C++实现简单的TCP服务器和TCP客户端_day87

简单的TCP服务器实现

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

#define SERVER_PORT 7000
void sys_err(const char *str)
{
  perror(str);
  exit(1);
}
int main(int agrc, char *argv[]){
  int ret;
  char buf[BUFSIZ];
  // 创建文件描述符
  int lfd = 0, cfd=0;
  // 创建addr地址的结构体
  struct sockaddr_in server_addr, client_addr;
  socklen_t client_addr_len;
  
  server_addr.sin_family = AF_INET;
  server_addr.sin_port = htons(SERVER_PORT);
  server_addr.sin_addr.s_addr = htonl(INADDR_ANY);
  
  // 创建socket
  lfd = socket(AF_INET, SOCK_STREAM, 0);
  if(lfd == -1){
    sys_err("socket error");
  }
  // 绑定端口
  bind(lfd, (struct sockaddr *)&server_addr, sizeof(server_addr));
  // 设置监听
  listen(lfd, 128);
  
  // 堵塞等待
  client_addr_len = sizeof(client_addr);
  cfd = accept(lfd, (struct sockaddr *)&client_addr, &client_addr_len);
  if (cfd == -1){
    sys_err("accept error");
  }
  
  while(1){
      // 读取内容
      ret = read(cfd, buf, sizeof(buf));
      write(STDOUT_FILENO, buf, ret);
      for (int i=0; i<ret; i++){
        buf[i] = toupper(buf[i]);
      }

      write(cfd, buf, ret);
  }
  
  close(lfd);
  close(cfd);
  
  return 0;
}