add utility function to check filename extension

include/Utils/filename.h

+/*******************************************************************************
+* CGoGN: Combinatorial and Geometric modeling with Generic N-dimensional Maps  *
+* version 0.1                                                                  *
+* Copyright (C) 2009-2012, IGG Team, LSIIT, University of Strasbourg           *
+*                                                                              *
+* This library 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.           *
+*                                                                              *
+* Web site: http://cgogn.unistra.fr/                                           *
+* Contact information: cgogn@unistra.fr                                        *
+*                                                                              *
+*******************************************************************************/
+
+#ifndef _CGOGN_FILENAME_H_
+#define _CGOGN_FILENAME_H_
+
+#include <fstream>
+
+namespace CGoGN
+{
+namespace Utils
+{
+
+inline std::string checkFileNameExtension(const std::string &filename, const std::string extension)
+{
+	std::size_t found = filename.rfind(extension);
+	if  ( (found==std::string::npos) || ((found+extension.length()) != filename.length()) )
+	{
+		if (filename[filename.size()-1]=='.')
+			return filename.substr(0,filename.size()-1) + extension;
+		return filename + extension;
+	}
+	return filename;
+}
+
+}
+}
+
+
+
+
+#endif
+