1 /*
2 * Very simple implementation of strtoul() for gawk,
3 * for old systems. Descriptive prose from the Linux man page.
4 *
5 * May 2004
6 */
7
8 /* #define TEST 1 */
9
10 #ifdef TEST
11 #include <stdio.h>
12 #include <stdlib.h>
13 #include <ctype.h>
14 #include <string.h>
15 #include <errno.h>
16 #include <limits.h>
17 #define strtoul mystrtoul
18 #endif
19
20 #ifndef ULONG_MAX
21 #define ULONG_MAX (~ 0UL)
22 #endif
23
24 unsigned long int
25 strtoul(nptr, endptr, base)
26 const char *nptr;
27 char **endptr;
28 int base;
29 {
30 static char lower[] = "abcdefghijklmnopqrstuvwxyz";
31
32 unsigned long result = 0UL;
33 char *nptr_orig = (char *) nptr;
34 bool neg = false;
35 char *cp, c;
36 int val;
37 bool sawdigs = false;
38
39 /*
40 * The strtoul() function converts the initial part of the
41 * string in nptr to an unsigned long integer value according
42 * to the given base, which must be between 2 and 36 inclusive,
43 * or be the special value 0.
44 */
45
46 if ((base != 0 && (base < 2 || base > 36)) || nptr == NULL) {
47 if (endptr != NULL)
48 *endptr = nptr_orig;
49 errno = EINVAL;
50 return 0;
51 }
52
53 /*
54 * The string must [sic] begin with an arbitrary amount of white space
55 * (as determined by isspace(3)) followed by a single optional
56 * `+' or `-' sign.
57 */
58 while (isspace(*nptr))
59 nptr++;
60
61 if (*nptr == '+')
62 nptr++;
63 else if (*nptr == '-') {
64 nptr++;
65 neg = true;
66 }
67
68 /*
69 * If base is zero or 16, the string may then include a `0x' prefix,
70 * and the number will be read in base 16; otherwise, a zero base is
71 * taken as 10 (decimal) unless the next character is `0', in which
72 * case it is taken as 8 (octal).
73 */
74 if ((base == 0 || base == 16)
75 && nptr[0] == '0'
76 && (nptr[1] == 'x' || nptr[1] == 'X')) {
77 base = 16; /* force it */
78 nptr += 2; /* skip 0x */
79 } else if ((base == 0 || base == 8) && nptr[0] == '0') {
80 base = 8;
81 nptr++;
82 } else if (base == 0)
83 base = 10;
84
85 /*
86 * The remainder of the string is converted to an unsigned long int
87 * value in the obvious manner, stopping at the first character
88 * which is not a valid digit in the given base. (In bases above 10,
89 * the letter `A' in either upper or lower case represents 10,
90 * `B' represents 11, and so forth, with `Z' representing 35.)
91 */
92 for (; *nptr != '\0'; nptr++) {
93 c = *nptr;
94 #if defined(HAVE_LOCALE_H)
95 if (base == 10
96 && loc.thousands_sep != NULL
97 && loc.thousands_sep[0] != '\0'
98 && c == loc.thousands_sep[0])
99 continue;
100 #endif
101 switch (c) {
102 case '0': case '1': case '2':
103 case '3': case '4': case '5':
104 case '6': case '7': case '8':
105 case '9':
106 val = c - '0';
107 if (val >= base) /* even base 2 allowed ... */
108 goto out;
109 result *= base;
110 result += val;
111 sawdigs = true;
112 break;
113 case 'A': case 'B': case 'C': case 'D': case 'E':
114 case 'F': case 'G': case 'H': case 'I': case 'J':
115 case 'K': case 'L': case 'M': case 'N': case 'O':
116 case 'P': case 'Q': case 'R': case 'S': case 'T':
117 case 'U': case 'V': case 'W': case 'X': case 'Y':
118 case 'Z':
119 c += 'a' - 'A'; /* downcase */
120 /* fall through */
121 case 'a': case 'b': case 'c': case 'd': case 'e':
122 case 'f': case 'g': case 'h': case 'i': case 'j':
123 case 'k': case 'l': case 'm': case 'n': case 'o':
124 case 'p': case 'q': case 'r': case 's': case 't':
125 case 'u': case 'v': case 'w': case 'x': case 'y':
126 case 'z':
127 cp = strchr(lower, c);
128 val = cp - lower;
129 val += 10; /* 'a' == 10 */
130 if (val >= base)
131 goto out;
132 result *= base;
133 result += val;
134 sawdigs = true;
135 break;
136 default:
137 goto out;
138 }
139 }
140 out:
141 /*
142 * If endptr is not NULL, strtoul() stores the address of the
143 * first invalid character in *endptr. If there were no digits
144 * at all, strtoul() stores the original value of nptr in *endptr
145 * (and returns 0). In particular, if *nptr is not `\0' but
146 * **endptr is `\0' on return, the entire string is valid.
147 */
148 if (endptr != NULL) {
149 if (! sawdigs) {
150 *endptr = nptr_orig;
151 return 0;
152 } else
153 *endptr = (char *) nptr;
154 }
155
156 /*
157 * RETURN VALUE
158 * The strtoul() function returns either the result of the
159 * conversion or, if there was a leading minus sign, the
160 * negation of the result of the conversion, unless the original
161 * (non-negated) value would overflow; in the latter case,
162 * strtoul() returns ULONG_MAX and sets the global variable errno
163 * to ERANGE.
164 */
165
166 /*
167 * ADR: This computation is probably bogus. If it's a
168 * problem, upgrade to a modern system.
169 */
170 if (neg && result == ULONG_MAX) {
171 errno = ERANGE;
172 return ULONG_MAX;
173 } else if (neg)
174 result = -result;
175
176 return result;
177 }
178
179 #ifdef TEST
180 #undef strtoul
181 int main(void)
182 {
183 char *endptr;
184 unsigned long res1, res2;
185
186 res1 = strtoul("0xdeadBeeF", & endptr, 0),
187 res2 = mystrtoul("0xdeadBeeF", & endptr, 0),
188 printf("(real,my)strtoul(\"0xdeadBeeF\", & endptr, 0) is %lu, %lu *endptr = %d\n",
189 res1, res2, *endptr);
190
191 res1 = strtoul("0101101", & endptr, 2),
192 res2 = mystrtoul("0101101", & endptr, 2),
193 printf("(real,my)strtoul(\"0101101\", & endptr, 2) is %lu, %lu *endptr = %d\n",
194 res1, res2, *endptr);
195
196 res1 = strtoul("01011012", & endptr, 2),
197 res2 = mystrtoul("01011012", & endptr, 2),
198 printf("(real,my)strtoul(\"01011012\", & endptr, 2) is %lu, %lu *endptr = %d\n",
199 res1, res2, *endptr);
200
201 res1 = strtoul(" +42a", & endptr, 0),
202 res2 = mystrtoul(" +42a", & endptr, 0),
203 printf("(real,my)strtoul(\" +42a\", & endptr, 0) is %lu, %lu *endptr = %d\n",
204 res1, res2, *endptr);
205
206 res1 = strtoul("0377", & endptr, 0),
207 res2 = mystrtoul("0377", & endptr, 0),
208 printf("(real,my)strtoul(\"0377\", & endptr, 0) is %lu, %lu *endptr = %d\n",
209 res1, res2, *endptr);
210
211 res1 = strtoul("Z", & endptr, 36),
212 res2 = mystrtoul("Z", & endptr, 36),
213 printf("(real,my)strtoul(\"Z\", & endptr, 36) is %lu, %lu *endptr = %d\n",
214 res1, res2, *endptr);
215
216 res1 = strtoul("qZ*", & endptr, 36),
217 res2 = mystrtoul("qZ*", & endptr, 36),
218 printf("(real,my)strtoul(\"qZ*\", & endptr, 36) is %lu, %lu *endptr = %d\n",
219 res1, res2, *endptr);
220 }
221 #endif