The 'strcmp' function returns 0 if corresponding strings are equal.

http://www.viva64.com/en/d/0115/print/

FileIO/RapidXmlIO/RapidStnInterface.cpp

@@ -52,7 +52,7 @@ std::vector<GeoLib::Point*> *RapidStnInterface::readStationFile(const std::strin
 	doc.parse<0>(buffer);
 
 	// parse content
-	if (std::string(doc.first_node()->name()).compare("OpenGeoSysSTN"))
+	if (std::string(doc.first_node()->name()).compare("OpenGeoSysSTN") != 0)
 	{
 		std::cout << "XmlStnInterface::readFile() - Unexpected XML root." << std::endl;
 		return NULL;

FileIO/TetGenInterface.cpp

@@ -58,7 +58,7 @@ bool TetGenInterface::readTetGenGeometry (std::string const& geo_fname,
 		return false;
 	}
 	std::string ext (BaseLib::getFileExtension(geo_fname));
-	if (ext.compare("smesh"))
+	if (ext.compare("smesh") != 0)
 	{
 		ERR ("TetGenInterface::readTetGenPoly() - unknown file type (only *.smesh are supported).");
 		return false;

FileIO/XmlIO/Qt/XmlStnInterface.cpp

@@ -340,7 +340,7 @@ int XmlStnInterface::rapidReadFile(const std::string &fileName)
 	doc.parse<0>(buffer);
 
 	// parse content
-	if (std::string(doc.first_node()->name()).compare("OpenGeoSysSTN"))
+	if (std::string(doc.first_node()->name()).compare("OpenGeoSysSTN") != 0)
 	{
 		ERR("XmlStnInterface::readFile() - Unexpected XML root.");
 		return 0;