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Serenity Operating System
1/*
2 * Copyright (c) 2000-2002 Opsycon AB (www.opsycon.se)
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 * 3. All advertising materials mentioning features or use of this software
13 * must display the following acknowledgement:
14 * This product includes software developed by Opsycon AB.
15 * 4. The name of the author may not be used to endorse or promote products
16 * derived from this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
19 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
20 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
22 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 *
30 */
31#include <ctype.h>
32#include <stdarg.h>
33#include <stdint.h>
34#include <stdio.h>
35#include <string.h>
36
37static const char* determine_base(const char* p, int& base)
38{
39 if (p[0] == '0') {
40 switch (p[1]) {
41 case 'x':
42 base = 16;
43 break;
44 case 't':
45 case 'n':
46 base = 10;
47 break;
48 case 'o':
49 base = 8;
50 break;
51 default:
52 base = 10;
53 return p;
54 }
55 return p + 2;
56 }
57 base = 10;
58 return p;
59}
60
61static int _atob(unsigned long* vp, const char* p, int base)
62{
63 unsigned long value, v1, v2;
64 const char *q;
65 char tmp[20];
66 int digit;
67
68 if (p[0] == '0' && (p[1] == 'x' || p[1] == 'X')) {
69 base = 16;
70 p += 2;
71 }
72
73 if (base == 16 && (q = strchr(p, '.')) != 0) {
74 if (q - p > (int)sizeof(tmp) - 1)
75 return 0;
76 strncpy(tmp, p, q - p);
77 tmp[q - p] = '\0';
78 if (!_atob(&v1, tmp, 16))
79 return 0;
80 ++q;
81 if (strchr(q, '.'))
82 return 0;
83 if (!_atob(&v2, q, 16))
84 return 0;
85 *vp = (v1 << 16) + v2;
86 return 1;
87 }
88
89 value = *vp = 0;
90 for (; *p; p++) {
91 if (*p >= '0' && *p <= '9')
92 digit = *p - '0';
93 else if (*p >= 'a' && *p <= 'f')
94 digit = *p - 'a' + 10;
95 else if (*p >= 'A' && *p <= 'F')
96 digit = *p - 'A' + 10;
97 else
98 return 0;
99
100 if (digit >= base)
101 return 0;
102 value *= base;
103 value += digit;
104 }
105 *vp = value;
106 return 1;
107}
108
109int atob(unsigned int* vp, const char* p, int base)
110{
111 unsigned long v;
112
113 if (base == 0)
114 p = determine_base(p, base);
115 if (_atob(&v, p, base)) {
116 *vp = v;
117 return 1;
118 }
119 return 0;
120}
121
122#define ISSPACE " \t\n\r\f\v"
123
124int vsscanf(const char* buf, const char* s, va_list ap)
125{
126 int base = 10;
127 char* t;
128 char tmp[BUFSIZ];
129 bool noassign = false;
130 int count = 0;
131 int width = 0;
132
133 while (*s && *buf) {
134 while (isspace(*s))
135 s++;
136 if (*s == '%') {
137 s++;
138 for (; *s; s++) {
139 if (strchr("dibouxcsefg%", *s))
140 break;
141 if (*s == '*')
142 noassign = true;
143 else if (*s >= '1' && *s <= '9') {
144 const char* tc;
145 for (tc = s; isdigit(*s); s++)
146 ;
147 strncpy(tmp, tc, s - tc);
148 tmp[s - tc] = '\0';
149 atob((uint32_t*)&width, tmp, 10);
150 s--;
151 }
152 }
153 if (*s == 's') {
154 while (isspace(*buf))
155 buf++;
156 if (!width)
157 width = strcspn(buf, ISSPACE);
158 if (!noassign) {
159 strncpy(t = va_arg(ap, char*), buf, width);
160 t[width] = '\0';
161 }
162 buf += width;
163 } else if (*s == 'c') {
164 if (!width)
165 width = 1;
166 if (!noassign) {
167 strncpy(t = va_arg(ap, char*), buf, width);
168 t[width] = '\0';
169 }
170 buf += width;
171 } else if (strchr("dobxu", *s)) {
172 while (isspace(*buf))
173 buf++;
174 if (*s == 'd' || *s == 'u')
175 base = 10;
176 else if (*s == 'x')
177 base = 16;
178 else if (*s == 'o')
179 base = 8;
180 else if (*s == 'b')
181 base = 2;
182 if (!width) {
183 if (isspace(*(s + 1)) || *(s + 1) == 0) {
184 width = strcspn(buf, ISSPACE);
185 } else {
186 auto* p = strchr(buf, *(s + 1));
187 if (p)
188 width = p - buf;
189 else {
190 noassign = true;
191 width = 0;
192 }
193 }
194 }
195 strncpy(tmp, buf, width);
196 tmp[width] = '\0';
197 buf += width;
198 if (!noassign) {
199 if (!atob(va_arg(ap, uint32_t*), tmp, base))
200 noassign = true;
201 }
202 }
203 if (!noassign)
204 ++count;
205 width = 0;
206 noassign = false;
207 ++s;
208 } else {
209 while (isspace(*buf))
210 buf++;
211 if (*s != *buf)
212 break;
213 else {
214 ++s;
215 ++buf;
216 }
217 }
218 }
219 return count;
220}