#include "pthread.h"
#include <sys/msg.h>

#include <sys/types.h>

#include <stdio.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
#include <stddef.h>
#include <fcntl.h>
#include <netinet/in.h>
#include <sys/shm.h>
#include <sys/socket.h>

#include <sys/ipc.h>

/*信号相关*/
#include<sys/signal.h>

/*信号量相关*/
#include <semaphore.h>

/*串口相关*/
#include <sys/stat.h>
#include <unistd.h>
#include <termios.h>

int wait_flag =1;
int stop = 1;
unsigned char buf[255] = {0};
int serial_fd;
/******************************************
 信号处理函数，设备wait_flag=FASLE
 ******************************************************/
void signal_handler_IO(int status)
{
   printf("received SIGIO signale.\n");
   wait_flag = 0;
}
void ReceiveTaskHandler(void *argv)
{

    int res;
    while(1)
     {
       usleep(100);
       /* after receving SIGIO ,wait_flag = FALSE,input is availabe and can be read*/
       if(wait_flag == 0)
       {
         memset(buf,0,255);
         res = read(serial_fd,buf,255);
         printf("nread=%d\n",res);
         for(int i=0 ;i <res; i++)
         {
        	 printf("%02x",buf[i]);
         }
          wait_flag = 1; /*wait for new input*/
       }
     }
}
int main()
{
    struct sigaction saio;

    struct termios old_cfg;
    struct termios new_cfg;

    //1.打开串口设备文件
    serial_fd = open("/dev/ttyS0", O_RDWR | O_NOCTTY | O_NDELAY);
    if (serial_fd == -1)
    {
        perror("open");
        exit(-1);
    }

    //2.备份现有的串口配置
    if (-1 == tcgetattr(serial_fd, &old_cfg))
    {
        perror("tcgetattr");
        exit(-1);
    }

    //3.原始模式
    new_cfg = old_cfg;
    cfmakeraw(&new_cfg);

    //4.配置波特率
    cfsetispeed(&new_cfg, B115200);
    cfsetospeed(&new_cfg, B115200);

    //5.设置控制标志
    new_cfg.c_cflag |= CREAD | CLOCAL;                                          //使能数据接收和本地模式

    //6.设置帧结构
    new_cfg.c_cflag &= ~CSTOPB;                                                 //1位停止位
    new_cfg.c_cflag &= ~CSIZE;                                                  //去掉数据位屏蔽
    new_cfg.c_cflag |= CS8;                                                     //8位数据位
    new_cfg.c_cflag &= ~PARENB;                                                 //无校验

    //7.设置阻塞模式
    tcflush(serial_fd, TCIOFLUSH);

    //无阻塞
    new_cfg.c_cc[VTIME] = 0;
    new_cfg.c_cc[VMIN] = 0;
    tcflush(serial_fd, TCIOFLUSH);

    /*注册信号*/
    saio.sa_handler = signal_handler_IO;
    sigemptyset(&saio.sa_mask);
    saio.sa_flags = 0;
    saio.sa_restorer = NULL;
    sigaction(SIGIO, &saio, NULL);

    //allow the process to receive SIGIO
    fcntl(serial_fd, F_SETOWN, getpid());
    //make the file descriptor asynchronous
    fcntl(serial_fd, F_SETFL, FASYNC);

    //8.使能配置生效
    if (-1 == tcsetattr(serial_fd, TCSANOW, &new_cfg))
    {
        perror("tcgetattr");
        exit(-1);
    }
    pthread_t id;
    pthread_create(&id, NULL, (void *)ReceiveTaskHandler, NULL);
    pthread_join(id,NULL);
    close(serial_fd);
	return 0;
}

1.windows端使用虚拟串口，通过串口工具发送消息

2.linux端，使用此代码读取

工具：vspd ，eclipse，串口调试助手

 window端