C語言獲得電腦的IP地址的小例子

代碼如下：

#include <stdio.h>
 #include <winsock2.h>

 #pragma comment(lib, "WS2_32.lib")

 int main()
 {
     char host_name[256]; // define host name (for example:xxx-PC)
     int WSA_return, i;
     WSADATA WSAData;
     HOSTENT *host_entry; // record host information
     WORD  wVersionRequested;

 
     wVersionRequested = MAKEWORD(2, 0);
     WSA_return = WSAStartup(wVersionRequested, &WSAData); // initialize Winsock service and then call other socket or dll file

     if (WSA_return == 0) // initialize success
     {
         gethostname(host_name, sizeof(host_name));
         host_entry = gethostbyname(host_name);

         for(i = 0; host_entry != NULL && host_entry->h_addr_list[i] != NULL; ++i)
         {
             // define pszAddr to record IP
             // inet_ntoa: Convert an IP into an Internet standard dotted format string
             const char *pszAddr = inet_ntoa (*(struct in_addr *)host_entry->h_addr_list[i]);
             printf("[IP]\t%s\n[Name]\t%s\n\n", pszAddr, host_name);
         }
     }
     else
     {
         printf("ERROR\n");
     }
     /* WSACleanup() finish use Winsock 2 DLL (Ws2_32.dll). Head:Winsock2.h. reference #pragma comment(lib, "ws2_32.lib") */
     WSACleanup();
     return 0;
 }