Fix more buffer overruns.

Also add some tests.

Bug: 20323050
Change-Id: I9eaf3dc04efd85206663c4cca4f8c1208620a89a
diff --git a/adb_utils.h b/adb_utils.h
new file mode 100644
index 0000000..ec8e8b5
--- /dev/null
+++ b/adb_utils.h
@@ -0,0 +1,26 @@
+/*
+ * Copyright (C) 2015 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 _ADB_UTILS_H_
+#define _ADB_UTILS_H_
+
+#include <string>
+
+bool directory_exists(const std::string& path);
+
+std::string escape_arg(const std::string& s);
+
+#endif