Linux 在线词典

引用自 http://blog.sina.com.cn/s/blog_6c9c71840101brdz.html

在线英英词典(sqlite3)

项目功能描述：

    1.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。

    2.单词在线翻译：根据客户端输入的单词在字典文件中搜索。

    3.历史记录查询

include.h

#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#define DATABASE "my.db"

typedef struct
{
    int type;
    char name[20];
    char data[256];   // password or word
}MSG;

server.c

#include "include.h"
void do_register(int connectfd, MSG *msg, sqlite3 *db)  //注册用户
{
    char sqlstr[128];
    char *errmsg;
    
    sprintf(sqlstr, "insert into usr values ('%s', '%s')", msg->name, msg->data);//封装SQL操作语句
    printf("%s\n", sqlstr);
    if (sqlite3_exec(db, sqlstr, NULL, NULL, &errmsg) != SQLITE_OK) //执行SQL操作语句 
    {
        sqlite3_free(errmsg);
        sprintf(msg->data, "user %s already exist!!!", msg->name);
    }
    else
    {
        strncpy(msg->data, "OK", 256);    // 操作成功
    }
    send(connectfd, msg, sizeof(MSG), 0);
    return;
}

void do_login(int connectfd, MSG *msg, sqlite3 *db)  //登录用户
{
    char sqlstr[128];
    char *errmsg, **result;
    int nrow, ncolumn;
    sprintf(sqlstr, "select * from usr where name = '%s' and pass = '%s'", msg->name, msg->data);
    if (sqlite3_get_table(db, sqlstr, &result, &nrow, &ncolumn, &errmsg) != SQLITE_OK)
    {
        printf("error : %s\n", errmsg);
        sqlite3_free(errmsg);
    }
    if (nrow == 0)        //没有找到登录的用户，报错
    {
        strncpy(msg->data, "name or password is wrong!!!", 256);
    }
    else                  //登录成功，发OK
    {
        strncpy(msg->data, "OK", 256);
    }
    send(connectfd, msg, sizeof(MSG), 0);
    sqlite3_free_table(result);
    return;
}
void get_date(char date[])  //获得历史记录的时间
{
    time_t t;
    struct tm *tp;
    time(&t);
    tp = localtime(&t);
    strftime(date, 64, "%Y-%m-%d %H:%M:%S", tp);
    return;
}

int do_searchword(int connectfd, MSG *msg)  //搜索单词
{
    FILE *fp;
    char s[300];

    char *p;

    if ((fp = fopen("dict.txt", "r")) == NULL)
    {
        strcpy(msg->data, "dict on server can't be opened :(");
        send(connectfd, msg, sizeof(MSG), 0);
    }
    printf("query word is %s\n", msg->data);

    while (fgets(s, 300, fp) != NULL)    
    {
        if (0 == strncmp(msg->data,s,strlen(msg->data)) )

{

p = s + strlen(msg->data);

while(0 == strncmp(p," ",1) ) p++;    //去掉这一行前面的单词和空格

strcpy(msg->data,p);                   //只发送解释的部分

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

fclose(fp);

return 1;     //返回1说明查找成功

}                        

    }
    fclose(fp);
    return 0;                //返回0说明查找失败
}

void do_query(int connectfd, MSG *msg, sqlite3 *db)  //将历史记录插入到record表中
{
    char sqlstr[128], *errmsg;
    int found = 0;
    char date[64], word[64];
    strcpy(word, msg->data);
    found = do_searchword(connectfd, msg);
    if ( found )          //判断找到单词是否成功
    {
        get_date(date);   //如果成功，记录时间，插入历史表
        sprintf(sqlstr, "insert into record values ('%s', '%s', '%s')", msg->name, date, word);
        if (sqlite3_exec(db, sqlstr, NULL, NULL, &errmsg) != SQLITE_OK)
        {
            printf("error : %s\n", errmsg);
            sqlite3_free(errmsg);
        }
    }
    else                 //如果失败，报错
    {
        strcpy(msg->data, "not found\n");
    }
    send(connectfd, msg, sizeof(MSG), 0);
    return;
}

int history_callback(void *arg, int f_num, char **f_value, char **f_name)//回调表中msg->name的记录
{
    int connectfd;
    MSG msg;
    connectfd = *(int *)arg;
    sprintf(msg.data, "%s : %s", f_value[1], f_value[2]);
    send(connectfd, &msg, sizeof(msg), 0);
    return 0;
}

void do_history(int connectfd, MSG *msg, sqlite3 *db)  //查找当前用户的历史记录
{
    char sqlstr[128], *errmsg;
    sprintf(sqlstr, "select * from record where name = '%s'", msg->name);
    if (sqlite3_exec(db, sqlstr, history_callback, (void *)&connectfd, &errmsg) != SQLITE_OK)
    {
        printf("error : %s\n", errmsg);
        sqlite3_free(errmsg);
    }
    msg->data[0] = '\0';               //表示回调结束
    send(connectfd, msg, sizeof(MSG), 0);
    
    return;
}

void do_client(int connectfd, sqlite3 *db)  //处理客户机发来的信息
{
    MSG msg;
    while (recv(connectfd, &msg, sizeof(msg), 0) > 0)  
    {
        switch ( msg.type )
        {
        case 1 :
            do_register(connectfd, &msg, db);    //注册
            break;
        case 2 :
            do_login(connectfd, &msg, db);    //登录
            break;
        case 3 :
            do_query(connectfd, &msg, db);    //查询单词
            break;
        case 4 :
            do_history(connectfd, &msg, db);    //历史记录
            break;
        }
    }
    printf("client quit\n");
    exit(0);
    return;
}

main_server.c

#include "include.h"

int main(int argc, char *argv[])

{
    int listenfd, connectfd;
    struct sockaddr_in server_addr;
    pid_t pid;
    sqlite3 *db;
 
    if (sqlite3_open(DATABASE, &db) != SQLITE_OK)
    {
        printf("error : %s\n", sqlite3_errmsg(db));
        exit(-1);
    }

//create table record (name text,date,text,word text);

//create table usr (name text primary key,pass text);

//这边没有创建数据库的表，请在my.db里自行创建以上两个表
    if ((listenfd = socket(PF_INET, SOCK_STREAM, 0)) < 0)
    {
        perror("fail to socket");
        exit(-1);
    }
    bzero(&server_addr, sizeof(server_addr));
    server_addr.sin_family = PF_INET;
    server_addr.sin_addr.s_addr = inet_addr("192.168.1.106");
    server_addr.sin_port = htons(8888);
    if (bind(listenfd, (struct sockaddr *)&server_addr, sizeof(server_addr)) < 0)
    {
        perror("fail to bind");
        exit(-1);
    }
    if (listen(listenfd, 5) < 0)
    {
        perror("fail to listen");
        exit(-1);
    }
    signal(SIGCHLD, SIG_IGN);  // 为了不生成僵尸进程
    while (1)
    {
        if ((connectfd = accept(listenfd, NULL, NULL)) < 0)
        {
            perror("fail to accept");
            exit(-1);
        }
        if ((pid = fork()) < 0)         //多进程以便多用户登录
        {
            perror("fail to fork");
            exit(-1);
        }
        if (pid == 0)             //子进程执行客户机函数
        {
            do_client(connectfd, db);
        }
        close(connectfd);
    }
    return 0;
}

client.c

#include "include.h"
void do_register(int socketfd, MSG *msg)  //注册用户
{
    msg->type = 1;
    printf("input name : ");
    scanf("%s", msg->name);
    printf("input password : ");
    scanf("%s", msg->data);
    send(socketfd, msg, sizeof(MSG), 0);
    recv(socketfd, msg, sizeof(MSG), 0);
    printf("register : %s\n", msg->data);
    return;
}
 
int do_login(int socketfd, MSG *msg)  //登录用户
{
    msg->type = 2;
    printf("input name : ");
    scanf("%s", msg->name);
    printf("input password : ");
    scanf("%s", msg->data);
    send(socketfd, msg, sizeof(MSG), 0);
    recv(socketfd, msg, sizeof(MSG), 0);
    if (strncmp(msg->data, "OK", 3) == 0)     //判断接受的是不是OK
    {
        printf("login : OK\n");
        return 1;                            //返回1说明登录成功
    }
    printf("login : %s\n", msg->data);       //打印报错的信息
    return 0;                                //返回0说明登录失败
}

void do_query(int socketfd, MSG *msg)  //把输入的单词发给服务器
{
    msg->type = 3;
    while (1)
    {
        scanf("%s", msg->data);
        if (strcmp(msg->data, "#") == 0) break;  //输入“#”退出
        send(socketfd, msg, sizeof(MSG), 0);
        recv(socketfd, msg, sizeof(MSG), 0);
        printf("%s\n",msg->data);          //打印单词解释，或是没有找到
    }
    return;
}
 
void do_history(int socketfd, MSG *msg)  //保存记录到历史记录里
{
    msg->type = 4;
    send(socketfd, msg, sizeof(MSG), 0);
    while (1)
    {
        recv(socketfd, msg, sizeof(MSG), 0);  //执行一次接收一条历史记录
        if (msg->data[0] == '\0') break;      //如果遇到'\0'表示回调历史记录结束
        printf("%s\n", msg->data);       //打印一条历史记录
    }
    return;
}

main_client.c

#include "include.h"

int main(int argc, char *argv[])

{
    int socketfd ;
    struct sockaddr_in server_addr;
    MSG msg;

    if ((socketfd = socket(PF_INET, SOCK_STREAM, 0)) < 0)
    {
        perror("fail to socket");
    }
    bzero(&server_addr, sizeof(server_addr));
    server_addr.sin_family = PF_INET;
    server_addr.sin_addr.s_addr = inet_addr("192.168.1.106");
    server_addr.sin_port = htons(8888);
    if (connect(socketfd, (struct sockaddr *)&server_addr, sizeof(server_addr)) < 0)
    {
        perror("fail to connect");
        exit(-1);
    }
    int n;
    while (1) //用户注册登录界面
    {
        printf("************************************\n");
        printf("* 1: register   2: login   3: quit *\n");
        printf("************************************\n");
        printf("please choose : ");
        if (scanf("%d", &n) <= 0)
        {
            perror("scanf");
            exit(-1);
        }
        switch (n)
        {
        case 1 :
            do_register(socketfd, &msg);
            break;
        case 2 :
            if (do_login(socketfd, &msg) == 1)
            {
                printf("\n");
                goto next; //登录成功则跳至查询单词的界面
            }