What linux api I can use to measure execution time of some functions in my program?

Question

I am working on a user side application in C on linux. What linux api I can use to measure execution time of some functions in my program? I would like the accuracy up to nano second.

I have google it, I find example in clock clicks. I need the result in nano second.

Thank you.

Answer 1

You could use the time.h library to get the begin and end times and get the difference! This is not Linux specific however!

Answer 2

man clock_gettime

struct timespec is in nano second.