xref: /netbsd/external/bsd/libbind/dist/bsd/strtoul.c (revision b5677b36)
1 /*	$NetBSD: strtoul.c,v 1.1.1.1 2009/04/12 15:33:26 christos Exp $	*/
2 
3 #if defined(LIBC_SCCS) && !defined(lint)
4 static const char sccsid[] = "@(#)strtoul.c	8.1 (Berkeley) 6/4/93";
5 static const char rcsid[] = "Id: strtoul.c,v 1.4 2008/02/18 03:49:08 marka Exp";
6 #endif /* LIBC_SCCS and not lint */
7 
8 /*
9  * Copyright (c) 1990, 1993
10  *    The Regents of the University of California.  All rights reserved.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  * 3. All advertising materials mentioning features or use of this software
21  *    must display the following acknowledgement:
22  * 	This product includes software developed by the University of
23  * 	California, Berkeley and its contributors.
24  * 4. Neither the name of the University nor the names of its contributors
25  *    may be used to endorse or promote products derived from this software
26  *    without specific prior written permission.
27  *
28  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
29  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
30  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
31  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
32  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
33  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
34  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
35  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
36  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
37  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38  * SUCH DAMAGE.
39  */
40 
41 #include "port_before.h"
42 
43 #include <sys/types.h>
44 #include <sys/param.h>
45 
46 #include <ctype.h>
47 #include <errno.h>
48 #include <limits.h>
49 #include <stdlib.h>
50 
51 #include "port_after.h"
52 
53 #ifndef NEED_STRTOUL
54 int __strtoul_unneeded__;
55 #else
56 
57 /*%
58  * Convert a string to an unsigned long integer.
59  *
60  * Ignores `locale' stuff.  Assumes that the upper and lower case
61  * alphabets and digits are each contiguous.
62  */
63 u_long
64 strtoul(const char *nptr, char **endptr, int base) {
65 	const char *s = nptr;
66 	u_long acc, cutoff;
67 	int neg, c, any, cutlim;
68 
69 	neg = 0;
70 
71 	/*
72 	 * See strtol for comments as to the logic used.
73 	 */
74 	do {
75 		c = *(const unsigned char *)s++;
76 	} while (isspace(c));
77 	if (c == '-') {
78 		neg = 1;
79 		c = *s++;
80 	} else if (c == '+')
81 		c = *s++;
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 	cutoff = (u_long)ULONG_MAX / (u_long)base;
91 	cutlim = (u_long)ULONG_MAX % (u_long)base;
92 	for (acc = 0, any = 0;; c = *(const unsigned char*)s++) {
93 		if (isdigit(c))
94 			c -= '0';
95 		else if (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 = ULONG_MAX;
111 		errno = ERANGE;
112 	} else if (neg)
113 		acc = -acc;
114 	if (endptr != 0)
115 		DE_CONST((any ? s - 1 : nptr), *endptr);
116 	return (acc);
117 }
118 
119 #endif /*NEED_STRTOUL*/
120 
121 /*! \file */
122