1 /* $OpenBSD: strptime.c,v 1.11 2005/08/08 08:05:38 espie Exp $ */
2 /* $NetBSD: strptime.c,v 1.12 1998/01/20 21:39:40 mycroft Exp $ */
3
4 /*-
5 * Copyright (c) 1997, 1998 The NetBSD Foundation, Inc.
6 * All rights reserved.
7 *
8 * This code was contributed to The NetBSD Foundation by Klaus Klein.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 * must display the following acknowledgement:
20 * This product includes software developed by the NetBSD
21 * Foundation, Inc. and its contributors.
22 * 4. Neither the name of The NetBSD Foundation nor the names of its
23 * contributors may be used to endorse or promote products derived
24 * from this software without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36 * POSSIBILITY OF SUCH DAMAGE.
37 */
38
39 //#include <sys/localedef.h>
40 #include <ctype.h>
41 #include <locale.h>
42 #include <string.h>
43 #include <time.h>
44 #include "tzfile.h"
45
46 static const struct {
47 const char *abday[7];
48 const char *day[7];
49 const char *abmon[12];
50 const char *mon[12];
51 const char *am_pm[2];
52 const char *d_t_fmt;
53 const char *d_fmt;
54 const char *t_fmt;
55 const char *t_fmt_ampm;
56 } _DefaultTimeLocale = {
57 {
58 "Sun","Mon","Tue","Wed","Thu","Fri","Sat",
59 },
60 {
61 "Sunday", "Monday", "Tuesday", "Wednesday", "Thursday",
62 "Friday", "Saturday"
63 },
64 {
65 "Jan", "Feb", "Mar", "Apr", "May", "Jun",
66 "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
67 },
68 {
69 "January", "February", "March", "April", "May", "June", "July",
70 "August", "September", "October", "November", "December"
71 },
72 {
73 "AM", "PM"
74 },
75 "%a %b %d %H:%M:%S %Y",
76 "%m/%d/%y",
77 "%H:%M:%S",
78 "%I:%M:%S %p"
79 };
80
81 #define _ctloc(x) (_DefaultTimeLocale.x)
82
83 /*
84 * We do not implement alternate representations. However, we always
85 * check whether a given modifier is allowed for a certain conversion.
86 */
87 #define _ALT_E 0x01
88 #define _ALT_O 0x02
89 #define _LEGAL_ALT(x) { if (alt_format & ~(x)) return (0); }
90
91
92 static int _conv_num(const unsigned char **, int *, int, int);
93 static unsigned char *_strptime(const unsigned char *, const char *, struct tm *, int);
94
95
96 char *
strptime(const char * buf,const char * fmt,struct tm * tm)97 strptime(const char *buf, const char *fmt, struct tm *tm)
98 {
99 return (char*)(_strptime((const unsigned char*)buf, fmt, tm, 1));
100 }
101
102 static unsigned char *
_strptime(const unsigned char * buf,const char * fmt,struct tm * tm,int initialize)103 _strptime(const unsigned char *buf, const char *fmt, struct tm *tm, int initialize)
104 {
105 unsigned char c;
106 const unsigned char *bp;
107 size_t len = 0;
108 int alt_format, i;
109 static int century, relyear;
110
111 if (initialize) {
112 century = TM_YEAR_BASE;
113 relyear = -1;
114 }
115
116 bp = (unsigned char *)buf;
117 while ((c = *fmt) != '\0') {
118 /* Clear `alternate' modifier prior to new conversion. */
119 alt_format = 0;
120
121 /* Eat up white-space. */
122 if (isspace(c)) {
123 while (isspace(*bp))
124 bp++;
125
126 fmt++;
127 continue;
128 }
129
130 if ((c = *fmt++) != '%')
131 goto literal;
132
133
134 again: switch (c = *fmt++) {
135 case '%': /* "%%" is converted to "%". */
136 literal:
137 if (c != *bp++)
138 return (NULL);
139
140 break;
141
142 /*
143 * "Alternative" modifiers. Just set the appropriate flag
144 * and start over again.
145 */
146 case 'E': /* "%E?" alternative conversion modifier. */
147 _LEGAL_ALT(0);
148 alt_format |= _ALT_E;
149 goto again;
150
151 case 'O': /* "%O?" alternative conversion modifier. */
152 _LEGAL_ALT(0);
153 alt_format |= _ALT_O;
154 goto again;
155
156 /*
157 * "Complex" conversion rules, implemented through recursion.
158 */
159 case 'c': /* Date and time, using the locale's format. */
160 _LEGAL_ALT(_ALT_E);
161 if (!(bp = _strptime(bp, _ctloc(d_t_fmt), tm, 0)))
162 return (NULL);
163 break;
164
165 case 'D': /* The date as "%m/%d/%y". */
166 _LEGAL_ALT(0);
167 if (!(bp = _strptime(bp, "%m/%d/%y", tm, 0)))
168 return (NULL);
169 break;
170
171 case 'R': /* The time as "%H:%M". */
172 _LEGAL_ALT(0);
173 if (!(bp = _strptime(bp, "%H:%M", tm, 0)))
174 return (NULL);
175 break;
176
177 case 'r': /* The time as "%I:%M:%S %p". */
178 _LEGAL_ALT(0);
179 if (!(bp = _strptime(bp, "%I:%M:%S %p", tm, 0)))
180 return (NULL);
181 break;
182
183 case 'T': /* The time as "%H:%M:%S". */
184 _LEGAL_ALT(0);
185 if (!(bp = _strptime(bp, "%H:%M:%S", tm, 0)))
186 return (NULL);
187 break;
188
189 case 'X': /* The time, using the locale's format. */
190 _LEGAL_ALT(_ALT_E);
191 if (!(bp = _strptime(bp, _ctloc(t_fmt), tm, 0)))
192 return (NULL);
193 break;
194
195 case 'x': /* The date, using the locale's format. */
196 _LEGAL_ALT(_ALT_E);
197 if (!(bp = _strptime(bp, _ctloc(d_fmt), tm, 0)))
198 return (NULL);
199 break;
200
201 /*
202 * "Elementary" conversion rules.
203 */
204 case 'A': /* The day of week, using the locale's form. */
205 case 'a':
206 _LEGAL_ALT(0);
207 for (i = 0; i < 7; i++) {
208 /* Full name. */
209 len = strlen(_ctloc(day[i]));
210 if (strncasecmp(_ctloc(day[i]), (const char*)bp, len) == 0)
211 break;
212
213 /* Abbreviated name. */
214 len = strlen(_ctloc(abday[i]));
215 if (strncasecmp(_ctloc(abday[i]), (const char*)bp, len) == 0)
216 break;
217 }
218
219 /* Nothing matched. */
220 if (i == 7)
221 return (NULL);
222
223 tm->tm_wday = i;
224 bp += len;
225 break;
226
227 case 'B': /* The month, using the locale's form. */
228 case 'b':
229 case 'h':
230 _LEGAL_ALT(0);
231 for (i = 0; i < 12; i++) {
232 /* Full name. */
233 len = strlen(_ctloc(mon[i]));
234 if (strncasecmp(_ctloc(mon[i]), (const char*)bp, len) == 0)
235 break;
236
237 /* Abbreviated name. */
238 len = strlen(_ctloc(abmon[i]));
239 if (strncasecmp(_ctloc(abmon[i]), (const char*)bp, len) == 0)
240 break;
241 }
242
243 /* Nothing matched. */
244 if (i == 12)
245 return (NULL);
246
247 tm->tm_mon = i;
248 bp += len;
249 break;
250
251 case 'C': /* The century number. */
252 _LEGAL_ALT(_ALT_E);
253 if (!(_conv_num(&bp, &i, 0, 99)))
254 return (NULL);
255
256 century = i * 100;
257 break;
258
259 case 'd': /* The day of month. */
260 case 'e':
261 _LEGAL_ALT(_ALT_O);
262 if (!(_conv_num(&bp, &tm->tm_mday, 1, 31)))
263 return (NULL);
264 break;
265
266 case 'k': /* The hour (24-hour clock representation). */
267 _LEGAL_ALT(0);
268 /* FALLTHROUGH */
269 case 'H':
270 _LEGAL_ALT(_ALT_O);
271 if (!(_conv_num(&bp, &tm->tm_hour, 0, 23)))
272 return (NULL);
273 break;
274
275 case 'l': /* The hour (12-hour clock representation). */
276 _LEGAL_ALT(0);
277 /* FALLTHROUGH */
278 case 'I':
279 _LEGAL_ALT(_ALT_O);
280 if (!(_conv_num(&bp, &tm->tm_hour, 1, 12)))
281 return (NULL);
282 break;
283
284 case 'j': /* The day of year. */
285 _LEGAL_ALT(0);
286 if (!(_conv_num(&bp, &tm->tm_yday, 1, 366)))
287 return (NULL);
288 tm->tm_yday--;
289 break;
290
291 case 'M': /* The minute. */
292 _LEGAL_ALT(_ALT_O);
293 if (!(_conv_num(&bp, &tm->tm_min, 0, 59)))
294 return (NULL);
295 break;
296
297 case 'm': /* The month. */
298 _LEGAL_ALT(_ALT_O);
299 if (!(_conv_num(&bp, &tm->tm_mon, 1, 12)))
300 return (NULL);
301 tm->tm_mon--;
302 break;
303
304 case 'p': /* The locale's equivalent of AM/PM. */
305 _LEGAL_ALT(0);
306 /* AM? */
307 len = strlen(_ctloc(am_pm[0]));
308 if (strncasecmp(_ctloc(am_pm[0]), (const char*)bp, len) == 0) {
309 if (tm->tm_hour > 12) /* i.e., 13:00 AM ?! */
310 return (NULL);
311 else if (tm->tm_hour == 12)
312 tm->tm_hour = 0;
313
314 bp += len;
315 break;
316 }
317 /* PM? */
318 len = strlen(_ctloc(am_pm[1]));
319 if (strncasecmp(_ctloc(am_pm[1]), (const char*)bp, len) == 0) {
320 if (tm->tm_hour > 12) /* i.e., 13:00 PM ?! */
321 return (NULL);
322 else if (tm->tm_hour < 12)
323 tm->tm_hour += 12;
324
325 bp += len;
326 break;
327 }
328
329 /* Nothing matched. */
330 return (NULL);
331
332 case 'S': /* The seconds. */
333 _LEGAL_ALT(_ALT_O);
334 if (!(_conv_num(&bp, &tm->tm_sec, 0, 61)))
335 return (NULL);
336 break;
337
338 case 'U': /* The week of year, beginning on sunday. */
339 case 'W': /* The week of year, beginning on monday. */
340 _LEGAL_ALT(_ALT_O);
341 /*
342 * XXX This is bogus, as we can not assume any valid
343 * information present in the tm structure at this
344 * point to calculate a real value, so just check the
345 * range for now.
346 */
347 if (!(_conv_num(&bp, &i, 0, 53)))
348 return (NULL);
349 break;
350
351 case 'w': /* The day of week, beginning on sunday. */
352 _LEGAL_ALT(_ALT_O);
353 if (!(_conv_num(&bp, &tm->tm_wday, 0, 6)))
354 return (NULL);
355 break;
356
357 case 'Y': /* The year. */
358 _LEGAL_ALT(_ALT_E);
359 if (!(_conv_num(&bp, &i, 0, 9999)))
360 return (NULL);
361
362 relyear = -1;
363 tm->tm_year = i - TM_YEAR_BASE;
364 break;
365
366 case 'y': /* The year within the century (2 digits). */
367 _LEGAL_ALT(_ALT_E | _ALT_O);
368 if (!(_conv_num(&bp, &relyear, 0, 99)))
369 return (NULL);
370 break;
371
372 /*
373 * Miscellaneous conversions.
374 */
375 case 'n': /* Any kind of white-space. */
376 case 't':
377 _LEGAL_ALT(0);
378 while (isspace(*bp))
379 bp++;
380 break;
381
382
383 default: /* Unknown/unsupported conversion. */
384 return (NULL);
385 }
386
387
388 }
389
390 /*
391 * We need to evaluate the two digit year spec (%y)
392 * last as we can get a century spec (%C) at any time.
393 */
394 if (relyear != -1) {
395 if (century == TM_YEAR_BASE) {
396 if (relyear <= 68)
397 tm->tm_year = relyear + 2000 - TM_YEAR_BASE;
398 else
399 tm->tm_year = relyear + 1900 - TM_YEAR_BASE;
400 } else {
401 tm->tm_year = relyear + century - TM_YEAR_BASE;
402 }
403 }
404
405 return (unsigned char*)bp;
406 }
407
408
409 static int
_conv_num(const unsigned char ** buf,int * dest,int llim,int ulim)410 _conv_num(const unsigned char **buf, int *dest, int llim, int ulim)
411 {
412 int result = 0;
413 int rulim = ulim;
414
415 if (**buf < '0' || **buf > '9')
416 return (0);
417
418 /* we use rulim to break out of the loop when we run out of digits */
419 do {
420 result *= 10;
421 result += *(*buf)++ - '0';
422 rulim /= 10;
423 } while ((result * 10 <= ulim) && rulim && **buf >= '0' && **buf <= '9');
424
425 if (result < llim || result > ulim)
426 return (0);
427
428 *dest = result;
429 return (1);
430 }
431