Lin George wrote: > 1. if the extension name is .cpp (or .cxx), then even if we invoke command gcc, g++ will be used; > 2. if the extension name is .c and even if we invoke g++, then the code will be compiled as C binary other than C++ binary (and at the same time, C system shared lib will be linked, other than C++ system shared lib). When you invoke the compiler as gcc, it will treat filenames ending in .cpp/.cxx/.cc/.C as C++ for the purposes of choosing what language to interpret the source as, but it will *not* add the necessary runtime support when linking. You only get that when you link using g++, regardless of filenames, since at that point you're dealing with objects not source files anyway. Brian
