/*************************************************************************   > File Name: Server.c   > Author: SongLee  ************************************************************************/  #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) {   // 聲明并初始化一個服務器端的socket地址結構   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);    // 創建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));    // 綁定socket和socket地址結構   if(-1 == (bind(server_socket_fd, (struct sockaddr*)&server_addr, sizeof(server_addr))))   {     perror("Server Bind Failed:");     exit(1);   }      // socket監聽   if(-1 == (listen(server_socket_fd, LENGTH_OF_LISTEN_QUEUE)))   {     perror("Server Listen Failed:");     exit(1);   }    while(1)   {     // 定義客戶端的socket地址結構     struct sockaddr_in client_addr;     socklen_t client_addr_length = sizeof(client_addr);      // 接受連接請求，返回一個新的socket(描述符)，這個新socket用于同連接的客戶端通信     // accept函數會把連接到的客戶端信息寫到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函數接收數據到緩沖區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;     }      // 然后從buffer(緩沖區)拷貝到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);      // 打開文件并讀取文件數據     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;       // 每讀取一段數據，便將其發送給客戶端，循環直到文件讀完為止       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);       }        // 關閉文件       fclose(fp);       printf("File:%s Transfer Successful!/n", file_name);     }     // 關閉與客戶端的連接     close(new_server_socket_fd);   }   // 關閉監聽用的socket   close(server_socket_fd);   return 0; } 

/*************************************************************************   > File Name: Client.c   > Author: SongLee  ************************************************************************/  #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() {   // 聲明并初始化一個客戶端的socket地址結構   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);    // 創建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);   }    // 綁定客戶端的socket和客戶端的socket地址結構 非必需   if(-1 == (bind(client_socket_fd, (struct sockaddr*)&client_addr, sizeof(client_addr))))   {     perror("Client Bind Failed:");     exit(1);   }    // 聲明一個服務器端的socket地址結構，并用服務器那邊的IP地址及端口對其進行初始化，用于后面的連接   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);    // 向服務器發起連接，連接成功后client_socket_fd代表了客戶端和服務器的一個socket連接   if(connect(client_socket_fd, (struct sockaddr*)&server_addr, server_addr_length) < 0)   {     perror("Can Not Connect To Server IP:");     exit(0);   }    // 輸入文件名 并放到緩沖區buffer中等待發送   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));      // 向服務器發送buffer中的數據   if(send(client_socket_fd, buffer, BUFFER_SIZE, 0) < 0)   {     perror("Send File Name Failed:");     exit(1);   }    // 打開文件，準備寫入   FILE *fp = fopen(file_name, "w");   if(NULL == fp)   {     printf("File:/t%s Can Not Open To Write/n", file_name);     exit(1);   }    // 從服務器接收數據到buffer中   // 每接收一段數據，便將其寫入文件中，循環直到文件接收完并寫完為止   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，關閉文件，關閉socket   printf("Receive File:/t%s From Server IP Successful!/n", file_name);   close(fp);   close(client_socket_fd);   return 0; }