服务端向客户端传输文件

//这是用socket传输文件的服务端

#include<netinet/in.h> // sockaddr_in   
#include<sys/types.h>  // socket   
#include<sys/socket.h> // socket   
#include<stdio.h>    // printf   
#include<stdlib.h>   // exit   
#include<string.h>   // 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);   
  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)))   
  {   
    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)   
    {   
      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("%sn", 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 Foundn", 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;   
}   

//这是用socket传输文件的客户端栗子

#include<netinet/in.h>  // sockaddr_in   
#include<sys/types.h>  // socket   
#include<sys/socket.h>  // socket   
#include<stdio.h>    // printf   
#include<stdlib.h>    // exit   
#include<string.h>    // 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;   
  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 Writen", 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 Failedn", 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;   
}