一、项目要求：

1. 登录注册功能，不能重复登录，重复注册

2. 单词查询功能

3. 历史记录功能，存储单词，意思，以及查询时间

4. 基于TCP，支持多客户端连接

5. 采用数据库保存用户信息与历史记录

格式要求： 1. main函数只跑逻辑，不允许跑功能代码 2. 功能代码封装成函数 

二、流程示意图

服务器：

客户端：

 

 三、实现代码

server.c代码部分：

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <sqlite3.h>
#include <signal.h>
#include <time.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>#define DATABASE "my.db"
#define N  16enum CMD{R=1,L,Q,H
};typedef struct sockaddr SA;typedef struct
{int type;char name[N];char data[256];   // password or word
} MSG;static sqlite3 *db;   //数据库句柄指针void do_register(int connfd, MSG *pbuf)    //用户注册模块
{char sqlstr[128];char *errmsg;sprintf(sqlstr, "insert into usr values ('%s', '%s')", pbuf->name, pbuf->data);printf("%s\n", sqlstr);if (sqlite3_exec(db, sqlstr, NULL, NULL, &errmsg) != SQLITE_OK)   //执行SQL语句并处理结果{sqlite3_free(errmsg);sprintf(pbuf->data, "user %s already exist!!!", pbuf->name);}else{strncpy(pbuf->data, "OK", 256);}send(connfd, pbuf, sizeof(MSG), 0);
}void do_login(int connfd, MSG *pbuf)  //用户登录模块
{char sqlstr[128];    //拼接后的查询语句char *errmsg, **result; //存放错误信息和查询到的结果int nrow, ncolumn;   //查询到的行数和列数sprintf(sqlstr, "select * from usr where name = '%s' and pass = '%s'", pbuf->name, pbuf->data);if (sqlite3_get_table(db, sqlstr, &result, &nrow, &ncolumn, &errmsg) != SQLITE_OK)  {printf("error : %s\n", errmsg);sqlite3_free(errmsg);}if (nrow == 0)   //查询到的条数为0条{strncpy(pbuf->data, "name or password is wrong!!!", 256);}else  //查询到的所需信息{strncpy(pbuf->data, "OK", 256);}send(connfd, pbuf, sizeof(MSG), 0);sqlite3_free_table(result);return;
}#if 0
int do_searchword(int connfd, MSG *pbuf)   //查询单词模块调用的查询单词函数方式一
{FILE *fp;char line[300];char *p;int len, result;len = strlen(pbuf->data); //要查询的单词长度if ((fp = fopen("dict.txt", "r")) == NULL)  //打开保存单词文件{strcpy(pbuf->data, "dict on server can't be opened :(");send(connfd, pbuf, sizeof(MSG), 0);return 0;}printf("query word is %s\n", pbuf->data); //打印一下客户端要查询的单词while (fgets(line, 300, fp) != NULL)  //读文件，每次读300个字符存放到字符数组line中，来查询单词{result = strncmp(pbuf->data, line, len); //比较一下要查询的单词和line中读取到的文件中每行的单词信息进行比较，比较的长度大小为要查询的单词大小if (result > 0) continue; //大于0，说明要查询的单词大小大于读取的单词大小，则继续下一行，比如abandon ,查询abc,则跳入下一行if (result < 0 || line[len] != ' ') break;//小于0，则说明要查找的单词小于读取的单词大小，但之前的都已比较完毕，则查询失败。不是空格也不行，比如查询ab,而读取的是abandon.p = line + len; //指针指到单词末尾while (*p == ' ') p++;  //指针移动到注释之前strcpy(pbuf->data, p); //拷贝单词注释fclose(fp);     //return 1;}fclose(fp);return 0;
}
#else
int do_searchword(int connfd, MSG *pbuf)   //查询单词模块调用的查询单词函数方式二
{char buf[128] = {0};printf("query word is %s\n", pbuf->data);sprintf(buf, "select * from dic where word='%s'", pbuf->data);char *errmsg;char **resultp;int n_row, n_cloum;if (sqlite3_get_table(db, buf, &resultp, &n_row, &n_cloum, &errmsg) != SQLITE_OK) {printf("err:%s\n", errmsg);return -1;}if(n_row != 1){return 0;}char **p;p = resultp + n_cloum;// printf("data=%s\n", p[1]);strcpy(pbuf->data, p[1]);return 1;
}
#endifvoid get_date(char date[])  //获取系统时间
{time_t t;struct tm *tp;time(&t);  //获取到一个时间秒数tp = localtime(&t);//进行时间格式转换/*//字符串拼接sprintf(date, "%d-%02d-%02d %02d:%02d:%02d", tp->tm_year+1900,tp->tm_mon+1, tp->tm_mday, tp->tm_hour, tp->tm_min, tp->tm_sec);*/strftime(date, 64, "%Y-%m-%d %H:%M:%S", tp);return;
}void do_query(int connfd, MSG *pbuf)   //查询单词模块
{char sqlstr[128], *errmsg;int len, result, found = 0;char date[64], word[64];strcpy(word, pbuf->data);  //拿出pbuf结构体中要查询的单词found = do_searchword(connfd, pbuf);  //调用do_searchword函数模块去查询if(found)  //返回值非0，表示找到了该单词，则将用户查询信息（包括用户名，时间和单词）插入到历史记录表中{get_date(date);//调用时间函数获取时间sprintf(sqlstr, "insert into record values ('%s', '%s', '%s')", pbuf->name, date, word);if (sqlite3_exec(db, sqlstr, NULL, NULL, &errmsg) != SQLITE_OK){printf("error : %s\n", errmsg);sqlite3_free(errmsg);}}else   //返回值为0，表示没有找到，发送没到到提示信息{strcpy(pbuf->data, "not found\n");}send(connfd, pbuf, sizeof(MSG), 0);   //把查找到的信息发送给客户端return;
}//得到查询结果，并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)
{int connfd;MSG buf;connfd = *(int *)arg;sprintf(buf.data, "%s : %s", f_value[1], f_value[2]);send(connfd, &buf, sizeof(buf), 0);return 0;
}void do_history(int connfd, MSG *pbuf)   //查询历史记录模块
{char sqlstr[128], *errmsg;sprintf(sqlstr, "select * from record where name = '%s'", pbuf->name);if (sqlite3_exec(db, sqlstr, history_callback, (void *)&connfd, &errmsg) != SQLITE_OK) //查询数据库{printf("error : %s\n", errmsg);sqlite3_free(errmsg);}pbuf->data[0] = '\0';         //所有的记录发送完毕之后，给客户端发送一个结束信息send(connfd, pbuf, sizeof(MSG), 0);return;
}void do_client(int connfd)     //处理客户端请求主模块，调用函数完成所需功能
{MSG buf;while(recv(connfd, &buf, sizeof(buf), 0) > 0){switch (buf.type) {case R:printf("will reg\n");do_register(connfd, &buf);break;case L:printf("will login\n");do_login(connfd, &buf);break;case Q:printf("will query\n");do_query(connfd, &buf);break;case H:printf("will history\n");do_history(connfd, &buf);break;default:break;}}exit(0);
}int main(int argc, char *argv[])    //主函数
{int listenfd, connfd;struct sockaddr_in myaddr;pid_t pid;MSG buf;if (argc < 3){printf("Usage : %s <ip> <port>\n", argv[0]);exit(-1);}//打开数据库if(sqlite3_open(DATABASE, &db) < 0){printf("fail to sqlite3_open : %s\n", sqlite3_errmsg(db));return -1;}//创建服务器socketlistenfd = socket(PF_INET, SOCK_STREAM, 0);if(listenfd < 0){perror("fail to socket");exit(-1);}bzero(&myaddr, sizeof(myaddr));myaddr.sin_family = PF_INET;myaddr.sin_port = htons(atoi(argv[2]));myaddr.sin_addr.s_addr = inet_addr(argv[1]);if (bind(listenfd, (SA *)&myaddr, sizeof(myaddr)) < 0){perror("fail to bind");exit(-1);}// 将套接字设为监听模式if (listen(listenfd, 5) < 0){perror("fail to listen");exit(-1);}//并发服务器模型while(1){if((connfd = accept(listenfd, NULL, NULL)) < 0){perror("fail to accept");exit(-1);}pid = fork();if(pid == -1){perror("fail to fork\n");exit(-1);}else if(pid == 0){ //子进程处理客户端具体的消息printf("a user comming\n");do_client(connfd);}else{  //父进程用于接收客户端的请求close(connfd);}}
}

client.c代码部分：

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <sqlite3.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>#define N  16
typedef struct sockaddr SA;enum CMD{R=1,L,Q,H
};typedef struct
{int type;char name[N];char data[256];   // password or word
} MSG;void do_register(int sockfd, MSG *pbuf)   //一级菜单用户注册模块
{pbuf->type = R;printf("input name : ");scanf("%s", pbuf->name);printf("input password : ");scanf("%s", pbuf->data);send(sockfd, pbuf, sizeof(MSG), 0);recv(sockfd, pbuf, sizeof(MSG), 0);printf("register : %s\n\n", pbuf->data);
}int do_login(int sockfd, MSG *pbuf)     //一级菜单用户登录模块
{pbuf->type = L;printf("input name : ");scanf("%s", pbuf->name);printf("input password : ");scanf("%s", pbuf->data);send(sockfd, pbuf, sizeof(MSG), 0);recv(sockfd, pbuf, sizeof(MSG), 0);if(strncmp(pbuf->data, "OK", 3) == 0){    //3个字节：O K /0printf("login sucess\n\n");return 1;}else{printf("login : %s\n\n", pbuf->data);return 0;}
}void do_history(int sockfd, MSG *pbuf)   //二级菜单查询单词历史记录模块
{pbuf->type = H;send(sockfd, pbuf, sizeof(MSG), 0);while ( 1 ){recv(sockfd, pbuf, sizeof(MSG), 0);if (pbuf->data[0] == '\0') break;printf("%s\n", pbuf->data);}return;
}void do_query(int sockfd, MSG *pbuf)  //二级菜单查询单词模块
{pbuf->type = Q;while ( 1 ){printf("input word(# to quit) : ");scanf("%s", pbuf->data);if (strcmp(pbuf->data, "#") == 0) break; //输入#返回上一级菜单send(sockfd, pbuf, sizeof(MSG), 0); //将要查询的单词发送给服务器recv(sockfd, pbuf, sizeof(MSG), 0); //等待接收服务器传递回来的单词信息printf("%s\n", pbuf->data);printf("\n");}return;
}void enter_query(int sockfd, MSG *buf)    //二级菜单主页面
{int input;char cleanbuf[64];while (1) {printf("***********************************************\n");printf("* 1: query_word   2: history_record   3: quit *\n");printf("***********************************************\n");printf("please choose : ");//获取用户输入if(scanf("%d", &input) == 0){fgets(cleanbuf, 64, stdin);  //类型错误需要重新清除输入缓冲区continue;}switch (input) {case 1:printf("\n");do_query(sockfd, buf);printf("\n");break;case 2:printf("\n");do_history(sockfd, buf);printf("\n");break;case 3:return;default:break;}}
}int main(int argc, char *argv[])      //主函数
{int sockfd, login = 0;struct sockaddr_in servaddr;MSG buf;char clean[64];if (argc < 3){printf("Usage : %s <serv_ip> <serv_port>\n", argv[0]);exit(-1);}//创建客户端socketif ((sockfd = socket(PF_INET, SOCK_STREAM, 0)) < 0){perror("fail to socket");exit(-1);}bzero(&servaddr, sizeof(servaddr));servaddr.sin_family = PF_INET;servaddr.sin_port = htons(atoi(argv[2]));servaddr.sin_addr.s_addr = inet_addr(argv[1]);//连接服务器if (connect(sockfd, (SA *)&servaddr, sizeof(servaddr)) < 0){perror("fail to connect");exit(-1);}int input;char cleanbuf[64];while(1){printf("************************************\n");printf("* 1: register   2: login   3: quit *\n");printf("************************************\n");printf("please choose : ");//获取用户输入if(scanf("%d", &input) == 0){fgets(cleanbuf, 64, stdin);  //类型错误需要重新清除输入缓冲区continue;}switch (input) {case 1:do_register(sockfd, &buf);break;case 2:if(do_login(sockfd, &buf) == 1){  //成功enter_query(sockfd, &buf);}break;case 3:close(sockfd);exit(0);break;default:break;}}
}

Makefile代码部分：

all:server clientserver:server.cgcc $< -o $@ -l sqlite3client:client.cgcc $< -o $@clean:rm server client