xref: /illumos-gate/usr/src/common/util/strtoull.c (revision 7c478bd9)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 /*	Copyright (c) 1988 AT&T	*/
30 /*	  All Rights Reserved  	*/
31 
32 
33 #pragma weak strtoull = _strtoull
34 
35 #include "synonyms.h"
36 #include <errno.h>
37 #include <ctype.h>
38 #include <limits.h>
39 #include <sys/types.h>
40 #include <stdlib.h>
41 
42 #define	DIGIT(x)	\
43 	(isdigit(x) ? (x) - '0' : islower(x) ? (x) + 10 - 'a' : (x) + 10 - 'A')
44 
45 #define	MBASE	('z' - 'a' + 1 + 10)
46 
47 
48 /*
49  * The following macro is a local version of isalnum() which limits
50  * alphabetic characters to the ranges a-z and A-Z; locale dependent
51  * characters will not return 1. The members of a-z and A-Z are
52  * assumed to be in ascending order and contiguous
53  */
54 #define	lisalnum(x)	\
55 	(isdigit(x) || ((x) >= 'a' && (x) <= 'z') || ((x) >= 'A' && (x) <= 'Z'))
56 
57 u_longlong_t
58 strtoull(const char *str, char **nptr, int base)
59 {
60 	u_longlong_t val;
61 	int c;
62 	int xx;
63 	u_longlong_t	multmax;
64 	u_longlong_t	ullong_max;
65 	int neg = 0;
66 	const char 	**ptr = (const char **)nptr;
67 	const unsigned char	*ustr = (const unsigned char *)str;
68 
69 	if (ptr != (const char **)0)
70 		*ptr = (char *)ustr; /* in case no number is formed */
71 
72 	ullong_max = ULLONG_MAX;   /* from a local version of limits.h */
73 
74 	if (base < 0 || base > MBASE || base == 1) {
75 		errno = EINVAL;
76 		return (0); /* base is invalid -- should be a fatal error */
77 	}
78 	if (!isalnum(c = *ustr)) {
79 		while (isspace(c))
80 			c = *++ustr;
81 		switch (c) {
82 		case '-':
83 			neg++;
84 			/* FALLTHROUGH */
85 		case '+':
86 			c = *++ustr;
87 		}
88 	}
89 	if (base == 0)
90 		if (c != '0')
91 			base = 10;
92 		else if (ustr[1] == 'x' || ustr[1] == 'X')
93 			base = 16;
94 		else
95 			base = 8;
96 	/*
97 	 * for any base > 10, the digits incrementally following
98 	 *	9 are assumed to be "abc...z" or "ABC...Z"
99 	 */
100 	if (!lisalnum(c) || (xx = DIGIT(c)) >= base)
101 		return (0); /* no number formed */
102 	if (base == 16 && c == '0' && (ustr[1] == 'x' || ustr[1] == 'X') &&
103 		isxdigit(ustr[2]))
104 		c = *(ustr += 2); /* skip over leading "0x" or "0X" */
105 
106 	multmax = ullong_max / (u_longlong_t)base;
107 	val = DIGIT(c);
108 	for (c = *++ustr; lisalnum(c) && (xx = DIGIT(c)) < base; ) {
109 		if (val > multmax)
110 			goto overflow;
111 		val *= base;
112 		if (ullong_max - val < xx)
113 			goto overflow;
114 		val += xx;
115 		c = *++ustr;
116 	}
117 	if (ptr != (const char **)0)
118 		*ptr = (char *)ustr;
119 	return (neg ? -val : val);
120 
121 overflow:
122 	for (c = *++ustr; lisalnum(c) && (xx = DIGIT(c)) < base; (c = *++ustr))
123 		;
124 	if (ptr != (const char **)0)
125 		*ptr = (char *)ustr;
126 	errno = ERANGE;
127 	return (ullong_max);
128 }
129