$ make re
$ ./raytracer 'path-to-the-config.cfg' 'path-to-the-file.ppm'
-- (both args are optional, default values are 'config.cfg' and 'result.ppm', the order is .cfg, then .ppm)
$ display test.ppm
To compile, launch and display image you might need to install this packages:
libconfig.x86_64, libconfig.i686, libconfig-devel.i686, libconfig-devel.x86_64, ImageMagick