[driver] added driver source code from isaac repository

include/tools/sys/getenv.hpp

@@ -0,0 +1,56 @@
+/*
+ * Copyright (c) 2015, PHILIPPE TILLET. All rights reserved.
+ *
+ * This file is part of ISAAC.
+ *
+ * ISAAC is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301  USA
+ */
+
+#ifndef TDL_TOOLS_SYS_GETENV_HPP
+#define TDL_TOOLS_SYS_GETENV_HPP
+
+#include <string>
+#include <cstdlib>
+
+namespace tdl
+{
+
+namespace tools
+{
+
+    inline std::string getenv(const char * name)
+    {
+        #ifdef _MSC_VER
+            char* cache_path = 0;
+            std::size_t sz = 0;
+            _dupenv_s(&cache_path, &sz, name);
+        #else
+            const char * cache_path = std::getenv(name);
+        #endif
+        if(!cache_path)
+            return "";
+        std::string result(cache_path);
+        #ifdef _MSC_VER
+            free(cache_path);
+        #endif
+        return result;
+    }
+
+}
+
+}
+
+#endif