在线词典编写

在线词典项目实战

1.在线词典项目介绍和框架搭建

有道词典服务器原理

本项目功能实现流程

• 在线英英词典
• 项目功能描述
• 用户注册和登录验证
• 服务器端将用户信息和历史记录保存在数据库中。客户端输入用户名和密码，服务器端在数据库
• 查找、匹配，返回结果
• 单词在线翻译
• 根据客户端输入的单词在字典文件中搜索
• 历史记录查询
• 项目分析
• 项目流程
• 定义数据库中表的结构
• 定义消息结构体
• 分析服务器端和客户端流程
• 编码实现
  客服端程序实现流程图
  
  服务器程序实现流程图
  

/*client.c*/
#include 
#include 
#include           /* See NOTES */
#include 
#include 
#include 
#include 

#define   N  32

#define  R  1   // user - register
#define  L  2   // user - login
#define  Q  3   // user - query
#define  H  4   // user - history

// 定义通信双方的信息结构体
typedef struct {
	int type;
	char name[N];
	char data[256];
}MSG;


int  do_register(int sockfd, MSG *msg)
{
	msg->type = R;

	printf("Input name:");
	scanf("%s", msg->name);
	getchar();

	printf("Input passwd:");
	scanf("%s", msg->data);

	if(send(sockfd, msg, sizeof(MSG),0) < 0)
	{
		printf("fail to send.\n");
		return -1;
	}

	if(recv(sockfd, msg, sizeof(MSG), 0) < 0)
	{
		printf("Fail to recv.\n");
		return -1;
	}

	// ok !  or  usr alread exist.
	printf("%s\n", msg->data);

	return 0;
}

int do_login(int sockfd, MSG *msg)
{
	msg->type = L;

	printf("Input name:");
	scanf("%s", msg->name);
	getchar();

	printf("Input passwd:");
	scanf("%s", msg->data);

	if(send(sockfd, msg, sizeof(MSG),0) < 0)
	{
		printf("fail to send.\n");
		return -1;
	}

	if(recv(sockfd, msg, sizeof(MSG), 0) < 0)
	{
		printf("Fail to recv.\n");
		return -1;
	}

	if(strncmp(msg->data, "OK", 3) == 0)
	{
		printf("Login ok!\n");
		return 1;
	}
	else 
	{
		printf("%s\n", msg->data);
	}

	return 0;
}

int do_query(int sockfd, MSG *msg)
{
	msg->type = Q;
	puts("--------------");

	while(1)
	{
		printf("Input word:");
		scanf("%s", msg->data);
		getchar();

		//客户端，输入#号，返回到上一级菜单
		if(strncmp(msg->data, "#", 1) == 0)
			break;

		//将要查询的单词发送给服务器
		if(send(sockfd,msg, sizeof(MSG), 0) < 0)
		{
			printf("Fail to send.\n");
			return -1;
		}

		// 等待接受服务器，传递回来的单词的注释信息
		if(recv(sockfd, msg,sizeof(MSG), 0) < 0)
		{
			printf("Fail to recv.\n");
			return -1;
		}
		printf("%s\n", msg->data);
	}
		
	return 0;
}

int do_history(int sockfd, MSG *msg)
{

	msg->type = H;

	send(sockfd, msg, sizeof(MSG), 0);
	
	// 接受服务器，传递回来的历史记录信息
	while(1)
	{
		recv(sockfd, msg, sizeof(MSG), 0);

		if(msg->data[0] == '\0')
			break;

		//输出历史记录信息
		printf("%s\n", msg->data);
	}

	return 0;
}

// ./server  192.168.3.196  10000
int main(int argc, const char *argv[])
{

	int sockfd;
	struct sockaddr_in  serveraddr;
	int n;
	MSG  msg;

	if(argc != 3)
	{
		printf("Usage:%s serverip  port.\n", argv[0]);
		return -1;
	}

	if((sockfd = socket(AF_INET, SOCK_STREAM,0)) < 0)
	{
		perror("fail to socket.\n");
		return -1;
	}

	bzero(&serveraddr, sizeof(serveraddr));
	serveraddr.sin_family = AF_INET;
	serveraddr.sin_addr.s_addr = inet_addr(argv[1]);
	serveraddr.sin_port = htons(atoi(argv[2]));

	if(connect(sockfd, (struct sockaddr *)&serveraddr, sizeof(serveraddr)) < 0)
	{
		perror("fail to connect");
		return -1;
	}

	while(1)
	{
		printf("*****************************************************************\n");
		printf("* 1.register          2.login              3.quit               *\n");
		printf("*****************************************************************\n");
		printf("Please choose:");

		scanf("%d", &n);
		getchar();

		switch(n)
		{
		case 1:
			do_register(sockfd, &msg);
			break;
		case 2:
			if(do_login(sockfd, &msg) == 1)
			{
				goto next;
			}
			break;
		case 3:
			close(sockfd);
			exit(0);
			break;
		default:
			printf("Invalid data cmd.\n");
		}

	}

next:
	while(1)
	{
		printf("*****************************************************\n");
		printf("* 1.query_word   2.history_record   3.quit          *\n");
		printf("*****************************************************\n");
		printf("Please choose:");
		scanf("%d", &n);
		getchar();

		switch(n)
		{
			case 1:
				do_query(sockfd, &msg);
				break;
			case 2:
				do_history(sockfd, &msg);
				break;
			case 3:
				close(sockfd);
				exit(0);
				break;
			default :
				printf("Invalid data cmd.\n");
		}

	}
	
	return 0;
}

/*sever.c*/
#include 
#include 
#include           /* See NOTES */
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 


#define   N  32

#define  R  1   // user - register
#define  L  2   // user - login
#define  Q  3   // user - query
#define  H  4   // user - history

#define  DATABASE  "my.db"

// 定义通信双方的信息结构体
typedef struct {
	int type;
	char name[N];
	char data[256];
}MSG;



int do_client(int acceptfd, sqlite3 *db);
void do_register(int acceptfd, MSG *msg, sqlite3 *db);
int do_login(int acceptfd, MSG *msg, sqlite3 *db);
int do_query(int acceptfd, MSG *msg, sqlite3 *db);
int do_history(int acceptfd, MSG *msg, sqlite3 *db);
int history_callback(void* arg,int f_num,char** f_value,char** f_name);
int do_searchword(int acceptfd, MSG *msg, char word[]);
int get_date(char *date);

// ./server  192.168.3.196  10000
int main(int argc, const char *argv[])
{

	int sockfd;
	struct sockaddr_in  serveraddr;
	int n;
	MSG  msg;
	sqlite3 *db;
	int acceptfd;
	pid_t pid;

	if(argc != 3)
	{
		printf("Usage:%s serverip  port.\n", argv[0]);
		return -1;
	}

	//打开数据库
	if(sqlite3_open(DATABASE, &db) != SQLITE_OK)
	{
		printf("%s\n", sqlite3_errmsg(db));
		return -1;
	}
	else
	{
		printf("open DATABASE success.\n");
	}

	if((sockfd = socket(AF_INET, SOCK_STREAM,0)) < 0)
	{
		perror("fail to socket.\n");
		return -1;
	}

	bzero(&serveraddr, sizeof(serveraddr));
	serveraddr.sin_family = AF_INET;
	serveraddr.sin_addr.s_addr = inet_addr(argv[1]);
	serveraddr.sin_port = htons(atoi(argv[2]));

	if(bind(sockfd, (struct sockaddr *)&serveraddr, sizeof(serveraddr)) < 0)
	{
		perror("fail to bind.\n");
		return -1;
	}

	// 将套接字设为监听模式
	if(listen(sockfd, 5) < 0)
	{
		printf("fail to listen.\n");
		return -1;
	}

	//处理僵尸进程
	signal(SIGCHLD, SIG_IGN);

	while(1)
	{
		if((acceptfd = accept(sockfd, NULL, NULL)) < 0)
		{
			perror("fail to accept");
			return -1;
		}

		if((pid = fork()) < 0)
		{
			perror("fail to fork");
			return -1;
		}
		else if(pid == 0)  // 儿子进程
		{
			//处理客户端具体的消息
			close(sockfd);
			do_client(acceptfd, db);

		}
		else  // 父亲进程,用来接受客户端的请求的
		{
			close(acceptfd);
		}
	}
	
	return 0;
}


int do_client(int acceptfd, sqlite3 *db)
{
	MSG msg;
	while(recv(acceptfd, &msg, sizeof(msg), 0) > 0)
	{
	  printf("type:%d\n", msg.type);
	   switch(msg.type)
	   {
	  	 case R:
			 do_register(acceptfd, &msg, db);
			 break;
		 case L:
			 do_login(acceptfd, &msg, db);
			 break;
		 case Q:
			 do_query(acceptfd, &msg, db);
			 break;
		 case H:
			 do_history(acceptfd, &msg, db);
			 break;
		 default:
			 printf("Invalid data msg.\n");
	   }

	}

	printf("client exit.\n");
	close(acceptfd);
	exit(0);

	return 0;
}

void do_register(int acceptfd, MSG *msg, sqlite3 *db)
{
	char * errmsg;
	char sql[128];

	sprintf(sql, "insert into usr values('%s', %s);", msg->name, msg->data);
	printf("%s\n", sql);

	if(sqlite3_exec(db,sql, NULL, NULL, &errmsg) != SQLITE_OK)
	{
		printf("%s\n", errmsg);
		strcpy(msg->data, "usr name already exist.");
	}
	else
	{
		printf("client  register ok!\n");
		strcpy(msg->data, "OK!");
	}

	if(send(acceptfd, msg, sizeof(MSG), 0) < 0)
	{
		perror("fail to send");
		return ;
	}

	return ;
}

int do_login(int acceptfd, MSG *msg , sqlite3 *db)
{
	char sql[128] = {};
	char *errmsg;
	int nrow;
	int ncloumn;
	char **resultp;

	sprintf(sql, "select * from usr where name = '%s' and pass = '%s';", msg->name, msg->data);
	printf("%s\n", sql);

	if(sqlite3_get_table(db, sql, &resultp, &nrow, &ncloumn, &errmsg)!= SQLITE_OK)
	{
		printf("%s\n", errmsg);
		return -1;
	}
	else
	{
		printf("get_table ok!\n");
	}

	// 查询成功，数据库中拥有此用户
	if(nrow == 1)
	{
		strcpy(msg->data, "OK");
		send(acceptfd, msg, sizeof(MSG), 0);
		return 1;
	}

	if(nrow == 0) // 密码或者用户名错误
	{
		strcpy(msg->data,"usr/passwd wrong.");
		send(acceptfd, msg, sizeof(MSG), 0);
	}

	return 0;
}

int do_searchword(int acceptfd, MSG *msg, char word[])
{
	FILE * fp;
	int len = 0;
	char temp[512] = {};
	int result;
	char *p;


	//打开文件，读取文件，进行比对
	
	if((fp = fopen("dict.txt", "r")) == NULL)
	{
		perror("fail to fopen.\n");
		strcpy(msg->data, "Failed to open dict.txt");
		send(acceptfd, msg, sizeof(MSG), 0);
		return -1;
	}

	//打印出，客户端要查询的单词
	len = strlen(word);
	printf("%s , len = %d\n", word, len);

	//读文件，来查询单词
	while(fgets(temp, 512, fp) != NULL)
	{

	//	printf("temp:%s\n", temp);

		// abandon  ab
		result = strncmp(temp,word,len);

		if(result < 0)
		{
			continue;
		}
		if(result > 0 || ((result == 0) && (temp[len]!=' ')))
		{
			break;
		}

		// 表示找到了，查询的单词
		p = temp + len; //  abandon   v.akdsf dafsjkj 
	//	printf("found word:%s\n", p);
		while(*p == ' ')
		{
			p++;
		}

		// 找到了注释，跳跃过所有的空格
		strcpy(msg->data, p);
		printf("found word:%s\n", msg->data);

		// 注释拷贝完毕之后，应该关闭文件
		fclose(fp);
		return 1;
	}

	fclose(fp);

	return 0;
}

int get_date(char *date)
{
	time_t t;
	struct tm *tp;

	time(&t);

	//进行时间格式转换
	tp = localtime(&t);

	sprintf(date, "%d-%d-%d %d:%d:%d", tp->tm_year + 1900, tp->tm_mon+1, tp->tm_mday, 
			tp->tm_hour, tp->tm_min , tp->tm_sec);
	printf("get date:%s\n", date);

	return 0;
}

int do_query(int acceptfd, MSG *msg , sqlite3 *db)
{
	char word[64];
	int found = 0;
	char date[128] = {};
	char sql[128] = {};
	char *errmsg;

	//拿出msg结构体中，要查询的单词
	strcpy(word, msg->data);

	found = do_searchword(acceptfd, msg, word);
	printf("查询一个单词完毕.\n");

	// 表示找到了单词，那么此时应该将 用户名，时间，单词，插入到历史记录表中去。
	if(found == 1)
	{
		// 需要获取系统时间
		get_date(date);

        sprintf(sql, "insert into record values('%s', '%s', '%s')", msg->name, date, word);

		if(sqlite3_exec(db, sql, NULL, NULL, &errmsg) != SQLITE_OK)
		{
			printf("%s\n", errmsg);
			return -1;
		}
		else
		{
			printf("Insert record done.\n");
		}

	}
	else  //表示没有找到
	{
		strcpy(msg->data, "Not found!");
	}

	// 将查询的结果，发送给客户端
	send(acceptfd, msg, sizeof(MSG), 0);

	return 0;
}

// 得到查询结果，并且需要将历史记录发送给客户端
int history_callback(void* arg,int f_num,char** f_value,char** f_name)
{
	// record  , name  , date  , word 
	int acceptfd;
	MSG msg;

	acceptfd = *((int *)arg);

	sprintf(msg.data, "%s , %s", f_value[1], f_value[2]);

	send(acceptfd, &msg, sizeof(MSG), 0);

	return 0;
}


int do_history(int acceptfd, MSG *msg, sqlite3 *db)
{
	char sql[128] = {};
	char *errmsg;

	sprintf(sql, "select * from record where name = '%s'", msg->name);

	//查询数据库
	if(sqlite3_exec(db, sql, history_callback,(void *)&acceptfd, &errmsg)!= SQLITE_OK)
	{
		printf("%s\n", errmsg);
	}
	else
	{
		printf("Query record done.\n");
	}

	// 所有的记录查询发送完毕之后，给客户端发出一个结束信息
	msg->data[0] = '\0';

	send(acceptfd, msg, sizeof(MSG), 0);

	return 0;
}