面向无连接UDP协议的文件传输

古灵精怪的前端攻城狮 2019-05-23 10:16:02

花了差不多一天的时间，参照郑老师上课的代码自己摸索出来的udp协议文件传输。具体功能如下 1.客户端向服务器发送一个想要下载的文件名 2.服务器接收这个文件名，打开相应的文件，读取文件内容，再发送回客户端，文件发送的完成用一个长度为0的udp报文段作为标志 3.客户端将接收的数据写入本地指定的文件名中。客户端代码： //客户端 #include<stdio.h> #include<string.h> #include<Winsock2.h> #pragma comment(lib,"ws2_32.lib") #define MAX_BUF 65536 int main() { WSAData wsaData; int err=WSAStartup(WINSOCK_VERSION,&wsaData); if(0!=err) { return -1; } SOCKET sock; sock=socket(AF_INET,SOCK_DGRAM,0); if(INVALID_SOCKET==sock) { printf("socket()Failed:%d\n",WSAGetLastError()); WSACleanup(); return -1; } char data[]="Hello World!"; char dest_ip[]="192.168.1.104 "; //目的IP unsigned short dest_port=20000;//目的端口 sockaddr_in RemoteAddr; RemoteAddr.sin_family = AF_INET; RemoteAddr.sin_port = htons(dest_port); RemoteAddr.sin_addr.s_addr=inet_addr(dest_ip); char rbuf[MAX_BUF]; memset(rbuf,0,MAX_BUF); int RemoteLen=sizeof(RemoteAddr); char path[100]={"0"}; char name[100]={"0"}; printf("发送文件名\n"); gets(path); FILE *fp=fopen(path,"wb"); if(!fp) { printf("打开文件失败!"); return 1; } else { printf("文件已打开，等待传输\n"); } while(1) { sendto(sock,path,strlen(path),0,(sockaddr*)&RemoteAddr,sizeof(RemoteAddr)); memset(rbuf,0,1024); int sByte = sendto(sock,rbuf,strlen(rbuf),0,(sockaddr*)&RemoteAddr,sizeof(RemoteAddr)); if(SOCKET_ERROR==sByte) { printf("sendto()Failed:%d\n",WSAGetLastError()); closesocket(sock); WSACleanup(); return -1; } recvfrom(sock,name,1024,0,(sockaddr*)&RemoteAddr,&RemoteLen); memset(rbuf,0,1024); int rByte=recvfrom(sock,rbuf,1024,0,(sockaddr*)&RemoteAddr,&RemoteLen); if(SOCKET_ERROR==rByte) { printf("recvfrom()Failed:%d\n",WSAGetLastError()); closesocket(sock); WSACleanup(); return -1; } fwrite(rbuf,1,strlen(rbuf),fp); fseek(fp,0,2); printf("写入的文件内容为：\n %s\n",rbuf); } fclose(fp); closesocket(sock); WSACleanup(); return 0; } 服务端代码： //服务端 #include<stdio.h> #include<string.h> #include<Winsock2.h> #pragma comment(lib,"ws2_32.lib") int main() { WSAData wsaData; int err=WSAStartup(WINSOCK_VERSION,&wsaData); if(0!=err) { return -1; } SOCKET sock; sock=socket(AF_INET,SOCK_DGRAM,0); if(INVALID_SOCKET==sock) { printf("socket()Failed:%d\n",WSAGetLastError()); WSACleanup(); return -1; } sockaddr_in LocalAddr; LocalAddr.sin_family=AF_INET; LocalAddr.sin_port=htons(20000); LocalAddr.sin_addr.s_addr=htonl(INADDR_ANY); err=bind(sock,(sockaddr*)&LocalAddr,sizeof(LocalAddr)); if(SOCKET_ERROR==err) { printf("bind()Failed:%d\n",WSAGetLastError()); closesocket(sock); WSACleanup(); return -1; } sockaddr_in RemoteAddr; int RemoteLen = sizeof(RemoteAddr); char path[100]={"0"}; char name[100]={"0"}; while(1) { printf("请输入文件路径\n"); gets(path); FILE* fp=fopen(path,"rb"); // 读写二进制文件记得加 b if(!fp) { printf("error!"); return 1; } else { printf("文件已经打开，等待传输...\n"); } char rbuf[1024]={0}; while(1) { recvfrom(sock,name,1024,0,(sockaddr*)&RemoteAddr,&RemoteLen); printf("文件名字为：\n %s\n",name); memset(rbuf,0,1024); int rByte=recvfrom(sock,rbuf,1024,0,(sockaddr*)&RemoteAddr,&RemoteLen); if(SOCKET_ERROR==rByte) { printf("recvfrom()Failed:%d\n",WSAGetLastError()); closesocket(sock); WSACleanup(); return -1; } while(!feof(fp)) { sendto(sock,path,strlen(path),0,(sockaddr*)&RemoteAddr,sizeof(RemoteAddr)); memset(rbuf,0,1024); fread(rbuf,1,1024,fp); int sByte=sendto(sock,rbuf,strlen(rbuf),0,(sockaddr*)&RemoteAddr,sizeof(RemoteAddr)); if(SOCKET_ERROR==sByte) { printf("sendto()Failed:%d\n",WSAGetLastError()); closesocket(sock); WSACleanup(); return -1; } } } fclose(fp); } closesocket(sock); WSACleanup(); return 0; }

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