Move background items left over from deleted apps to the Trash

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ## Unreleased
 
+- Background Items marks items left over from a deleted app, whose program is no longer on the Mac, and has a minus button to stop one and move it to the Trash, from where it can be dragged back. `removemacai background` marks them as left over too (#66).
 - The app has a Check for Updates… item in the RemoveMacAI menu. It asks GitHub for the latest release and offers to open its download page. It only checks when you choose it, so RemoveMacAI still makes no network requests on its own (#44).
 - The app has an Install Command Line Tool… item in the RemoveMacAI menu. It asks first, then links `/usr/local/bin/removemacai` to the app, so the app from the zip gets the `removemacai` command too. It never replaces a file there that isn't a link (#60).
 - `removemacai background` with an action other than `off` or `on`, such as the typo `of`, now fails and says which actions it takes, instead of listing the items and exiting 0 (#82).

Localization/ru.lproj/Localizable.strings

@@ -413,6 +413,10 @@
 "RemoveMacAI needs your password to change background items for all users." = "RemoveMacAI требуется ваш пароль, чтобы изменить фоновые объекты для всех пользователей.";
 "RemoveMacAI needs your password to move items only an administrator can change." = "RemoveMacAI требуется ваш пароль, чтобы переместить объекты, которые может изменять только администратор.";
 "Turn off everything except 1 kept feature" = "Выключить всё, кроме 1 оставленной функции";
+"What it runs is gone, so it's left over from a deleted app." = "Программы, которую он запускает, больше нет, — это остаток удалённого приложения.";
+"Move this leftover background item to the Trash?" = "Переместить этот оставшийся фоновый объект в Корзину?";
+"%@ runs something that is no longer on this Mac. It goes to the Trash, so you can drag it back to restore it. Items marked All users ask for your password." = "%@ запускает то, чего на этом Mac больше нет. Объект переместится в Корзину, и его можно будет перетащить обратно, чтобы восстановить. Для объектов с пометкой «Все пользователи» потребуется пароль.";
+"RemoveMacAI needs your password to move background items only an administrator can change." = "RemoveMacAI требуется ваш пароль, чтобы переместить фоновые объекты, которые может изменять только администратор.";
 "RemoveMacAI %@ is available." = "Доступна версия RemoveMacAI %@.";
 "You have %@. Download the new version from GitHub and replace this app with it." = "У вас версия %@. Скачайте новую версию с GitHub и замените ею это приложение.";
 "Download" = "Скачать";

Sources/removemacai/App/AppModel.swift

@@ -316,6 +316,19 @@ final class AppModel {
 
   // MARK: background items
 
+  func trashBackground(_ item: BackgroundItem) {
+    backgroundBusy = true
+    Task.detached(priority: .userInitiated) {
+      let problems = BackgroundItems.trash([item])
+      await MainActor.run {
+        self.backgroundBusy = false
+        self.loadBackground()
+        self.journal = Engine.loadJournal()
+        if !problems.isEmpty { self.run = .finished(problems: problems, freed: nil) }
+      }
+    }
+  }
+
   func setBackground(_ item: BackgroundItem, off: Bool) {
     backgroundBusy = true
     Task.detached(priority: .userInitiated) {

Sources/removemacai/App/Pages.swift

@@ -366,6 +366,7 @@ struct TweakRow: View {
 
 struct BackgroundView: View {
   @Environment(AppModel.self) private var model
+  @State private var trashing: BackgroundItem?
 
   var body: some View {
     Form {
@@ -374,27 +375,36 @@ struct BackgroundView: View {
           Text("No background items from other apps.").foregroundStyle(.secondary)
         }
         ForEach(model.background) { item in
-          Toggle(isOn: Binding(
-            get: { !model.backgroundOff.contains(item.id) },
-            set: { model.setBackground(item, off: !$0) }
-          )) {
-            VStack(alignment: .leading, spacing: 2) {
-              HStack(spacing: 6) {
-                Text(item.owner)
-                if item.system {
-                  Text("All users").font(.caption2.weight(.medium)).padding(.horizontal, 5).padding(.vertical, 1)
-                    .background(Capsule().fill(.quaternary))
+          HStack(spacing: 10) {
+            Toggle(isOn: Binding(
+              get: { !model.backgroundOff.contains(item.id) },
+              set: { model.setBackground(item, off: !$0) }
+            )) {
+              VStack(alignment: .leading, spacing: 2) {
+                HStack(spacing: 6) {
+                  Text(item.owner)
+                  if item.system {
+                    Text("All users").font(.caption2.weight(.medium)).padding(.horizontal, 5).padding(.vertical, 1)
+                      .background(Capsule().fill(.quaternary))
+                  }
+                }
+                Text(item.label).font(.caption.monospaced()).foregroundStyle(.secondary)
+                Text(item.program).font(.caption2.monospaced()).foregroundStyle(.tertiary)
+                  .lineLimit(1).truncationMode(.middle)
+                if item.isLeftover {
+                  Label("What it runs is gone, so it's left over from a deleted app.", systemImage: "questionmark.folder").font(.caption).foregroundStyle(.secondary)
+                } else if item.warning != nil {
+                  Label(String(localized: "Not an updater. Turning it off can stop \(item.owner) working."), systemImage: "exclamationmark.triangle").font(.caption).foregroundStyle(.orange)
                 }
               }
-              Text(item.label).font(.caption.monospaced()).foregroundStyle(.secondary)
-              Text(item.program).font(.caption2.monospaced()).foregroundStyle(.tertiary)
-                .lineLimit(1).truncationMode(.middle)
-              if item.warning != nil {
-                Label(String(localized: "Not an updater. Turning it off can stop \(item.owner) working."), systemImage: "exclamationmark.triangle").font(.caption).foregroundStyle(.orange)
-              }
+            }
+            .toggleStyle(.switch)
+            if item.isLeftover {
+              Button { trashing = item } label: { Image(systemName: "minus.circle") }
+                .buttonStyle(.borderless)
+                .help("Move to Trash")
             }
           }
-          .toggleStyle(.switch)
           .disabled(model.backgroundBusy)
         }
       } header: {
@@ -406,6 +416,15 @@ struct BackgroundView: View {
     }
     .formStyle(.grouped)
     .navigationTitle("Background Items")
+    .confirmationDialog(
+      "Move this leftover background item to the Trash?",
+      isPresented: Binding(get: { trashing != nil }, set: { if !$0 { trashing = nil } }),
+      presenting: trashing
+    ) { item in
+      Button("Move to Trash") { model.trashBackground(item) }
+    } message: { item in
+      Text(String(localized: "\(item.label) runs something that is no longer on this Mac. It goes to the Trash, so you can drag it back to restore it. Items marked All users ask for your password."))
+    }
     .toolbar {
       ToolbarItem {
         Button { model.loadBackground() } label: { Label("Reload", systemImage: "arrow.clockwise") }

Sources/removemacai/BackgroundItems.swift

@@ -23,6 +23,28 @@ struct BackgroundItem: Identifiable, Hashable {
     [label, (program as NSString).lastPathComponent].contains { $0.lowercased().contains("update") }
   }
 
+  /// Whether what it runs is gone, as when its app was deleted and the agent
+  /// stayed behind. Such an item can't run, so it can go to the Trash. Only a
+  /// path macOS confirms is missing counts, and a command an interpreter runs
+  /// with -c or -e is never judged, so a working item isn't offered.
+  var isLeftover: Bool {
+    var path = program
+    if Self.interpreters.contains((program as NSString).lastPathComponent) {
+      let rest = arguments.dropFirst()
+      let inline = rest.contains { $0.hasPrefix("-") && !$0.hasPrefix("--") && ($0.contains("c") || $0.contains("e")) }
+      guard !inline, let script = rest.first(where: { !$0.hasPrefix("-") }) else { return false }
+      path = script
+    }
+    return Self.confirmedMissing(path)
+  }
+
+  /// True only when macOS says the path doesn't exist, not when it can't look.
+  static func confirmedMissing(_ path: String) -> Bool {
+    guard path.hasPrefix("/") else { return false }
+    var info = stat()
+    return stat(path, &info) != 0 && (errno == ENOENT || errno == ENOTDIR)
+  }
+
   /// What switching it off can break, or nil for an updater.
   var warning: String? {
     isUpdater ? nil : "Not an updater. Turning it off can stop \(owner) working."
@@ -128,6 +150,76 @@ enum BackgroundItems {
     return problems
   }
 
+  /// Stops leftover items and moves their files to the Trash. An item that is
+  /// no longer left over, or that is still loaded after bootout, stays where
+  /// it is. Files another user owns share one administrator prompt; they land
+  /// in the Trash without Finder's Put Back, as in Storage.
+  static func trash(_ items: [BackgroundItem]) -> [String] {
+    var journal = Engine.loadJournal()
+    if let blocked = Engine.journalBlocked { return [blocked] }
+    var problems: [String] = []
+    var adminCommands: [String] = []
+    let trash = Storage.home + "/.Trash"
+    var taken = Set<String>()
+    func trashPath(_ plist: String) -> String {
+      let name = (plist as NSString).lastPathComponent
+      let stem = (name as NSString).deletingPathExtension, ext = (name as NSString).pathExtension
+      var candidate = Storage.uniqueName(name, in: trash)
+      var n = 2
+      while taken.contains(candidate) {
+        candidate = Storage.uniqueName(ext.isEmpty ? "\(stem) \(n)" : "\(stem) \(n).\(ext)", in: trash)
+        n += 1
+      }
+      taken.insert(candidate)
+      return trash + "/" + candidate
+    }
+    for item in items {
+      // What it runs may have come back since the list was read.
+      guard item.isLeftover else {
+        problems.append("\(item.label) runs something that is on this Mac again, so it stayed")
+        continue
+      }
+      // -n never overwrites; a move that doesn't happen is reported below.
+      let move = "/bin/mv -n \(Shell.quote(item.plist)) \(Shell.quote(trashPath(item.plist)))"
+      if item.system {
+        let target = Shell.quote(item.target)
+        adminCommands.append(
+          "/bin/launchctl bootout \(target) 2>/dev/null; if /bin/launchctl print \(target) >/dev/null 2>&1; then "
+            + "echo \(Shell.quote("\(item.label) couldn't be stopped, so it stayed")) >&2; exit 1; fi; \(move)")
+        continue
+      }
+      Shell.run("/bin/launchctl", ["bootout", item.target])
+      guard !isLoaded(item) else {
+        problems.append("\(item.label) couldn't be stopped, so it stayed")
+        continue
+      }
+      do {
+        try FileManager.default.trashItem(at: URL(fileURLWithPath: item.plist), resultingItemURL: nil)
+      } catch {
+        guard FileManager.default.fileExists(atPath: item.plist) else { continue }
+        adminCommands.append(move)
+      }
+    }
+    if !adminCommands.isEmpty {
+      let result = Shell.admin(adminCommands, prompt: String(localized: "RemoveMacAI needs your password to move background items only an administrator can change."))
+      if !result.ok { problems.append(Shell.adminError(result)) }
+    }
+    for item in items {
+      if !FileManager.default.fileExists(atPath: item.plist) {
+        journal.entries[item.id] = nil
+      } else if item.isLeftover && !problems.contains(where: { $0.hasPrefix(item.label + " ") }) {
+        problems.append("\(item.label) is still in \((item.plist as NSString).deletingLastPathComponent)")
+      }
+    }
+    Engine.save(journal)
+    return problems
+  }
+
+  /// Whether launchd still has the item loaded. Works for the system domain without a password.
+  static func isLoaded(_ item: BackgroundItem) -> Bool {
+    Shell.run("/bin/launchctl", ["print", item.target]).ok
+  }
+
   /// Undoes one journal entry, for revert-everything.
   static func revert(_ id: String, journal: inout Engine.Journal) -> [String] {
     guard let entry = journal.entries[id] else { return [] }

Sources/removemacai/SelfTest.swift

@@ -286,6 +286,28 @@ func selfTest() -> Bool {
   let helper = BackgroundItem(label: "dev.orbstack.OrbStack.privhelper", plist: "",
     program: "/Library/PrivilegedHelperTools/dev.orbstack.OrbStack.privhelper", system: true)
   check(script.owner == "sync.sh" && helper.owner == "OrbStack", "background items are named after what they run")
+  let goneApp = BackgroundItem(label: "com.example.gone", plist: "", program: "/Applications/Gone-\(UUID().uuidString).app/Contents/MacOS/helper", system: false)
+  let goneScript = BackgroundItem(label: "com.example.gone-script", plist: "", program: "/bin/bash",
+    arguments: ["/bin/bash", "/nonexistent-\(UUID().uuidString)/sync.sh"], system: false)
+  let present = BackgroundItem(label: "com.example.present", plist: "", program: "/bin/bash",
+    arguments: ["/bin/bash", "/bin/sh"], system: false)
+  let bare = BackgroundItem(label: "com.example.bare", plist: "", program: "helper", system: false)
+  check(goneApp.isLeftover && goneScript.isLeftover && !present.isLeftover && !bare.isLeftover,
+    "a background item is left over only when what it runs is gone")
+  let inline = BackgroundItem(label: "com.example.inline", plist: "", program: "/bin/bash",
+    arguments: ["/bin/bash", "-c", "echo ok", "/nonexistent-\(UUID().uuidString)"], system: false)
+  let inlineScript = BackgroundItem(label: "com.example.inline-script", plist: "", program: "/bin/sh",
+    arguments: ["/bin/sh", "-c", "/bin/sh --version"], system: false)
+  let optioned = BackgroundItem(label: "com.example.optioned", plist: "", program: "/bin/zsh",
+    arguments: ["/bin/zsh", "-l", "/nonexistent-\(UUID().uuidString)/sync.sh"], system: false)
+  check(!inline.isLeftover && !inlineScript.isLeftover && optioned.isLeftover,
+    "a command run with -c is never judged left over, and options before a script are skipped")
+  let locked = FileManager.default.temporaryDirectory.appendingPathComponent("removemacai-locked-\(UUID().uuidString)")
+  try? FileManager.default.createDirectory(at: locked, withIntermediateDirectories: false, attributes: [.posixPermissions: 0o000])
+  defer { try? FileManager.default.setAttributes([.posixPermissions: 0o700], ofItemAtPath: locked.path); try? FileManager.default.removeItem(at: locked) }
+  check(!BackgroundItem.confirmedMissing(locked.appendingPathComponent("helper").path)
+    && BackgroundItem.confirmedMissing("/nonexistent-\(UUID().uuidString)/helper"),
+    "a path RemoveMacAI can't look into doesn't count as missing")
 
   let ranAll = Shell.run("/bin/sh", ["-c", Shell.adminScript(["false", "echo second"])])
   check(!ranAll.ok && ranAll.output.contains("second"), "one failed administrator step doesn't skip the rest")

Sources/removemacai/TweakCommands.swift

@@ -153,7 +153,7 @@ enum TweakCommands {
         let state = off ? Term.dim(Term.pad("off", 5)) : Term.green(Term.pad("on", 5))
         let kind = item.isUpdater ? Term.dim("updater") : Term.yellow("helper")
         print("  " + Term.pad(item.label, 48) + Term.pad(item.owner, 22) + state + kind
-          + (item.system ? Term.dim("  (all users)") : ""))
+          + (item.system ? Term.dim("  (all users)") : "") + (item.isLeftover ? Term.dim("  (left over)") : ""))
       }
       print()
       print(Term.dim("Turning off a helper can stop its app working, for example a VPN or Docker."))