]> git.zerfleddert.de Git - micropolis/blame - src/tcl/compat/strtoul.c
XINCLUDE: use /usr/X11R6/include everywhere
[micropolis] / src / tcl / compat / strtoul.c
CommitLineData
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
17static 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
28static 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
59unsigned long int
60strtoul(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}
Impressum, Datenschutz