_strtoul.h revision 1.3 
1/* $NetBSD: _strtoul.h,v 1.3 2012/03/22 15:57:29 christos 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 * Original version ID:
32 * NetBSD: src/lib/libc/locale/_wcstoul.h,v 1.2 2003/08/07 16:43:03 agc Exp
33 */
34
35/*
36 * function template for strtoul, strtoull and strtoumax.
37 *
38 * parameters:
39 *	_FUNCNAME  : function name
40 *      __UINT     : return type
41 *      __UINT_MAX : upper limit of the return type
42 */
43
44__UINT
45_FUNCNAME(const char *nptr, char **endptr, int base)
46{
47	const char *s;
48	__UINT acc, cutoff;
49	unsigned char c;
50	int i, neg, any, cutlim;
51
52	_DIAGASSERT(nptr != NULL);
53	/* endptr may be NULL */
54
55	/* check base value */
56	if (base && (base < 2 || base > 36)) {
57#if !defined(_KERNEL) && !defined(_STANDALONE)
58		errno = EINVAL;
59		return(0);
60#else
61		panic("%s: invalid base %d", __func__, base);
62#endif
63	}
64
65	/*
66	 * Skip white space and pick up leading +/- sign if any.
67	 * If base is 0, allow 0x for hex and 0 for octal, else
68	 * assume decimal; if base is already 16, allow 0x.
69	 */
70	s = nptr;
71	do {
72		c = *s++;
73	} while (isspace(c));
74	if (c == '-') {
75		neg = 1;
76		c = *s++;
77	} else {
78		neg = 0;
79		if (c == '+')
80			c = *s++;
81	}
82	if ((base == 0 || base == 16) &&
83	    c == '0' && (*s == 'x' || *s == 'X')) {
84		c = s[1];
85		s += 2;
86		base = 16;
87	}
88	if (base == 0)
89		base = (c == '0' ? 8 : 10);
90
91	/*
92	 * See strtol for comments as to the logic used.
93	 */
94	cutoff = ((__UINT)__UINT_MAX / (__UINT)base);
95	cutlim = (int)((__UINT)__UINT_MAX % (__UINT)base);
96	for (acc = 0, any = 0;; c = *s++) {
97		if (isdigit(c))
98			i = c - '0';
99		else if (isalpha(c))
100			i = c - (isupper(c) ? 'A' - 10 : 'a' - 10);
101		else
102			break;
103		if (i >= base)
104			break;
105		if (any < 0)
106			continue;
107		if (acc > cutoff || (acc == cutoff && i > cutlim)) {
108			acc = __UINT_MAX;
109#if !defined(_KERNEL) && !defined(_STANDALONE)
110			any = -1;
111			errno = ERANGE;
112#else
113			any = 0;
114			break;
115#endif
116		} else {
117			any = 1;
118			acc *= (__UINT)base;
119			acc += i;
120		}
121	}
122	if (neg && any > 0)
123		acc = -acc;
124	if (endptr != NULL)
125		/* LINTED interface specification */
126		*endptr = __UNCONST(any ? s - 1 : nptr);
127	return(acc);
128}
129