网络编程实战之在线电子词典

1.头文件

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>          /* See NOTES */
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <string.h>
#include <unistd.h>
#include <sqlite3.h>
#include <signal.h>
#include <time.h>

2.宏定义

#define  R  1   // user - register
#define  L  2   // user - login
#define  Q  3   // user - query
#define  H  4   // user - history
#define N 128
//char *errmsg=NULL;
typedef struct{char type;char name[N];char data[512];
}MSG;//规定传输的格式

3.服务器主程序

服务器创建一个套接字即所谓的sockfd用于监听，绑定，以及创建用于通信的套接字——调用accept函数，当一个进程连接上就会返回一个通信套接字，另一个进程连上会返回一个看似一样但是不一样的通讯套接字，就像是sql语言中NULL永远会不同于其他字符，哪怕是另一个NULL依然有效。

我们将父进程的通用套接字关闭，只用于监听是否有客户端连接，子进程只用于接收，避免了同一时间只能连接一个用户的囧境。

int main(int argc, const char *argv[])
{MSG msg;sqlite3 *db;int sockfd;char *errmsg=NULL;if(0!=sqlite3_open("test.db",&db)){fprintf(stderr,"sqlite_open failed:%s",sqlite3_errmsg(db));return -1;}printf("sqlite_open ok;\n");sqlite3_exec(db,"create table if not exits usr (name char,password char);",NULL,NULL,&errmsg);
sqlite3_exec(db,"create table if not exits record_test(name char,data char,word char);",NULL,NULL,&errmsg)!=0);printf("the table create ok\n");sockfd=socket(AF_INET,SOCK_STREAM,0);struct sockaddr_in serveraddr;struct sockaddr_in clientaddr;
//填充结构体serveraddr.sin_family=AF_INET;serveraddr.sin_port=htons(8898);serveraddr.sin_addr.s_addr=inet_addr("127.0.0.1");socklen_t addrlen=sizeof(serveraddr);socklen_t clientlen=sizeof(clientaddr);
//绑定if(bind(sockfd,(struct sockaddr *)&serveraddr,addrlen)<0){perror("bind");exit(1);}printf("bind\n");
//监听if(0> listen(sockfd,5)){perror("listen");exit(1);}printf("listen\n");pid_t pid;char buf[N]={0};int acceptfd;
// 处理僵尸进程signal(SIGCHLD,handler);while(1){acceptfd=accept(sockfd,(struct sockaddr *)&clientaddr,&clientlen);pid=fork();
//fork函数创建进程
//1.创建失败 2.子进程 3.父进程：父进程用于监听和连接，子进程用于通信if(pid<0){perror("failed to fork");exit(1);}else if(pid==0){ close(sockfd);do_client(acceptfd,db);}elseclose(acceptfd);} sqlite3_close(db);return 0;
}

4.客户端信号的处理

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': process_register(acceptfd,&msg,db);break;case 'L': process_login(acceptfd,&msg,db);break;case 'Q': process_query(acceptfd,&msg,db);break;case 'H': process_history(acceptfd,&msg,db);break;default:printf("invalid data msg.\n");}}printf("client exit\n");close(acceptfd);exit(0);}

5.客户端的主函数（字符界面）

int main(int argc, const char *argv[])
{int sockfd;MSG msg;MSG *msgp = NULL;sockfd=socket(AF_INET,SOCK_STREAM,0);if(sockfd<0){perror("sockfd.");exit(1);}struct sockaddr_in serveraddr;bzero(&serveraddr,sizeof(serveraddr));//清零 serveraddr.sin_family=AF_INET;serveraddr.sin_port=htons(8898);serveraddr.sin_addr.s_addr=inet_addr("127.0.0.1");socklen_t addrlen=sizeof(serveraddr);connect(sockfd,(struct sockaddr *)&serveraddr,addrlen);char buf[N]={0};int n;while(1){printf("***********************\n");printf("******1:register****\n");printf("******2:login*******\n");printf("******3.quit********\n");printf("***********************\n");printf("please choose\n");fgets(buf,sizeof(buf),stdin);printf("%s\n",buf);switch(buf[0]){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("input again\n");continue;}}while(1){
next:printf("************************************\n");printf("**1:querry_word**2:history**3:quit**\n");printf("************************************\n");printf("please choose:\n");fgets(buf,sizeof(buf),stdin);switch(buf[0]){case '1':do_query(sockfd,&msg);break;case '2':do_history(sockfd,&msg);break;case '3':close(sockfd);exit(0);default:printf("invalid data\n");}}return 0;
}

6.注册功能实现

（1）客户端

int do_register(int sockfd,MSG *msg)
{ msg->type='R';printf("your usrname:\n");scanf("%s",msg->name);printf("your password:\n");scanf("%s",msg->data);printf("%c,%s,%s\n",msg->type,msg->name,msg->data);pid_t pid;if(send(sockfd,msg,512,0)<0){printf("failed to send\n");return 1;}if(recv(sockfd,msg,sizeof(MSG),0)<0){printf("failed to recv\n");return 1;}printf("%s\n",msg->data);return 0;
}

（2）服务器端

void process_register(int acceptfd,MSG *msg, sqlite3 * db)
{char sql[64]={0};char *errmsg=NULL;sprintf(sql,"insert into usr values('%s','%s');",msg->name,msg->data);printf("%s\n",sql);if(0!= sqlite3_exec(db,sql,NULL,NULL,&errmsg)){printf("%s\n",errmsg);strcpy(msg->data,"usrname already exit.");}else{printf("client register ok.\n");strcpy(msg->data,"OK!");}if(send(acceptfd,msg,sizeof(MSG),0)<0){perror("failed to send");return;}return;}

7.登录功能的实现

（1）客户端

int do_login(int sockfd,MSG *msg)
{pid_t pid;msg->type='L';printf("input your name\n");scanf("%s",msg->name);getchar();printf("input your password\n");scanf("%s",msg->data);getchar();send(sockfd,msg,sizeof(MSG),0);printf("%s\n",msg->data);recv(sockfd,msg,sizeof(MSG),0);printf("%s\n",msg->data);if(strncmp(msg->data,"OK",3)==0){printf("Login ok\n");return 1;}else {printf("%s",msg->data);return 0;}}

（2）服务器端

int  process_login(int acceptfd,MSG *msg,sqlite3 *db)
{   char **resultp=NULL;int nrow,ncolumn;char *errmsg=NULL;char sql[512]={0};printf("a2\n");sprintf(sql,"select * from usr where name = '%s' and password = '%s';",msg->name,msg->data);if(0!= sqlite3_get_table(db,sql,&resultp,&nrow,&ncolumn,&errmsg)){printf("%s\n",errmsg);return -1;}else{printf("get_table ok!\n");}if(nrow==0){strcpy(msg->data,"usr/pwd wrony");send(acceptfd,msg,sizeof(MSG),0);   }else if(nrow==1){strcpy(msg->data,"OK");send(acceptfd,msg,sizeof(MSG),0);return 1;}return 0;
}

8.查询功能

（1）客户端

void do_query(int sockfd,MSG *msg)
{msg->type='Q';puts("-----------------------------");while(1){printf("input word:");fgets(msg->data,sizeof(msg->data),stdin);msg->data[strlen(msg->data)-1]='\0';if(strncmp(msg->data,"#",1)==0)break;if(send(sockfd,msg,sizeof(MSG),0)<0){printf("failed to send\n");return ;}printf("%c,%s",msg->type,msg->data);printf("send ok.\n");if(recv(sockfd,msg,1024,0)<0){printf("failed to recv\n");return ;}printf("%s\n",msg->data);}return ;
}

（2）服务器端

int do_searchword(int acceptfd,MSG *msg,char word[])
{FILE *fp=NULL;char buffer[1024]={0};int len;if((fp=fopen("./dict.txt","r"))==NULL){perror("fail to fopen.\n");strcpy(msg->data, "Failed to open dict.txt");send(acceptfd,(MSG*)&msg, sizeof(MSG), 0);return 1;}len=strlen(word);printf("%s,len=%d\n",word,len);int result;char *p=NULL;while(fgets(buffer,1024,fp)!=NULL){   result=strncmp(buffer,word,len);if(result<0){continue;}if(result>0||((result == 0)&&(buffer[len]!=' ')))break;p=buffer + len;while(*p== ' '){p++;}strcpy(msg->data,p);printf("%s\n",msg->data);fclose(fp);return 1;}fclose(fp);return 0;
}
int get_time(char *data)
{struct tm *tm_p=NULL;time_t dtime;time(&dtime);tm_p=localtime(&dtime);sprintf(data,"%d-%d-%d %d:%d:%d\n",tm_p->tm_year + 1900,tm_p->tm_mon + 1,\tm_p->tm_mday,tm_p->tm_hour,tm_p->tm_min,tm_p->tm_sec);printf("get data:%s\n",data);return 0;
}
void process_query(int acceptfd,MSG *msg,sqlite3 *db)
{int found;char word[64]={0};char data[128]={0};char sql[128]={0};char *errmsg =NULL;strcpy(word,msg->data);found=do_searchword(acceptfd,msg,word);if(found==1){get_time(data);sprintf(sql,"insert into record_test values('%s','%s','%s')",msg->name,data,word);if(0!=sqlite3_exec(db,sql,NULL,NULL,&errmsg)){printf("%s\n",errmsg);return ;}else{printf("insert record done.\n");}}else{strcpy(msg->data,"NO found");printf("aaaa\n");}if(send(acceptfd,msg,sizeof(MSG),0)<0){perror("failed to send");}
}

9 历史查询

（1）客户端

void do_history(int sockfd,MSG *msg)
{ msg->type='H';send(sockfd,msg,sizeof(MSG),0);while(1){recv(sockfd,msg,sizeof(MSG),0);if(msg->data[0]=='\0')break;printf("%s\n",msg->data);}}

（2）服务器端

int history_callback(void* arg,int f_num,char** f_value,char** f_name)
{int accptfd;MSG msg;accptfd=*((int *)arg);sprintf(msg.data,"%s ,%s",f_value[1],f_value[2]);send(accptfd,&msg,sizeof(msg),0);return 0;
}void process_history(int acceptfd,MSG *msg,sqlite3 * db)
{char sql[128]={0};char *errmsg=NULL;sprintf(sql,"select * from record where name ='%s';",msg->name);if(0!=sqlite3_exec(db,sql,history_callback,(void *)&acceptfd,&errmsg)){printf("%s\n",errmsg);}else{printf("record done.\n");}msg->data[0]='\0';send(acceptfd,msg,sizeof(MSG),0);
}

10 僵尸进程处理函数

void handler(int signum)
{if(SIGCHLD==signum)waitpid(-1,NULL,WNOHANG);
}

本文纯属个人笔记，如有错误，还望不吝指点，如有雷同，你来打我呀

网络编程实战之在线电子词典相关推荐

北京迅为IMX6ULL开发板 DHT11网络编程实战练习
转自:[北京迅为i.mx6ull终结者开发板使用手册]第六十三章 QT 实战项目硬件平台:IMX6ULL开发板 63.1 DHT11&网络编程实战练习本项目为阶段性练习,内容简洁实用, ...
迅为-i.MX6ULL开发板-QT实战项目DHT11网络编程实战练习（一）
迅为-i.MX6ULL开发板-QT实战项目DHT11&网络编程实战练习(一) 发布时间:2021-7-2 09:49 发布者:落风 |编辑文章目录1 项目前准备2 软件流程图3 Lin ...
陈硕《网络编程实战》01 网络编程概要
陈硕<网络编程实战> 01 网络编程概要站在巨人的肩膀之上. 按照录像整理,部分专有名词不太肯定,版权归陈硕大神. 大家好,我是陈硕,受邀讲授一门有关网络编程的在线课程,这门课程的名称是 ...
基于Winsock API的VC网络编程实战
基于Winsock API的VC网络编程实战随着计算机信息技术的飞速发展,互联网与人类社会的工作.生活越来越紧密相关,它已经成为人类获取.交流信息的重要途径和手段.所以当前对于开发人员来说,网络编程 ...
NIO网络编程实战之简单多人聊天室
NIO网络编程实战利用NIO编程知识,实现多人聊天室. 1. NIO编程实现步骤第一步:创建Selector 第二步:创建ServerSocketChannel,并绑定监听端口第三步:将Chan ...
Java并发编程实战_阿里P9整理分享的亿级流量Java高并发与网络编程实战PDF
前言为了帮助初级开发者快速掌握高并发.网络编程.微服务.海量数据的处理这些实用技术,本文以"理论+范例"的形式对各个知识点进行了详细的讲解,力争让读者在实践中快速掌握相关知识. ...
Netty网络编程实战2，使用Netty开发聊天室功能
目录一.服务端 1.主程序类 2.自定义初始化器 3.自定义处理器二.客户端 1.主程序类 2.自定义初始化器 3.自定义处理器三.启动服务端.客户端 1.服务端:你好,我是服务端,哪吒编程 2 ...
Qt网络编程实战之HTTP服务器-安晓辉-专题视频课程
Qt网络编程实战之HTTP服务器-30196人已学习课程介绍设计了一个实用的HTTP服务器,基于Qt的网络框架实现.先详细介绍Qt的网络.IO.线程..自定义事件.配置文件等类库的 ...
【基于TCP 在线电子词典】
基于TCP 在线电子词典项目功能流程图客户端服务器端功能实现服务器客户端功能演示注册功能登录功能查询单词功能查询记录注销登录(返回上级) 不允许重复登录 Ctrl + C注销 ...
java网络编程技术学习笔记（b站【狂神说Java】网络编程实战讲解）
b站视频链接:[狂神说Java]网络编程实战讲解文章目录网络编程 1.1.概述 1.2.网络通信的要素 1.3.IP 1.4.端口 1.5.通信协议 1.6.TCP 文件发送 1.7.UDP 1. ...

网络编程实战之在线电子词典

网络编程实战之在线电子词典相关推荐

最新文章

热门文章