gcc에서 core 갯수 알아오는 함수가 있을까요?

[bushi@rose kernel-2.6]$ 
[bushi@rose kernel-2.6]$ getconf _NPROCESSORS_ONLN
4
[bushi@rose kernel-2.6]$ 
[bushi@rose kernel-2.6]$ cat c.c
#include <stdio.h>
#include <unistd.h>
 
int main()
{
        return printf("online cpu: %ld\n", sysconf(_SC_NPROCESSORS_ONLN));
}
[bushi@rose kernel-2.6]$ 
[bushi@rose kernel-2.6]$ gcc -s -o c c.c -Wall
[bushi@rose kernel-2.6]$ 
[bushi@rose kernel-2.6]$ ./c
online cpu: 4
[bushi@rose kernel-2.6]$ 

[bushi@rose kernel-2.6]$ cat /proc/cpuinfo | grep processor
processor       : 0
processor       : 1
processor       : 2
processor       : 3
[bushi@rose kernel-2.6]$