IO服用实现linux socket聊天程序（select）

//////////////////////////////////////server.c////////////////////////////////////////////// 

#include<stdio.h>
#include<strings.h>
#include<unistd.h>
#include<sys/types.h>
#include<sys/socket.h>
#include<netinet/in.h>
#include<arpa/inet.h>
#include<sys/select.h>
#include<sys/time.h>
#include<sys/wait.h>

#define PORT 1234
#define BACKLOG 10
#define MAXDATASIZE 100
char buf[MAXDATASIZE] = "server";

void pro_c(int connectfd, struct sockaddr_in client);
int  main()
{
 int listenfd, connectfd;
 struct sockaddr_in server;
 struct sockaddr_in client;
 socklen_t addrlen;
 pid_t pid;
 
 if((listenfd = socket(AF_INET, SOCK_STREAM, 0)) == -1)
 {
  perror("socket() error.");
  exit(1); 
 }
 
 int opt = SO_REUSEADDR;
 setsockopt(listenfd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
 
 bzero(&server, sizeof(server));
 server.sin_family = AF_INET;
 server.sin_port = htons(PORT);
 server.sin_addr.s_addr = htonl(INADDR_ANY);
 if(bind(listenfd, (struct sockaddr *)&server, sizeof(server)) == -1)
 {
  perror("bind() error.");
  exit(1); 
 } 
 if(listen(listenfd, BACKLOG) == -1)
 {  
  perror("listen() error.");
  exit(1); 
 }
 
 addrlen = sizeof(client);
 
  while(1)
 { 
  if((connectfd = accept(listenfd, (struct sockaddr *)&client, &addrlen )) == -1)
  {
  perror("accept() error.");
  exit(1); 
  }
  printf("You got a connection from client ip is: %s,port is:%d/n"
   ,inet_ntoa(client.sin_addr), htons(client.sin_port));
  if((pid = fork()) >0)
  { 
   close(connectfd); 
   continue;
  }
  else if(pid == 0)
  {
   close(listenfd);
   pro_c(connectfd, client);
   exit(0);
  }
  else
  {
   perror("error fork()");
   exit(0);
  }
 } 
 close(listenfd);
 
}

void pro_c(int connectfd, struct sockaddr_in client)
{
 //char buf[MAXDATASIZE] = "server";
 fd_set rfds;      // 
 int maxfd = -1;  /*设置select最大描述符*/
 while(1)
 {
  FD_ZERO(&rfds);  /*初始化*/
  FD_SET(0, &rfds);
  maxfd = 0;
  FD_SET(connectfd, &rfds);
  if(connectfd > maxfd)
   maxfd = connectfd;

  switch(select(maxfd+1, &rfds, NULL, NULL, NULL))
  {
  case -1:
   perror("select error."); exit(1); break;
  case 0:
   perror("time out ."); break;
  default :

   if(FD_ISSET(connectfd, &rfds))
   {
    bzero(buf, MAXDATASIZE);
    recv(connectfd, buf, MAXDATASIZE,0);
    printf("the IP %s says: %s",inet_ntoa(client.sin_addr), buf);
   }
   if(FD_ISSET(0, &rfds))
   {
    bzero(buf, MAXDATASIZE);
    if(fgets(buf, MAXDATASIZE, stdin)>0)
    send(connectfd, buf, MAXDATASIZE, 0);
   }
  break;
  }
 }
 close(connectfd);
  
}

 

 

 

 

 

 

 

 

 

 

////////////////////client.c/////////////////////

 

#include<stdio.h>
#include<unistd.h>
#include<strings.h>
#include<sys/types.h>
#include<sys/socket.h>
#include<netinet/in.h>
#include<netdb.h>
#include<sys/select.h>
#include<sys/time.h>

#define PORT 1234
#define MAXDATASIZE 100

int main ( int argc, char *argv[])
{
 int sockfd, num;
 char buf[MAXDATASIZE] = "client";
 struct hostent *he;
 struct sockaddr_in server;
 //struct timeval *timeout;  //
 fd_set rfds; //
 int maxfd = -1;

 if(argc!=2)
 {
  printf("usage %s<ip address>/n",argv[0]);
  exit(1); 
 }
 if((he = gethostbyname(argv[1])) == NULL)
 {
  printf("gethostbyname error/n");
  exit(1);
 }
 if((sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1)
 {
  printf("socket() error /n");
  exit(1);
 }
 bzero(&server, sizeof(server));
 server.sin_family = AF_INET;
 server.sin_port = htons(PORT);
 server.sin_addr = *((struct in_addr *)he->h_addr);
 if(connect(sockfd, (struct sockaddr *)&server, sizeof(server)) == -1)
 {
  printf("connetc() error/n");
  exit(1);
 }
 while(1)
 {
  FD_ZERO(&rfds);  /*初始化*/
  FD_SET(0, &rfds);
  maxfd = 0;
  FD_SET(sockfd, &rfds);
  if(sockfd > maxfd)
   maxfd = sockfd;
  //timeout->tv_sec = 0.2;
  //timeout->tv_usec = 0;

  switch(select(maxfd+1, &rfds, NULL, NULL, NULL))
  {
  case -1:
   perror("select error."); exit(1); break;
  case 0:
   perror("time out ."); break;
  default :
   if(FD_ISSET(0, &rfds))
   {
    if(fgets(buf, MAXDATASIZE, stdin)>0)
    send(sockfd, buf, MAXDATASIZE, 0);
   }
   if(FD_ISSET(sockfd, &rfds))
   {
    recv(sockfd, buf, MAXDATASIZE,0);
    printf("the server says: %s/n",buf);
   }
   break;
  }

  
 }
 close(sockfd);  
}