-#TODO NEED TO TEST IF PATHS ARE ALREADY SET BY CMAKE
-SET(CMAKE_C_FLAGS "${CMAKE_C_FLAGS}-I${HAVE_RNGSTREAM_H} -L${GTNETS_LIB_PATH} ")
+string(REGEX MATCH "-L${GTNETS_LIB_PATH} " operation "${CMAKE_C_FLAGS}")
+if(NOT operation)
+ SET(CMAKE_C_FLAGS "${CMAKE_C_FLAGS}-L${GTNETS_LIB_PATH} ")
+endif(NOT operation)
+
+string(REGEX MATCH "-I${HAVE_RNGSTREAM_H} " operation "${CMAKE_C_FLAGS}")
+if(NOT operation)
+ SET(CMAKE_C_FLAGS "${CMAKE_C_FLAGS}-I${HAVE_RNGSTREAM_H} ")
+endif(NOT operation)
+