undefined reference to `std::ios_base::Init::Init()’
You can resolve this in several ways: Use g++ in stead of gcc: g++ -g -o MatSim MatSim.cpp Add -lstdc++: gcc -g -o MatSim MatSim.cpp -lstdc++ Replace <string.h> by <string> This is a linker problem, not a compiler issue. The same problem is covered in the question iostream linker error – it explains what is … Read more