xref: /netbsd-src/lib/libc/stdlib/strtouq.c (revision 2a399c6883d870daece976daec6ffa7bb7f934ce)
1 /*	$NetBSD: strtouq.c,v 1.7 1997/07/13 20:17:04 christos Exp $	*/
2 
3 /*-
4  * Copyright (c) 1992 The Regents of the University of California.
5  * 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. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #include <sys/cdefs.h>
37 #if defined(LIBC_SCCS) && !defined(lint)
38 #if 0
39 static char sccsid[] = "@(#)strtouq.c	5.1 (Berkeley) 6/26/92";
40 #else
41 __RCSID("$NetBSD: strtouq.c,v 1.7 1997/07/13 20:17:04 christos Exp $");
42 #endif
43 #endif /* LIBC_SCCS and not lint */
44 
45 #include "namespace.h"
46 #include <sys/types.h>
47 
48 #include <ctype.h>
49 #include <errno.h>
50 #include <limits.h>
51 #include <stdlib.h>
52 
53 /*
54  * Convert a string to an unsigned quad integer.
55  *
56  * Ignores `locale' stuff.  Assumes that the upper and lower case
57  * alphabets and digits are each contiguous.
58  */
59 u_quad_t
60 _strtouq(nptr, endptr, base)
61 	const char *nptr;
62 	char **endptr;
63 	register int base;
64 {
65 	register const char *s;
66 	register u_quad_t acc, cutoff;
67 	register int c;
68 	register int neg, any, cutlim;
69 
70 	/*
71 	 * See strtoq for comments as to the logic used.
72 	 */
73 	s = nptr;
74 	do {
75 		c = (unsigned char) *s++;
76 	} while (isspace(c));
77 	if (c == '-') {
78 		neg = 1;
79 		c = *s++;
80 	} else {
81 		neg = 0;
82 		if (c == '+')
83 			c = *s++;
84 	}
85 	if ((base == 0 || base == 16) &&
86 	    c == '0' && (*s == 'x' || *s == 'X')) {
87 		c = s[1];
88 		s += 2;
89 		base = 16;
90 	}
91 	if (base == 0)
92 		base = c == '0' ? 8 : 10;
93 
94 	cutoff = UQUAD_MAX / (u_quad_t)base;
95 	cutlim = UQUAD_MAX % (u_quad_t)base;
96 	for (acc = 0, any = 0;; c = (unsigned char) *s++) {
97 		if (isdigit(c))
98 			c -= '0';
99 		else if (isalpha(c))
100 			c -= isupper(c) ? 'A' - 10 : 'a' - 10;
101 		else
102 			break;
103 		if (c >= base)
104 			break;
105 		if (any < 0)
106 			continue;
107 		if (acc > cutoff || (acc == cutoff && c > cutlim)) {
108 			any = -1;
109 			acc = UQUAD_MAX;
110 			errno = ERANGE;
111 		} else {
112 			any = 1;
113 			acc *= (u_quad_t)base;
114 			acc += c;
115 		}
116 	}
117 	if (neg && any > 0)
118 		acc = -acc;
119 	if (endptr != 0)
120 		*endptr = (char *) (any ? s - 1 : nptr);
121 	return (acc);
122 }
123