stupid c++ (almost c) program to write data to serial port. Input string is hex. serialecho /dev/ttyUSB0 9600 "63 69 61 6f"

serialecho.cpp

/*
 * main.cpp
 *
 *  Created on: Jun 10, 2013
 *      Author: pez
 */

#include <termios.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <cstdlib>
#include <stdio.h>

void parseData(const char* dataStr, unsigned char* data, int* length) {
	::memset(data, 0, sizeof(data));
	const char* ds = dataStr;
	unsigned char* d = data;
	char byteStr[3] = { 0 };
	while (true) {
		if (ds[0] == ' ') {
			++ds;
		}
		if (ds[0] == 0 || ds[1] == 0) {
			break;
		}
		byteStr[0] = ds[0];
		byteStr[1] = ds[1];
		char* endPtr = 0;
		int num = strtoul(byteStr, &endPtr, 16);
		printf("%c %c => %i\n", ds[0], ds[1], num);
		*d = num;
		++(*length);
		ds += 2;
		++d;
	}
}

#define CASE_SPEED(speed) case speed: return B ## speed;

int to_speed_t(int speedInt) {
	switch (speedInt) {
	CASE_SPEED(0);
	CASE_SPEED(50);
	CASE_SPEED(75);
	CASE_SPEED(150);
	CASE_SPEED(200);
	CASE_SPEED(300);
	CASE_SPEED(600);
	CASE_SPEED(1200);
	CASE_SPEED(1800);
	CASE_SPEED(2400);
	CASE_SPEED(4800);
	CASE_SPEED(9600);
	CASE_SPEED(19200);
	CASE_SPEED(38400);
	CASE_SPEED(57600);
	CASE_SPEED(115200);
	CASE_SPEED(230400);
	CASE_SPEED(460800);
	CASE_SPEED(500000);
	CASE_SPEED(576000);
	CASE_SPEED(921600);
	CASE_SPEED(1000000);
	CASE_SPEED(1152000);
	CASE_SPEED(1500000);
	CASE_SPEED(2000000);
	CASE_SPEED(2500000);
	CASE_SPEED(3000000);
	CASE_SPEED(3500000);
	CASE_SPEED(4000000);
	default:
		return 0;
	}
}

int main(int argc, char* argv[]) {
	const char* devFilename = argv[1];
	const char* speedStr = argv[2];
	const char* dataStr = argv[3];
	int dev = ::open(devFilename, O_RDWR | O_NONBLOCK);
	::tcflush(dev, TCIOFLUSH);
	termios tio = { 0 };
	::memset(&tio, 0, sizeof(termios));
	::tcgetattr(dev, &tio);
	tio.c_iflag &= ~(ICRNL | IMAXBEL);
	tio.c_iflag |= (BRKINT);
	tio.c_oflag &= ~(OPOST | ONLCR);
	tio.c_cflag &= ~(PARENB | CSTOPB | CSIZE);
	tio.c_cflag |= (CS8 | CLOCAL | CREAD);
	tio.c_lflag &= ~(ICANON | ISIG | ECHO);
	tio.c_lflag |= (IEXTEN | ECHOK | ECHOCTL | ECHOKE);
	tio.c_cc[VTIME] = 0;
	tio.c_cc[VMIN] = 0;
	int speed = to_speed_t(::atoi(speedStr));
	::cfsetispeed(&tio, speed);
	::cfsetospeed(&tio, speed);
	::tcsetattr(dev, TCSANOW, &tio);
	unsigned char data[1024];
	int length = 0;
	parseData(dataStr, data, &length);
	::write(dev, data, length);
	::close(dev);
}