Linux系统下获取系统的内存使用情况(C语言代码)

一、功能介绍

通过sysinfo函数获取系统内存的使用情况。

sysinfo函数的帮助页如下：

wbyq@wbyq:/mnt/hgfs/linux-share-dir/linux_c$ man sysinfo
SYSINFO(2)                           Linux Programmer's Manual                          SYSINFO(2)

NAME
       sysinfo - return system information

SYNOPSIS
       #include <sys/sysinfo.h>

       int sysinfo(struct sysinfo *info);

DESCRIPTION
       sysinfo() returns certain statistics on memory and swap usage, as well as the load average.

       Until Linux 2.3.16, sysinfo() returned information in the following structure:

           struct sysinfo {
               long uptime;             /* Seconds since boot */
               unsigned long loads[3];  /* 1, 5, and 15 minute load averages */
               unsigned long totalram;  /* Total usable main memory size */
               unsigned long freeram;   /* Available memory size */
               unsigned long sharedram; /* Amount of shared memory */
               unsigned long bufferram; /* Memory used by buffers */
               unsigned long totalswap; /* Total swap space size */
               unsigned long freeswap;  /* Swap space still available */
               unsigned short procs;    /* Number of current processes */
               char _f[22];             /* Pads structure to 64 bytes */
           };

       In the above structure, the sizes of the memory and swap fields are given in bytes.

二、程序源码

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/sysinfo.h>

int main(int argc,char **argv)
{
    /*2. 获取当前系统内存使用情况*/
    struct sysinfo s_info;
    char info_buff[100];
    while(1)
    {
        if(sysinfo(&s_info)==0)
        {
            sprintf(info_buff,"总内存: %.ld M",s_info.totalram/1024/1024);
            printf("%s\n",info_buff);

            sprintf(info_buff,"未使用内存: %.ld M",s_info.freeram/1024/1024);
            printf("%s\n",info_buff);

            sprintf(info_buff,"交换区总内存: %.ld M",s_info.totalswap/1024/1024);
            printf("%s\n",info_buff);

            sprintf(info_buff,"交换区未使用内存: %.ld M",s_info.freeswap/1024/1024);
            printf("%s\n",info_buff);

            sprintf(info_buff,"系统运行时间: %.ld 分钟",s_info.uptime/60);
            printf("%s\n",info_buff);

            printf("\n\n");
        }
        sleep(1);
    }
    return 0;
}

三、运行效果

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