用C++写一个串口通信的通用代码

好的，下面是一个使用C语言编写的串口通信的通用代码示例：

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

int set_interface_attribs(int fd, int speed, int parity)
{
    struct termios tty;
    memset(&tty, 0, sizeof tty);
    if (tcgetattr(fd, &tty) != 0) {
        printf("error %d from tcgetattr", errno);
        return -1;
    }

    cfsetospeed(&tty, speed);
    cfsetispeed(&tty, speed);

    tty.c_cflag = (tty.c_cflag & ~CSIZE) | CS8;     // 8-bit chars
    // disable IGNBRK for mismatched speed tests; otherwise receive break
    // as \000 chars
    tty.c_iflag &= ~IGNBRK;         // disable break processing
    tty.c_lflag = 0;                // no signaling chars, no echo,
                                    // no canonical processing
    tty.c_oflag = 0;                // no remapping, no delays
    tty.c_cc[VMIN]  = 0;            // read doesn't block
    tty.c_cc[VTIME] = 5;            // 0.5 seconds read timeout

    tty.c_iflag &= ~(IXON | IXOFF | IXANY); // shut off xon/xoff ctrl

    tty.c_cflag |= (CLOCAL | CREAD);// ignore modem controls,
                                    // enable reading
    tty.c_cflag &= ~(PARENB | PARODD);      // shut off parity
    tty.c_cflag |= parity;
    tty.c_cflag &= ~CSTOPB;
    tty.c_cflag &= ~CRTSCTS;

    if (tcsetattr(fd, TCSANOW, &tty) != 0) {
        printf("error %d from tcsetattr", errno);
        return -1;
    }
    return 0;
}

void set_blocking(int fd, int should_block)
{
    struct termios tty;
    memset(&tty, 0, sizeof tty);
    if (tcgetattr(fd, &tty) != 0) {
        printf("error %d from tggetattr", errno);
        return;
    }

    tty.c_cc[VMIN]  = should_block ? 1 : 0;
    tty.c_cc[VTIME] = 5;            // 0.5 seconds read timeout

    if (tcsetattr(fd, TCSANOW, &tty) != 0) {
        printf("error %d setting term attributes", errno);
    }
}

int main(int argc, char** argv)
{
    if (argc != 2) {
        printf("Usage: serialport /dev/ttyUSB0\n");
        return 1;
    }

    char *portname = argv[1];
    int fd = open(portname, O_RDWR | O_NOCTTY | O_SYNC);
    if (fd < 0) {
        printf("error %d opening %s: %s", errno, portname, strerror(errno));
        return 1;
    }

    set_interface_attribs(fd, B9600, 0);  // set speed to 9600 bps, 8n1 (no parity)
    set_blocking(fd, 0);                // set no blocking

    char buf[256];
    int n;

    while (1) {
        memset(buf, 0, sizeof buf);
        n = read(fd, buf, sizeof buf