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