linux獲取cpu核心數c語言接口

接口原型：

#include <unistd.h>

long sysconf(int name);

接口描述：該接口用於獲取一些系統配置，如_SC_NPROCESSORS_ONLN表示The number of processors currently online (available).等等

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

int main(int argc, char *argv[])
{
    unsigned int ngx_ncpu = 0;
    
    ngx_ncpu = sysconf(_SC_NPROCESSORS_ONLN);
    printf("ncpu = %d\n", ngx_ncpu);
    
    return 0;
}