7 @@ type Flags struct {
 	HideIcon         bool
 	ShowReadableSize bool
 	ShowVersion      bool
+	ShowDirsOnly     bool
 	HideSummary      bool
 	RespectGitIgnore bool
 	TreeDepth        int

service/service.go

@@ -68,7 +68,7 @@ func dispatcher(options module.Options, output io.Writer) error {
 		return nil
 	}
 
-	return printNumberOfFilesAndDirectories(output, fileCount, dirCount)
+	return printNumberOfFilesAndDirectories(output, fileCount, dirCount, options.Flags)
 }
 
 // listDirectory func - lists the content of the directory.
@@ -198,6 +198,10 @@ func shouldShowFile(file os.FileInfo, options directoryOptions) bool {
 		return false
 	}
 
+	if options.Flags.ShowDirsOnly && !file.IsDir() {
+		return false
+	}
+
 	if options.gitIgnore == nil {
 		return true
 	}
@@ -245,7 +249,12 @@ func processDirectory(file os.FileInfo, options directoryOptions, output io.Writ
 var errGetwd = errors.New("get current working directory")
 
 // printNumberOfFilesAndDirectories returns number of files and directories
-func printNumberOfFilesAndDirectories(output io.Writer, fileCount, dirCount int) error {
+func printNumberOfFilesAndDirectories(output io.Writer, fileCount, dirCount int, flags module.Flags) error {
+	if flags.ShowDirsOnly {
+		_, err := fmt.Fprintf(output, "\n%d directories\n", dirCount)
+		return err
+	}
+
 	_, err := fmt.Fprintf(output, "\n%d directories, %d files\n", dirCount, fileCount)
 	return err
 }

service/service_test.go

@@ -206,6 +206,128 @@ func TestDispatcher_NoSummary(t *testing.T) {
 	}
 }
 
+func TestDispatcher_DirsOnly(t *testing.T) {
+	dir := t.TempDir()
+	mustMkdir(t, filepath.Join(dir, "cmd"))
+	mustMkdir(t, filepath.Join(dir, "service"))
+	mustWriteFile(t, filepath.Join(dir, "README.md"), "readme")
+	mustWriteFile(t, filepath.Join(dir, "main.go"), "package main")
+
+	tests := []struct {
+		name  string
+		flags module.Flags
+	}{
+		{
+			name:  "flat mode",
+			flags: module.Flags{HideIcon: true, ShowDirsOnly: true},
+		},
+		{
+			name:  "tree mode",
+			flags: module.Flags{HideIcon: true, ShowDirsOnly: true, ShowTreeView: true},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			var output bytes.Buffer
+			err := dispatcher(module.Options{Directory: dir, Flags: tt.flags}, &output)
+			if err != nil {
+				t.Fatalf("dispatcher() error = %v, want nil", err)
+			}
+
+			got := stripANSI(output.String())
+			for _, want := range []string{"cmd", "service", "2 directories"} {
+				if !strings.Contains(got, want) {
+					t.Fatalf("dispatcher() output = %q, want to contain %q", got, want)
+				}
+			}
+			if strings.Contains(got, "0 files") {
+				t.Fatalf("dispatcher() output = %q, want no file count in dirs-only summary", got)
+			}
+			for _, missing := range []string{"README.md", "main.go"} {
+				if strings.Contains(got, missing) {
+					t.Fatalf("dispatcher() output = %q, want not to contain %q", got, missing)
+				}
+			}
+		})
+	}
+}
+
+func TestDispatcher_DirsOnlyWithDepth(t *testing.T) {
+	dir := t.TempDir()
+	mustMkdir(t, filepath.Join(dir, "cmd"))
+	mustMkdir(t, filepath.Join(dir, "cmd", "internal"))
+	mustWriteFile(t, filepath.Join(dir, "cmd", "main.go"), "package main")
+	mustMkdir(t, filepath.Join(dir, "service"))
+
+	var output bytes.Buffer
+	err := dispatcher(module.Options{
+		Directory: dir,
+		Flags: module.Flags{
+			HideIcon:       true,
+			ShowTreeView:   true,
+			ShowDirsOnly:   true,
+			TreeDepth:      1,
+			LimitTreeDepth: true,
+		},
+	}, &output)
+	if err != nil {
+		t.Fatalf("dispatcher() error = %v, want nil", err)
+	}
+
+	got := stripANSI(output.String())
+	for _, want := range []string{"cmd", "service", "2 directories"} {
+		if !strings.Contains(got, want) {
+			t.Fatalf("dispatcher() output = %q, want to contain %q", got, want)
+		}
+	}
+	if strings.Contains(got, "0 files") {
+		t.Fatalf("dispatcher() output = %q, want no file count in dirs-only summary", got)
+	}
+	for _, missing := range []string{"internal", "main.go"} {
+		if strings.Contains(got, missing) {
+			t.Fatalf("dispatcher() output = %q, want not to contain %q", got, missing)
+		}
+	}
+}
+
+func TestDispatcher_DirsOnlyWithGitIgnore(t *testing.T) {
+	dir := t.TempDir()
+	mustWriteFile(t, filepath.Join(dir, ".gitignore"), "ignored-dir/\n")
+	mustMkdir(t, filepath.Join(dir, "ignored-dir"))
+	mustMkdir(t, filepath.Join(dir, "visible-dir"))
+	mustWriteFile(t, filepath.Join(dir, "main.go"), "package main")
+
+	var output bytes.Buffer
+	err := dispatcher(module.Options{
+		Directory: dir,
+		Flags: module.Flags{
+			HideIcon:         true,
+			ShowTreeView:     true,
+			ShowDirsOnly:     true,
+			RespectGitIgnore: true,
+		},
+	}, &output)
+	if err != nil {
+		t.Fatalf("dispatcher() error = %v, want nil", err)
+	}
+
+	got := stripANSI(output.String())
+	for _, want := range []string{"visible-dir", "1 directories"} {
+		if !strings.Contains(got, want) {
+			t.Fatalf("dispatcher() output = %q, want to contain %q", got, want)
+		}
+	}
+	if strings.Contains(got, "0 files") {
+		t.Fatalf("dispatcher() output = %q, want no file count in dirs-only summary", got)
+	}
+	for _, missing := range []string{"ignored-dir", "main.go"} {
+		if strings.Contains(got, missing) {
+			t.Fatalf("dispatcher() output = %q, want not to contain %q", got, missing)
+		}
+	}
+}
+
 func TestDispatcher_ListDirectoryGitIgnore(t *testing.T) {
 	dir := t.TempDir()
 	mustWriteFile(t, filepath.Join(dir, ".gitignore"), "*.log\nignored-dir/\n!keep.log\n")