Reimplement scandir(3).

The old scandir implementation didn't take into account the varying
size of directory entries, and didn't correctly clean up on its
error exits.

Bug: 7339844
Change-Id: Ib40e3564709752241a3119a496cbb2192e3f9abe
diff --git a/libc/private/ScopedReaddir.h b/libc/private/ScopedReaddir.h
new file mode 100644
index 0000000..797809a
--- /dev/null
+++ b/libc/private/ScopedReaddir.h
@@ -0,0 +1,50 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef SCOPED_READDIR_H
+#define SCOPED_READDIR_H
+
+#include <dirent.h>
+
+class ScopedReaddir {
+ public:
+  ScopedReaddir(const char* path) {
+    dir_ = opendir(path);
+  }
+
+  ~ScopedReaddir() {
+    if (dir_ != NULL) {
+      closedir(dir_);
+    }
+  }
+
+  bool IsBad() {
+    return dir_ == NULL;
+  }
+
+  dirent* ReadEntry() {
+    return readdir(dir_);
+  }
+
+ private:
+  DIR* dir_;
+
+  // Disallow copy and assignment.
+  ScopedReaddir(const ScopedReaddir&);
+  void operator=(const ScopedReaddir&);
+};
+
+#endif // SCOPED_READDIR_H