#include<stdio.h>
#include<stdlib.h>
#include<assert.h>
#include<string.h>
#include<sys/types.h>
#include<sys/socket.h>
#include<arpa/inet.h>
#include<netinet/in.h>
#include<pthread.h>
 //20191223
void* communication(void* arg);
 
int main()
{
 int sockfd=socket(PF_INET,SOCK_STREAM,0);
 assert(-1!=sockfd);
 
 struct sockaddr_in ser,cli;
 ser.sin_family=AF_INET;
 ser.sin_port=htons(6000);
 ser.sin_addr.s_addr=inet_addr("127.0.0.1");
 int res=bind(sockfd,(struct sockaddr*)&ser,sizeof(ser));
 assert(-1!=res);
 
 listen(sockfd,5);
 
 while(1)//保证服务器可以连接多个客户端
 {
  int len=sizeof(cli);
  int c=accept(sockfd,(struct sockaddr*)&cli,&len);
        if(c<0)
        {
            printf("link error\n");
            continue;
        }
 
  pthread_t id;
  int n=pthread_create(&id,NULL,communication,(void*)c);//创建线程，将文件描述符强转为void*，此处只能是值传递，地址传递的话，可能函数线程还没拿到该地址的值，就被主线程更改
  assert(n==0);
 }
    close(sockfd);
}
 
void* communication(void* arg)//函数线程完成与客户端的交互
{
 while(1)//实现与一个客户端的多次交互
 {
     char buff[128]={0};
     int c=(int)arg;//将文件描述符转回int型
     int n=recv(c,buff,127,0);
     if(n<=0)
     {
   close(c);
   printf("%d client over\n",c);
   break;
     }
     printf("%d:%s\n",c,buff);
 
  send(c,"OK",2,0);
 }
}