/**
 *项目名称：查询本机或指定主机的IP地址信息
 *编译方法：gcc getbyname,c -lws2_32 -0 getbyname,exe
 *zaiwenjian winsock2.h头文件中：
 *struck      hostent {
 *   char     *h_name;
 *   char     **h_aliases;
 *   short    h_addrtype;
 *   short    h_length;
 *   char     **h_addr_list;
 *   #define  h_addr  h_addr_list[0]
 *};
 *
 */
#include <iostream>
#include <stdio.h>
#include <winsock2.h>
/* run this program using the console pauser or add your own getch, system("pause") or input loop */

int main(int argc, char *argv[])
{   
    WSADATA wsaData;
    int retvalue;
    DWORD errcode;
    int i = 0;
    struct hostent *remotehost;
    char *host_name;
    struct in_addr addr;
    char **palias;
     
    char local_host[256];
     
    if(argc != 2)
    {
         printf("用法：getbyname 主机名\n       getbyname localhost\
              查询本地主机的IP地址");
           
        return 1;
                 
    }
     
    retvalue = WSAStartup(MAKEWORD(2,2), &wsaData);
    if (retvalue != 0)
     
    {
    printf("WSAStartup失败:%d\n",retvalue);
   
    return 1;
    }
     
    if (strcmp(argv[1],"localhost") == 0)
    {
         retvalue = gethostname(local_host,sizeof(local_host));
         if (retvalue != 0)
         {
              printf("获取本地主机名失败: %d\n", retvalue);
               
              return 1;
        }
         
        host_name = local_host;
    }
    else
    {
         host_name = argv[1];
    }
     
    printf("主机名: %s\n",host_name);
    remotehost = gethostbyname(host_name);
     
     
    if (remotehost == NULL)
    {
        errcode = WSAGetLastError();
        if (errcode == WSAHOST_NOT_FOUND)
         
        {
             printf("主机没有找到！");
            
             return 1;
        }
        else if(errcode == WSANO_DATA)
        {
             printf("没找到相应的数据记录！");
            
             return 1;
        }
        else
        {
             printf("函数调用失败:%ld\n", errcode);
            
             return 1;
        }
    }
    else
    {
         printf("查询结果: \n");
         printf("\t 主机名: %s\n",remotehost->h_name);
         
         for (palias = remotehost->h_aliases; *palias != 0; palias++)
         {
            printf("\t 别名 #%d: %s\n", ++i, *palias);
         }
         
         printf("\t 地址类型：");
        switch (remotehost->h_addrtype)
        {
            case AF_INET:
                 printf("AF_INET\n");
                 break;
            case AF_NETBIOS:
                printf("AF_NETBIOS\n");
                break;
            default:
                printf("%d\n", remotehost->h_addrtype);
                break;
        }
        printf("\t 地址长度: %d\n", remotehost->h_length);
        
        i = 0;
        if (remotehost->h_addrtype == AF_INET)
        {
            while (remotehost->h_addr_list[i] != 0)
            {
                addr.s_addr = *(u_long *)remotehost->h_addr_list[i++];
                printf("\tIP 地址#%d: %s\n",i, inet_ntoa(addr));
            }
        }
        else if (remotehost->h_addrtype == AF_NETBIOS)
        {
            printf("返回的是NETBIOS地址");
            
            WSACleanup();
            
            return 0;
        }
     }






下面是错误信息 调试失败
C:\Users\Administrator\Desktop\main.o    main.cpp:(.text+0x176): undefined reference to `__imp_gethostbyname'
C:\Users\Administrator\Desktop\main.o    main.cpp:(.text+0x190): undefined reference to `__imp_WSAGetLastError'
C:\Users\Administrator\Desktop\main.o    main.cpp:(.text+0x345): undefined reference to `__imp_inet_ntoa'
C:\Users\Administrator\Desktop\main.o    main.cpp:(.text+0x3aa): undefined reference to `__imp_WSACleanup'
D:\C++\collect2.exe    [Error] ld returned 1 exit status
D:\C++\Makefile.win    recipe for target 'firstp.exe' failed

[此贴子已经被作者于2022-10-1 15:49编辑过]