Timer function in C++

alright, so I got my program written out in c++, but I want to know how long it takes to run. So I'm wondering if anyone knows anysort of timer functions? I need the most time effecient one, granted it would only run once (or twice depending on the function), but there is still an emphasis on time. as for operating system I am using Yoper linux, I don't know if it matters, but I've heard it does.

In C++11, there is std::chrono::high_resolution_clock which is typically accurate to nanoseconds on POSIX systems, or hundreds of nanoseconds on Windows.