Linux网络编程：socket文件传输范例

转自http://blog.csdn.net/lisonglisonglisong/article/details/22699675

基于TCP流协议的socket网络文件传输Demo：

实现：C语言
功能：文件传输（可以传任何格式的文件）

 /*************************************************************************
     > File Name: Server.c
     > Author: SongLee
     > E-mail: [email protected]
     > Created Time: 2014年03月13日 星期四 22时17分43秒
     > Personal Blog: http://songlee24.github.io/
  ************************************************************************/

 #include  // sockaddr_in
 #include   // socket
 #include  // socket
 #include       // printf
 #include      // exit
 #include      // bzero

 #define SERVER_PORT 8000
 #define LENGTH_OF_LISTEN_QUEUE 20
 #define BUFFER_SIZE 1024
 #define FILE_NAME_MAX_SIZE 512

 int main(void)
 {
     // 声明并初始化一个服务器端的socket地址结构
     struct sockaddr_in server_addr;
     bzero(&server_addr, sizeof(server_addr));
     server_addr.sin_family = AF_INET;
     server_addr.sin_addr.s_addr = htons(INADDR_ANY);  //任意IP地址
     server_addr.sin_port = htons(SERVER_PORT);

     // 创建socket，若成功，返回socket描述符
     int server_socket_fd = socket(PF_INET, SOCK_STREAM, 0);
     if(server_socket_fd < 0)
     {
         perror("Create Socket Failed:");
         exit(1);
     }
     int opt = 1;
     setsockopt(server_socket_fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));

     // 绑定socket和socket地址结构
     if(-1 == (bind(server_socket_fd, (struct sockaddr*)&server_addr, sizeof(server_addr))))
     {
         perror("Server Bind Failed:");
         exit(1);
     }

     // socket监听
     if(-1 == (listen(server_socket_fd, LENGTH_OF_LISTEN_QUEUE)))  //LENGTH_OF_LISTEN_QUEUE
 //参考http://blog.csdn.net/wm_1991/article/details/52176287
     {
         perror("Server Listen Failed:");
         exit(1);
     }

     while(1)
     {
         // 定义客户端的socket地址结构
         struct sockaddr_in client_addr;
         socklen_t client_addr_length = sizeof(client_addr);

         // 接受连接请求，返回一个新的socket(描述符)，这个新socket用于同连接的客户端通信
         // accept函数会把连接到的客户端信息写到client_addr中
         int new_server_socket_fd = accept(server_socket_fd, (struct sockaddr*)&client_addr, &client_addr_length);
         if(new_server_socket_fd < 0)
         {
             perror("Server Accept Failed:");
             break;
         }

         // recv函数接收数据到缓冲区buffer中
         char buffer[BUFFER_SIZE];
         bzero(buffer, BUFFER_SIZE);
         if(recv(new_server_socket_fd, buffer, BUFFER_SIZE, 0) < 0)  //BUFFER_SIZE=1024
         {
             perror("Server Recieve Data Failed:");
             break;
         }

         // 然后从buffer(缓冲区)拷贝到file_name中
         char file_name[FILE_NAME_MAX_SIZE+1];
         bzero(file_name, FILE_NAME_MAX_SIZE+1);
         strncpy(file_name, buffer, strlen(buffer)>FILE_NAME_MAX_SIZE?FILE_NAME_MAX_SIZE:strlen(buffer));
         printf("%s\n", file_name);

         // 打开文件并读取文件数据
         FILE *fp = fopen(file_name, "r");
         if(NULL == fp)
         {
             printf("File:%s Not Found\n", file_name);
         }
         else
         {
             bzero(buffer, BUFFER_SIZE);
             int length = 0;
             // 每读取一段数据，便将其发送给客户端，循环直到文件读完为止
             while((length = fread(buffer, sizeof(char), BUFFER_SIZE, fp)) > 0)
             {
                 if(send(new_server_socket_fd, buffer, length, 0) < 0)
                 {
                     printf("Send File:%s Failed./n", file_name);
                     break;
                 }
                 bzero(buffer, BUFFER_SIZE);
             }

             // 关闭文件
             fclose(fp);
             printf("File:%s Transfer Successful!\n", file_name);
         }
         // 关闭与客户端的连接
         close(new_server_socket_fd);
     }
     // 关闭监听用的socket
     close(server_socket_fd);
     return 0;
 }

 /*************************************************************************
     > File Name: Client.c
     > Author: SongLee
     > E-mail: [email protected]
     > Created Time: 2014年03月14日 星期五 09时41分46秒
     > Personal Blog: http://songlee24.github.io/
  ************************************************************************/

 #include   // sockaddr_in
 #include    // socket
 #include   // socket
 #include        // printf
 #include       // exit
 #include       // bzero

 #define SERVER_PORT 8000
 #define BUFFER_SIZE 1024
 #define FILE_NAME_MAX_SIZE 512

 int main()
 {
     // 声明并初始化一个客户端的socket地址结构
     struct sockaddr_in client_addr;
     bzero(&client_addr, sizeof(client_addr));
     client_addr.sin_family = AF_INET;
     client_addr.sin_addr.s_addr = htons(INADDR_ANY);
     client_addr.sin_port = htons(0);

     // 创建socket，若成功，返回socket描述符
     int client_socket_fd = socket(AF_INET, SOCK_STREAM, 0);
     if(client_socket_fd < 0)
     {
         perror("Create Socket Failed:");
         exit(1);
     }

     // 绑定客户端的socket和客户端的socket地址结构 非必需
     if(-1 == (bind(client_socket_fd, (struct sockaddr*)&client_addr, sizeof(client_addr))))
     {
         perror("Client Bind Failed:");
         exit(1);
     }

     // 声明一个服务器端的socket地址结构，并用服务器那边的IP地址及端口对其进行初始化，用于后面的连接
     struct sockaddr_in server_addr;
     bzero(&server_addr, sizeof(server_addr));
     server_addr.sin_family = AF_INET;
  
      
      //inet_pton：将“点分十进制” －> “二进制整数” 
      
      
      //int inet_pton(int af, const char *src, void *dst); 
      
      
      //这个函数转换字符串到网络地址，第一个参数af是地址簇，第二个参数*src是来源地址，第三个参数* dst接收转换后//的数据。
     if(inet_pton(AF_INET, "127.0.0.1", &server_addr.sin_addr) == 0)
     {
         perror("Server IP Address Error:");
         exit(1);
     }
     server_addr.sin_port = htons(SERVER_PORT);
     socklen_t server_addr_length = sizeof(server_addr);

     // 向服务器发起连接，连接成功后client_socket_fd代表了客户端和服务器的一个socket连接
     if(connect(client_socket_fd, (struct sockaddr*)&server_addr, server_addr_length) < 0)
     {
         perror("Can Not Connect To Server IP:");
         exit(0);
     }

     // 输入文件名 并放到缓冲区buffer中等待发送
     char file_name[FILE_NAME_MAX_SIZE+1];
     bzero(file_name, FILE_NAME_MAX_SIZE+1);
     printf("Please Input File Name On Server:\t");
     scanf("%s", file_name);

     char buffer[BUFFER_SIZE];
     bzero(buffer, BUFFER_SIZE);
     strncpy(buffer, file_name, strlen(file_name)>BUFFER_SIZE?BUFFER_SIZE:strlen(file_name));

     // 向服务器发送buffer中的数据
     if(send(client_socket_fd, buffer, BUFFER_SIZE, 0) < 0)
     {
         perror("Send File Name Failed:");
         exit(1);
     }

     // 打开文件，准备写入
     FILE *fp = fopen(file_name, "w");
     if(NULL == fp)
     {
         printf("File:\t%s Can Not Open To Write\n", file_name);
         exit(1);
     }

     // 从服务器接收数据到buffer中
     // 每接收一段数据，便将其写入文件中，循环直到文件接收完并写完为止
     bzero(buffer, BUFFER_SIZE);
     int length = 0;
     while((length = recv(client_socket_fd, buffer, BUFFER_SIZE, 0)) > 0)
     {
         if(fwrite(buffer, sizeof(char), length, fp) < length)
         {
             printf("File:\t%s Write Failed\n", file_name);
             break;
         }
         bzero(buffer, BUFFER_SIZE);
     }

     // 接收成功后，关闭文件，关闭socket
     printf("Receive File:\t%s From Server IP Successful!\n", file_name);
     close(fp);
     close(client_socket_fd);
     return 0;
 }