/*
 * Copyright (C) 2009, 2010 Nick Johnson <nickbjohnson4224 at gmail.com>
 * 
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <stdint.h>
#include <stdlib.h>
#include <ctype.h>

/****************************************************************************
 * atoi
 *
 * Convert the contents of a string containing a decimal number to a signed
 * integer.
 */

int atoi(const char *nptr) {
	int i, sum;

	if (nptr[0] == '-') {
		return -atoi(&nptr[1]);
	}

	for (sum = 0, i = 0; isdigit(nptr[i]); i++) {
		sum *= 10;
		sum += nptr[i] - '0';
	}

	return sum;
}
