Annotation of sys/lib/libsa/strtoll.c, Revision 1.1.1.1
1.1 nbrk 1: /* $OpenBSD: strtoll.c,v 1.1 2006/09/18 21:12:57 mpf Exp $ */
2: /* Modified strtoll() from stdlib */
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. Neither the name of the University nor the names of its contributors
16: * may be used to endorse or promote products derived from this software
17: * without specific prior written permission.
18: *
19: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29: * SUCH DAMAGE.
30: */
31:
32: #include <sys/param.h>
33: #include "stand.h"
34:
35: /*
36: * Convert a string to a long long.
37: *
38: * Ignores `locale' stuff. Assumes that the upper and lower case
39: * alphabets and digits are each contiguous.
40: */
41: long long
42: strtoll(const char *nptr, char **endptr, int base)
43: {
44: const char *s;
45: long long acc, cutoff;
46: int c;
47: int neg, any, cutlim;
48:
49: /*
50: * Skip white space and pick up leading +/- sign if any.
51: * If base is 0, allow 0x for hex and 0 for octal, else
52: * assume decimal; if base is already 16, allow 0x.
53: */
54: s = nptr;
55: do {
56: c = (unsigned char) *s++;
57: } while (isspace(c));
58: if (c == '-') {
59: neg = 1;
60: c = *s++;
61: } else {
62: neg = 0;
63: if (c == '+')
64: c = *s++;
65: }
66: if ((base == 0 || base == 16) &&
67: c == '0' && (*s == 'x' || *s == 'X')) {
68: c = s[1];
69: s += 2;
70: base = 16;
71: }
72: if (base == 0)
73: base = c == '0' ? 8 : 10;
74:
75: /*
76: * Compute the cutoff value between legal numbers and illegal
77: * numbers. That is the largest legal value, divided by the
78: * base. An input number that is greater than this value, if
79: * followed by a legal input character, is too big. One that
80: * is equal to this value may be valid or not; the limit
81: * between valid and invalid numbers is then based on the last
82: * digit. For instance, if the range for long longs is
83: * [-9223372036854775808..9223372036854775807] and the input base
84: * is 10, cutoff will be set to 922337203685477580 and cutlim to
85: * either 7 (neg==0) or 8 (neg==1), meaning that if we have
86: * accumulated a value > 922337203685477580, or equal but the
87: * next digit is > 7 (or 8), the number is too big, and we will
88: * return a range error.
89: *
90: * Set any if any `digits' consumed; make it negative to indicate
91: * overflow.
92: */
93: cutoff = neg ? LLONG_MIN : LLONG_MAX;
94: cutlim = cutoff % base;
95: cutoff /= base;
96: if (neg) {
97: if (cutlim > 0) {
98: cutlim -= base;
99: cutoff += 1;
100: }
101: cutlim = -cutlim;
102: }
103: for (acc = 0, any = 0;; c = (unsigned char) *s++) {
104: if (isdigit(c))
105: c -= '0';
106: else if (isalpha(c))
107: c -= isupper(c) ? 'A' - 10 : 'a' - 10;
108: else
109: break;
110: if (c >= base)
111: break;
112: if (any < 0)
113: continue;
114: if (neg) {
115: if (acc < cutoff || (acc == cutoff && c > cutlim)) {
116: any = -1;
117: acc = LLONG_MIN;
118: } else {
119: any = 1;
120: acc *= base;
121: acc -= c;
122: }
123: } else {
124: if (acc > cutoff || (acc == cutoff && c > cutlim)) {
125: any = -1;
126: acc = LLONG_MAX;
127: } else {
128: any = 1;
129: acc *= base;
130: acc += c;
131: }
132: }
133: }
134: if (endptr != 0)
135: *endptr = (char *) (any ? s - 1 : nptr);
136: return (acc);
137: }
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