tty tester

artest.c

/**
 * $ gcc artest.c -o artest
 * $ ./artest /dev/ttyUSB0
 */

#include <assert.h>
#include <stdint.h>
#include <stdio.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <poll.h>

int main(int argc, char **argv)
{
	uint8_t buf;
	struct pollfd pfd;
	int fd;

	assert(argc > 1);
	assert((fd = open(argv[1], O_RDONLY | O_NONBLOCK)) > 0);

	pfd.fd = fd;
	pfd.events = POLLIN;

	do {
		assert(poll(&pfd, 1, -1) > 0);

		while (read(fd, &buf, 1) > 0)
			printf("%02X ", buf);
		printf("\n");
	} while (1);

	close(fd);
	return 0;
}