xref: /freebsd/lib/libc/stdlib/strtoul.c (revision 6ae1554a5d9b318f8ad53ccc39fa5a961403da73)
1 /*
2  * Copyright (c) 1990, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Copyright (c) 2011 The FreeBSD Foundation
6  * All rights reserved.
7  * Portions of this software were developed by David Chisnall
8  * under sponsorship from the FreeBSD Foundation.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 #if defined(LIBC_SCCS) && !defined(lint)
36 static char sccsid[] = "@(#)strtoul.c	8.1 (Berkeley) 6/4/93";
37 #endif /* LIBC_SCCS and not lint */
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
40 
41 #include <limits.h>
42 #include <ctype.h>
43 #include <errno.h>
44 #include <stdlib.h>
45 #include "xlocale_private.h"
46 
47 /*
48  * Convert a string to an unsigned long integer.
49  *
50  * Assumes that the upper and lower case
51  * alphabets and digits are each contiguous.
52  */
53 unsigned long
54 strtoul_l(const char * __restrict nptr, char ** __restrict endptr, int base, locale_t locale)
55 {
56 	const char *s;
57 	unsigned long acc;
58 	char c;
59 	unsigned long cutoff;
60 	int neg, any, cutlim;
61 	FIX_LOCALE(locale);
62 
63 	/*
64 	 * See strtol for comments as to the logic used.
65 	 */
66 	s = nptr;
67 	do {
68 		c = *s++;
69 	} while (isspace_l((unsigned char)c, locale));
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 	    ((s[1] >= '0' && s[1] <= '9') ||
81 	    (s[1] >= 'A' && s[1] <= 'F') ||
82 	    (s[1] >= 'a' && s[1] <= 'f'))) {
83 		c = s[1];
84 		s += 2;
85 		base = 16;
86 	}
87 	if (base == 0)
88 		base = c == '0' ? 8 : 10;
89 	acc = any = 0;
90 	if (base < 2 || base > 36)
91 		goto noconv;
92 
93 	cutoff = ULONG_MAX / base;
94 	cutlim = ULONG_MAX % base;
95 	for ( ; ; c = *s++) {
96 		if (c >= '0' && c <= '9')
97 			c -= '0';
98 		else if (c >= 'A' && c <= 'Z')
99 			c -= 'A' - 10;
100 		else if (c >= 'a' && c <= 'z')
101 			c -= 'a' - 10;
102 		else
103 			break;
104 		if (c >= base)
105 			break;
106 		if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim))
107 			any = -1;
108 		else {
109 			any = 1;
110 			acc *= base;
111 			acc += c;
112 		}
113 	}
114 	if (any < 0) {
115 		acc = ULONG_MAX;
116 		errno = ERANGE;
117 	} else if (!any) {
118 noconv:
119 		errno = EINVAL;
120 	} else if (neg)
121 		acc = -acc;
122 	if (endptr != NULL)
123 		*endptr = (char *)(any ? s - 1 : nptr);
124 	return (acc);
125 }
126 unsigned long
127 strtoul(const char * __restrict nptr, char ** __restrict endptr, int base)
128 {
129 	return strtoul_l(nptr, endptr, base, __get_locale());
130 }
131