teensy-cores/teensy3/nonstd.c

/* Teensyduino Core Library
 * http://www.pjrc.com/teensy/
 * Copyright (c) 2013 PJRC.COM, LLC.
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * 1. The above copyright notice and this permission notice shall be 
 * included in all copies or substantial portions of the Software.
 *
 * 2. If the Software is incorporated into a build system that allows 
 * selection among a list of target devices, then similar target
 * devices manufactured by PJRC.COM must be included in the list of
 * target devices and selectable in the same manner.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include "avr_functions.h"
#include <string.h>
#include <stdio.h>

size_t strlen(const char *s)
{
	size_t n=0;

	while (*s++) n++;
	return n;
}


char * ultoa(unsigned long val, char *buf, int radix) 	
{
	unsigned digit;
	int i=0, j;
	char t;

	while (1) {
		digit = val % radix;
		buf[i] = ((digit < 10) ? '0' + digit : 'A' + digit - 10);
		val /= radix;
		if (val == 0) break;
		i++;
	}
	buf[i + 1] = 0;
	for (j=0; j < i; j++, i--) {
		t = buf[j];
		buf[j] = buf[i];
		buf[i] = t;
	}
	return buf;
}

char * ltoa(long val, char *buf, int radix)
{
	if (val >= 0) {
		return ultoa(val, buf, radix);
	} else {
		buf[0] = '-';
		ultoa(-val, buf + 1, radix);
		return buf;
	}
}

// TODO: actually write an efficient dtostrf()....
char * dtostrf(float val, int width, unsigned int precision, char *buf)
{
	char format[20];
	sprintf(format, "%%%d.%df", width, precision);
	sprintf(buf, format, val);
	return buf;
}