### 2.2 Compiling and Linking

The library header files are installed in their own `gsl` directory. You should write any preprocessor include statements with a `gsl/` directory prefix thus,

    #include <gsl/gsl_math.h>

If the directory is not installed on the standard search path of your compiler you will also need to provide its location to the preprocessor as a command line flag. The default location of the `gsl` directory is `/usr/local/include/gsl`. A typical compilation command for a source file `example.c` with the GNU C compiler `gcc` is,

    $ gcc -Wall -I/usr/local/include -c example.c

This results in an object file `example.o`. The default include path for `gcc` searches `/usr/local/include` automatically so the `-I` option can actually be omitted when GSL is installed in its default location.