多客户端/服务器模型

Linux网络编程：简单的多客户端/服务器模型

服务端

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

#define ERR_EXIT(m) \
        do \
        { \
                perror(m); \
                exit(EXIT_FAILURE); \
        } while(0)
void do_service(int conn)
{
    char recvbuf[1024];
        while(1)
        {
            memset(recvbuf,0,sizeof(recvbuf));
            int ret = read(conn,recvbuf,sizeof(recvbuf));
            if (ret ==0)
            {
                printf("client_close\n");
            }
            fputs(recvbuf,stdout);
            write(conn,recvbuf,ret);
        }
}
int main(void)
{
    int listenfd;
    if ((listenfd = socket(PF_INET,SOCK_STREAM,IPPROTO_TCP)) < 0)
        ERR_EXIT("socket");
    
    struct sockaddr_in servaddr;
    memset(&servaddr,0,sizeof(servaddr));
    servaddr.sin_family = AF_INET;
    servaddr.sin_port = htons(5188);
    servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
    
    int on = 1;
    if (setsockopt(listenfd,SOL_SOCKET,SO_REUSEADDR,&on,sizeof(on))<0)
        ERR_EXIT("setsockopt");
    
    if (bind(listenfd,(struct sockaddr *)&servaddr,sizeof(servaddr))<0)
        ERR_EXIT("bind");
    
    if (listen(listenfd,SOMAXCONN)<0)
        ERR_EXIT("listen");

    struct sockaddr_in peeraddr;
    socklen_t peerlen = sizeof(peeraddr);
    int conn;
    
    pid_t pid;
    while (1)
    {

        if ((conn=accept(listenfd,(struct sockaddr *)&peeraddr,&peerlen))<0)
            ERR_EXIT("accpet");
    
        printf("客户端的ip = %s, port=%d\n",inet_ntoa(peeraddr.sin_addr),ntohs(peeraddr.sin_port));
    
        pid = fork();
        if (pid == -1)
            ERR_EXIT("fork");
        if (pid == 0)
        {
            close(listenfd);
            do_service(conn);
            exit(EXIT_SUCCESS);
        }
        else
            close(conn);
   
    }
    return 0;
    
}

客户端

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

#define ERR_EXIT(m) \
        do \
        { \
                perror(m); \
                exit(EXIT_FAILURE); \
        } while(0)

int main(void)
{
    int sock;
    if ((sock = socket(PF_INET,SOCK_STREAM,IPPROTO_TCP)) < 0)
        ERR_EXIT("socket");
    
    struct sockaddr_in servaddr;
    memset(&servaddr,0,sizeof(servaddr));
    servaddr.sin_family = AF_INET;
    servaddr.sin_port = htons(5188);
    servaddr.sin_addr.s_addr = inet_addr("192.168.16.44");
    

    if (connect(sock,(struct sockaddr *)&servaddr,sizeof(servaddr))<0)
        ERR_EXIT("connect");
    
    char sendbuf[1024] ={0};
    char recvbuf[1024] ={0};

    while(fgets(sendbuf,sizeof(sendbuf),stdin) !=NULL)
    {
        write(sock,sendbuf,strlen(sendbuf));
        read(sock,recvbuf,strlen(recvbuf));
        fputs(recvbuf,stdout);
        memset(sendbuf,0,sizeof(sendbuf));
        memset(sendbuf,0,sizeof(recvbuf));
    }
   
    close(sock);

    return 0;
    
}