"Eddie Diener" <eddielee@xxxxxxxxxxxxxx> writes: > How does GCC/G++ know where to look for its system header files ? It's based on stuff figured out by the 'configure' script, when gcc is configured, before it is built from source code. You can run: $ gcc -v hello.cc to see where gcc looks for header files. If you need to chage where GCC looks for header from the command line, see http://xrl.us/btf4 and read about -I, -I-, and so forth. -I is usually sufficient. > I am using GCC/G++ with MingW/DevCpp on Windows. In the DevCpp distribution, > which used GCC 3.2.3, the C header files are in the DevCpp\include directory > and the C++ header files are off of the DevCpp\include\c++ directory. Yet > when I downloaded the latest MingW/GCC/G++ implementation, 3.3.1, there are > no C header files in the release and the C++ header files are placed off of > the DevCpp\include\c++\3.3.1 directory. > > So I am confused. First, why there are no C header files in the > distribution, [snip] GCC does not come with an implementation of the standard C library; it relies on the systm provided C library.