How to find out the number of cores or processors available in C

[zak100]

Hi,
I got a following program to return the number of cores:

#include <stdio.h>
#include <libcpuid.h>

int main(void)
{
    struct cpu_raw_data_t raw;
    struct cpu_id_t data;

    cpuid_get_raw_data(&raw);
    cpu_identify(&raw, &data);
    printf("No. of Physical Core(s) : %d\n", data.num_cores);
    return 0;
}

I am getting error on #include <libcpuid.h>. I am working on ubuntu 18.04.
Can somebody please guide me how to find the number of cores?

Zulfi.

[Ganado]

Why don't you tell us what the error is? We can't control your computer.

I see directions for installation here: https://github.com/anrieff/libcpuid (scroll down to the Readme).

For the compiler commands of the test program, see: http://libcpuid.sourceforge.net/documentation.html
If your error is that it can't find the .h file,

The development headers must be placed in your search path. Under UNIX-like OSes with pkg-config, this is achieved with "pkg-config libcpuid --cflags".

I don't currently have the ability to install it myself, but try to understand both of those pages.