电子词典项目

代码块

• 客户端代码

#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
#define  R  1   //  user register
#define  L  2   //  user login
#define  Q  3   //  query word
#define  H  4   //  history record
#define  COL 50

#define DATABASE "my.db"

typedef struct sockaddr SA;

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

void do_register(int sockfd, MSG *pbuf)
{
    //封装注册MSG包
    pbuf->type = R;
    printf("input name : ");
    scanf("%s", pbuf->name);
    printf("input password : ");
    scanf("%s", pbuf->data);
    //发送注册包
    send(sockfd, pbuf, sizeof(MSG), 0);
    //接收服务器反馈   
    recv(sockfd, pbuf, sizeof(MSG), 0);
    printf("register : %s\n", pbuf->data);

    return;
}

int do_login(int sockfd, MSG *pbuf)
{
    //封装登录MSG包
    pbuf->type = L;
    printf("input name : ");
    scanf("%s", pbuf->name);
    printf("input password : ");
    scanf("%s", pbuf->data);
    //发送登录包
    send(sockfd, pbuf, sizeof(MSG), 0);
    //接收服务器反馈
    recv(sockfd, pbuf, sizeof(MSG), 0);
    if (strncmp(pbuf->data, "OK", 3) == 0) 
    {
        printf("login : OK\n");
        return 1;
    }
    printf("login : %s\n", pbuf->data);

    return 0;
}

void print(char *p)
{
    int count = 0, len;
    char *q;

    printf("   ");
    while ( *p )
    {
        if (*p == ‘ ‘ && count == 0) p++;
        printf("%c", *p++);
        count++;

        /* if a new word will begin */
        if (*(p-1) == ‘ ‘ && *p != ‘ ‘)
        {
            q = p;
            len = 0;
            /* count the length of next word */
            while (*q != ‘ ‘ && *q != ‘\0‘) 
            {
                len++;
                q++;
            }
            if ((COL - count) < len) 
            {
                printf("\n   ");
                count = 0;
            }
        }
        if (count == 50)
        {
            count = 0;
            printf("\n   ");
        }
    }

    return;
}

void do_query(int sockfd, MSG *pbuf)
{
    //封装查询包
    pbuf->type = Q;
    while ( 1 )
    {
        printf("input word : ");
        scanf("%s", pbuf->data);
        if (strcmp(pbuf->data, "#") == 0) 
            break;
        //发送查询包
        send(sockfd, pbuf, sizeof(MSG), 0);
        //接收服务器反馈
        recv(sockfd, pbuf, sizeof(MSG), 0);
        print(pbuf->data);
        printf("\n");
    }

    return;
}

void do_history(int sockfd, MSG *pbuf)
{
    //封装查询历史包
    pbuf->type = H;
    //发送历史包
    send(sockfd, pbuf, sizeof(MSG), 0);
    while ( 1 )
    {
        //接收服务器反馈的历史信息
        recv(sockfd, pbuf, sizeof(MSG), 0);
        if (pbuf->data[0] == ‘\0‘) 
            break;
        printf("%s\n", pbuf->data);
    }

    return;
}

int main(int argc, char *argv[])
{
    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socket，用于下一步建立连接
    if ((sockfd = socket(PF_INET, SOCK_STREAM, 0)) < 0)
    {
        perror("fail to socket");
        exit(-1);
    }

    //servaddr，服务器端的地址结构
    bzero(&servaddr, sizeof(servaddr));
    servaddr.sin_family = PF_INET; //地址族
    servaddr.sin_port = htons(atoi(argv[2])); //端口号
    servaddr.sin_addr.s_addr = inet_addr(argv[1]); //IP地址

    // 建立客户端与服务器之间的连接
    if (connect(sockfd, (SA *)&servaddr, sizeof(servaddr)) < 0)
    {
        perror("fail to connect");
        exit(-1);
    }

    int n;
    while ( 1 )
    {
        printf("************************************\n");
        printf("* 1: register   2: login   3: quit *\n");
        printf("************************************\n");
        printf("please choose : ");
        if (scanf("%d", &n) == 0)
        {
            fgets(clean, 64, stdin);
            printf("\n");
            continue;
        }
        switch ( n )
        {
        case 1 :
            printf("\n");
            do_register(sockfd, &buf);
            printf("\n");
            break;
        case 2 :
            printf("\n");
            if (do_login(sockfd, &buf) == 1)
            {
                printf("\n");
                goto next;
            }
            printf("\n");
            break;
        case 3 :
            close(sockfd);
            exit(0);
        }
    }

next:

    while ( 1 )
    {
        printf("***********************************************\n");
        printf("* 1: query_word   2: history_record   3: quit *\n");
        printf("***********************************************\n");
        printf("please choose : ");

        if (scanf("%d", &n) == 0)
        {
            fgets(clean, 64, stdin);
            printf("\n");
            continue;
        }
        switch ( n )
        {
        case 1 :
            printf("\n");
            do_query(sockfd, &buf);
            printf("\n");
            break;
        case 2 :
            printf("\n");
            do_history(sockfd, &buf);
            printf("\n");
            break;
        case 3 :
            close(sockfd);
            exit(0);
        }
    }

    return 0;
}

• 服务器端代码

#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  N  16
#define  R  1   //  user register
#define  L  2   //  user login
#define  Q  3   //  query word
#define  H  4   //  history record

#define DATABASE "my.db"

typedef struct sockaddr SA;

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

void do_register(int connfd, MSG *pbuf, sqlite3 *db)
{
    char sqlstr[128];
    char *errmsg;

    //组合SQL语句，插入一条用户注册信息
    sprintf(sqlstr, "insert into usr values (‘%s‘, ‘%s‘)", pbuf->name, pbuf->data);
    printf("%s\n", sqlstr);
    //执行SQL语句
    if (sqlite3_exec(db, sqlstr, NULL, NULL, &errmsg) != SQLITE_OK)
    {
        sqlite3_free(errmsg);
        sprintf(pbuf->data, "user %s already exist!!!", pbuf->name);
    }
    else
    {
        strncpy(pbuf->data, "OK", 256);
    }
    //向客户端反馈信息，如，注册成功OK
    send(connfd, pbuf, sizeof(MSG), 0);

    return;
}

/******************************************************************************/

void do_login(int connfd, MSG *pbuf, sqlite3 *db)
{
    char sqlstr[128];
    char *errmsg, **result;
    int nrow, ncolumn;

    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)
    {
        strncpy(pbuf->data, "name or password is wrong!!!", 256);
    }
    else
    {
        strncpy(pbuf->data, "OK", 256);
    }
    send(connfd, pbuf, sizeof(MSG), 0);
    sqlite3_free_table(result);

    return;
}

/******************************************************************************/

void get_date(char date[])
{
    time_t t;
    struct tm *tp;

    time(&t);

    tp = localtime(&t);
    /*
    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;
}

int do_searchword(int connfd, MSG *pbuf)
{
    FILE *fp;
    char line[300];
    char *p;
    int len, result;

    len = strlen(pbuf->data);
    //读词库文件dict.txt
    if ((fp = fopen("dict.txt", "r")) == NULL)
    {
        strcpy(pbuf->data, "dict on server can‘t be opened :(");
        send(connfd, pbuf, sizeof(MSG), 0);
    }
    printf("query word is %s\n", pbuf->data);
    //取一行数据
    while (fgets(line, 300, fp) != NULL)
    {
        result = strncmp(pbuf->data, line, len);
        if (result > 0) continue;
        if (result < 0 || line[len] != ‘ ‘) break;

        p = line + len;
        while (*p == ‘ ‘) p++;
        strcpy(pbuf->data, p);
        fclose(fp);
        return 1;
    }
    fclose(fp);

    return 0;
}

void do_query(int connfd, MSG *pbuf, sqlite3 *db)
{
    char sqlstr[128], *errmsg;
    int len, result, found = 0;
    char date[64], word[64];

    strcpy(word, pbuf->data);//pbuf->data，用户查询的单词
    found = do_searchword(connfd, pbuf);
    if ( found )
    {
        get_date(date);
        //向历史记录表中插入一条记录信息
        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
    {
        strcpy(pbuf->data, "not found\n");
    }
    //向用户反馈信息，如，"not found"
    send(connfd, pbuf, sizeof(MSG), 0);

    return;
}

/***************************************************************************/

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, sqlite3 *db)
{
    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)
    {
        printf("error : %s\n", errmsg);
        sqlite3_free(errmsg);
    }
    pbuf->data[0] = ‘\0‘;
    send(connfd, pbuf, sizeof(MSG), 0);

    return;
}

/******************************************************************************/

void do_client(int connfd, sqlite3 *db)
{
    MSG buf;
    //接收客户端数据，并存放到MSG包
    while (recv(connfd, &buf, sizeof(buf), 0) > 0)  // receive request
    {
        //根据包的类型，做相应的处理
        switch ( buf.type )
        {
        case R : //客户端发来注册包
            do_register(connfd, &buf, db);
            break;
        case L ://客户端发来登录包
            do_login(connfd, &buf, db);
            break;
        case Q ://客户端发来查询包
            do_query(connfd, &buf, db);
            break;
        case H ://客户端发来查询历史包
            do_history(connfd, &buf, db);
            break;
        }
    }
    printf("client quit\n");
    exit(0);

    return;
}

int main(int argc, char *argv[])
{
    int listenfd, connfd;
    struct sockaddr_in myaddr;
    pid_t pid;
    MSG buf;
    sqlite3 *db;

    if (argc < 3)
    {
        printf("Usage : %s <ip> <port>\n", argv[0]);
        exit(-1);
    }

    //打开或创建数据库
    if (sqlite3_open(DATABASE, &db) != SQLITE_OK)
    {
        printf("error : %s\n", sqlite3_errmsg(db));
        exit(-1);
    }

    // 创建socket
    if ((listenfd = socket(PF_INET, SOCK_STREAM, 0)) < 0)
    {
        perror("fail to socket");
        exit(-1);
    }

    //绑定服务器地址，myaddr服务器地址结构
    bzero(&myaddr, sizeof(myaddr));
    myaddr.sin_family = PF_INET; //地址族
    myaddr.sin_port = htons(atoi(argv[2])); //端口号
    myaddr.sin_addr.s_addr = inet_addr(argv[1]); //服务器IP
    if (bind(listenfd, (SA *)&myaddr, sizeof(myaddr)) < 0)
    {
        perror("fail to bind");
        exit(-1);
    }

    // 设置监听队列的长度
    if (listen(listenfd, 5) < 0)
    {
        perror("fail to listen");
        exit(-1);
    }

    signal(SIGCHLD, SIG_IGN);
    //循环与客户端建立连接，实现客户端通信（send/recv）
    while ( 1 )
    {
        //接受客户端建立连接
        if ((connfd = accept(listenfd, NULL, NULL)) < 0)
        {
            perror("fail to accept");
            exit(-1);
        }
        if ((pid = fork()) < 0)
        {
            perror("fail to fork");
            exit(-1);
        }
        else if (pid == 0)
        {
            do_client(connfd, db);
        }
        close(connfd);
    }

    return 0;
}