11573Srgrimes/*	$OpenBSD: strtoul.c,v 1.7 2005/08/08 08:05:37 espie Exp $ */
21573Srgrimes/*
31573Srgrimes * Copyright (c) 1990 Regents of the University of California.
41573Srgrimes * All rights reserved.
51573Srgrimes *
61573Srgrimes * Redistribution and use in source and binary forms, with or without
71573Srgrimes * modification, are permitted provided that the following conditions
81573Srgrimes * are met:
91573Srgrimes * 1. Redistributions of source code must retain the above copyright
101573Srgrimes *    notice, this list of conditions and the following disclaimer.
111573Srgrimes * 2. Redistributions in binary form must reproduce the above copyright
121573Srgrimes *    notice, this list of conditions and the following disclaimer in the
131573Srgrimes *    documentation and/or other materials provided with the distribution.
141573Srgrimes * 3. Neither the name of the University nor the names of its contributors
151573Srgrimes *    may be used to endorse or promote products derived from this software
161573Srgrimes *    without specific prior written permission.
171573Srgrimes *
181573Srgrimes * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
191573Srgrimes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
201573Srgrimes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
211573Srgrimes * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
221573Srgrimes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
231573Srgrimes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
241573Srgrimes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
251573Srgrimes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
261573Srgrimes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
271573Srgrimes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
281573Srgrimes * SUCH DAMAGE.
291573Srgrimes */
301573Srgrimes
311573Srgrimes/* OPENBSD ORIGINAL: lib/libc/stdlib/strtoul.c */
321573Srgrimes
3392986Sobrien#include "includes.h"
3492986Sobrien#ifndef HAVE_STRTOUL
351573Srgrimes
361573Srgrimes#include <ctype.h>
371573Srgrimes#include <errno.h>
381573Srgrimes#include <limits.h>
391573Srgrimes#include <stdlib.h>
401573Srgrimes
411573Srgrimes/*
421573Srgrimes * Convert a string to an unsigned long integer.
431573Srgrimes *
441573Srgrimes * Ignores `locale' stuff.  Assumes that the upper and lower case
451573Srgrimes * alphabets and digits are each contiguous.
461573Srgrimes */
47251575Sjillesunsigned long
48251575Sjillesstrtoul(const char *nptr, char **endptr, int base)
49251575Sjilles{
50251575Sjilles	const char *s;
51251575Sjilles	unsigned long acc, cutoff;
521573Srgrimes	int c;
53	int neg, any, cutlim;
54
55	/*
56	 * See strtol for comments as to the logic used.
57	 */
58	s = nptr;
59	do {
60		c = (unsigned char) *s++;
61	} while (isspace(c));
62	if (c == '-') {
63		neg = 1;
64		c = *s++;
65	} else {
66		neg = 0;
67		if (c == '+')
68			c = *s++;
69	}
70	if ((base == 0 || base == 16) &&
71	    c == '0' && (*s == 'x' || *s == 'X')) {
72		c = s[1];
73		s += 2;
74		base = 16;
75	}
76	if (base == 0)
77		base = c == '0' ? 8 : 10;
78
79	cutoff = ULONG_MAX / (unsigned long)base;
80	cutlim = ULONG_MAX % (unsigned long)base;
81	for (acc = 0, any = 0;; c = (unsigned char) *s++) {
82		if (isdigit(c))
83			c -= '0';
84		else if (isalpha(c))
85			c -= isupper(c) ? 'A' - 10 : 'a' - 10;
86		else
87			break;
88		if (c >= base)
89			break;
90		if (any < 0)
91			continue;
92		if (acc > cutoff || acc == cutoff && c > cutlim) {
93			any = -1;
94			acc = ULONG_MAX;
95			errno = ERANGE;
96		} else {
97			any = 1;
98			acc *= (unsigned long)base;
99			acc += c;
100		}
101	}
102	if (neg && any > 0)
103		acc = -acc;
104	if (endptr != 0)
105		*endptr = (char *) (any ? s - 1 : nptr);
106	return (acc);
107}
108#endif /* !HAVE_STRTOUL */
109