strptime.c revision 1.14 1 /* $NetBSD: strptime.c,v 1.14 1998/05/05 14:15:32 tv Exp $ */
2
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 #include <sys/cdefs.h>
39 #if defined(LIBC_SCCS) && !defined(lint)
40 __RCSID("$NetBSD: strptime.c,v 1.14 1998/05/05 14:15:32 tv Exp $");
41 #endif
42
43 #include "namespace.h"
44 #include <sys/localedef.h>
45 #include <ctype.h>
46 #include <locale.h>
47 #include <string.h>
48 #include <time.h>
49 #include <tzfile.h>
50
51 #ifdef __weak_alias
52 __weak_alias(strptime,_strptime);
53 #endif
54
55 #define _ctloc(x) __CONCAT(_CurrentTimeLocale->,x)
56
57 /*
58 * We do not implement alternate representations. However, we always
59 * check whether a given modifier is allowed for a certain conversion.
60 */
61 #define _ALT_E 0x01
62 #define _ALT_O 0x02
63 #define _LEGAL_ALT(x) { if (alt_format & ~(x)) return (0); }
64
65
66 static int _conv_num __P((const char **, int *, int, int));
67
68
69 char *
70 strptime(buf, fmt, tm)
71 const char *buf, *fmt;
72 struct tm *tm;
73 {
74 char c;
75 const char *bp;
76 int alt_format, i, len, split_year = 0;
77
78 bp = buf;
79
80 while ((c = *fmt) != '\0') {
81 /* Clear `alternate' modifier prior to new conversion. */
82 alt_format = 0;
83
84 /* Eat up white-space. */
85 if (isspace(c)) {
86 while (isspace(*bp))
87 bp++;
88
89 fmt++;
90 continue;
91 }
92
93 if ((c = *fmt++) != '%')
94 goto literal;
95
96
97 again: switch (c = *fmt++) {
98 case '%': /* "%%" is converted to "%". */
99 literal:
100 if (c != *bp++)
101 return (0);
102 break;
103
104 /*
105 * "Alternative" modifiers. Just set the appropriate flag
106 * and start over again.
107 */
108 case 'E': /* "%E?" alternative conversion modifier. */
109 _LEGAL_ALT(0);
110 alt_format |= _ALT_E;
111 goto again;
112
113 case 'O': /* "%O?" alternative conversion modifier. */
114 _LEGAL_ALT(0);
115 alt_format |= _ALT_O;
116 goto again;
117
118 /*
119 * "Complex" conversion rules, implemented through recursion.
120 */
121 case 'c': /* Date and time, using the locale's format. */
122 _LEGAL_ALT(_ALT_E);
123 if (!(bp = strptime(bp, _ctloc(d_t_fmt), tm)))
124 return (0);
125 break;
126
127 case 'D': /* The date as "%m/%d/%y". */
128 _LEGAL_ALT(0);
129 if (!(bp = strptime(bp, "%m/%d/%y", tm)))
130 return (0);
131 break;
132
133 case 'R': /* The time as "%H:%M". */
134 _LEGAL_ALT(0);
135 if (!(bp = strptime(bp, "%H:%M", tm)))
136 return (0);
137 break;
138
139 case 'r': /* The time in 12-hour clock representation. */
140 _LEGAL_ALT(0);
141 if (!(bp = strptime(bp, _ctloc(t_fmt_ampm), tm)))
142 return (0);
143 break;
144
145 case 'T': /* The time as "%H:%M:%S". */
146 _LEGAL_ALT(0);
147 if (!(bp = strptime(bp, "%H:%M:%S", tm)))
148 return (0);
149 break;
150
151 case 'X': /* The time, using the locale's format. */
152 _LEGAL_ALT(_ALT_E);
153 if (!(bp = strptime(bp, _ctloc(t_fmt), tm)))
154 return (0);
155 break;
156
157 case 'x': /* The date, using the locale's format. */
158 _LEGAL_ALT(_ALT_E);
159 if (!(bp = strptime(bp, _ctloc(d_fmt), tm)))
160 return (0);
161 break;
162
163 /*
164 * "Elementary" conversion rules.
165 */
166 case 'A': /* The day of week, using the locale's form. */
167 case 'a':
168 _LEGAL_ALT(0);
169 for (i = 0; i < 7; i++) {
170 /* Full name. */
171 len = strlen(_ctloc(day[i]));
172 if (strncasecmp(_ctloc(day[i]), bp, len) == 0)
173 break;
174
175 /* Abbreviated name. */
176 len = strlen(_ctloc(abday[i]));
177 if (strncasecmp(_ctloc(abday[i]), bp, len) == 0)
178 break;
179 }
180
181 /* Nothing matched. */
182 if (i == 7)
183 return (0);
184
185 tm->tm_wday = i;
186 bp += len;
187 break;
188
189 case 'B': /* The month, using the locale's form. */
190 case 'b':
191 case 'h':
192 _LEGAL_ALT(0);
193 for (i = 0; i < 12; i++) {
194 /* Full name. */
195 len = strlen(_ctloc(mon[i]));
196 if (strncasecmp(_ctloc(mon[i]), bp, len) == 0)
197 break;
198
199 /* Abbreviated name. */
200 len = strlen(_ctloc(abmon[i]));
201 if (strncasecmp(_ctloc(abmon[i]), bp, len) == 0)
202 break;
203 }
204
205 /* Nothing matched. */
206 if (i == 12)
207 return (0);
208
209 tm->tm_mon = i;
210 bp += len;
211 break;
212
213 case 'C': /* The century number. */
214 _LEGAL_ALT(_ALT_E);
215 if (!(_conv_num(&bp, &i, 0, 99)))
216 return (0);
217
218 if (split_year) {
219 tm->tm_year = (tm->tm_year % 100) + (i * 100);
220 } else {
221 tm->tm_year = i * 100;
222 split_year = 1;
223 }
224 break;
225
226 case 'd': /* The day of month. */
227 case 'e':
228 _LEGAL_ALT(_ALT_O);
229 if (!(_conv_num(&bp, &tm->tm_mday, 1, 31)))
230 return (0);
231 break;
232
233 case 'k': /* The hour (24-hour clock representation). */
234 _LEGAL_ALT(0);
235 /* FALLTHROUGH */
236 case 'H':
237 _LEGAL_ALT(_ALT_O);
238 if (!(_conv_num(&bp, &tm->tm_hour, 0, 23)))
239 return (0);
240 break;
241
242 case 'l': /* The hour (12-hour clock representation). */
243 _LEGAL_ALT(0);
244 /* FALLTHROUGH */
245 case 'I':
246 _LEGAL_ALT(_ALT_O);
247 if (!(_conv_num(&bp, &tm->tm_hour, 1, 12)))
248 return (0);
249 if (tm->tm_hour == 12)
250 tm->tm_hour = 0;
251 break;
252
253 case 'j': /* The day of year. */
254 _LEGAL_ALT(0);
255 if (!(_conv_num(&bp, &i, 1, 366)))
256 return (0);
257 tm->tm_yday = i - 1;
258 break;
259
260 case 'M': /* The minute. */
261 _LEGAL_ALT(_ALT_O);
262 if (!(_conv_num(&bp, &tm->tm_min, 0, 59)))
263 return (0);
264 break;
265
266 case 'm': /* The month. */
267 _LEGAL_ALT(_ALT_O);
268 if (!(_conv_num(&bp, &i, 1, 12)))
269 return (0);
270 tm->tm_mon = i - 1;
271 break;
272
273 case 'p': /* The locale's equivalent of AM/PM. */
274 _LEGAL_ALT(0);
275 /* AM? */
276 if (strcasecmp(_ctloc(am_pm[0]), bp) == 0) {
277 if (tm->tm_hour > 11)
278 return (0);
279
280 bp += strlen(_ctloc(am_pm[0]));
281 break;
282 }
283 /* PM? */
284 else if (strcasecmp(_ctloc(am_pm[1]), bp) == 0) {
285 if (tm->tm_hour > 11)
286 return (0);
287
288 tm->tm_hour += 12;
289 bp += strlen(_ctloc(am_pm[1]));
290 break;
291 }
292
293 /* Nothing matched. */
294 return (0);
295
296 case 'S': /* The seconds. */
297 _LEGAL_ALT(_ALT_O);
298 if (!(_conv_num(&bp, &tm->tm_sec, 0, 61)))
299 return (0);
300 break;
301
302 case 'U': /* The week of year, beginning on sunday. */
303 case 'W': /* The week of year, beginning on monday. */
304 _LEGAL_ALT(_ALT_O);
305 /*
306 * XXX This is bogus, as we can not assume any valid
307 * information present in the tm structure at this
308 * point to calculate a real value, so just check the
309 * range for now.
310 */
311 if (!(_conv_num(&bp, &i, 0, 53)))
312 return (0);
313 break;
314
315 case 'w': /* The day of week, beginning on sunday. */
316 _LEGAL_ALT(_ALT_O);
317 if (!(_conv_num(&bp, &tm->tm_wday, 0, 6)))
318 return (0);
319 break;
320
321 case 'Y': /* The year. */
322 _LEGAL_ALT(_ALT_E);
323 if (!(_conv_num(&bp, &i, 0, INT_MAX)))
324 return (0);
325
326 tm->tm_year = i - TM_YEAR_BASE;
327 break;
328
329 case 'y': /* The year within 100 years of the epoch. */
330 _LEGAL_ALT(_ALT_E | _ALT_O);
331 if (!(_conv_num(&bp, &i, 0, 99)))
332 return (0);
333
334 if (split_year) {
335 tm->tm_year = ((tm->tm_year / 100) * 100) + i;
336 break;
337 }
338 split_year = 1;
339 if (i <= 68)
340 tm->tm_year = i + 2000 - TM_YEAR_BASE;
341 else
342 tm->tm_year = i + 1900 - TM_YEAR_BASE;
343 break;
344
345 /*
346 * Miscellaneous conversions.
347 */
348 case 'n': /* Any kind of white-space. */
349 case 't':
350 _LEGAL_ALT(0);
351 while (isspace(*bp))
352 bp++;
353 break;
354
355
356 default: /* Unknown/unsupported conversion. */
357 return (0);
358 }
359
360
361 }
362
363 return ((char *)bp);
364 }
365
366
367 static int
368 _conv_num(buf, dest, llim, ulim)
369 const char **buf;
370 int *dest;
371 int llim, ulim;
372 {
373 *dest = 0;
374
375 if (**buf < '0' || **buf > '9')
376 return (0);
377
378 do {
379 *dest *= 10;
380 *dest += *(*buf)++ - '0';
381 } while ((*dest * 10 <= ulim) && **buf >= '0' && **buf <= '9');
382
383 if (*dest < llim || *dest > ulim)
384 return (0);
385
386 return (1);
387 }
388