1 /** @file
2 strptime implementation
3
4 Copyright (c) 2011, Intel Corporation. All rights reserved.<BR>
5 This program and the accompanying materials are licensed and made available under
6 the terms and conditions of the BSD License that accompanies this distribution.
7 The full text of the license may be found at
8 http://opensource.org/licenses/bsd-license.php.
9
10 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
11 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
12
13 * Copyright (c) 1997, 1998, 2005, 2008 The NetBSD Foundation, Inc.
14 * All rights reserved.
15 *
16 * This code was contributed to The NetBSD Foundation by Klaus Klein.
17 * Heavily optimised by David Laight
18 *
19 * Redistribution and use in source and binary forms, with or without
20 * modification, are permitted provided that the following conditions
21 * are met:
22 * 1. Redistributions of source code must retain the above copyright
23 * notice, this list of conditions and the following disclaimer.
24 * 2. Redistributions in binary form must reproduce the above copyright
25 * notice, this list of conditions and the following disclaimer in the
26 * documentation and/or other materials provided with the distribution.
27 *
28 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
29 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
30 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
31 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
32 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
33 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
34 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
35 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
36 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
37 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
38 * POSSIBILITY OF SUCH DAMAGE.
39
40 $NetBSD: strptime.c,v 1.28 2008/04/28 20:23:01 martin Exp $
41
42 **/
43
44 #if defined(_MSC_VER) /* Handle Microsoft VC++ compiler specifics. */
45 #pragma warning ( disable : 4244 )
46 #pragma warning ( disable : 4018 )
47 #endif
48
49 #include <LibConfig.h>
50
51 #include <sys/cdefs.h>
52
53 #include "namespace.h"
54 #include <time.h>
55 #include "tzfile.h"
56 #include <TimeVals.h>
57 #include <fcntl.h>
58
59 #include <sys/localedef.h>
60
61 #include <ctype.h>
62 #include <locale.h>
63 #include <string.h>
64
65 #ifdef __weak_alias
66 __weak_alias(strptime,_strptime)
67 #endif
68
69 #define _ctloc(x) (_CurrentTimeLocale->x)
70
71 /*
72 * We do not implement alternate representations. However, we always
73 * check whether a given modifier is allowed for a certain conversion.
74 */
75 #define ALT_E 0x01
76 #define ALT_O 0x02
77 #define LEGAL_ALT(x) { if (alt_format & ~(x)) return NULL; }
78
79 static const unsigned char *conv_num(const unsigned char *, int *, unsigned int, unsigned int);
80 static const unsigned char *find_string(const unsigned char *, int *, const char * const *,
81 const char * const *, int);
82
83
84 char *
strptime(const char * buf,const char * fmt,struct tm * tm)85 strptime(const char *buf, const char *fmt, struct tm *tm)
86 {
87 unsigned char c;
88 const unsigned char *bp;
89 int alt_format, i, split_year = 0;
90 const char *new_fmt;
91
92 bp = (const unsigned char *)buf;
93
94 while (bp != NULL && (c = *fmt++) != '\0') {
95 /* Clear `alternate' modifier prior to new conversion. */
96 alt_format = 0;
97 i = 0;
98
99 /* Eat up white-space. */
100 if (isspace(c)) {
101 while (isspace(*bp))
102 bp++;
103 continue;
104 }
105
106 if (c != '%')
107 goto literal;
108
109
110 again: switch (c = *fmt++) {
111 case '%': /* "%%" is converted to "%". */
112 literal:
113 if (c != *bp++)
114 return NULL;
115 LEGAL_ALT(0);
116 continue;
117
118 /*
119 * "Alternative" modifiers. Just set the appropriate flag
120 * and start over again.
121 */
122 case 'E': /* "%E?" alternative conversion modifier. */
123 LEGAL_ALT(0);
124 alt_format |= ALT_E;
125 goto again;
126
127 case 'O': /* "%O?" alternative conversion modifier. */
128 LEGAL_ALT(0);
129 alt_format |= ALT_O;
130 goto again;
131
132 /*
133 * "Complex" conversion rules, implemented through recursion.
134 */
135 case 'c': /* Date and time, using the locale's format. */
136 new_fmt = _ctloc(d_t_fmt);
137 goto recurse;
138
139 case 'D': /* The date as "%m/%d/%y". */
140 new_fmt = "%m/%d/%y";
141 LEGAL_ALT(0);
142 goto recurse;
143
144 case 'F': /* The date as "%Y-%m-%d". */
145 new_fmt = "%Y-%m-%d";
146 LEGAL_ALT(0);
147 goto recurse;
148
149 case 'R': /* The time as "%H:%M". */
150 new_fmt = "%H:%M";
151 LEGAL_ALT(0);
152 goto recurse;
153
154 case 'r': /* The time in 12-hour clock representation. */
155 new_fmt =_ctloc(t_fmt_ampm);
156 LEGAL_ALT(0);
157 goto recurse;
158
159 case 'T': /* The time as "%H:%M:%S". */
160 new_fmt = "%H:%M:%S";
161 LEGAL_ALT(0);
162 goto recurse;
163
164 case 'X': /* The time, using the locale's format. */
165 new_fmt =_ctloc(t_fmt);
166 goto recurse;
167
168 case 'x': /* The date, using the locale's format. */
169 new_fmt =_ctloc(d_fmt);
170 recurse:
171 bp = (const unsigned char *)strptime((const char *)bp,
172 new_fmt, tm);
173 LEGAL_ALT(ALT_E);
174 continue;
175
176 /*
177 * "Elementary" conversion rules.
178 */
179 case 'A': /* The day of week, using the locale's form. */
180 case 'a':
181 bp = find_string(bp, &tm->tm_wday, _ctloc(day),
182 _ctloc(abday), 7);
183 LEGAL_ALT(0);
184 continue;
185
186 case 'B': /* The month, using the locale's form. */
187 case 'b':
188 case 'h':
189 bp = find_string(bp, &tm->tm_mon, _ctloc(mon),
190 _ctloc(abmon), 12);
191 LEGAL_ALT(0);
192 continue;
193
194 case 'C': /* The century number. */
195 i = 20;
196 bp = conv_num(bp, &i, 0, 99);
197
198 i = i * 100 - TM_YEAR_BASE;
199 if (split_year)
200 i += tm->tm_year % 100;
201 split_year = 1;
202 tm->tm_year = i;
203 LEGAL_ALT(ALT_E);
204 continue;
205
206 case 'd': /* The day of month. */
207 case 'e':
208 bp = conv_num(bp, &tm->tm_mday, 1, 31);
209 LEGAL_ALT(ALT_O);
210 continue;
211
212 case 'k': /* The hour (24-hour clock representation). */
213 LEGAL_ALT(0);
214 /* FALLTHROUGH */
215 case 'H':
216 bp = conv_num(bp, &tm->tm_hour, 0, 23);
217 LEGAL_ALT(ALT_O);
218 continue;
219
220 case 'l': /* The hour (12-hour clock representation). */
221 LEGAL_ALT(0);
222 /* FALLTHROUGH */
223 case 'I':
224 bp = conv_num(bp, &tm->tm_hour, 1, 12);
225 if (tm->tm_hour == 12)
226 tm->tm_hour = 0;
227 LEGAL_ALT(ALT_O);
228 continue;
229
230 case 'j': /* The day of year. */
231 i = 1;
232 bp = conv_num(bp, &i, 1, 366);
233 tm->tm_yday = i - 1;
234 LEGAL_ALT(0);
235 continue;
236
237 case 'M': /* The minute. */
238 bp = conv_num(bp, &tm->tm_min, 0, 59);
239 LEGAL_ALT(ALT_O);
240 continue;
241
242 case 'm': /* The month. */
243 i = 1;
244 bp = conv_num(bp, &i, 1, 12);
245 tm->tm_mon = i - 1;
246 LEGAL_ALT(ALT_O);
247 continue;
248
249 case 'p': /* The locale's equivalent of AM/PM. */
250 bp = find_string(bp, &i, _ctloc(am_pm), NULL, 2);
251 if (tm->tm_hour > 11)
252 return NULL;
253 tm->tm_hour += i * 12;
254 LEGAL_ALT(0);
255 continue;
256
257 case 'S': /* The seconds. */
258 bp = conv_num(bp, &tm->tm_sec, 0, 61);
259 LEGAL_ALT(ALT_O);
260 continue;
261
262 case 'U': /* The week of year, beginning on sunday. */
263 case 'W': /* The week of year, beginning on monday. */
264 /*
265 * XXX This is bogus, as we can not assume any valid
266 * information present in the tm structure at this
267 * point to calculate a real value, so just check the
268 * range for now.
269 */
270 bp = conv_num(bp, &i, 0, 53);
271 LEGAL_ALT(ALT_O);
272 continue;
273
274 case 'w': /* The day of week, beginning on sunday. */
275 bp = conv_num(bp, &tm->tm_wday, 0, 6);
276 LEGAL_ALT(ALT_O);
277 continue;
278
279 case 'Y': /* The year. */
280 i = TM_YEAR_BASE; /* just for data sanity... */
281 bp = conv_num(bp, &i, 0, 9999);
282 tm->tm_year = i - TM_YEAR_BASE;
283 LEGAL_ALT(ALT_E);
284 continue;
285
286 case 'y': /* The year within 100 years of the epoch. */
287 /* LEGAL_ALT(ALT_E | ALT_O); */
288 bp = conv_num(bp, &i, 0, 99);
289
290 if (split_year)
291 /* preserve century */
292 i += (tm->tm_year / 100) * 100;
293 else {
294 split_year = 1;
295 if (i <= 68)
296 i = i + 2000 - TM_YEAR_BASE;
297 else
298 i = i + 1900 - TM_YEAR_BASE;
299 }
300 tm->tm_year = i;
301 continue;
302
303 case 'Z':
304 tzset();
305 if (strncmp((const char *)bp, gmt, 3) == 0) {
306 tm->tm_isdst = 0;
307 #ifdef TM_GMTOFF
308 tm->TM_GMTOFF = 0;
309 #endif
310 #ifdef TM_ZONE
311 tm->TM_ZONE = gmt;
312 #endif
313 bp += 3;
314 } else {
315 const unsigned char *ep;
316
317 ep = find_string(bp, &i,
318 (const char * const *)tzname,
319 NULL, 2);
320 if (ep != NULL) {
321 tm->tm_isdst = i;
322 #ifdef TM_GMTOFF
323 tm->TM_GMTOFF = -(timezone);
324 #endif
325 #ifdef TM_ZONE
326 tm->TM_ZONE = tzname[i];
327 #endif
328 }
329 bp = ep;
330 }
331 continue;
332
333 /*
334 * Miscellaneous conversions.
335 */
336 case 'n': /* Any kind of white-space. */
337 case 't':
338 while (isspace(*bp))
339 bp++;
340 LEGAL_ALT(0);
341 continue;
342
343
344 default: /* Unknown/unsupported conversion. */
345 return NULL;
346 }
347 }
348
349 return __UNCONST(bp);
350 }
351
352
353 static const unsigned char *
conv_num(const unsigned char * buf,int * dest,unsigned int llim,unsigned int ulim)354 conv_num(const unsigned char *buf, int *dest, unsigned int llim, unsigned int ulim)
355 {
356 unsigned int result = 0;
357 unsigned char ch;
358
359 /* The limit also determines the number of valid digits. */
360 unsigned int rulim = ulim;
361
362 ch = *buf;
363 if (ch < '0' || ch > '9')
364 return NULL;
365
366 do {
367 result *= 10;
368 result += ch - '0';
369 rulim /= 10;
370 ch = *++buf;
371 } while ((result * 10 <= ulim) && rulim && ch >= '0' && ch <= '9');
372
373 if (result < llim || result > ulim)
374 return NULL;
375
376 *dest = result;
377 return buf;
378 }
379
380 static const unsigned char *
find_string(const unsigned char * bp,int * tgt,const char * const * n1,const char * const * n2,int c)381 find_string(const unsigned char *bp, int *tgt, const char * const *n1,
382 const char * const *n2, int c)
383 {
384 int i;
385 size_t len;
386
387 /* check full name - then abbreviated ones */
388 for (; n1 != NULL; n1 = n2, n2 = NULL) {
389 for (i = 0; i < c; i++, n1++) {
390 len = strlen(*n1);
391 if (strncasecmp(*n1, (const char *)bp, len) == 0) {
392 *tgt = i;
393 return bp + len;
394 }
395 }
396 }
397
398 /* Nothing matched */
399 return NULL;
400 }
401