Always read the docs of your system. All of the xxprintf functions are not the same. They are sneaky and look the same on the surface. Even silly things like what the % items do can vary between platforms, or have different meanings, or be missing all together.

This has annoyed me a lot, crazy you can't rely on the print functions being the same on different platforms. This is why I always add stb_sprintf and make an allocSprintf() that allocates the right sized buffer first.