1 有道词典流程分析及本项目功能描述

1.1 抽取项目原理分析

本项目功能描述
- 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,服务器端在数据库中查找、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
1.2 项目流程
- 定义数据库中表的结构
- 定义消息结构体
- 分析服务端与客户端流程
- 编码实现
表结构
usr表
name(primary key) passwd
record表
name date word
单词表
使用文件查询,如使用数据库的话代码会更简单
消息结构体
#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;1.3 客户端流程分析
连接服务端
一级菜单提示:1注册 2登录 3退出
如果登录成功,跳转至二级菜单
二级菜单提示:1查询 2历史 3退出 #返回上级菜单
分别实现对应功能

1.4 服务端流程分析

2 代码开发
2.1 客户端开发
#include <stdio.h>
#include <sys/types.h>          /* See NOTES */
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#define N 32
#define R 1   //注册
#define L 2   //登录
#define Q 3   //查询单词
#define H 4   //历史
typedef struct
{
	int type;
	char name[N];
	char data[256]; //password or word
	int root_flag;
}MSG_t;
int do_register(int sockfd, MSG_t *msg);
int do_login(int sockfd, MSG_t *msg);
int do_query(int sockfd, MSG_t *msg);
int do_history(int sockfd, MSG_t *msg);
int main(int argc, char *argv[])
{
	int sockfd;
	int n;
	struct sockaddr_in addr;
	MSG_t msg;
	bzero(&msg, sizeof(MSG_t));
	//参数检查
	if(argc != 3)
	{
		printf("%s <ip> <port>\n",argv[0]);
		exit(0);
	}
	//创建socket
	sockfd = socket(AF_INET, SOCK_STREAM, 0);
	if(sockfd < 0)
	{
		perror("socket");
		exit(0);
	}
	//连接connect
	addr.sin_family = AF_INET;
	addr.sin_port = htons(atoi(argv[2]));
	addr.sin_addr.s_addr = inet_addr(argv[1]);
	if(connect(sockfd, (struct sockaddr *)&addr, sizeof(addr)) < 0)
	{
		perror("connect");
		exit(0);
	}
	while(1)
	{
		printf("***********************************\n");
		printf("*1:register    2:login    3:quit  *\n");
		printf("***********************************\n");
		printf("Please choose:");
		scanf("%d", &n);
		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);
		}
	}
next:
		while(1)
		{
			printf("***********************************\n");
			printf("*1:search    2:history    3:quit  *\n");
			printf("***********************************\n");
			printf("Please choose:");
			scanf("%d", &n);
			switch(n)
			{
			case 1:
				do_query(sockfd, &msg);
				break;
			case 2:
				do_history(sockfd, &msg);
				break;
			case 3:
				close(sockfd);
				exit(0);
			case 4:
				break;
			}
		}
	
	return 0;
}
int do_register(int sockfd,MSG_t *msg)
{
	msg->type = R;
	
	printf("Input name:");
	scanf("%s", msg->name);
	getchar();
	printf("Input passwd:");
	scanf("%s", msg->data);
	if(write(sockfd, msg, sizeof(MSG_t)) < 0)
	{
		perror("write");
		return -1;
	}
	if(read(sockfd, msg, sizeof(MSG_t)) < 0)
	{
		perror("read");
		return -1;
	}
	//成功或者用户已经注册
	printf("%s\n", msg->data);
	return 0;
}
int do_login(int sockfd, MSG_t *msg)
{
	msg->type = L;
	printf("Input name:");
	scanf("%s", msg->name);
	getchar();
	if(strcmp(msg->name, "root") == 0)
	{
		msg->root_flag = 1;
	}
	else
	{
		msg->root_flag = 0;
	}
	printf("Input passwd:");
	scanf("%s", msg->data);
	if(send(sockfd, msg, sizeof(MSG_t), 0) < 0)
	{
		perror("write");
		return -1;
	}
	
	if(recv(sockfd, msg, sizeof(MSG_t), 0) < 0)
	{
		perror("read");
		return -1;
	}
	if(strncmp(msg->data, "OK", 3) == 0)
	{
		printf("Login success.\n");
		return 1;
	}
	else
	{
		printf("%s\n",msg->data);
	}
	return 0;
}
int do_query(int sockfd,MSG_t *msg)
{
	msg->type = Q;
	printf("--------------------------\n");
	while(1)
	{
		printf("Input word:");
		scanf("%s",msg->data);
		getchar();
		//输入#返回上级菜单
		if(strncmp(msg->data, "#", 1) == 0)
		{
			break;
		}
		if(write(sockfd, msg, sizeof(MSG_t)) < 0)
		{
			perror("write");
			return -1;
		}
		if(read(sockfd, msg, sizeof(MSG_t)) < 0)
		{
			perror("read");
			return -1;
		}
		printf("%s\n",msg->data);
	}
	return 0;
}
int do_history(int sockfd, MSG_t *msg)
{
	msg->type = H;
	if(write(sockfd, msg, sizeof(MSG_t)) < 0)
	{
		perror("write");
		return -1;
	}
	while(1)
	{
		if(read(sockfd, msg, sizeof(MSG_t)) < 0)
		{
			perror("read");
			return -1;
		}
		if(msg->data[0] == '0')
			break;
		printf("%s\n",msg->data);
	}
	return 0;
}
2.2 服务端开发
表设计,创建usr表用于管理登录,创建record表用于记录查询历史
linux@linux:~/Desktop/dictionary$ sqlite3 my.db
SQLite version 3.8.2 2013-12-06 14:53:30
Enter ".help" for instructions
Enter SQL statements terminated with a ";"
sqlite> .database
seq  name             file                                                      
---  ---------------  ----------------------------------------------------------
0    main             /home/linux/Desktop/dictionary/my.db                      
sqlite> create table usr(name text, passwd text);
sqlite> create table record(name text, date text, word text);
sqlite> :q
代码设计,接收客户端后fork出子进程,用于多客户端连接使用
#include <stdio.h>
#include <sys/types.h>          /* See NOTES */
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <sqlite3.h>
#include <signal.h>
#include <time.h>
#define N 32
#define R 1  //register
#define L 2  //login
#define Q 3  //query
#define H 4  //history
#define DATABSAE "my.db"
typedef struct
{
	int type;
	char name[N];
	char data[256]; //password or word
	int root_flag;
}MSG_t;
int do_client(int acceptfd, sqlite3 *db);
void do_register(int acceptfd, MSG_t *msg, sqlite3 *db);
int do_login(int acceptfd, MSG_t *msg, sqlite3 *db);
int do_query(int acceptfd, MSG_t *msg, sqlite3 *db);
int do_history(int acceptfd, MSG_t *msg,sqlite3 *db);
int history_callback(void *arg, int f_num, char **f_value, char **f_name);
int do_searchword(int acceptfd, MSG_t *msg, char word[]);
int get_date(char *date);
int main(int argc, char *argv[])
{
	int sockfd;
	int acceptfd;
	struct sockaddr_in serveraddr;
	MSG_t msg;
	sqlite3 *db;
	pid_t pid;
	bzero(&msg, sizeof(MSG_t));
	//参数检查
	if(argc != 3)
	{
		printf("%s <ip> <port>\n",argv[0]);
		exit(0);
	}
	//打开数据库
	if(sqlite3_open(DATABSAE, &db) != SQLITE_OK)
	{
		printf("%s\n",sqlite3_errmsg(db));
		exit(0);
	}
	else
	{
		printf("open DATABSAE success.\n");
	}
	//创建socket
	sockfd = socket(AF_INET, SOCK_STREAM, 0);
	if(sockfd < 0)
	{
		perror("socket");
		exit(0);
	}
	//绑定bind
	bzero(&serveraddr,sizeof(serveraddr));
	serveraddr.sin_family = AF_INET;
	serveraddr.sin_port = htons(atoi(argv[2]));
	serveraddr.sin_addr.s_addr = inet_addr(argv[1]);
	if(bind(sockfd, (struct sockaddr *)&serveraddr, sizeof(serveraddr)) < 0)
	{
		perror("bind");
		exit(0);
	}
	//监听listen
	if(listen(sockfd, 5) < 0)
	{
		printf("listen");
		exit(0);
	}
	//处理僵尸进程
	signal(SIGCHLD, SIG_IGN);
	while(1)
	{
		if((acceptfd = accept(sockfd, NULL, NULL)) < 0)
		{
			perror("accept");
			exit(0);
		}
		if((pid = fork()) < 0)
		{
			perror("fork");
			exit(0);
		}
		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                  //父进程
		{
			close(acceptfd);
		}
	}
	return 0;
}
int do_client(int acceptfd, sqlite3 *db)
{
	MSG_t msg;
	while(read(acceptfd, &msg, sizeof(msg)) > 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_t *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_t), 0) < 0)
	{
		perror("fail to send");
		return ;
	}
	return ;
}
int do_login(int acceptfd, MSG_t *msg , sqlite3 *db)
{
	char sql[128] = {};
	char *errmsg;
	int nrow;
	int ncloumn;
	char **resultp;
	sprintf(sql, "select * from usr where name = '%s' and passwd = '%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_t), 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_t), 0);
	}
	return 0;
}
int do_searchword(int acceptfd, MSG_t *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_t), 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)  //每次读取512字节
	{
	//	printf("temp:%s\n", temp);
		// abandon  ab
		result = strncmp(temp,word,len);  
		if(result < 0)  //不相等
		{
			continue;
		}                
		if(result > 0 || ((result == 0) && (temp[len]!=' ')))  //第一个字符串>第二个或者两者相同但后面不是空格,表示在注释里出现的单词
		{
			break;
		}
		// 表示找到了,查询的单词result == 0 且 temp[len] == ' '。
		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_t *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_t), 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_t msg;
	acceptfd = *((int *)arg);
	sprintf(msg.data, "%s , %s", f_value[1], f_value[2]);
	send(acceptfd, &msg, sizeof(MSG_t), 0);
	return 0;
}
int do_history(int acceptfd, MSG_t *msg, sqlite3 *db)
{
	char sql[128] = {};
	char *errmsg;
	
	if(msg->root_flag == 1)
	{
		sprintf(sql, "select * from record");	
	}
	else
	{
		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_t), 0);
	return 0;
}
效果




















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