Linux C Socket编程：文件上传

一个服务端等待， 客户端上传文件到服务端，通过输入要上传的文件名，目前只做到仅对当前执行文件的目录下的文件，应该在服务端收到文件路径之后进行处理的。

服务端代码：

 #include <netinet/in.h>    // for sockaddr_in
 #include <sys/types.h>    // for socket
 #include <sys/socket.h>    // for socket
 #include <stdio.h>        // for printf
 #include <stdlib.h>        // for exit
 #include <string.h>        // for bzero

 #define SERVER_PORT 6666
 #define LISTEN_QUEUE  20
 #define BUFFER_SIZE 1024
 #define FILE_NAME_MAX_SIZE 512

 int main(int argc, char **argv)
 {
     //设置一个socket地址结构server_addr,代表服务器internet地址, 端口
     struct sockaddr_in server_addr;
     bzero(&server_addr, sizeof(server_addr)); //把一段内存区的内容全部设置为0
     server_addr.sin_family = AF_INET;
     server_addr.sin_addr.s_addr = htons(INADDR_ANY);
     server_addr.sin_port = htons(SERVER_PORT);

     //创建用于internet的流协议(TCP)socket,用server_socket代表服务器socket
     int server_socket = socket(PF_INET, SOCK_STREAM, );
     if (server_socket < )
     {
         printf("Create Socket Failed!");
         exit();
     }

     //把socket和socket地址结构联系起来
     if (bind(server_socket, (struct sockaddr*) &server_addr,
             sizeof(server_addr)))
     {
         printf("Server Bind Port: %d Failed!\n", SERVER_PORT);
         exit();
     }

     //server_socket用于监听
     if (listen(server_socket, LISTEN_QUEUE))
     {
         printf("Server Listen Failed!");
         exit();
     }

     while ()
     {
         //定义客户端的socket地址结构client_addr
         char buffer[BUFFER_SIZE];
         struct sockaddr_in client_addr;
         socklen_t length = sizeof(client_addr);

         int client_socket = accept(server_socket,
                 (struct sockaddr*) &client_addr, &length);
         if (client_socket < )
         {
             printf("Server Accept Failed!\n");
             break;
         }
         bzero(buffer, BUFFER_SIZE);
         // 获取客户端要传输的文件名
         length = recv(client_socket, buffer, BUFFER_SIZE, );
         if (length < )
         {
             printf("Server Recieve Data Failed!\n");
             break;
         }
         char file_name[FILE_NAME_MAX_SIZE + ];
         bzero(file_name, FILE_NAME_MAX_SIZE + );
         strncpy(
                 file_name,
                 buffer,
                 strlen(buffer) > FILE_NAME_MAX_SIZE? FILE_NAME_MAX_SIZE : strlen(buffer));

         // 新建文件
         FILE * fp = fopen(file_name, "w");
         if (NULL == fp)
         {
             printf("File: %s CAN NOT WRITE!\n", file_name);
         }
         else
         {
             bzero(buffer, BUFFER_SIZE);
             int file_block_length = ;
             while ((file_block_length = recv(client_socket, buffer, BUFFER_SIZE, )) > )
             {
                 if (file_block_length < )
                 {
                     printf("Recieve Data From Client Failed!\n");
                     break;
                 }
                 int write_length = fwrite(buffer, sizeof(char), file_block_length, fp);
                 if (write_length < file_block_length)
                 {
                     printf("File: %s Write Failed\n", file_name);
                     break;
                 }
                 bzero(buffer, BUFFER_SIZE);
             }
             fclose(fp);
             printf("File: %s Transfer Finished\n\n", file_name);
         }
         //关闭与客户端的连接
         close(client_socket);
     }
     //关闭监听用的socket
     close(server_socket);
     return ;
 }

客户端代码：

 #include <netinet/in.h>    // for sockaddr_in
 #include <sys/types.h>    // for socket
 #include <sys/socket.h>    // for socket
 #include <stdio.h>        // for printf
 #include <stdlib.h>        // for exit
 #include <string.h>        // for bzero
 /*
  #include <sys/types.h>
  #include <sys/stat.h>
  #include <fcntl.h>
  #include <unistd.h>
  */

 #define SERVER_PORT 6666
 #define BUFFER_SIZE 1024
 #define FILE_NAME_MAX_SIZE 512

 int main(int argc, char **argv)
 {
     if (argc != )
     {
         printf("Please input the IP address of the server \n", argv[]);
         exit();
     }

     //设置一个socket地址结构client_addr,代表客户机internet地址, 端口
     struct sockaddr_in client_addr;
     bzero(&client_addr, sizeof(client_addr)); //把一段内存区的内容全部设置为0
     client_addr.sin_family = AF_INET; //internet协议族
     client_addr.sin_addr.s_addr = htons(INADDR_ANY); //INADDR_ANY表示自动获取本机地址
     client_addr.sin_port = htons(); //0表示让系统自动分配一个空闲端口
     //创建用于internet的流协议(TCP)socket,用client_socket代表客户机socket
     int client_socket = socket(AF_INET, SOCK_STREAM, );
     if (client_socket < )
     {
         printf("Create Socket Failed!\n");
         exit();
     }
     //把客户机的socket和客户机的socket地址结构联系起来
     if (bind(client_socket, (struct sockaddr*) &client_addr,
             sizeof(client_addr)))
     {
         printf("Client Bind Port Failed!\n");
         exit();
     }

     //设置一个socket地址结构server_addr,代表服务器的internet地址, 端口
     struct sockaddr_in server_addr;
     bzero(&server_addr, sizeof(server_addr));
     server_addr.sin_family = AF_INET;
     if (inet_aton(argv[], &server_addr.sin_addr) == ) //服务器的IP地址来自程序的参数
     {
         printf("Server IP Address Error! \n");
         exit();
     }

     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代表了客户机和服务器的一个socket连接
     if (connect(client_socket, (struct sockaddr*) &server_addr,
             server_addr_length) < )
     {
         printf("Can Not Connect To %s!\n", argv[]);
         exit();
     }

     // 连接上服务器, 选择要上传的文件
     char file_name[FILE_NAME_MAX_SIZE + ];bzero
     (file_name, FILE_NAME_MAX_SIZE + );
     printf("Please Input File Name Upload To Server: ");
     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));

     FILE * fp = fopen(file_name, "r");
     if (NULL == fp)
     {
         printf("File: %s NOT FOUND! \n", file_name);
         exit();
     }

     // 发送文件名
     int nameLength = send(client_socket, buffer, BUFFER_SIZE, );
     if (nameLength < )
     {
         printf("File name Error! \n");
         exit();
     }

     bzero(buffer, BUFFER_SIZE);
     int file_block_length = ;

     while ((file_block_length = fread(buffer, sizeof(char), BUFFER_SIZE, fp))
             > )
     {
         if (send(client_socket, buffer, file_block_length, ) < )
         {
             printf("Send File:\t%s Failed\n", file_name);
             break;
         }
         bzero(buffer, BUFFER_SIZE);
     }
     printf("File:\t%s Transfer Finished\n", file_name);
     fclose(fp);
     close(client_socket);
     return ;
 }

代码很多是复制的，慢慢看一行行看懂之后把原来别人的客户端下载改成客户端上传，其实都差不多，服务端与客户端connect之后基本上就是文件读写的事了。

来自：http://www.cnblogs.com/lycheng/archive/2011/11/08/2240518.html