获取Linux操作系统的位数

FILE *fp = NULL;  
fp = popen("getconf LONG_BIT","r");
if(fp == NULL)
{
	return;
}

char buf[256] = {0};
fgets(buf, 256, fp);//含回车键\n
buf[strlen(buf)-1] = '\0';
std::string strBuf(buf,strlen(buf));
pclose(fp);