FTDI Friend経由でArduinoがシリアルポートに書いた出力を読んで時刻とともに表示する

serial-read.c

/* http://www.cmrr.umn.edu/~strupp/serial.html */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <termios.h>
#include <signal.h>
#include <time.h>

#define BUFFER_SIZE 256
#define SERIAL_PORT "/dev/ttyUSB0"

int continuing;
void terminate(int signum);

void
terminate(int signum)
{
	continuing = 0;
}

int
main(void)
{
	int fd;
	struct termios options, orig_options;
	char buffer[BUFFER_SIZE], timestr[BUFFER_SIZE];
	ssize_t n;
	struct tm tm;
	time_t t;

	fd = open(SERIAL_PORT, O_RDONLY | O_NOCTTY);
	if (fd == -1)
		{
			perror("open");
			return EXIT_FAILURE;
		}

	tcgetattr(fd, &options);
	memcpy(&orig_options, &options, sizeof(options));
	options.c_cflag |= (CLOCAL | CREAD);

	/* https://learn.adafruit.com/ftdi-friend/com-slash-serial-port-name */
	/* 9600 baud, 8 bit, no parity, 1 stop bit, no flow control */
	cfsetispeed(&options, B9600);
	options.c_cflag &= ~CSIZE;
	options.c_cflag &= ~PARENB;
	options.c_cflag &= ~CSTOPB;
	options.c_cflag &= ~CSIZE;
	options.c_cflag |= CS8;
	options.c_cflag &= ~CRTSCTS;
	options.c_iflag |= (INPCK | ISTRIP);
	options.c_iflag &= ~(IXON | IXOFF | IXANY);

	/* canonical input, no echo, enable interruptions */
	options.c_lflag |= ICANON;
	options.c_lflag &= ~(ECHO | ECHOE);

	tcsetattr(fd, TCSANOW, &options);

	signal(SIGINT, terminate);
	signal(SIGTERM, terminate);

	continuing = 1;
	while(continuing)
		{
			n = read(fd, buffer, sizeof(buffer));
			if (n < 1)
				{
					if (n == -1) perror("read");
					break;
				}
			time(&t);
			localtime_r(&t, &tm);
			strftime(timestr, sizeof(timestr), "%Y-%m-%d %H:%M:%S ", &tm);
			fputs(timestr, stdout);
			fwrite(buffer, n, 1, stdout);
			fflush(stdout);
		}
	
	fputs("Stopping\n", stdout);
	tcsetattr(fd, TCSANOW, &orig_options);
	return EXIT_SUCCESS;
}

Ctrl-Cを押しても入力が来るまで終われない問題がある。