[网络协议]TCP服务端和客户端实例代码

1、TCP服务器

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<unistd.h>
#include<arpa/inet.h>
#include<sys/socket.h>

void error_handling(char * message)
{
fputs(message, stderr);
fputc(’\n’, stderr);
exit(1);
}

int main(int argc, char*argv[])
{
int serv_sock;
int clnt_sock;
struct sockaddr_in serv_addr;
struct sockaddr_in clnt_addr;
socklen_t clnt_addr_size;
char message[] = “hello world”;

if(argc != 2)
{
    printf("usage:%s <port>\n", argv[0]);
    exit(1);
}
//创建socket
serv_sock = socket(PF_INET, SOCK_STREAM,0);
if(serv_sock == -1)
{
    error_handling("socket() error\n");
}

memset(&serv_addr, 0, sizeof(serv_addr));
serv_addr.sin_family = AF_INET;
serv_addr.sin_addr.s_addr = htonl(INADDR_ANY);
serv_addr.sin_port = htons(atoi(argv[1]));

//绑定地址和端口号
if(bind(serv_sock, (struct sockaddr*)&serv_addr, sizeof(serv_addr)) == -1)
{
    error_handling("bind() error\n");
}
//将创建得socket激活设置为监听状态
if(listen(serv_sock, 5) == -1)
{
    error_handling("listen() error\n");
}

clnt_addr_size = sizeof(clnt_addr);
//接受客户端socket的连接
clnt_sock = accept(serv_sock, (struct sockaddr*)&clnt_addr, &clnt_addr_size);
if(clnt_sock == -1)
{
    error_handling("accept() error\n");
}
//向客户端发送数据
write(clnt_sock, message, sizeof(message));
close(clnt_sock);
close(serv_sock);
return 0;    

}

2、TCP客户端

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<unistd.h>
#include<arpa/inet.h>
#include<sys/socket.h>

void error_handling(char * message)
{
    fputs(message, stderr);
    fputc('\n', stderr);
    exit(1);
}


int main(int argc, char*argv[])
{
    int sock;    
    struct sockaddr_in serv_addr;
    char message[30];
    int str_len;

    if(argc != 3)
    {
        printf("usage:%s <port>\n", argv[0]);
        exit(1);
    }
    //创建socket
   sock = socket(PF_INET, SOCK_STREAM,0);
    if(sock == -1)
    {
        error_handling("socket() error\n");
    }

    memset(&serv_addr, 0, sizeof(serv_addr));
    serv_addr.sin_family = AF_INET;
    serv_addr.sin_addr.s_addr = inet_addr(argv[1]);
    serv_addr.sin_port = htons(atoi(argv[2]));

    //绑定地址和端口号
    if(connect(sock, (struct sockaddr*)&serv_addr, sizeof(serv_addr)) == -1)
    {
        error_handling("connect() error\n");
    }
    str_len = read(sock, message, sizeof(message)- 1);
    if(str_len == -1)
    {
        error_handling("read() error! \n");
    }
    printf("message from server :%s\n", message);
    close(sock);
    return 0;    
}

参考：《TCP/IP网络编程》尹圣雨著 金国哲译