gethostname的使用问题

C/C++ code

CString GetLocalIp(){    struct hostent* phost;    char ip[20];    char hostname[50];    gethostname(hostname,50);    phost = gethostbyname(hostname);    char ** names;    names = phost->h_aliases;    char ** iplist;    iplist = phost->h_addr_list;    while( * iplist)    {        strcpy(ip,inet_ntoa( * (struct in_addr * ) * iplist));        iplist ++;    }    CString LocalIp = ip;    return LocalIp;}

请问这段代码里面的gethostname需要什么头文件啊，编译的时候老提示不知道gethostname是什么东西。我在网上查了下好像是系统的函数啊

[解决办法]
http://msdn.microsoft.com/en-us/library/windows/desktop/ms738527(v=vs.85).aspx

Header Winsock2.h
Library Ws2_32.lib
DLL Ws2_32.dll