一个简单的C程序

该程序的主要目的是:统计出以MAP开头的行中，不同IP所占的行数

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

#define buf_size 85
#define ip_size 15
#define ipfile “ipfilter.txt”

char tmp[ip_size]={0};

typedef struct node
{
 char ip[ip_size];
 int num;
 struct node *next;
} IpInfo;

/*=============链表函数===========*/
IpInfo *Create(IpInfo *h)  
{
    IpInfo *p, *cp;
   
    if((p=(IpInfo *)malloc(sizeof(IpInfo)))==NULL)
    {
        printf(“memory malloc failed!”);
        exit(0);
    }
    p->next= NULL;

    cp= h;
    while(cp->next!=NULL)
          cp= cp->next;

    cp->next= p;

    return p;
}

char* SubChar(char *ip)
{
    if (strlen(ip) > 23)
    {
        strncpy(tmp,ip+5,1);
        if (strcmp(tmp,”M”)==0)
            strncpy(tmp, ip+9, ip_size);
        else
            strcpy(tmp, “”);
     }

    return(tmp);
}

void HandleData(IpInfo *root)
{
 FILE *fp;
 IpInfo *c;
 char *buf;
 char *oldip, *newip;

        c=root;
        oldip=(char *)malloc((ip_size+1)*sizeof(char));
        newip=(char *)malloc((ip_size+1)*sizeof(char));

 if((fp=fopen(ipfile,”r”))==NULL)
 {
              printf(“file ‘%s’ open error!\n”, ipfile);
       exit(0);
 }

 printf(“Now analysing… \n”);
 fgets(buf, buf_size, fp);
 strcpy(newip, SubChar(buf));
 strcpy(oldip, newip);

 while (!feof(fp))
 {
            fgets(buf, buf_size, fp);
     strcpy(newip, SubChar(buf));
            if (strcmp(newip, oldip)==0)
               c->num++;
            else
           {
               strcpy(oldip, newip);
               c = Create(root);
               strcpy(c->ip, newip);
               c->num =1;
           }
 }
        free(newip);
        free(oldip);
 fclose(fp);

}

void ShowAbnormalIp(IpInfo *h, int limit)
{
    IpInfo *p;
   
    p= h;
    while((p->next!= NULL)||(p->num != 0))
    {
        if (p->num > limit)
           printf(“Abnormal IP is:%s \n”,p->ip);
        if (p->next != NULL)
           p= p->next;
        else
           break;
    }

}

void main(int argc, char *argv[])
{
    IpInfo *root; //头指针
    int limit;

    if (argc >1)
        if ((limit=atoi(argv[1]))<0) limit= 2000;

    root=(IpInfo*)malloc(sizeof(IpInfo));
    strcpy(root->ip, “.”);
    root->num=0;
    root->next=NULL;

    HandleData(root);              //分析文件
    ShowAbnormalIp(root, limit);  //显示结果

}

ipfilter.txt文件格式

   1
   1 List of active MAP/Redirect filters:
   1 List of active sessions:
   1 MAP 172.172.0.207   1025  <- -> 61.132.92.51    1025  [58.60.13.8 8080]
   1 MAP 172.172.0.207   1025  <- -> 61.132.92.45    1025  [58.60.13.8 8080]
   1 MAP 172.172.0.207   1025  <- -> 61.132.92.55    1025  [58.60.13.8 8080]
   1 MAP 172.172.0.207   1025  <- -> 61.132.92.33    1025  [58.60.13.8 8080]
   1 MAP 172.172.0.207   1025  <- -> 61.132.92.45    1025  [58.60.13.8 8080]
           …
   1 MAP 172.172.0.202   1025  <- -> 61.132.92.51    1025  [58.60.13.8 8080]
   1 MAP 172.172.0.202   1025  <- -> 61.132.92.52    1025  [58.60.13.8 8080]
   1 MAP 172.172.0.203   1025  <- -> 61.132.92.53    1025  [58.60.13.8 8080]
   1 MAP 172.172.0.203   1025  <- -> 61.132.92.54    1025  [58.60.13.8 8080]
   1 RDR 192.168.66.8    80    <- -> 61.132.92.51    80    [222.71.195.216 1081]
   1 map xl0 172.172.0.0/16 -> 61.132.92.51/32
   1 map xl0 192.168.0.0/16 -> 61.132.92.51/32
   1 rdr xl0 61.132.92.51/32 port 3389 -> 192.168.66.8 port 3389 tcp
   1 rdr xl0 61.132.92.51/32 port 5001 -> 172.172.7.8 port 5001 tcp
   1 rdr xl0 61.132.92.51/32 port 80 -> 192.168.66.8 port 80 tcp