项目：

制作一个简易的聊天室，实现实时非单机聊天

知识点：

总体框架：

socket() 创造套接字函数：

然后设置 bind() ，调整 IP 参数：

然后设置 listen() ： 

 然后设置 accept() ：

收发数据 recv(), send()/sendto(), read(), write() ：

最后关闭 close() ：

因为本身 socket 是一种文件描述符，所以最后要关闭打开的文件

 服务端：

1.创建sd

//创建sdsd = socket(AF_INET,SOCK_STREAM,0);if(sd == -1){perror("create sd failed");return -1;}

2.配置ip，端口属性

//设置ip，端口server_ip.sin_family = AF_INET;server_ip.sin_port = htons(5678);server_ip.sin_addr.s_addr = htonl(INADDR_ANY);memset(server_ip.sin_zero,0,8);

3.绑定ip和客户端 

//绑定ip和客户端error = bind(sd,(struct sockaddr *) (&server_ip),sizeof(struct sockaddr));if(error == -1){perror("create bind failed");close(sd);return -1;}

4.设置最大链接数，这个宏定义MAX_LISLEN=2，因为我这里只连接2个客户端，可以设置多个

//设置最大链接数error = listen(sd, MAX_LISLEN);if(error == -1){perror("create listem failed");close(sd);return -1;}

 5.等待客户端连接

ad[i] = accept(sd,(struct sockaddr *)(&remote_ip),&remote_len);if(ad[i] == -1){perror("create ad failed");close(sd);return -1;}

6.创造新线程，不断读取客户端发送的数据，别写入另外一个客户端

void * pthread_fun(void * arg){while(1){memset(buf,0,100);read(ad[(int )arg],buf,100);write(ad[((int )arg + 1) % 2],buf,100);}return (void *) 0;}

客户端 ：

 1.创建sd

//创建sdsd = socket(AF_INET,SOCK_STREAM,0);if(sd == -1){perror("create sd failed");return -1;}

2.配置ip，端口属性

//设置ip，端口server_ip.sin_family = AF_INET;server_ip.sin_port = htons(5678);server_ip.sin_addr.s_addr = htonl(INADDR_ANY);memset(server_ip.sin_zero,0,8);

3.连接服务端

//链接服务端error = connect(sd, (struct sockaddr *) (&server_ip),sizeof(struct sockaddr));if(error == -1){perror("create connect failed");close(sd);return -1;}

 4.创建两个新线程，不断写数据个服务端，不断从服务端读数据

void * pthread_fun_write(void * arg){while(1){memset(buf_write,0,100);scanf("%s",buf_write);write(sd,buf_write,100);}}void * pthread_fun_read(void * arg){while(1){memset(buf_read,0,100);read(sd,buf_read,100);printf("client2:%s\n",buf_read);}}

附录 

服务端代码

#include<stdio.h>#include<pthread.h>#include <sys/types.h> /* See NOTES */#include <sys/socket.h>#include <string.h>#include <arpa/inet.h>#include <unistd.h>#include <netinet/in.h>#include <unistd.h>#define MAX_LISLEN 2char buf_write[100];char buf[100];int ad[2];struct sockaddr_in server_ip, remote_ip;void * pthread_fun(void * arg){while(1){memset(buf,0,100);read(ad[(int )arg],buf,100);write(ad[((int )arg + 1) % 2],buf,100);}return (void *) 0;}int main(){pthread_t tid[2];int server_len , remote_len;int error, sd ;int i = 0;//创建sdsd = socket(AF_INET, SOCK_STREAM ,0);if(sd == -1){perror("create sd failed");return -1;//close(sd);}//设置ip，端口server_ip.sin_family = AF_INET;server_ip.sin_port = htons(5678);server_ip.sin_addr.s_addr = htonl(INADDR_ANY);memset(server_ip.sin_zero,0,8);//绑定ip和客户端error = bind(sd,(struct sockaddr *) (&server_ip),sizeof(struct sockaddr));if(error == -1){perror("create bind failed");close(sd);return -1;}//设置最大链接数error = listen(sd, MAX_LISLEN);if(error == -1){perror("create listem failed");close(sd);return -1;}remote_len = sizeof(struct sockaddr);while(1){//等待客户端申请ad[i] = accept(sd,(struct sockaddr *)(&remote_ip),&remote_len);if(ad[i] == -1){perror("create ad failed");close(sd);return -1;} else{printf("client%d 加入聊天室\n",i+1);} //新线程，功能：不断读数据error = pthread_create(&tid[i],NULL,pthread_fun,(void*) i);if(error != 0){perror("create pthread_fun failed");close(ad[i]);close(sd);return -1;} i++;}close(sd);return 0;}

客户端1代码 

#include<stdio.h>#include<pthread.h>#include <sys/types.h> /* See NOTES */#include <sys/socket.h>#include <string.h>#include <arpa/inet.h>#include <unistd.h>#include <netinet/in.h>#include <unistd.h>int sd;char buf_write[100];char buf_read[100];struct sockaddr_in server_ip, remote_ip;void * pthread_fun_write(void * arg){while(1){memset(buf_write,0,100);scanf("%s",buf_write);write(sd,buf_write,100);}}void * pthread_fun_read(void * arg){while(1){memset(buf_read,0,100);read(sd,buf_read,100);printf("client2:%s\n",buf_read);}}int main(){int server_len,remote_len;pthread_t tid_read,tid_write;int error;sd = socket(AF_INET,SOCK_STREAM,0);if(sd == -1){perror("create sd failed");return -1;}//设置ip，端口server_ip.sin_family = AF_INET;server_ip.sin_port = htons(5678);server_ip.sin_addr.s_addr = htonl(INADDR_ANY);memset(server_ip.sin_zero,0,8);//链接服务端error = connect(sd, (struct sockaddr *) (&server_ip),sizeof(struct sockaddr));if(error == -1){perror("create connect failed");close(sd);return -1;}error = pthread_create(&tid_write,NULL,pthread_fun_write,NULL);if(error != 0){perror("create pthread write failed");close(sd);return -1;} error = pthread_create(&tid_read,NULL,pthread_fun_read,NULL);if(error != 0){perror("create pthread read failed");close(sd);return -1;} pthread_join(tid_write,NULL);pthread_join(tid_read,NULL);return 0;}

客户端2代码 

#include<stdio.h>#include<pthread.h>#include <sys/types.h> /* See NOTES */#include <sys/socket.h>#include <string.h>#include <arpa/inet.h>#include <unistd.h>#include <netinet/in.h>#include <unistd.h>int sd;char buf_write[100];char buf_read[100];struct sockaddr_in server_ip, remote_ip;void * pthread_fun_write(void * arg){while(1){memset(buf_write,0,100);scanf("%s",buf_write);write(sd,buf_write,100);}}void * pthread_fun_read(void * arg){while(1){memset(buf_read,0,100);read(sd,buf_read,100);printf("client1:%s\n",buf_read);}}int main(){int server_len,remote_len;pthread_t tid_read,tid_write;int error;sd = socket(AF_INET,SOCK_STREAM,0);if(sd == -1){perror("create sd failed");return -1;}//设置ip，端口server_ip.sin_family = AF_INET;server_ip.sin_port = htons(5678);server_ip.sin_addr.s_addr = htonl(INADDR_ANY);memset(server_ip.sin_zero,0,8);error = connect(sd, (struct sockaddr *) (&server_ip),sizeof(struct sockaddr));if(error == -1){perror("create connect failed");close(sd);return -1;}error = pthread_create(&tid_write,NULL,pthread_fun_write,NULL);if(error != 0){perror("create pthread write failed");close(sd);return -1;} error = pthread_create(&tid_read,NULL,pthread_fun_read,NULL);if(error != 0){perror("create pthread read failed");close(sd);return -1;} pthread_join(tid_write,NULL);pthread_join(tid_read,NULL);return 0;}

写运行服务端创建sd，再运行客户端连接服务端，再不断加入客户端，注意最大加入数

运行结果：

想得美，直接动手