1 /* -*- mode: c; c-file-style: "bsd"; indent-tabs-mode: t -*- */
2 /* lib/krb5/krb/strptime.c */
3 /*
4 * Copyright (c) 1997, 1998 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code was contributed to The NetBSD Foundation by Klaus Klein.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. All advertising materials mentioning features or use of this software
18 * must display the following acknowledgement:
19 * This product includes software developed by the NetBSD
20 * Foundation, Inc. and its contributors.
21 * 4. Neither the name of The NetBSD Foundation nor the names of its
22 * contributors may be used to endorse or promote products derived
23 * from this software without specific prior written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
26 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
27 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
28 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
29 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
30 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
33 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35 * POSSIBILITY OF SUCH DAMAGE.
36 */
37
38 #if defined(LIBC_SCCS) && !defined(lint)
39 __RCSID("$NetBSD: strptime.c,v 1.18 1999/04/29 02:58:30 tv Exp $");
40 #endif
41
42 #include <ctype.h>
43 #include <string.h>
44 #include <time.h>
45
46 #undef _ctloc
47 #define _ctloc(x) _CurrentTimeLocale->x
48
49 /*
50 * We do not implement alternate representations. However, we always
51 * check whether a given modifier is allowed for a certain conversion.
52 */
53 #define ALT_E 0x01
54 #define ALT_O 0x02
55 #define LEGAL_ALT(x) { if (alt_format & ~(x)) return (0); }
56
57
58 static int conv_num __P((const char **, int *, int, int));
59
60
61 static char *
strptime(buf,fmt,tm)62 strptime(buf, fmt, tm)
63 const char *buf, *fmt;
64 struct tm *tm;
65 {
66 char c;
67 const char *bp;
68 size_t len = 0;
69 int alt_format, i, split_year = 0;
70
71 bp = buf;
72
73 while ((c = *fmt) != '\0') {
74 /* Clear `alternate' modifier prior to new conversion. */
75 alt_format = 0;
76
77 /* Eat up white-space. */
78 if (isspace(c)) {
79 while (isspace(*bp))
80 bp++;
81
82 fmt++;
83 continue;
84 }
85
86 if ((c = *fmt++) != '%')
87 goto literal;
88
89
90 again: switch (c = *fmt++) {
91 case '%': /* "%%" is converted to "%". */
92 literal:
93 if (c != *bp++)
94 return (0);
95 break;
96
97 /*
98 * "Alternative" modifiers. Just set the appropriate flag
99 * and start over again.
100 */
101 case 'E': /* "%E?" alternative conversion modifier. */
102 LEGAL_ALT(0);
103 alt_format |= ALT_E;
104 goto again;
105
106 case 'O': /* "%O?" alternative conversion modifier. */
107 LEGAL_ALT(0);
108 alt_format |= ALT_O;
109 goto again;
110
111 /*
112 * "Complex" conversion rules, implemented through recursion.
113 */
114 case 'c': /* Date and time, using the locale's format. */
115 LEGAL_ALT(ALT_E);
116 if (!(bp = strptime(bp, _ctloc(d_t_fmt), tm)))
117 return (0);
118 break;
119
120 case 'D': /* The date as "%m/%d/%y". */
121 LEGAL_ALT(0);
122 if (!(bp = strptime(bp, "%m/%d/%y", tm)))
123 return (0);
124 break;
125
126 case 'R': /* The time as "%H:%M". */
127 LEGAL_ALT(0);
128 if (!(bp = strptime(bp, "%H:%M", tm)))
129 return (0);
130 break;
131
132 case 'r': /* The time in 12-hour clock representation. */
133 LEGAL_ALT(0);
134 if (!(bp = strptime(bp, _ctloc(t_fmt_ampm), tm)))
135 return (0);
136 break;
137
138 case 'T': /* The time as "%H:%M:%S". */
139 LEGAL_ALT(0);
140 if (!(bp = strptime(bp, "%H:%M:%S", tm)))
141 return (0);
142 break;
143
144 case 'X': /* The time, using the locale's format. */
145 LEGAL_ALT(ALT_E);
146 if (!(bp = strptime(bp, _ctloc(t_fmt), tm)))
147 return (0);
148 break;
149
150 case 'x': /* The date, using the locale's format. */
151 LEGAL_ALT(ALT_E);
152 if (!(bp = strptime(bp, _ctloc(d_fmt), tm)))
153 return (0);
154 break;
155
156 /*
157 * "Elementary" conversion rules.
158 */
159 case 'A': /* The day of week, using the locale's form. */
160 case 'a':
161 LEGAL_ALT(0);
162 for (i = 0; i < 7; i++) {
163 /* Full name. */
164 len = strlen(_ctloc(day[i]));
165 if (strncasecmp(_ctloc(day[i]), bp, len) == 0)
166 break;
167
168 /* Abbreviated name. */
169 len = strlen(_ctloc(abday[i]));
170 if (strncasecmp(_ctloc(abday[i]), bp, len) == 0)
171 break;
172 }
173
174 /* Nothing matched. */
175 if (i == 7)
176 return (0);
177
178 tm->tm_wday = i;
179 bp += len;
180 break;
181
182 case 'B': /* The month, using the locale's form. */
183 case 'b':
184 case 'h':
185 LEGAL_ALT(0);
186 for (i = 0; i < 12; i++) {
187 /* Full name. */
188 len = strlen(_ctloc(mon[i]));
189 if (strncasecmp(_ctloc(mon[i]), bp, len) == 0)
190 break;
191
192 /* Abbreviated name. */
193 len = strlen(_ctloc(abmon[i]));
194 if (strncasecmp(_ctloc(abmon[i]), bp, len) == 0)
195 break;
196 }
197
198 /* Nothing matched. */
199 if (i == 12)
200 return (0);
201
202 tm->tm_mon = i;
203 bp += len;
204 break;
205
206 case 'C': /* The century number. */
207 LEGAL_ALT(ALT_E);
208 if (!(conv_num(&bp, &i, 0, 99)))
209 return (0);
210
211 if (split_year) {
212 tm->tm_year = (tm->tm_year % 100) + (i * 100);
213 } else {
214 tm->tm_year = i * 100;
215 split_year = 1;
216 }
217 break;
218
219 case 'd': /* The day of month. */
220 case 'e':
221 LEGAL_ALT(ALT_O);
222 if (!(conv_num(&bp, &tm->tm_mday, 1, 31)))
223 return (0);
224 break;
225
226 case 'k': /* The hour (24-hour clock representation). */
227 LEGAL_ALT(0);
228 /* FALLTHROUGH */
229 case 'H':
230 LEGAL_ALT(ALT_O);
231 if (!(conv_num(&bp, &tm->tm_hour, 0, 23)))
232 return (0);
233 break;
234
235 case 'l': /* The hour (12-hour clock representation). */
236 LEGAL_ALT(0);
237 /* FALLTHROUGH */
238 case 'I':
239 LEGAL_ALT(ALT_O);
240 if (!(conv_num(&bp, &tm->tm_hour, 1, 12)))
241 return (0);
242 if (tm->tm_hour == 12)
243 tm->tm_hour = 0;
244 break;
245
246 case 'j': /* The day of year. */
247 LEGAL_ALT(0);
248 if (!(conv_num(&bp, &i, 1, 366)))
249 return (0);
250 tm->tm_yday = i - 1;
251 break;
252
253 case 'M': /* The minute. */
254 LEGAL_ALT(ALT_O);
255 if (!(conv_num(&bp, &tm->tm_min, 0, 59)))
256 return (0);
257 break;
258
259 case 'm': /* The month. */
260 LEGAL_ALT(ALT_O);
261 if (!(conv_num(&bp, &i, 1, 12)))
262 return (0);
263 tm->tm_mon = i - 1;
264 break;
265
266 case 'p': /* The locale's equivalent of AM/PM. */
267 LEGAL_ALT(0);
268 /* AM? */
269 if (strcasecmp(_ctloc(am_pm[0]), bp) == 0) {
270 if (tm->tm_hour > 11)
271 return (0);
272
273 bp += strlen(_ctloc(am_pm[0]));
274 break;
275 }
276 /* PM? */
277 else if (strcasecmp(_ctloc(am_pm[1]), bp) == 0) {
278 if (tm->tm_hour > 11)
279 return (0);
280
281 tm->tm_hour += 12;
282 bp += strlen(_ctloc(am_pm[1]));
283 break;
284 }
285
286 /* Nothing matched. */
287 return (0);
288
289 case 'S': /* The seconds. */
290 LEGAL_ALT(ALT_O);
291 if (!(conv_num(&bp, &tm->tm_sec, 0, 61)))
292 return (0);
293 break;
294
295 case 'U': /* The week of year, beginning on sunday. */
296 case 'W': /* The week of year, beginning on monday. */
297 LEGAL_ALT(ALT_O);
298 /*
299 * XXX This is bogus, as we can not assume any valid
300 * information present in the tm structure at this
301 * point to calculate a real value, so just check the
302 * range for now.
303 */
304 if (!(conv_num(&bp, &i, 0, 53)))
305 return (0);
306 break;
307
308 case 'w': /* The day of week, beginning on sunday. */
309 LEGAL_ALT(ALT_O);
310 if (!(conv_num(&bp, &tm->tm_wday, 0, 6)))
311 return (0);
312 break;
313
314 case 'Y': /* The year. */
315 LEGAL_ALT(ALT_E);
316 if (!(conv_num(&bp, &i, 0, 9999)))
317 return (0);
318
319 tm->tm_year = i - TM_YEAR_BASE;
320 break;
321
322 case 'y': /* The year within 100 years of the epoch. */
323 LEGAL_ALT(ALT_E | ALT_O);
324 if (!(conv_num(&bp, &i, 0, 99)))
325 return (0);
326
327 if (split_year) {
328 tm->tm_year = ((tm->tm_year / 100) * 100) + i;
329 break;
330 }
331 split_year = 1;
332 if (i <= 68)
333 tm->tm_year = i + 2000 - TM_YEAR_BASE;
334 else
335 tm->tm_year = i + 1900 - TM_YEAR_BASE;
336 break;
337
338 /*
339 * Miscellaneous conversions.
340 */
341 case 'n': /* Any kind of white-space. */
342 case 't':
343 LEGAL_ALT(0);
344 while (isspace(*bp))
345 bp++;
346 break;
347
348
349 default: /* Unknown/unsupported conversion. */
350 return (0);
351 }
352
353
354 }
355
356 /* LINTED functional specification */
357 return ((char *)bp);
358 }
359
360
361 static int
conv_num(buf,dest,llim,ulim)362 conv_num(buf, dest, llim, ulim)
363 const char **buf;
364 int *dest;
365 int llim, ulim;
366 {
367 int result = 0;
368
369 /* The limit also determines the number of valid digits. */
370 int rulim = ulim;
371
372 if (**buf < '0' || **buf > '9')
373 return (0);
374
375 do {
376 result *= 10;
377 result += *(*buf)++ - '0';
378 rulim /= 10;
379 } while ((result * 10 <= ulim) && rulim && **buf >= '0' && **buf <= '9');
380
381 if (result < llim || result > ulim)
382 return (0);
383
384 *dest = result;
385 return (1);
386 }
387