xref: /illumos-gate/usr/src/common/util/strtoull.c (revision 7257d1b4)
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 (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*	Copyright (c) 1988 AT&T	*/
28 /*	  All Rights Reserved  	*/
29 
30 #pragma ident	"%Z%%M%	%I%	%E% SMI"
31 
32 #include "lint.h"
33 #include <errno.h>
34 #include <ctype.h>
35 #include <limits.h>
36 #include <sys/types.h>
37 #include <stdlib.h>
38 
39 #define	DIGIT(x)	\
40 	(isdigit(x) ? (x) - '0' : islower(x) ? (x) + 10 - 'a' : (x) + 10 - 'A')
41 
42 #define	MBASE	('z' - 'a' + 1 + 10)
43 
44 
45 /*
46  * The following macro is a local version of isalnum() which limits
47  * alphabetic characters to the ranges a-z and A-Z; locale dependent
48  * characters will not return 1. The members of a-z and A-Z are
49  * assumed to be in ascending order and contiguous
50  */
51 #define	lisalnum(x)	\
52 	(isdigit(x) || ((x) >= 'a' && (x) <= 'z') || ((x) >= 'A' && (x) <= 'Z'))
53 
54 u_longlong_t
55 strtoull(const char *str, char **nptr, int base)
56 {
57 	u_longlong_t val;
58 	int c;
59 	int xx;
60 	u_longlong_t	multmax;
61 	u_longlong_t	ullong_max;
62 	int neg = 0;
63 	const char 	**ptr = (const char **)nptr;
64 	const unsigned char	*ustr = (const unsigned char *)str;
65 
66 	if (ptr != (const char **)0)
67 		*ptr = (char *)ustr; /* in case no number is formed */
68 
69 	ullong_max = ULLONG_MAX;   /* from a local version of limits.h */
70 
71 	if (base < 0 || base > MBASE || base == 1) {
72 		errno = EINVAL;
73 		return (0); /* base is invalid -- should be a fatal error */
74 	}
75 	if (!isalnum(c = *ustr)) {
76 		while (isspace(c))
77 			c = *++ustr;
78 		switch (c) {
79 		case '-':
80 			neg++;
81 			/* FALLTHROUGH */
82 		case '+':
83 			c = *++ustr;
84 		}
85 	}
86 	if (base == 0)
87 		if (c != '0')
88 			base = 10;
89 		else if (ustr[1] == 'x' || ustr[1] == 'X')
90 			base = 16;
91 		else
92 			base = 8;
93 	/*
94 	 * for any base > 10, the digits incrementally following
95 	 *	9 are assumed to be "abc...z" or "ABC...Z"
96 	 */
97 	if (!lisalnum(c) || (xx = DIGIT(c)) >= base)
98 		return (0); /* no number formed */
99 	if (base == 16 && c == '0' && (ustr[1] == 'x' || ustr[1] == 'X') &&
100 	    isxdigit(ustr[2]))
101 		c = *(ustr += 2); /* skip over leading "0x" or "0X" */
102 
103 	multmax = ullong_max / (u_longlong_t)base;
104 	val = DIGIT(c);
105 	for (c = *++ustr; lisalnum(c) && (xx = DIGIT(c)) < base; ) {
106 		if (val > multmax)
107 			goto overflow;
108 		val *= base;
109 		if (ullong_max - val < xx)
110 			goto overflow;
111 		val += xx;
112 		c = *++ustr;
113 	}
114 	if (ptr != (const char **)0)
115 		*ptr = (char *)ustr;
116 	return (neg ? -val : val);
117 
118 overflow:
119 	for (c = *++ustr; lisalnum(c) && (xx = DIGIT(c)) < base; (c = *++ustr))
120 		;
121 	if (ptr != (const char **)0)
122 		*ptr = (char *)ustr;
123 	errno = ERANGE;
124 	return (ullong_max);
125 }
126