getnetinfo.c

读取TCP连接数

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

#ifdef __ia64__
#define USE_EFI
#endif /* __ia64__ */

#include "getnetinfo.h"

#define GET_NETSTAT_S_CMD  "netstat -s"
#define TCP_BEGIN_LABEL  "Tcp:"
#define TCP_ACTIVE_CONN_OPENS  "passive connection openings"
#define UDP_BEGIN_LABEL  "Udp:"
#define UDP_PKG_RECEIVED  "packets received"
#define UDP_PKG_SENT  "packets sent"

//全局网络连接信息结构体
TCP_UDP_Info g_tcp_udp_info;

int getnetstatInfo(void)
{
    FILE *pFile  = NULL;
    char buf[256];
    char number[32];
    char *pFind;
    pFile = popen(GET_NETSTAT_S_CMD , "r");

    if (!pFile)
    {
        return -1;
    }
    g_tcp_udp_info._tcp_passive_conn = 0;
    g_tcp_udp_info._udp_pkg_rec = 0;
    g_tcp_udp_info._udp_pkg_snd = 0;
    while(!feof(pFile))
    {       
        bzero(buf,sizeof(buf));
        if (!(fgets(buf, sizeof(buf), pFile)))
            break;         
        
        //分析TCP连接数.
        pFind=strstr(buf,TCP_BEGIN_LABEL);
        if(pFind!=NULL)
        {
            //向下走两行就是:TCP_ACTIVE_CONN_OPENS
            if (!(fgets(buf, sizeof(buf), pFile)))
               break; 
            if (!(fgets(buf, sizeof(buf), pFile)))
               break; 
            pFind=strstr(buf,TCP_ACTIVE_CONN_OPENS);
            if(pFind!=NULL)
            {
                //这一行就是TCP的被动连接数.             
                sscanf(buf, "%*[ ]%d",&g_tcp_udp_info._tcp_passive_conn);  //只读取数字字符      
            }
        }
        //分析UPD连接.
        pFind=strstr(buf,UDP_BEGIN_LABEL);
        if(pFind!=NULL)
        {
            //向下走一行就是:UDP_PKG_RECEIVED
            if (!(fgets(buf, sizeof(buf), pFile)))
               break; 
            pFind=strstr(buf,UDP_PKG_RECEIVED);
            if(pFind!=NULL)
            {
                //这一行就是upd的包接收数
                sscanf(buf, "%*[ ]%d",&g_tcp_udp_info._udp_pkg_rec);  
            }
            for(unsigned int i=0;i<3;++i)
            {
                if (!(fgets(buf, sizeof(buf), pFile)))
                    break; 
            }
            pFind=strstr(buf,UDP_PKG_SENT);
            if(pFind!=NULL)
            {
                //这一行就是upd的包发送数
                sscanf(buf, "%*[ ]%d",&g_tcp_udp_info._udp_pkg_snd);  
            }
        }
    }
    pclose(pFile);

    printf("TCP:active connections openings=%ld\n",g_tcp_udp_info._tcp_passive_conn);
    printf("UDP:packets received=%ld\n",g_tcp_udp_info._udp_pkg_rec);
    printf("UDP:packets sent=%ld\n",g_tcp_udp_info._udp_pkg_snd);    
    return 0;
}