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6a5fa4e0 MG |
1 | /* |
2 | * strtoul.c -- | |
3 | * | |
4 | * Source code for the "strtoul" library procedure. | |
5 | * | |
6 | * Copyright 1988 Regents of the University of California | |
7 | * Permission to use, copy, modify, and distribute this | |
8 | * software and its documentation for any purpose and without | |
9 | * fee is hereby granted, provided that the above copyright | |
10 | * notice appear in all copies. The University of California | |
11 | * makes no representations about the suitability of this | |
12 | * software for any purpose. It is provided "as is" without | |
13 | * express or implied warranty. | |
14 | */ | |
15 | ||
16 | #ifndef lint | |
17 | static char rcsid[] = "$Header: /sprite/src/lib/tcl/compat/RCS/strtoul.c,v 1.2 91/09/22 14:04:43 ouster Exp $ SPRITE (Berkeley)"; | |
18 | #endif /* not lint */ | |
19 | ||
20 | #include <ctype.h> | |
21 | ||
22 | /* | |
23 | * The table below is used to convert from ASCII digits to a | |
24 | * numerical equivalent. It maps from '0' through 'z' to integers | |
25 | * (100 for non-digit characters). | |
26 | */ | |
27 | ||
28 | static char cvtIn[] = { | |
29 | 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, /* '0' - '9' */ | |
30 | 100, 100, 100, 100, 100, 100, 100, /* punctuation */ | |
31 | 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, /* 'A' - 'Z' */ | |
32 | 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, | |
33 | 30, 31, 32, 33, 34, 35, | |
34 | 100, 100, 100, 100, 100, 100, /* punctuation */ | |
35 | 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, /* 'a' - 'z' */ | |
36 | 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, | |
37 | 30, 31, 32, 33, 34, 35}; | |
38 | \f | |
39 | /* | |
40 | *---------------------------------------------------------------------- | |
41 | * | |
42 | * strtoul -- | |
43 | * | |
44 | * Convert an ASCII string into an integer. | |
45 | * | |
46 | * Results: | |
47 | * The return value is the integer equivalent of string. If endPtr | |
48 | * is non-NULL, then *endPtr is filled in with the character | |
49 | * after the last one that was part of the integer. If string | |
50 | * doesn't contain a valid integer value, then zero is returned | |
51 | * and *endPtr is set to string. | |
52 | * | |
53 | * Side effects: | |
54 | * None. | |
55 | * | |
56 | *---------------------------------------------------------------------- | |
57 | */ | |
58 | ||
59 | unsigned long int | |
60 | strtoul(string, endPtr, base) | |
61 | char *string; /* String of ASCII digits, possibly | |
62 | * preceded by white space. For bases | |
63 | * greater than 10, either lower- or | |
64 | * upper-case digits may be used. | |
65 | */ | |
66 | char **endPtr; /* Where to store address of terminating | |
67 | * character, or NULL. */ | |
68 | int base; /* Base for conversion. Must be less | |
69 | * than 37. If 0, then the base is chosen | |
70 | * from the leading characters of string: | |
71 | * "0x" means hex, "0" means octal, anything | |
72 | * else means decimal. | |
73 | */ | |
74 | { | |
75 | register char *p; | |
76 | register unsigned long int result = 0; | |
77 | register unsigned digit; | |
78 | int anyDigits = 0; | |
79 | ||
80 | /* | |
81 | * Skip any leading blanks. | |
82 | */ | |
83 | ||
84 | p = string; | |
85 | while (isspace(*p)) { | |
86 | p += 1; | |
87 | } | |
88 | ||
89 | /* | |
90 | * If no base was provided, pick one from the leading characters | |
91 | * of the string. | |
92 | */ | |
93 | ||
94 | if (base == 0) | |
95 | { | |
96 | if (*p == '0') { | |
97 | p += 1; | |
98 | if (*p == 'x') { | |
99 | p += 1; | |
100 | base = 16; | |
101 | } else { | |
102 | ||
103 | /* | |
104 | * Must set anyDigits here, otherwise "0" produces a | |
105 | * "no digits" error. | |
106 | */ | |
107 | ||
108 | anyDigits = 1; | |
109 | base = 8; | |
110 | } | |
111 | } | |
112 | else base = 10; | |
113 | } else if (base == 16) { | |
114 | ||
115 | /* | |
116 | * Skip a leading "0x" from hex numbers. | |
117 | */ | |
118 | ||
119 | if ((p[0] == '0') && (p[1] == 'x')) { | |
120 | p += 2; | |
121 | } | |
122 | } | |
123 | ||
124 | /* | |
125 | * Sorry this code is so messy, but speed seems important. Do | |
126 | * different things for base 8, 10, 16, and other. | |
127 | */ | |
128 | ||
129 | if (base == 8) { | |
130 | for ( ; ; p += 1) { | |
131 | digit = *p - '0'; | |
132 | if (digit > 7) { | |
133 | break; | |
134 | } | |
135 | result = (result << 3) + digit; | |
136 | anyDigits = 1; | |
137 | } | |
138 | } else if (base == 10) { | |
139 | for ( ; ; p += 1) { | |
140 | digit = *p - '0'; | |
141 | if (digit > 9) { | |
142 | break; | |
143 | } | |
144 | result = (10*result) + digit; | |
145 | anyDigits = 1; | |
146 | } | |
147 | } else if (base == 16) { | |
148 | for ( ; ; p += 1) { | |
149 | digit = *p - '0'; | |
150 | if (digit > ('z' - '0')) { | |
151 | break; | |
152 | } | |
153 | digit = cvtIn[digit]; | |
154 | if (digit > 15) { | |
155 | break; | |
156 | } | |
157 | result = (result << 4) + digit; | |
158 | anyDigits = 1; | |
159 | } | |
160 | } else { | |
161 | for ( ; ; p += 1) { | |
162 | digit = *p - '0'; | |
163 | if (digit > ('z' - '0')) { | |
164 | break; | |
165 | } | |
166 | digit = cvtIn[digit]; | |
167 | if (digit >= base) { | |
168 | break; | |
169 | } | |
170 | result = result*base + digit; | |
171 | anyDigits = 1; | |
172 | } | |
173 | } | |
174 | ||
175 | /* | |
176 | * See if there were any digits at all. | |
177 | */ | |
178 | ||
179 | if (!anyDigits) { | |
180 | p = string; | |
181 | } | |
182 | ||
183 | if (endPtr != 0) { | |
184 | *endPtr = p; | |
185 | } | |
186 | ||
187 | return result; | |
188 | } |