linux 获取CPU个数

#include<stdio.h>
#include<unistd.h>

int main()
{
int cpu_num;
cpu_num = sysconf(_SC_NPROCESSORS_CONF);
printf("_SC_NPROCESSORS_CONF=%d\n",cpu_num);

cpu_num = sysconf(_SC_NPROCESSORS_ONLN);
printf("_SC_NPROCESSORS_ONLN=%d\n",cpu_num);

return 0;
}
/*
* - _SC_NPROCESSORS_CONF
*       The number of processors configured.
*
* - _SC_NPROCESSORS_ONLN
*       The number of processors currently online (available).
*/

/* 
* - _SC_NPROCESSORS_CONF
*       The number of processors configured.
* 
* - _SC_NPROCESSORS_ONLN
*       The number of processors currently online (available).
*/ 
#include
#include

int main()
{
int cpu_num;
cpu_num = sysconf(_SC_NPROCESSORS_CONF);
printf("_SC_NPROCESSORS_CONF=%d\n",cpu_num);

cpu_num = sysconf(_SC_NPROCESSORS_ONLN);
printf("_SC_NPROCESSORS_ONLN=%d\n",cpu_num);

return 0;
}