linux串口接收和发送数据丢失

#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>
#include <termios.h>

int main() {
    int fd;
    struct termios options;

    // 打开串口设备
    fd = open("/dev/ttyS0", O_RDWR | O_NOCTTY | O_NDELAY);
    if (fd == -1) {
        perror("open_port: Unable to open /dev/ttyS0");
        return -1;
    }

    // 配置串口
    tcgetattr(fd, &options);
    cfsetispeed(&options, B9600);
    cfsetospeed(&options, B9600);
    options.c_cflag |= (CLOCAL | CREAD);
    options.c_cflag &= ~PARENB;
    options.c_cflag &= ~CSTOPB;
    options.c_cflag &= ~CSIZE;
    options.c_cflag |= CS8;
    tcsetattr(fd, TCSANOW, &options);

    // 发送数据
    char *send_data = "Hello, World!";
    write(fd, send_data, strlen(send_data));

    // 接收数据
    char receive_data[256];
    int n = read(fd, receive_data, sizeof(receive_data) - 1);
    if (n > 0) {
        receive_data[n] = '\0';
        printf("Received data: %s\n", receive_data);
    }

    // 关闭串口
    close(fd);

    return 0;
}