source: heimdal/trunk/lib/roken/strptime.c@ 5

Last change on this file since 5 was 1, checked in by Paul Smedley, 10 years ago

Initial commit of Heimdal 1.5.3
File size: 9.2 KB
Line 
1/*
2 * Copyright (c) 1999, 2003, 2005 Kungliga Tekniska Högskolan
3 * (Royal Institute of Technology, Stockholm, Sweden).
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 *
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * 3. Neither the name of KTH nor the names of its contributors may be
18 * used to endorse or promote products derived from this software without
19 * specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY KTH AND ITS CONTRIBUTORS ``AS IS'' AND ANY
22 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
24 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL KTH OR ITS CONTRIBUTORS BE
25 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
26 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
27 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
28 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
29 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
30 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
31 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */
32
33#include <config.h>
34#include "roken.h"
35#ifdef TEST_STRPFTIME
36#include "strpftime-test.h"
37#endif
38#include <ctype.h>
39
40static const char *abb_weekdays[] = {
41 "Sun",
42 "Mon",
43 "Tue",
44 "Wed",
45 "Thu",
46 "Fri",
47 "Sat",
48 NULL
49};
50
51static const char *full_weekdays[] = {
52 "Sunday",
53 "Monday",
54 "Tuesday",
55 "Wednesday",
56 "Thursday",
57 "Friday",
58 "Saturday",
59 NULL
60};
61
62static const char *abb_month[] = {
63 "Jan",
64 "Feb",
65 "Mar",
66 "Apr",
67 "May",
68 "Jun",
69 "Jul",
70 "Aug",
71 "Sep",
72 "Oct",
73 "Nov",
74 "Dec",
75 NULL
76};
77
78static const char *full_month[] = {
79 "January",
80 "February",
81 "March",
82 "April",
83 "May",
84 "June",
85 "July",
86 "August",
87 "September",
88 "October",
89 "November",
90 "December",
91 NULL,
92};
93
94static const char *ampm[] = {
95 "am",
96 "pm",
97 NULL
98};
99
100/*
101 * Try to match `*buf' to one of the strings in `strs'. Return the
102 * index of the matching string (or -1 if none). Also advance buf.
103 */
104
105static int
106match_string (const char **buf, const char **strs)
107{
108 int i = 0;
109
110 for (i = 0; strs[i] != NULL; ++i) {
111 int len = strlen (strs[i]);
112
113 if (strncasecmp (*buf, strs[i], len) == 0) {
114 *buf += len;
115 return i;
116 }
117 }
118 return -1;
119}
120
121/*
122 * Try to match `*buf' to at the most `n' characters and return the
123 * resulting number in `num'. Returns 0 or an error. Also advance
124 * buf.
125 */
126
127static int
128parse_number (const char **buf, int n, int *num)
129{
130 char *s, *str;
131 int i;
132
133 str = malloc(n + 1);
134 if (str == NULL)
135 return -1;
136
137 /* skip whitespace */
138 for (; **buf != '\0' && isspace((unsigned char)(**buf)); (*buf)++)
139 ;
140
141 /* parse at least n characters */
142 for (i = 0; **buf != '\0' && i < n && isdigit((unsigned char)(**buf)); i++, (*buf)++)
143 str[i] = **buf;
144 str[i] = '\0';
145
146 *num = strtol (str, &s, 10);
147 free(str);
148 if (s == str)
149 return -1;
150
151 return 0;
152}
153
154/*
155 * tm_year is relative this year
156 */
157
158const int tm_year_base = 1900;
159
160/*
161 * Return TRUE iff `year' was a leap year.
162 */
163
164static int
165is_leap_year (int year)
166{
167 return (year % 4) == 0 && ((year % 100) != 0 || (year % 400) == 0);
168}
169
170/*
171 * Return the weekday [0,6] (0 = Sunday) of the first day of `year'
172 */
173
174static int
175first_day (int year)
176{
177 int ret = 4;
178
179 for (; year > 1970; --year)
180 ret = (ret + (is_leap_year (year) ? 366 : 365)) % 7;
181 return ret;
182}
183
184/*
185 * Set `timeptr' given `wnum' (week number [0, 53])
186 */
187
188static void
189set_week_number_sun (struct tm *timeptr, int wnum)
190{
191 int fday = first_day (timeptr->tm_year + tm_year_base);
192
193 timeptr->tm_yday = wnum * 7 + timeptr->tm_wday - fday;
194 if (timeptr->tm_yday < 0) {
195 timeptr->tm_wday = fday;
196 timeptr->tm_yday = 0;
197 }
198}
199
200/*
201 * Set `timeptr' given `wnum' (week number [0, 53])
202 */
203
204static void
205set_week_number_mon (struct tm *timeptr, int wnum)
206{
207 int fday = (first_day (timeptr->tm_year + tm_year_base) + 6) % 7;
208
209 timeptr->tm_yday = wnum * 7 + (timeptr->tm_wday + 6) % 7 - fday;
210 if (timeptr->tm_yday < 0) {
211 timeptr->tm_wday = (fday + 1) % 7;
212 timeptr->tm_yday = 0;
213 }
214}
215
216/*
217 * Set `timeptr' given `wnum' (week number [0, 53])
218 */
219
220static void
221set_week_number_mon4 (struct tm *timeptr, int wnum)
222{
223 int fday = (first_day (timeptr->tm_year + tm_year_base) + 6) % 7;
224 int offset = 0;
225
226 if (fday < 4)
227 offset += 7;
228
229 timeptr->tm_yday = offset + (wnum - 1) * 7 + timeptr->tm_wday - fday;
230 if (timeptr->tm_yday < 0) {
231 timeptr->tm_wday = fday;
232 timeptr->tm_yday = 0;
233 }
234}
235
236/*
237 *
238 */
239
240ROKEN_LIB_FUNCTION char * ROKEN_LIB_CALL
241strptime (const char *buf, const char *format, struct tm *timeptr)
242{
243 char c;
244
245 for (; (c = *format) != '\0'; ++format) {
246 char *s;
247 int ret;
248
249 if (isspace ((unsigned char)c)) {
250 while (isspace ((unsigned char)*buf))
251 ++buf;
252 } else if (c == '%' && format[1] != '\0') {
253 c = *++format;
254 if (c == 'E' || c == 'O')
255 c = *++format;
256 switch (c) {
257 case 'A' :
258 ret = match_string (&buf, full_weekdays);
259 if (ret < 0)
260 return NULL;
261 timeptr->tm_wday = ret;
262 break;
263 case 'a' :
264 ret = match_string (&buf, abb_weekdays);
265 if (ret < 0)
266 return NULL;
267 timeptr->tm_wday = ret;
268 break;
269 case 'B' :
270 ret = match_string (&buf, full_month);
271 if (ret < 0)
272 return NULL;
273 timeptr->tm_mon = ret;
274 break;
275 case 'b' :
276 case 'h' :
277 ret = match_string (&buf, abb_month);
278 if (ret < 0)
279 return NULL;
280 timeptr->tm_mon = ret;
281 break;
282 case 'C' :
283 if (parse_number(&buf, 2, &ret))
284 return NULL;
285 timeptr->tm_year = (ret * 100) - tm_year_base;
286 break;
287 case 'c' :
288 abort ();
289 case 'D' : /* %m/%d/%y */
290 s = strptime (buf, "%m/%d/%y", timeptr);
291 if (s == NULL)
292 return NULL;
293 buf = s;
294 break;
295 case 'd' :
296 case 'e' :
297 if (parse_number(&buf, 2, &ret))
298 return NULL;
299 timeptr->tm_mday = ret;
300 break;
301 case 'H' :
302 case 'k' :
303 if (parse_number(&buf, 2, &ret))
304 return NULL;
305 timeptr->tm_hour = ret;
306 break;
307 case 'I' :
308 case 'l' :
309 if (parse_number(&buf, 2, &ret))
310 return NULL;
311 if (ret == 12)
312 timeptr->tm_hour = 0;
313 else
314 timeptr->tm_hour = ret;
315 break;
316 case 'j' :
317 if (parse_number(&buf, 3, &ret))
318 return NULL;
319 if (ret == 0)
320 return NULL;
321 timeptr->tm_yday = ret - 1;
322 break;
323 case 'm' :
324 if (parse_number(&buf, 2, &ret))
325 return NULL;
326 if (ret == 0)
327 return NULL;
328 timeptr->tm_mon = ret - 1;
329 break;
330 case 'M' :
331 if (parse_number(&buf, 2, &ret))
332 return NULL;
333 timeptr->tm_min = ret;
334 break;
335 case 'n' :
336 while (isspace ((unsigned char)*buf))
337 buf++;
338 break;
339 case 'p' :
340 ret = match_string (&buf, ampm);
341 if (ret < 0)
342 return NULL;
343 if (timeptr->tm_hour == 0) {
344 if (ret == 1)
345 timeptr->tm_hour = 12;
346 } else
347 timeptr->tm_hour += 12;
348 break;
349 case 'r' : /* %I:%M:%S %p */
350 s = strptime (buf, "%I:%M:%S %p", timeptr);
351 if (s == NULL)
352 return NULL;
353 buf = s;
354 break;
355 case 'R' : /* %H:%M */
356 s = strptime (buf, "%H:%M", timeptr);
357 if (s == NULL)
358 return NULL;
359 buf = s;
360 break;
361 case 'S' :
362 if (parse_number(&buf, 2, &ret))
363 return NULL;
364 timeptr->tm_sec = ret;
365 break;
366 case 't' :
367 while (isspace ((unsigned char)*buf))
368 buf++;
369 break;
370 case 'T' : /* %H:%M:%S */
371 case 'X' :
372 s = strptime (buf, "%H:%M:%S", timeptr);
373 if (s == NULL)
374 return NULL;
375 buf = s;
376 break;
377 case 'u' :
378 if (parse_number(&buf, 1, &ret))
379 return NULL;
380 if (ret <= 0)
381 return NULL;
382 timeptr->tm_wday = ret - 1;
383 break;
384 case 'w' :
385 if (parse_number(&buf, 1, &ret))
386 return NULL;
387 timeptr->tm_wday = ret;
388 break;
389 case 'U' :
390 if (parse_number(&buf, 2, &ret))
391 return NULL;
392 set_week_number_sun (timeptr, ret);
393 break;
394 case 'V' :
395 if (parse_number(&buf, 2, &ret))
396 return NULL;
397 set_week_number_mon4 (timeptr, ret);
398 break;
399 case 'W' :
400 if (parse_number(&buf, 2, &ret))
401 return NULL;
402 set_week_number_mon (timeptr, ret);
403 break;
404 case 'x' :
405 s = strptime (buf, "%Y:%m:%d", timeptr);
406 if (s == NULL)
407 return NULL;
408 buf = s;
409 break;
410 case 'y' :
411 if (parse_number(&buf, 2, &ret))
412 return NULL;
413 if (ret < 70)
414 timeptr->tm_year = 100 + ret;
415 else
416 timeptr->tm_year = ret;
417 break;
418 case 'Y' :
419 if (parse_number(&buf, 4, &ret))
420 return NULL;
421 timeptr->tm_year = ret - tm_year_base;
422 break;
423 case 'Z' :
424 abort ();
425 case '\0' :
426 --format;
427 /* FALLTHROUGH */
428 case '%' :
429 if (*buf == '%')
430 ++buf;
431 else
432 return NULL;
433 break;
434 default :
435 if (*buf == '%' || *++buf == c)
436 ++buf;
437 else
438 return NULL;
439 break;
440 }
441 } else {
442 if (*buf == c)
443 ++buf;
444 else
445 return NULL;
446 }
447 }
448 return rk_UNCONST(buf);
449}
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