strtoumax.c revision 1.1 
1/*	$NetBSD: strtoumax.c,v 1.1 2006/04/22 15:33:33 thorpej Exp $	*/
2
3/*
4 * Copyright (c) 1990, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32#if !defined(_KERNEL) && !defined(_STANDALONE)
33#include <sys/cdefs.h>
34#if defined(LIBC_SCCS) && !defined(lint)
35#if 0
36static char sccsid[] = "from: @(#)strtoul.c	8.1 (Berkeley) 6/4/93";
37#else
38__RCSID("$NetBSD: strtoumax.c,v 1.1 2006/04/22 15:33:33 thorpej Exp $");
39#endif
40#endif /* LIBC_SCCS and not lint */
41
42#include "namespace.h"
43
44#include <assert.h>
45#include <ctype.h>
46#include <errno.h>
47#include <inttypes.h>
48#include <stddef.h>
49
50#ifdef __weak_alias
51__weak_alias(strtoumax, _strtoumax)
52#endif
53
54#else /* !_KERNEL && !_STANDALONE */
55#include <sys/param.h>
56#include <lib/libkern/libkern.h>
57#endif /* !_KERNEL && !_STANDALONE */
58
59/*
60 * Convert a string to an uintmax_t.
61 *
62 * Ignores `locale' stuff.  Assumes that the upper and lower case
63 * alphabets and digits are each contiguous.
64 */
65uintmax_t
66strtoumax(nptr, endptr, base)
67	const char *nptr;
68	char **endptr;
69	int base;
70{
71	const char *s;
72	uintmax_t acc, cutoff;
73	int c;
74	int neg, any, cutlim;
75
76	_DIAGASSERT(nptr != NULL);
77	/* endptr may be NULL */
78
79	/*
80	 * See strtol for comments as to the logic used.
81	 */
82	s = nptr;
83	do {
84		c = (unsigned char) *s++;
85	} while (isspace(c));
86	if (c == '-') {
87		neg = 1;
88		c = *s++;
89	} else {
90		neg = 0;
91		if (c == '+')
92			c = *s++;
93	}
94	if ((base == 0 || base == 16) &&
95	    c == '0' && (*s == 'x' || *s == 'X')) {
96		c = s[1];
97		s += 2;
98		base = 16;
99	}
100	if (base == 0)
101		base = c == '0' ? 8 : 10;
102
103	cutoff = UINTMAX_MAX / (uintmax_t)base;
104	cutlim = (int)(UINTMAX_MAX % (uintmax_t)base);
105	for (acc = 0, any = 0;; c = (unsigned char) *s++) {
106		if (isdigit(c))
107			c -= '0';
108		else if (isalpha(c)) {
109#if defined(_KERNEL) || defined(_STANDALONE)
110			c = toupper(c) - 'A' + 10;
111#else
112			c -= isupper(c) ? 'A' - 10 : 'a' - 10;
113#endif
114		} else
115			break;
116		if (c >= base)
117			break;
118		if (any < 0)
119			continue;
120		if (acc > cutoff || (acc == cutoff && c > cutlim)) {
121#if defined(_KERNEL) || defined(_STANDALONE)
122			if (endptr)
123				*endptr = __UNCONST(nptr);
124			return UINTMAX_MAX;
125#else
126			any = -1;
127			acc = UINTMAX_MAX;
128			errno = ERANGE;
129#endif
130		} else {
131			any = 1;
132			acc *= (uintmax_t)base;
133			acc += c;
134		}
135	}
136	if (neg && any > 0)
137		acc = -acc;
138	if (endptr != 0)
139		*endptr = __UNCONST(any ? s - 1 : nptr);
140	return (acc);
141}
142