socket服务器编程1：server端将接收到的字符串转换为大写字母并输出

//server.hpp

*/
#ifndef _SOCKET_HPP_
#define _SOCKET_HPP_

#include <sys/socket.h>
#include <sys/types.h>
#include <arpa/inet.h>
#include <string.h>
#include <ctype.h>

#endif

/*===============================================================
*  Copyright(C) 2020 Burgess Fan aLL rights reserved.
*  
*  文件名称：server.cpp
*   创 建 者：Burgess
*   创建日期：2020年05月14日
================================================================
*/

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include "socket.hpp"

#define SERV_PORT 8000
#define SERV_IP "192.168.35.139"

#define handle_err(msg) 
    do{perror(msg);exit(EXIT_FAILURE);}while(0)
#define MAX_SOCK_QUEUE 128
#define BUFSIZE    128

int main()
{   
    int serv_fd,c_fd;
    struct sockaddr_in serv_addr,c_addr;
    socklen_t c_addr_len;
    int n,i;
    char r_buf[BUFSIZE];
    //1.建立套接字socket()
    serv_fd=socket(AF_INET,SOCK_STREAM,0);
    if(serv_fd<0)
    {
        handle_err("socket error");
    }
    serv_addr.sin_family=AF_INET;
    serv_addr.sin_port=htons(SERV_PORT);//host to network long
    serv_addr.sin_addr.s_addr=htons(INADDR_ANY);
    //serv_addr.sin_addr.s_addr=inet_addr(SERV_IP);
    //2.绑定IP端口号bind()
    int ret=bind(serv_fd,(struct sockaddr*)&serv_addr,sizeof(serv_addr));
    if(ret<0)
    {
        handle_err("bind error");
    }
    //3.指定最大同时发起连接数
    int listen_ret=listen(serv_fd,MAX_SOCK_QUEUE);
    if(listen_ret<0)
    {
        handle_err("listen_ret");
    }
    c_addr_len=sizeof(c_addr);
    //4.accept阻塞等待客户端发起连接
    c_fd=accept(serv_fd,(struct sockaddr*)&c_addr,&c_addr_len);
    memset(r_buf,0,sizeof(BUFSIZE));
    //5.read()
    while(1)
    {
        n=read(c_fd,r_buf,sizeof(r_buf));
        //6.小写字母变为大写字母
        for(i=0;i<n;++i)
        {
            r_buf[i]=toupper(r_buf[i]);
        }
    //7.write()
        write(c_fd,r_buf,n);
        printf("%s",r_buf);
    }
    close(serv_fd);
    close(c_fd);
}