1 /*-
2  * Copyright (c) 1992, 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 #include <limits.h>
35 #include <errno.h>
36 #include <ctype.h>
37 #include <stdlib.h>
38 
39 /*
40  * Convert a string to an unsigned long long integer.
41  *
42  * Assumes that the upper and lower case
43  * alphabets and digits are each contiguous.
44  */
45 unsigned long long
strtoull(const char * nptr,char ** endptr,int base)46 strtoull(const char *nptr, char **endptr, int base)
47 {
48 	const char *s;
49 	unsigned long long acc;
50 	char c;
51 	unsigned long long cutoff;
52 	int neg, any, cutlim;
53 
54 	/*
55 	 * See strtoq for comments as to the logic used.
56 	 */
57 	s = nptr;
58 	do {
59 		c = *s++;
60 	} while (isspace((unsigned char)c));
61 	if (c == '-') {
62 		neg = 1;
63 		c = *s++;
64 	} else {
65 		neg = 0;
66 		if (c == '+')
67 			c = *s++;
68 	}
69 	if ((base == 0 || base == 16) &&
70 	    c == '0' && (*s == 'x' || *s == 'X') &&
71 	    ((s[1] >= '0' && s[1] <= '9') ||
72 	    (s[1] >= 'A' && s[1] <= 'F') ||
73 	    (s[1] >= 'a' && s[1] <= 'f'))) {
74 		c = s[1];
75 		s += 2;
76 		base = 16;
77 	}
78 	if (base == 0)
79 		base = c == '0' ? 8 : 10;
80 	acc = any = 0;
81 	if (base < 2 || base > 36)
82 		goto noconv;
83 
84 	cutoff = ULLONG_MAX / base;
85 	cutlim = ULLONG_MAX % base;
86 	for ( ; ; c = *s++) {
87 		if (c >= '0' && c <= '9')
88 			c -= '0';
89 		else if (c >= 'A' && c <= 'Z')
90 			c -= 'A' - 10;
91 		else if (c >= 'a' && c <= 'z')
92 			c -= 'a' - 10;
93 		else
94 			break;
95 		if (c >= base)
96 			break;
97 		if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim))
98 			any = -1;
99 		else {
100 			any = 1;
101 			acc *= base;
102 			acc += c;
103 		}
104 	}
105 	if (any < 0) {
106 		acc = ULLONG_MAX;
107 		errno = ERANGE;
108 	} else if (!any) {
109 noconv:
110 		errno = EINVAL;
111 	} else if (neg)
112 		acc = -acc;
113 	if (endptr != NULL)
114 		*endptr = (char *)(any ? s - 1 : nptr);
115 	return (acc);
116 }
117