Server端:

#include <iostream> 
#include <stdio.h>  
#include <stdlib.h>  
#include <errno.h>  
#include <string.h>  
#include <sys/types.h>  
#include <netinet/in.h>  
#include <sys/socket.h>  
#include <sys/wait.h>  
#include <pthread.h>  
#include <unistd.h>  
#include <arpa/inet.h>  

#define MYPORT 3490  //定義埠  
#define BACKLOG 10  
#define MAXDATASIZE 1024  
  
int sockfd,new_fd;  
pthread_t accthread,recthread;
void* recmessage(void*){  //接收客戶端資訊函式  
    while(1){  
        int numbytes;  
        char buf[MAXDATASIZE];  
        if((numbytes = recv(new_fd,buf,MAXDATASIZE,0))==-1){  
            perror("recv");  
            exit(1);  
        }  
        buf[numbytes]='\0';  
        if(strcmp(buf,"exit")==0){  //若收到的是exit字元，則代表退出通訊  
            printf("Client is closed\n");  
            close(new_fd);  
            close(sockfd);  
            exit(1);  
        }  
        printf("client:%s\n",buf);  
    }/*while*/  
}  
void* acceptconnect(void*){  //接受客戶端連線請求函式  
    struct sockaddr_in their_addr;  
    socklen_t sin_size = sizeof(struct sockaddr_in);  
    // if (( accept_fd = accept(socket_fd, (struct sockaddr *) &remote_addr, &sin_size)) == -1 )
    if((new_fd = accept(sockfd,(struct sockaddr *)&their_addr,&sin_size))==-1){  
        perror("accept");  
        exit(1);  
    }  
    printf("server:got connection from %s\n",inet_ntoa(their_addr.sin_addr));  
    /*建立子執行緒，用於接收資訊*/  
    if((pthread_create(&recthread,NULL,recmessage,NULL)) != 0){  
        printf("create thread error!\r\n");  
        exit(1);  
    }
}
int main(void){  
    struct sockaddr_in my_addr;  
    /*建立套接字*/  
    if((sockfd = socket(AF_INET,SOCK_STREAM,0)) == -1){  
        perror("socket");  
        exit(1);  
    }  
    /*初始化sockaddr_in結構體相關引數*/  
    my_addr.sin_family = AF_INET;  
    my_addr.sin_port = htons(MYPORT);  
    my_addr.sin_addr.s_addr = INADDR_ANY;  
    bzero(&(my_addr.sin_zero),8);  
  
    /*繫結埠與套接字*/  
    if(bind(sockfd,(struct sockaddr*)&my_addr,sizeof(struct sockaddr)) == -1){  
        perror("bind");  
        exit(1);  
    }  
    /*監聽客戶端套接字*/  
    if(listen(sockfd,BACKLOG)== -1){  
        perror("listen");  
        exit(1);  
    }  
    printf("listening...\n");  
    /*建立子執行緒，用於接收資訊*/  
     if((pthread_create(&accthread,NULL,acceptconnect,NULL))!=0){  
        printf("create thread error!\n");  
        exit(1);  
    }  
    while(1){  
        char msg[MAXDATASIZE];  
        scanf("%s",msg);  
        if(send(new_fd,msg,strlen(msg),0) == -1){  //傳送資訊，與客戶端交流  
            perror("send");  
            exit(1);  
        }  
        if(strcmp(msg,"exit") ==0){  
            printf("byebye\n");  
            close(new_fd);  
            close(sockfd);  
            exit(1);  
        }  
    }/*while*/  
    return 0;  
}/*main*/  
 

#include <iostream>  
#include <stdio.h>  
#include <stdlib.h>  
#include <errno.h>  
#include <string.h>  
#include <sys/types.h>  
#include <netinet/in.h>  
#include <sys/socket.h>  
#include <sys/wait.h>  
#include <pthread.h>  
#include <netdb.h>  
#include <unistd.h>  
#include <arpa/inet.h>

#define PORT 3490  
#define BACKLOG 10  
#define MAXDATASIZE 1024 
#define SERVERIP "127.0.0.1"
int sockfd;  
pthread_t recthread;  
  
/*接收資訊函式*/  
void* recmessage(void*){  
    while(1){  
        int numbytes;  
        char buf[MAXDATASIZE];  
          
        if((numbytes = recv(sockfd,buf,MAXDATASIZE,0))==-1){  
            perror("recv");  
            exit(1);  
        }  
        buf[numbytes]='\0';  
        if(strcmp(buf,"exit")==0){  
            printf("Server is closed\n");  
            close(sockfd);  
            exit(1);  
        }  
        printf("Server:%s\n",buf);  
    }/*while*/  
}  
int main(){  
    struct hostent *he;  /*獲取主機IP地址*/  
    struct sockaddr_in their_addr;  

    /*獲取主機IP地址*/  
    if((he = gethostbyname(SERVERIP)) == NULL){  
        herror("gethostbyname");  
        exit(1);  
    }  
    /*建立套接字*/  
    if((sockfd = socket(AF_INET,SOCK_STREAM,0)) == -1){  
        perror("socket");  
        exit(1);  
    }  
     /*初始化sockaddr_in結構體*/  
    their_addr.sin_family = AF_INET;  
    their_addr.sin_port = htons(PORT);  
    their_addr.sin_addr = *((struct in_addr *)he->h_addr);  
    bzero(&(their_addr.sin_zero),8);  
    /*向伺服器傳送連線請求*/  
    if(connect(sockfd,(struct sockaddr *)&their_addr,sizeof(struct sockaddr)) == -1){  
        perror("connect");  
        exit(1);  
    }  
    /*建立子執行緒，用於接收資訊*/  
    if((pthread_create(&recthread,NULL,recmessage,NULL))!= 0){  
        printf("create thread error!\r\n");  
        exit(1);  
    }  
    /*傳送資訊。接收發送資訊用的是同一埠，都 是sockfd*/  
    while(1){  
        char msg[MAXDATASIZE];  
        scanf("%s",msg);  
        if(send(sockfd,msg,strlen(msg),0) == -1){  
            perror("send");  
            exit(1);  
        }  
        if(strcmp(msg,"exit") ==0){  
            printf("byebye\n");  
            close(sockfd);  
            exit(1);  
        }  
    }/*while*/  
    return 0;  
}