xref: /openbsd-src/lib/libc/stdlib/strtoull.c (revision 33b4f39fbeffad07bc3206f173cff9f3c9901cd1)
1 /*-
2  * Copyright (c) 1992 The Regents of the University of California.
3  * 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. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #if defined(LIBC_SCCS) && !defined(lint)
31 static const char rcsid[] = "$OpenBSD: strtoull.c,v 1.2 2003/06/02 20:18:38 millert Exp $";
32 #endif /* LIBC_SCCS and not lint */
33 
34 #include <sys/types.h>
35 
36 #include <ctype.h>
37 #include <errno.h>
38 #include <limits.h>
39 #include <stdlib.h>
40 
41 /*
42  * Convert a string to an unsigned long long.
43  *
44  * Ignores `locale' stuff.  Assumes that the upper and lower case
45  * alphabets and digits are each contiguous.
46  */
47 unsigned long long
48 strtoull(nptr, endptr, base)
49 	const char *nptr;
50 	char **endptr;
51 	int base;
52 {
53 	const char *s;
54 	unsigned long long acc, cutoff;
55 	int c;
56 	int neg, any, cutlim;
57 
58 	/*
59 	 * See strtoq for comments as to the logic used.
60 	 */
61 	s = nptr;
62 	do {
63 		c = (unsigned char) *s++;
64 	} while (isspace(c));
65 	if (c == '-') {
66 		neg = 1;
67 		c = *s++;
68 	} else {
69 		neg = 0;
70 		if (c == '+')
71 			c = *s++;
72 	}
73 	if ((base == 0 || base == 16) &&
74 	    c == '0' && (*s == 'x' || *s == 'X')) {
75 		c = s[1];
76 		s += 2;
77 		base = 16;
78 	}
79 	if (base == 0)
80 		base = c == '0' ? 8 : 10;
81 
82 	cutoff = ULLONG_MAX / (unsigned long long)base;
83 	cutlim = ULLONG_MAX % (unsigned long long)base;
84 	for (acc = 0, any = 0;; c = (unsigned char) *s++) {
85 		if (isdigit(c))
86 			c -= '0';
87 		else if (isalpha(c))
88 			c -= isupper(c) ? 'A' - 10 : 'a' - 10;
89 		else
90 			break;
91 		if (c >= base)
92 			break;
93 		if (any < 0)
94 			continue;
95 		if (acc > cutoff || (acc == cutoff && c > cutlim)) {
96 			any = -1;
97 			acc = ULLONG_MAX;
98 			errno = ERANGE;
99 		} else {
100 			any = 1;
101 			acc *= (unsigned long long)base;
102 			acc += c;
103 		}
104 	}
105 	if (neg && any > 0)
106 		acc = -acc;
107 	if (endptr != 0)
108 		*endptr = (char *) (any ? s - 1 : nptr);
109 	return (acc);
110 }
111 
112 #ifdef __weak_alias
113 __weak_alias(strtouq, strtoull);
114 #else
115 u_quad_t
116 strtouq(nptr, endptr, base)
117 	const char *nptr;
118 	char **endptr;
119 	int base;
120 {
121 
122 	return ((u_quad_t)strtoull(nptr, endptr, base);
123 }
124 #endif
125