diff options
Diffstat (limited to 'src/lib/libc/stdlib/strtol.c')
-rw-r--r-- | src/lib/libc/stdlib/strtol.c | 146 |
1 files changed, 146 insertions, 0 deletions
diff --git a/src/lib/libc/stdlib/strtol.c b/src/lib/libc/stdlib/strtol.c new file mode 100644 index 0000000000..1c39720794 --- /dev/null +++ b/src/lib/libc/stdlib/strtol.c | |||
@@ -0,0 +1,146 @@ | |||
1 | /*- | ||
2 | * Copyright (c) 1990 The Regents of the University of California. | ||
3 | * 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. Neither the name of the University nor the names of its contributors | ||
14 | * may be used to endorse or promote products derived from this software | ||
15 | * without specific prior written permission. | ||
16 | * | ||
17 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND | ||
18 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | ||
19 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | ||
20 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE | ||
21 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | ||
22 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | ||
23 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | ||
24 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | ||
25 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | ||
26 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | ||
27 | * SUCH DAMAGE. | ||
28 | */ | ||
29 | |||
30 | #if defined(LIBC_SCCS) && !defined(lint) | ||
31 | static char *rcsid = "$OpenBSD: strtol.c,v 1.5 2003/06/02 20:18:38 millert Exp $"; | ||
32 | #endif /* LIBC_SCCS and not lint */ | ||
33 | |||
34 | #include <ctype.h> | ||
35 | #include <errno.h> | ||
36 | #include <limits.h> | ||
37 | #include <stdlib.h> | ||
38 | |||
39 | |||
40 | /* | ||
41 | * Convert a string to a long integer. | ||
42 | * | ||
43 | * Ignores `locale' stuff. Assumes that the upper and lower case | ||
44 | * alphabets and digits are each contiguous. | ||
45 | */ | ||
46 | long | ||
47 | strtol(nptr, endptr, base) | ||
48 | const char *nptr; | ||
49 | char **endptr; | ||
50 | register int base; | ||
51 | { | ||
52 | register const char *s; | ||
53 | register long acc, cutoff; | ||
54 | register int c; | ||
55 | register int neg, any, cutlim; | ||
56 | |||
57 | /* | ||
58 | * Skip white space and pick up leading +/- sign if any. | ||
59 | * If base is 0, allow 0x for hex and 0 for octal, else | ||
60 | * assume decimal; if base is already 16, allow 0x. | ||
61 | */ | ||
62 | s = nptr; | ||
63 | do { | ||
64 | c = (unsigned char) *s++; | ||
65 | } while (isspace(c)); | ||
66 | if (c == '-') { | ||
67 | neg = 1; | ||
68 | c = *s++; | ||
69 | } else { | ||
70 | neg = 0; | ||
71 | if (c == '+') | ||
72 | c = *s++; | ||
73 | } | ||
74 | if ((base == 0 || base == 16) && | ||
75 | c == '0' && (*s == 'x' || *s == 'X')) { | ||
76 | c = s[1]; | ||
77 | s += 2; | ||
78 | base = 16; | ||
79 | } | ||
80 | if (base == 0) | ||
81 | base = c == '0' ? 8 : 10; | ||
82 | |||
83 | /* | ||
84 | * Compute the cutoff value between legal numbers and illegal | ||
85 | * numbers. That is the largest legal value, divided by the | ||
86 | * base. An input number that is greater than this value, if | ||
87 | * followed by a legal input character, is too big. One that | ||
88 | * is equal to this value may be valid or not; the limit | ||
89 | * between valid and invalid numbers is then based on the last | ||
90 | * digit. For instance, if the range for longs is | ||
91 | * [-2147483648..2147483647] and the input base is 10, | ||
92 | * cutoff will be set to 214748364 and cutlim to either | ||
93 | * 7 (neg==0) or 8 (neg==1), meaning that if we have accumulated | ||
94 | * a value > 214748364, or equal but the next digit is > 7 (or 8), | ||
95 | * the number is too big, and we will return a range error. | ||
96 | * | ||
97 | * Set any if any `digits' consumed; make it negative to indicate | ||
98 | * overflow. | ||
99 | */ | ||
100 | cutoff = neg ? LONG_MIN : LONG_MAX; | ||
101 | cutlim = cutoff % base; | ||
102 | cutoff /= base; | ||
103 | if (neg) { | ||
104 | if (cutlim > 0) { | ||
105 | cutlim -= base; | ||
106 | cutoff += 1; | ||
107 | } | ||
108 | cutlim = -cutlim; | ||
109 | } | ||
110 | for (acc = 0, any = 0;; c = (unsigned char) *s++) { | ||
111 | if (isdigit(c)) | ||
112 | c -= '0'; | ||
113 | else if (isalpha(c)) | ||
114 | c -= isupper(c) ? 'A' - 10 : 'a' - 10; | ||
115 | else | ||
116 | break; | ||
117 | if (c >= base) | ||
118 | break; | ||
119 | if (any < 0) | ||
120 | continue; | ||
121 | if (neg) { | ||
122 | if (acc < cutoff || acc == cutoff && c > cutlim) { | ||
123 | any = -1; | ||
124 | acc = LONG_MIN; | ||
125 | errno = ERANGE; | ||
126 | } else { | ||
127 | any = 1; | ||
128 | acc *= base; | ||
129 | acc -= c; | ||
130 | } | ||
131 | } else { | ||
132 | if (acc > cutoff || acc == cutoff && c > cutlim) { | ||
133 | any = -1; | ||
134 | acc = LONG_MAX; | ||
135 | errno = ERANGE; | ||
136 | } else { | ||
137 | any = 1; | ||
138 | acc *= base; | ||
139 | acc += c; | ||
140 | } | ||
141 | } | ||
142 | } | ||
143 | if (endptr != 0) | ||
144 | *endptr = (char *) (any ? s - 1 : nptr); | ||
145 | return (acc); | ||
146 | } | ||