xref: /haiku/src/system/libroot/posix/stdlib/strtoul.c (revision e81a954787e50e56a7f06f72705b7859b6ab06d1)
1 /*
2  * Copyright (c) 1990, 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 
34 
35 #include <limits.h>
36 #include <ctype.h>
37 #include <errno.h>
38 #include <stdlib.h>
39 
40 #include <errno_private.h>
41 
42 
43 /*
44  * Convert a string to an unsigned long integer.
45  *
46  * Assumes that the upper and lower case
47  * alphabets and digits are each contiguous.
48  */
49 
50 unsigned long
51 strtoul(const char * __restrict nptr, char ** __restrict endptr, int base)
52 {
53 	const char *s;
54 	unsigned long acc;
55 	char c;
56 	unsigned long cutoff;
57 	int neg, any, cutlim;
58 
59 	/*
60 	 * See strtol for comments as to the logic used.
61 	 */
62 	s = nptr;
63 	do {
64 		c = *s++;
65 	} while (isspace((unsigned char)c));
66 	if (c == '-') {
67 		neg = 1;
68 		c = *s++;
69 	} else {
70 		neg = 0;
71 		if (c == '+')
72 			c = *s++;
73 	}
74 	if ((base == 0 || base == 16) &&
75 	    c == '0' && (*s == 'x' || *s == 'X')) {
76 		c = s[1];
77 		s += 2;
78 		base = 16;
79 	}
80 	if (base == 0)
81 		base = c == '0' ? 8 : 10;
82 	acc = any = 0;
83 	if (base < 2 || base > 36)
84 		goto noconv;
85 
86 	cutoff = ULONG_MAX / base;
87 	cutlim = ULONG_MAX % base;
88 	for ( ; ; c = *s++) {
89 		if (c >= '0' && c <= '9')
90 			c -= '0';
91 		else if (c >= 'A' && c <= 'Z')
92 			c -= 'A' - 10;
93 		else if (c >= 'a' && c <= 'z')
94 			c -= 'a' - 10;
95 		else
96 			break;
97 		if (c >= base)
98 			break;
99 		if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim))
100 			any = -1;
101 		else {
102 			any = 1;
103 			acc *= base;
104 			acc += c;
105 		}
106 	}
107 	if (any < 0) {
108 		acc = ULONG_MAX;
109 		__set_errno(ERANGE);
110 	} else if (!any) {
111 noconv:
112 		__set_errno(EINVAL);
113 	} else if (neg)
114 		acc = -acc;
115 	if (endptr != NULL)
116 		*endptr = (char *)(any ? s - 1 : nptr);
117 	return (acc);
118 }
119 
120 
121 unsigned long __strtoul_internal(const char *number, char **_end, int base, int group);
122 
123 unsigned long
124 __strtoul_internal(const char *number, char **_end, int base, int group)
125 {
126 	// ToDo: group is currently not supported!
127 	(void)group;
128 
129 	return strtoul(number, _end, base);
130 }
131 
132