系统属性

man一下sysconf，解释这个函数用来获取系统执行的配置信息。例如页大小、最大页数、cpu个数、打开句柄的最大个数等等。详细说明可以参考man，还可以写个实例进行测试输出，如下：

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

#define ONE_MB (1024 * 1024)

int main()
{
    printf("The number of processors configured is :%ld\n",sysconf(_SC_NPROCESSORS_CONF));
    printf("The number of processors currently online (available) is :%ld\n",sysconf(_SC_NPROCESSORS_ONLN));
    printf ("The pagesize: %ld\n", sysconf(_SC_PAGESIZE));
    printf ("The number of pages: %ld\n", sysconf(_SC_PHYS_PAGES));
    printf ("The number of available pages: %ld\n", sysconf(_SC_AVPHYS_PAGES));
    printf ("The memory size: %lld MB\n",(long long)sysconf(_SC_PAGESIZE) * (long long)sysconf(_SC_PHYS_PAGES) / ONE_MB );
    printf ("The number of files max opened:: %ld\n", sysconf(_SC_OPEN_MAX));
    printf("The number of ticks per second: %ld\n", sysconf(_SC_CLK_TCK));
    printf ("The max length of host name: %ld\n", sysconf(_SC_HOST_NAME_MAX));
    printf ("The max length of login name: %ld\n", sysconf(_SC_LOGIN_NAME_MAX));
    return 0;
}

运行后输出如下结果：

The number of processors configured is :4
The number of processors currently online (available) is :4
The pagesize: 4096
The number of pages: 2016183
The number of available pages: 173676
The memory size: 7875 MB
The number of files max opened:: 1048576
The number of ticks per second: 100
The max length of host name: 64
The max length of login name: 256