socket模拟http版下载者代码分享。本人才疏学浅，抛砖引玉，欢迎大牛指导。

#include <stdio.h>#include <string.h>#include <winsock2.h>#pragma  comment(lib,"WS2_32.lib")#define  KBYTES  1024struct sockaddr_in server;struct hostent *hostinfo;WSADATA wsaData;WORD wVersionRequested;SOCKET LocalSock;char IpAddr[16];char buff[100*KBYTES];FILE *pMyDownFile=NULL;int nWriteBytes=0;int FindEntityMsgPos=0;int MsgInfoSize=0;char *pHostName="www.xxx.com";int main(int argc,char *argv[]){memset(IpAddr,0,sizeof(IpAddr));    memset(buff,0,sizeof(buff));     char *pRequestHeader="GET /xxx.exe HTTP/1.1\r\n""Accept: image/gif, image/x-xbitmap, image/jpeg, image/pjpeg, application/x-shockwave-flash, application/x-ms-application, application/x-ms-xbap, application/vnd.ms-xpsdocument, application/xaml+xml, application/x-silverlight, application/vnd.ms-excel\r\n""Accept-Language: zh-cn\r\n""UA-CPU: x86\r\n""Accept-Encoding: gzip, deflate\r\n""User-Agent: Mozilla/12.0 (compatible; MSIE 7.0; Windows NT 5.1; .NET CLR 2.0.50727; .NET CLR 3.0.04506.648; .NET CLR 3.5.21022)\r\n""Host:www.xxxx.com\r\n"        "Connection: Keep-Alive\r\n\r\n";wVersionRequested = MAKEWORD( 2, 2 );if (WSAStartup(wVersionRequested , &wsaData)){printf("Winsock Initialization failed.\n");exit(1);}if ((LocalSock=socket(AF_INET,SOCK_STREAM,0))==INVALID_SOCKET){printf("Can not create socket.\n");exit(1);}if ((hostinfo=gethostbyname(pHostName))!=NULL){memcpy(IpAddr,inet_ntoa(*(struct   in_addr   *)*hostinfo-> h_addr_list),sizeof(IpAddr));}else{WSACleanup();exit(1);}server.sin_family = AF_INET;server.sin_port = htons(80);server.sin_addr.s_addr= inet_addr(IpAddr);if (connect(LocalSock,(struct sockaddr*)&server,sizeof(server))==0){int nSendedByte=send(LocalSock,pRequestHeader,strlen(pRequestHeader),0);printf("the sended data's length:%d bytes\n\n",nSendedByte);printf("RequestHeader1 :\n%s\n",pRequestHeader);int nRecvBytes=recv(LocalSock,buff,sizeof(buff),0);printf("the recieved data's length is :%d bytes\n\n",nRecvBytes);printf("ResponseHeader1 :\n%s\n",buff);int i=0;while(true){if ((buff[i]=='\r')&&(buff[i+1]=='\n')&&(buff[i+2]=='\r')&&(buff[i+3]=='\n')){FindEntityMsgPos=i+4;break;}i++;}if(pMyDownFile=fopen("C:\\download.html","w+")){printf("openfile success\n");while(FindEntityMsgPos!=nRecvBytes){fputc(buff[FindEntityMsgPos++],pMyDownFile);MsgInfoSize++;}printf("file download success\n");printf("total size %d bytes \n",nRecvBytes);printf("response header size:%d bytes\n",nRecvBytes-MsgInfoSize);printf("request header size :%d bytes\n",MsgInfoSize);}elseprintf("open file fail\n");exit(1);}fclose(pMyDownFile);closesocket(LocalSock);WSACleanup();getchar();return(1);}