strtoumax.c revision 87027 
1/*-
2 * Copyright (c) 1992, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *	This product includes software developed by the University of
16 *	California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 * $FreeBSD: head/lib/libc/stdlib/strtoumax.c 87027 2001-11-28 03:37:06Z fenner $
34 */
35
36#if defined(LIBC_SCCS) && !defined(lint)
37static char sccsid[] = "from @(#)strtoul.c	8.1 (Berkeley) 6/4/93";
38#endif /* LIBC_SCCS and not lint */
39
40#include <ctype.h>
41#include <errno.h>
42#include <stdlib.h>
43#include <inttypes.h>
44
45/*
46 * Convert a string to a uintmax_t integer.
47 *
48 * Assumes that the upper and lower case
49 * alphabets and digits are each contiguous.
50 */
51uintmax_t
52strtoumax(nptr, endptr, base)
53	const char *nptr;
54	char **endptr;
55	int base;
56{
57	const char *s;
58	uintmax_t acc;
59	unsigned char c;
60	uintmax_t cutoff;
61	int neg, any, cutlim;
62
63	/*
64	 * See strtoimax for comments as to the logic used.
65	 */
66	s = nptr;
67	do {
68		c = *s++;
69	} while (isspace(c));
70	if (c == '-') {
71		neg = 1;
72		c = *s++;
73	} else {
74		neg = 0;
75		if (c == '+')
76			c = *s++;
77	}
78	if ((base == 0 || base == 16) &&
79	    c == '0' && (*s == 'x' || *s == 'X')) {
80		c = s[1];
81		s += 2;
82		base = 16;
83	}
84	if (base == 0)
85		base = c == '0' ? 8 : 10;
86	acc = any = 0;
87	if (base < 2 || base > 36)
88		goto noconv;
89
90	cutoff = UINTMAX_MAX / base;
91	cutlim = UINTMAX_MAX % base;
92	for ( ; ; c = *s++) {
93		if (isxdigit(c))
94			c = digittoint(c);
95		else if (isascii(c) && isalpha(c))
96			c -= isupper(c) ? 'A' - 10 : 'a' - 10;
97		else
98			break;
99		if (c >= base)
100			break;
101		if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim))
102			any = -1;
103		else {
104			any = 1;
105			acc *= base;
106			acc += c;
107		}
108	}
109	if (any < 0) {
110		acc = UINTMAX_MAX;
111		errno = ERANGE;
112	} else if (!any) {
113noconv:
114		errno = EINVAL;
115	} else if (neg)
116		acc = -acc;
117	if (endptr != NULL)
118		*endptr = (char *)(any ? s - 1 : nptr);
119	return (acc);
120}
121