What is librt.so? How can I use it directly?

Question

I find some libraries are linked to librt.so, while others are not. I am wondering in what circumstances it is linked.

I have never used this library directly. Is there any demo showing the direct usage of it? Is there a header file related to it?

Answer 1

The functions are for Real Time Solaris (Real Time means guaranteed response in a time boundary), which has since been integrated into mainline Solaris and is part of libc. Librt is present only for historical, backward compatibility reasons and you do not need to reference it.