1 /*-
2 * Copyright (c) 1990, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Chris Torek.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the University nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 *
32 * $FreeBSD: src/sys/libkern/strtouq.c,v 1.3 1999/12/01 22:56:51 archie Exp $
33 */
34
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/ctype.h>
38 #include <machine/limits.h>
39
40 /*
41 * Convert a string to an unsigned quad integer.
42 *
43 * Ignores `locale' stuff. Assumes that the upper and lower case
44 * alphabets and digits are each contiguous.
45 */
46 u_quad_t
strtouq(const char * nptr,char ** endptr,int base)47 strtouq(const char *nptr, char **endptr, int base)
48 {
49 const char *s;
50 u_quad_t acc;
51 unsigned char c;
52 u_quad_t qbase, cutoff;
53 int neg, any, cutlim;
54
55 /*
56 * See strtoq for comments as to the logic used.
57 */
58 s = nptr;
59 do {
60 c = *s++;
61 } while (isspace(c));
62 if (c == '-') {
63 neg = 1;
64 c = *s++;
65 } else {
66 neg = 0;
67 if (c == '+')
68 c = *s++;
69 }
70 if ((base == 0 || base == 16) &&
71 c == '0' && (*s == 'x' || *s == 'X')) {
72 c = s[1];
73 s += 2;
74 base = 16;
75 }
76 if (base == 0)
77 base = c == '0' ? 8 : 10;
78 qbase = (unsigned)base;
79 cutoff = (u_quad_t)UQUAD_MAX / qbase;
80 cutlim = (u_quad_t)UQUAD_MAX % qbase;
81 for (acc = 0, any = 0;; c = *s++) {
82 if (!isascii(c))
83 break;
84 if (isdigit(c))
85 c -= '0';
86 else if (isalpha(c))
87 c -= isupper(c) ? 'A' - 10 : 'a' - 10;
88 else
89 break;
90 if (c >= base)
91 break;
92 if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim))
93 any = -1;
94 else {
95 any = 1;
96 acc *= qbase;
97 acc += c;
98 }
99 }
100 if (any < 0) {
101 acc = UQUAD_MAX;
102 } else if (neg)
103 acc = -acc;
104 if (endptr != NULL)
105 *((const char **)(void *)endptr) = any ? s - 1 : nptr;
106 return (acc);
107 }
108