feat: remove runtime directory if it's empty

Signed-off-by: ComixHe <[email protected]>

apps/ll-cli/src/main.cpp

@@ -150,10 +150,11 @@ int lockCheck() noexcept
         ::close(fd);
     });
 
-    struct flock lock_info
-    {
-        .l_type = F_RDLCK, .l_whence = SEEK_SET, .l_start = 0, .l_len = 0, .l_pid = 0
-    };
+    struct flock lock_info{ .l_type = F_RDLCK,
+                            .l_whence = SEEK_SET,
+                            .l_start = 0,
+                            .l_len = 0,
+                            .l_pid = 0 };
 
     if (::fcntl(fd, F_GETLK, &lock_info) == -1) {
         qCritical() << "failed to get lock" << lock;
@@ -556,6 +557,18 @@ ll-cli list --upgradable
           auto userContainerDir =
             std::filesystem::path{ "/run/linglong" } / std::to_string(::getuid());
           ensureDirectory(userContainerDir);
+          auto removeIfEmpty = linglong::utils::finally::finally([&userContainerDir] {
+              std::error_code ec;
+              if (!std::filesystem::remove(userContainerDir, ec) && ec) {
+                  if (ec == std::errc::directory_not_empty
+                      || ec == std::errc::no_such_file_or_directory) {
+                      return;
+                  }
+
+                  qWarning() << "failed to remove" << userContainerDir.c_str() << ":"
+                             << ec.message().c_str();
+              }
+          });
 
           while (true) {
               auto lockOwner = lockCheck();