mapsize 1.2.0: permanent delete and in-map reveal when headless

On a headless Linux or BSD system (no DISPLAY or WAYLAND_DISPLAY) nothing
empties the freedesktop trash, so trashing never freed space. There, d now
deletes permanently after an explicit confirmation, checking owner and type
against the scan and removing through an os.Root on the parent so a swapped
symlink cannot redirect it. o shows the folder in the map instead of
launching a file manager. Desktop sessions, macOS and Windows are unchanged.

ARCHITECTURE.md

@@ -301,4 +301,7 @@ Filenames and snapshot contents are untrusted.
   Aggregates are recomputed with saturating arithmetic rather than trusted.
 * No shell is ever invoked. "Open/reveal" and trash use direct `exec` with
   argument vectors or native APIs; paths are passed as single arguments.
+* Permanent delete (headless only) checks the item's owner and type against
+  the scan and removes it through an `os.Root` on the parent directory, so
+  a symlink swapped in since the scan cannot redirect it.
 * `--read-only` disables every mutating action in the UI.

CHANGELOG.md

@@ -1,5 +1,14 @@
 # Changelog
 
+## 1.2.0 — 2026-10-03
+
+### Changed
+- On a headless Linux or BSD system (no `DISPLAY` or `WAYLAND_DISPLAY`), `d`
+  deletes permanently after an "are you sure" confirmation instead of moving
+  to a trash nobody empties, and `o` shows the folder in the map instead of
+  trying to open a file manager. Desktop sessions, macOS and Windows still
+  use the trash and the file manager.
+
 ## 1.1.0 — 2026-10-03
 
 ### Fixed

README.md

@@ -56,8 +56,8 @@ file-manager integration have not yet been tested there.
 | x, g, e | file types, top lists, scan info & errors |
 | D | find duplicates |
 | a | toggle allocated / logical size |
-| c, o | copy path, reveal in file manager |
-| d | move to trash (asks; disabled with `--read-only`) |
+| c, o | copy path, reveal in file manager (headless: show the folder in the map) |
+| d | move to trash, or delete permanently when headless (asks; disabled with `--read-only`) |
 | s, r | save snapshot, rescan |
 | T | cycle theme |
 | ? | help |
@@ -160,9 +160,16 @@ uses ordinary filesystem APIs, and duplicate detection reads file content
 
 `d` moves the selected item to the system trash (freedesktop.org trash on
 Linux, `~/.Trash` on macOS, the Recycle Bin on Windows) after confirmation,
-using native file operations — never a shell. Permanent deletion is not
-offered. Trash is unavailable while scanning, for snapshots, and in
-read-only mode.
+using native file operations — never a shell.
+
+On a headless Linux or BSD system (neither `DISPLAY` nor `WAYLAND_DISPLAY`
+set) nothing ever empties the trash, so trashing would not free any space.
+There `d` deletes permanently instead, after a confirmation that says it
+cannot be undone, and `o` shows the folder in the map rather than opening a
+file manager.
+
+Deletion is unavailable while scanning, for snapshots, and in read-only
+mode.
 
 ## Documentation
 

docs/mapsize.1

@@ -1,5 +1,5 @@
 .\" Manual page for mapsize. View with: man -l docs/mapsize.1
-.TH MAPSIZE 1 "October 2026" "mapsize 1.1.0" "User Commands"
+.TH MAPSIZE 1 "October 2026" "mapsize 1.2.0" "User Commands"
 .SH NAME
 mapsize \- interactive terminal disk usage analyser with a navigable treemap
 .SH SYNOPSIS
@@ -95,7 +95,7 @@ Useful over SSH, where \fBCOLORTERM\fR is often not forwarded.
 Disable mouse support. Everything works from the keyboard.
 .TP
 .B \-\-read\-only
-Disable every action that modifies the filesystem (moving to trash) and
+Disable every action that modifies the filesystem (trash and delete) and
 show \fBREAD ONLY\fR in the header. Saving a snapshot file is still
 allowed. This does not make
 .B mapsize
@@ -223,10 +223,14 @@ Toggle allocated / logical size.
 Copy the selected path to the clipboard (OSC 52; terminal support varies).
 .TP
 .B o
-Reveal the selected item in the desktop file manager.
+Reveal the selected item in the desktop file manager. On a headless system
+(no \fBDISPLAY\fR or \fBWAYLAND_DISPLAY\fR), show the folder in the map
+instead.
 .TP
 .BR d ", " Delete
-Move the selected item to the trash after confirmation. Disabled with
+Move the selected item to the trash after confirmation. On a headless
+Linux or BSD system, where nothing would empty the trash, delete it
+permanently instead after a confirmation that says so. Disabled with
 \fB\-\-read\-only\fR, for snapshots, and while scanning.
 .TP
 .B s

internal/brand/brand.go

@@ -8,4 +8,4 @@ const (
 )
 
 // Version is stamped at release time via -ldflags -X.
-var Version = "1.1.0"
+var Version = "1.2.0"

internal/platform/delete_unix.go

@@ -0,0 +1,35 @@
+//go:build unix
+
+package platform
+
+import (
+	"errors"
+	"io/fs"
+	"os"
+	"path/filepath"
+	"syscall"
+)
+
+// Delete permanently removes path (recursively for a directory) if it still
+// matches want. The check and the removal both go through an os.Root on the
+// parent directory, so a symlink swapped in since the scan cannot redirect
+// the removal outside it.
+func Delete(path string, want Expect) error {
+	if err := checkAbs(path); err != nil {
+		return err
+	}
+	dir, base := filepath.Dir(path), filepath.Base(path)
+	root, err := os.OpenRoot(dir)
+	if err != nil {
+		return err
+	}
+	defer root.Close()
+	fi, err := root.Lstat(base)
+	if err != nil {
+		return err
+	}
+	if fi.Sys().(*syscall.Stat_t).Uid != want.UID || fi.Mode()&fs.ModeType != want.Mode&fs.ModeType {
+		return errors.New("item changed since the scan (owner or type differs); rescan first")
+	}
+	return root.RemoveAll(base)
+}

internal/platform/ops_darwin.go

@@ -75,3 +75,7 @@ func volumeOf(path string) string {
 	}
 	return ""
 }
+
+// Headless is always false: macOS has Finder and the Trash even without
+// $DISPLAY (which it does not use).
+func Headless() bool { return false }

internal/platform/ops_linux.go

@@ -123,3 +123,10 @@ func mountTop(path string, dev uint64) string {
 		cur = parent
 	}
 }
+
+// Headless reports whether there is no graphical session (no X or Wayland
+// display), so there is no file manager to open and no desktop trash anyone
+// will empty.
+func Headless() bool {
+	return os.Getenv("DISPLAY") == "" && os.Getenv("WAYLAND_DISPLAY") == ""
+}

internal/platform/ops_linux_test.go

@@ -113,3 +113,43 @@ func TestTrashRefusesSwappedItem(t *testing.T) {
 		t.Fatal(err)
 	}
 }
+
+func TestDeletePermanently(t *testing.T) {
+	base := t.TempDir()
+	dir := filepath.Join(base, "S01")
+	os.MkdirAll(filepath.Join(dir, "extras"), 0o755)
+	os.WriteFile(filepath.Join(dir, "extras", "E01.mkv"), []byte("x"), 0o644)
+	// A symlink inside must be removed, not followed.
+	keep := filepath.Join(base, "keep")
+	os.WriteFile(keep, []byte("k"), 0o644)
+	os.Symlink(keep, filepath.Join(dir, "link"))
+
+	w := want(t, dir)
+	if err := Delete(dir, Expect{UID: w.UID, Mode: 0}); err == nil {
+		t.Fatal("type mismatch accepted")
+	}
+	if err := Delete(dir, w); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := os.Lstat(dir); !os.IsNotExist(err) {
+		t.Fatal("directory still present")
+	}
+	if _, err := os.Lstat(keep); err != nil {
+		t.Fatal("symlink target was deleted")
+	}
+	if err := Delete("relative/path", Expect{}); err == nil {
+		t.Fatal("relative paths must be refused")
+	}
+}
+
+func TestHeadless(t *testing.T) {
+	t.Setenv("DISPLAY", "")
+	t.Setenv("WAYLAND_DISPLAY", "")
+	if !Headless() {
+		t.Fatal("no display should be headless")
+	}
+	t.Setenv("WAYLAND_DISPLAY", "wayland-0")
+	if Headless() {
+		t.Fatal("wayland session reported headless")
+	}
+}

internal/platform/ops_other.go

@@ -2,7 +2,10 @@
 
 package platform
 
-import "errors"
+import (
+	"errors"
+	"os"
+)
 
 // TrashName is the user-facing name of the trash.
 const TrashName = "trash"
@@ -12,3 +15,10 @@ func Reveal(string) error { return errors.New("not supported on this platform")
 
 // Trash is unsupported on this platform.
 func Trash(string, Expect) error { return errors.New("trash not supported on this platform") }
+
+// Headless reports whether there is no graphical session (no X or Wayland
+// display), so there is no file manager to open and no desktop trash anyone
+// will empty.
+func Headless() bool {
+	return os.Getenv("DISPLAY") == "" && os.Getenv("WAYLAND_DISPLAY") == ""
+}

internal/platform/ops_windows.go

@@ -70,3 +70,9 @@ func Trash(path string, _ Expect) error {
 	}
 	return nil
 }
+
+// Headless is always false: Windows always has Explorer and the Recycle Bin.
+func Headless() bool { return false }
+
+// Delete is not offered on Windows; items go to the Recycle Bin.
+func Delete(string, Expect) error { return errors.New("permanent delete not supported on Windows") }

internal/tui/actions.go

@@ -21,10 +21,13 @@ type trashDoneMsg struct {
 	tree *inventory.Tree // the tree id belongs to; results for a replaced tree are dropped
 	id   inventory.NodeID
 	err  error
+	done string // "Moved to trash" or "Deleted"
 }
 
 // requestTrash asks for confirmation before moving the selection to the
-// trash. Permanent deletion is deliberately not offered.
+// trash. On a headless system (no desktop, so nobody empties the trash and
+// the space is never freed) it deletes permanently instead, after a
+// confirmation that says so.
 func (m *Model) requestTrash() tea.Cmd {
 	switch {
 	case m.opts.ReadOnly:
@@ -32,7 +35,7 @@ func (m *Model) requestTrash() tea.Cmd {
 	case m.snapshot:
 		return m.warn("Snapshot view: nothing to delete on the live filesystem")
 	case m.scanning:
-		return m.warn("Wait for the scan to finish before trashing items")
+		return m.warn("Wait for the scan to finish before deleting items")
 	}
 	id := m.selectedNode()
 	if id == inventory.NoNode || id == m.tree.Root() {
@@ -45,15 +48,29 @@ func (m *Model) requestTrash() tea.Cmd {
 	if n.IsDir() {
 		what = fmt.Sprintf("directory with %s files", textutil.Count(int64(n.Files)))
 	}
+	body := []string{textutil.Sanitize(path), "", fmt.Sprintf("%s · %s", what, textutil.Size(n.Total(m.sizeMode))), ""}
+	if platform.Headless() {
+		m.openModal(&confirmModal{
+			ttl: "Delete permanently? Are you sure?",
+			body: append(body, "This is a headless system (no X or Wayland display), so there is no trash:",
+				"it will be permanently deleted and cannot be recovered."),
+			yes: "delete permanently",
+			onYes: func(m *Model) tea.Cmd {
+				t := m.tree
+				return func() tea.Msg { return trashDoneMsg{t, id, platform.Delete(path, want), "Deleted"} }
+			},
+		})
+		return nil
+	}
 	m.openModal(&confirmModal{
-		ttl: "Move to trash?",
-		body: []string{textutil.Sanitize(path), "",
-			fmt.Sprintf("%s · %s", what, textutil.Size(n.Total(m.sizeMode))),
-			"", "It will be moved to the " + platform.TrashName + ", not permanently deleted."},
-		yes: "move to " + platform.TrashName,
+		ttl:  "Move to trash?",
+		body: append(body, "It will be moved to the "+platform.TrashName+", not permanently deleted."),
+		yes:  "move to " + platform.TrashName,
 		onYes: func(m *Model) tea.Cmd {
 			t := m.tree
-			return func() tea.Msg { return trashDoneMsg{t, id, platform.Trash(path, want)} }
+			return func() tea.Msg {
+				return trashDoneMsg{t, id, platform.Trash(path, want), "Moved to " + platform.TrashName}
+			}
 		},
 	})
 	return nil
@@ -61,11 +78,11 @@ func (m *Model) requestTrash() tea.Cmd {
 
 func (m *Model) trashDone(msg trashDoneMsg) tea.Cmd {
 	if msg.err != nil {
-		return m.warn("Trash failed: " + textutil.Sanitize(msg.err.Error()))
+		return m.warn("Delete failed: " + textutil.Sanitize(msg.err.Error()))
 	}
 	if msg.tree != m.tree || m.scanning {
 		// A rescan replaced the inventory; the new scan reflects the change.
-		return m.info("Moved to " + platform.TrashName)
+		return m.info(msg.done)
 	}
 	// The scan has finished, so the UI goroutine is the tree's only writer.
 	t := m.tree
@@ -87,7 +104,7 @@ func (m *Model) trashDone(msg trashDoneMsg) tea.Cmd {
 	name := n.Name
 	t.Unlock()
 	m.invalidate()
-	return m.info("Moved to " + platform.TrashName + ": " + textutil.Sanitize(name))
+	return m.info(msg.done + ": " + textutil.Sanitize(name))
 }
 
 // ---- Duplicates ----------------------------------------------------------

internal/tui/keys.go

@@ -226,6 +226,17 @@ func (m *Model) reveal() tea.Cmd {
 	if !ok {
 		return nil
 	}
+	if platform.Headless() {
+		// No file manager: show the folder in the map instead.
+		id := m.selectedNode()
+		if m.tree.Node(id).IsDir() && len(m.kidsOf(id).ids) > 0 {
+			m.zoomTo(id)
+			m.setViewByName("Map")
+		} else {
+			m.jumpTo(id)
+		}
+		return m.info("Showing " + textutil.Sanitize(m.tree.Path(m.zoom)))
+	}
 	if err := platform.Reveal(p); err != nil {
 		return m.warn("Open failed: " + textutil.Sanitize(err.Error()))
 	}

internal/tui/modals.go

@@ -39,9 +39,9 @@ func (*infoModal) width() int { return 72 }
 func (md *infoModal) title() string { return "Item information" }
 
 func (md *infoModal) footer(m *Model) string {
-	s := "Esc close  ·  c copy path  ·  o reveal  ·  Space go to"
+	s := "Esc close  ·  c copy path  ·  o " + revealVerb() + "  ·  Space go to"
 	if !m.opts.ReadOnly && !m.snapshot {
-		s += "  ·  d trash"
+		s += "  ·  d " + deleteVerb()
 	}
 	return s
 }
@@ -168,7 +168,8 @@ func (md *infoModal) key(m *Model, k string) (bool, tea.Cmd) {
 		return false, m.copyPath(m.tree.Path(md.id))
 	case "o":
 		m.sel = int64(md.id)
-		return false, m.reveal()
+		// Headless, o navigates the map, which the modal would cover.
+		return platform.Headless(), m.reveal()
 	case "enter":
 		return true, nil
 	case "g", "right":
@@ -273,9 +274,9 @@ func (helpModal) content(m *Model, _ int) []line {
 	sec("APPLICATION")
 	row("a", "toggle allocated / logical (apparent) size")
 	row("c", "copy path to clipboard")
-	row("o", "reveal in file manager")
+	row("o", revealVerb())
 	if !m.opts.ReadOnly {
-		row("d", "move to trash (asks first)")
+		row("d", deleteVerb()+" (asks first)")
 	}
 	row("s", "save snapshot")
 	row("r", "rescan")
@@ -372,3 +373,19 @@ func (md *saveModal) key(m *Model, k string) (bool, tea.Cmd) {
 	}
 	return false, nil
 }
+
+// revealVerb and deleteVerb describe o and d, which change meaning on a
+// headless system.
+func revealVerb() string {
+	if platform.Headless() {
+		return "show folder in map"
+	}
+	return "reveal in file manager"
+}
+
+func deleteVerb() string {
+	if platform.Headless() {
+		return "delete permanently"
+	}
+	return "move to " + platform.TrashName
+}

internal/tui/nest_test.go

@@ -70,3 +70,20 @@ func TestNestingReachesDeepMedia(t *testing.T) {
 		t.Fatalf("only %d episode blocks drawn", files)
 	}
 }
+
+// Headless, o shows the selected folder in the map instead of launching a
+// file manager.
+func TestRevealHeadlessZoomsMap(t *testing.T) {
+	t.Setenv("DISPLAY", "")
+	t.Setenv("WAYLAND_DISPLAY", "")
+	tr := rootTree()
+	m := newModel(Options{Start: func(context.Context) (*scan.Scanner, *inventory.Tree, error) { return nil, tr, nil }}, nil, tr, func() {})
+	send(m, size(160, 45))
+	mnt := m.kidsOf(m.zoom).ids[0]
+	m.snapshot = false // reveal is refused for snapshots
+	m.sel, m.userSel = int64(mnt), true
+	send(m, key("o"))
+	if m.zoom != mnt {
+		t.Fatalf("zoom = %q, want mnt", tr.Path(m.zoom))
+	}
+}