No definition of _SC_CLK_TCK

Question

I'm working with a embedded Linux 2.6.36

I need that sequence:

ticksPerSecond=sysconf(_SC_CLK_TCK); // ticks per sec

But I got this error

semLib.c:96: error: '_SC_CLK_TCK' undeclared (first use in this function)
semLib.c:96: error: (Each undeclared identifier is reported only once
semLib.c:96: error: for each function it appears in.)

I didn't find a define of

_SC_CLK_TCK

I found out that it should be in linux/time.h. But it isn't.

Answer 1

Try #include <unistd.h>. It includes the header with this and other definitions.