基于socket的服务器与客户端程序

服务器端程序，可服务多个客户

#include <sys/types.h>
#include <sys/socket.h>
#include <stdio.h>
#include <netinet/in.h>
#include <signal.h>
#include <unistd.h>
#include <stdlib.h>

int main()
{
    int server_sockfd, client_sockfd;
    int server_len, clinet_len;
    struct sockaddr_in server_address;
    struct sockaddr_in client_address;

    server_sockfd = socket(AF_INET, SOCK_STREAM, 0);

    server_address.sin_family = AF_INET;
    server_address.sin_addr.s_addr = htonl(INADDR_ANY);
    server_address.sin_port = htons(9734);
    server_len = sizeof(server_address);

    bind(server_sockfd, (struct sockaddr *)&server_address, server_len);

    //创建一个连接队列，忽略子进程的退出细节，等待客户的到来
    listen(server_sockfd, 5);

    signal(SIGCHLD, SIG_IGN);

    while(1)
    {
        char ch;
        printf("server waiting\n");

        //接受连接
        client_len = sizeof(client_address);
        client_sockfd = accept(server_sockfd, (struct sockaddr*)&client_address, &client_len);

        //通过fork调用为这个客户创建一个子进程，然后测试你是在父进程中还是子进程中
        if(fork()==0)    //如果在子进程中，就可以对client_sockfd的客户进程读写操作
        {
            read(client_sockfd, &ch, 1);
            sleep(5);    //仅为了演示
            ch++;
            write(client_sockfd, &ch, 1);
            close(client_sockfd);
            exit(0);
        }
        else            //在父进程中，需要关闭这个客户
            close(client_sockfd);
    }
}

 

客户端程序

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

int main()
{
    int sockfd;
    int len;
    struct sockaddr_in address;
    int result;
    char ch = 'A';

    //创建套接字
    sockfd = socket(AF_INET, SOCK_STREAM, 0);

    address.sin_family = AF_INET;
    address.sin_addr.s_addr = inet_addr("219.223.242.244");
    address.sin_port = htons(9734);
    len = sizeof(address);

    //将创建的套接字连接到服务器套接字
    result = connect(sockfd, (struct sockaddr *)&addresss, len);
    if(result==-1)
    {
        perror("oops: client1");
        exit(1);
    }

    write(sockfd, &ch, 1);
    read(sockfd, &ch, 1);
    printf("char from server = c%\n",ch);
    close(sockfd);
    exit(0);
}

注：以上程序均摘自《Linux程序设计》