strptime.c revision 54301 
1/*
2 * Powerdog Industries kindly requests feedback from anyone modifying
3 * this function:
4 *
5 * Date: Thu, 05 Jun 1997 23:17:17 -0400
6 * From: Kevin Ruddy <kevin.ruddy@powerdog.com>
7 * To: James FitzGibbon <james@nexis.net>
8 * Subject: Re: Use of your strptime(3) code (fwd)
9 *
10 * The reason for the "no mod" clause was so that modifications would
11 * come back and we could integrate them and reissue so that a wider
12 * audience could use it (thereby spreading the wealth).  This has
13 * made it possible to get strptime to work on many operating systems.
14 * I'm not sure why that's "plain unacceptable" to the FreeBSD team.
15 *
16 * Anyway, you can change it to "with or without modification" as
17 * you see fit.  Enjoy.
18 *
19 * Kevin Ruddy
20 * Powerdog Industries, Inc.
21 */
22/*
23 * Copyright (c) 1994 Powerdog Industries.  All rights reserved.
24 *
25 * Redistribution and use in source and binary forms, with or without
26 * modification, are permitted provided that the following conditions
27 * are met:
28 * 1. Redistributions of source code must retain the above copyright
29 *    notice, this list of conditions and the following disclaimer.
30 * 2. Redistributions in binary form must reproduce the above copyright
31 *    notice, this list of conditions and the following disclaimer
32 *    in the documentation and/or other materials provided with the
33 *    distribution.
34 * 3. All advertising materials mentioning features or use of this
35 *    software must display the following acknowledgement:
36 *      This product includes software developed by Powerdog Industries.
37 * 4. The name of Powerdog Industries may not be used to endorse or
38 *    promote products derived from this software without specific prior
39 *    written permission.
40 *
41 * THIS SOFTWARE IS PROVIDED BY POWERDOG INDUSTRIES ``AS IS'' AND ANY
42 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
44 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE POWERDOG INDUSTRIES BE
45 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
46 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
47 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
48 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
49 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
50 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
51 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
52 */
53
54#ifdef LIBC_RCS
55static const char rcsid[] =
56  "$FreeBSD: head/lib/libc/stdtime/strptime.c 54301 1999-12-08 11:11:40Z sheldonh $";
57#endif
58
59#ifndef lint
60#ifndef NOID
61static char copyright[] =
62"@(#) Copyright (c) 1994 Powerdog Industries.  All rights reserved.";
63static char sccsid[] = "@(#)strptime.c	0.1 (Powerdog) 94/03/27";
64#endif /* !defined NOID */
65#endif /* not lint */
66
67#include <time.h>
68#include <ctype.h>
69#include <string.h>
70#ifdef	_THREAD_SAFE
71#include <pthread.h>
72#include "pthread_private.h"
73#endif
74#include "timelocal.h"
75
76static char * _strptime(const char *, const char *, struct tm *);
77
78#ifdef	_THREAD_SAFE
79static struct pthread_mutex	_gotgmt_mutexd = PTHREAD_MUTEX_STATIC_INITIALIZER;
80static pthread_mutex_t		gotgmt_mutex   = &_gotgmt_mutexd;
81#endif
82static int got_GMT;
83
84#define asizeof(a)	(sizeof (a) / sizeof ((a)[0]))
85
86static char *
87_strptime(const char *buf, const char *fmt, struct tm *tm)
88{
89	char	c;
90	const char *ptr;
91	int	i,
92		len;
93	int Ealternative, Oalternative;
94
95	ptr = fmt;
96	while (*ptr != 0) {
97		if (*buf == 0)
98			break;
99
100		c = *ptr++;
101
102		if (c != '%') {
103			if (isspace((unsigned char)c))
104				while (*buf != 0 && isspace((unsigned char)*buf))
105					buf++;
106			else if (c != *buf++)
107				return 0;
108			continue;
109		}
110
111		Ealternative = 0;
112		Oalternative = 0;
113label:
114		c = *ptr++;
115		switch (c) {
116		case 0:
117		case '%':
118			if (*buf++ != '%')
119				return 0;
120			break;
121
122		case '+':
123			buf = _strptime(buf, Locale->date_fmt, tm);
124			if (buf == 0)
125				return 0;
126			break;
127
128		case 'C':
129			if (!isdigit((unsigned char)*buf))
130				return 0;
131
132			for (i = 0; *buf != 0 && isdigit((unsigned char)*buf); buf++) {
133				i *= 10;
134				i += *buf - '0';
135			}
136			if (i < 19)
137				return 0;
138
139			tm->tm_year = i * 100 - 1900;
140			break;
141
142		case 'c':
143			buf = _strptime(buf, Locale->c_fmt, tm);
144			if (buf == 0)
145				return 0;
146			break;
147
148		case 'D':
149			buf = _strptime(buf, "%m/%d/%y", tm);
150			if (buf == 0)
151				return 0;
152			break;
153
154		case 'E':
155			if (Ealternative || Oalternative)
156				break;
157			Ealternative++;
158			goto label;
159
160		case 'O':
161			if (Ealternative || Oalternative)
162				break;
163			Oalternative++;
164			goto label;
165
166		case 'F':
167		case 'f':
168			if (!Ealternative)
169				break;
170			buf = _strptime(buf, (c == 'f') ? Locale->Ef_fmt : Locale->EF_fmt, tm);
171			if (buf == 0)
172				return 0;
173			break;
174
175		case 'R':
176			buf = _strptime(buf, "%H:%M", tm);
177			if (buf == 0)
178				return 0;
179			break;
180
181		case 'r':
182			buf = _strptime(buf, "%I:%M:%S %p", tm);
183			if (buf == 0)
184				return 0;
185			break;
186
187		case 'T':
188			buf = _strptime(buf, "%H:%M:%S", tm);
189			if (buf == 0)
190				return 0;
191			break;
192
193		case 'X':
194			buf = _strptime(buf, Locale->X_fmt, tm);
195			if (buf == 0)
196				return 0;
197			break;
198
199		case 'x':
200			buf = _strptime(buf, Locale->x_fmt, tm);
201			if (buf == 0)
202				return 0;
203			break;
204
205		case 'j':
206			if (!isdigit((unsigned char)*buf))
207				return 0;
208
209			for (i = 0; *buf != 0 && isdigit((unsigned char)*buf); buf++) {
210				i *= 10;
211				i += *buf - '0';
212			}
213			if (i < 1 || i > 366)
214				return 0;
215
216			tm->tm_yday = i - 1;
217			break;
218
219		case 'M':
220		case 'S':
221			if (*buf == 0 || isspace((unsigned char)*buf))
222				break;
223
224			if (!isdigit((unsigned char)*buf))
225				return 0;
226
227			for (i = 0; *buf != 0 && isdigit((unsigned char)*buf); buf++) {
228				i *= 10;
229				i += *buf - '0';
230			}
231
232			if (c == 'M') {
233				if (i > 59)
234					return 0;
235				tm->tm_min = i;
236			} else {
237				if (i > 60)
238					return 0;
239				tm->tm_sec = i;
240			}
241
242			if (*buf != 0 && isspace((unsigned char)*buf))
243				while (*ptr != 0 && !isspace((unsigned char)*ptr))
244					ptr++;
245			break;
246
247		case 'H':
248		case 'I':
249		case 'k':
250		case 'l':
251			if (!isdigit((unsigned char)*buf))
252				return 0;
253
254			for (i = 0; *buf != 0 && isdigit((unsigned char)*buf); buf++) {
255				i *= 10;
256				i += *buf - '0';
257			}
258			if (c == 'H' || c == 'k') {
259				if (i > 23)
260					return 0;
261			} else if (i > 12)
262				return 0;
263
264			tm->tm_hour = i;
265
266			if (*buf != 0 && isspace((unsigned char)*buf))
267				while (*ptr != 0 && !isspace((unsigned char)*ptr))
268					ptr++;
269			break;
270
271		case 'p':
272			len = strlen(Locale->am);
273			if (strncasecmp(buf, Locale->am, len) == 0) {
274				if (tm->tm_hour > 12)
275					return 0;
276				if (tm->tm_hour == 12)
277					tm->tm_hour = 0;
278				buf += len;
279				break;
280			}
281
282			len = strlen(Locale->pm);
283			if (strncasecmp(buf, Locale->pm, len) == 0) {
284				if (tm->tm_hour > 12)
285					return 0;
286				if (tm->tm_hour != 12)
287					tm->tm_hour += 12;
288				buf += len;
289				break;
290			}
291
292			return 0;
293
294		case 'A':
295		case 'a':
296			for (i = 0; i < asizeof(Locale->weekday); i++) {
297				if (c == 'A') {
298					len = strlen(Locale->weekday[i]);
299					if (strncasecmp(buf,
300							Locale->weekday[i],
301							len) == 0)
302						break;
303				} else {
304					len = strlen(Locale->wday[i]);
305					if (strncasecmp(buf,
306							Locale->wday[i],
307							len) == 0)
308						break;
309				}
310			}
311			if (i == asizeof(Locale->weekday))
312				return 0;
313
314			tm->tm_wday = i;
315			buf += len;
316			break;
317
318		case 'U':
319		case 'W':
320			/*
321			 * XXX This is bogus, as we can not assume any valid
322			 * information present in the tm structure at this
323			 * point to calculate a real value, so just check the
324			 * range for now.
325			 */
326			if (!isdigit((unsigned char)*buf))
327				return 0;
328
329			for (i = 0; *buf != 0 && isdigit((unsigned char)*buf); buf++) {
330				i *= 10;
331				i += *buf - '0';
332			}
333			if (i > 53)
334				return 0;
335
336			if (*buf != 0 && isspace((unsigned char)*buf))
337				while (*ptr != 0 && !isspace((unsigned char)*ptr))
338					ptr++;
339			break;
340
341		case 'w':
342			if (!isdigit((unsigned char)*buf))
343				return 0;
344
345			for (i = 0; *buf != 0 && isdigit((unsigned char)*buf); buf++) {
346				i *= 10;
347				i += *buf - '0';
348			}
349			if (i > 6)
350				return 0;
351
352			tm->tm_wday = i;
353
354			if (*buf != 0 && isspace((unsigned char)*buf))
355				while (*ptr != 0 && !isspace((unsigned char)*ptr))
356					ptr++;
357			break;
358
359		case 'd':
360		case 'e':
361			if (!isdigit((unsigned char)*buf))
362				return 0;
363
364			for (i = 0; *buf != 0 && isdigit((unsigned char)*buf); buf++) {
365				i *= 10;
366				i += *buf - '0';
367			}
368			if (i > 31)
369				return 0;
370
371			tm->tm_mday = i;
372
373			if (*buf != 0 && isspace((unsigned char)*buf))
374				while (*ptr != 0 && !isspace((unsigned char)*ptr))
375					ptr++;
376			break;
377
378		case 'B':
379		case 'b':
380		case 'h':
381			for (i = 0; i < asizeof(Locale->month); i++) {
382				if (Oalternative) {
383					if (c == 'B') {
384						len = strlen(Locale->alt_month[i]);
385						if (strncasecmp(buf,
386								Locale->alt_month[i],
387								len) == 0)
388							break;
389					}
390				} else {
391					if (c == 'B') {
392						len = strlen(Locale->month[i]);
393						if (strncasecmp(buf,
394								Locale->month[i],
395								len) == 0)
396							break;
397					} else {
398						len = strlen(Locale->mon[i]);
399						if (strncasecmp(buf,
400								Locale->mon[i],
401								len) == 0)
402							break;
403					}
404				}
405			}
406			if (i == asizeof(Locale->month))
407				return 0;
408
409			tm->tm_mon = i;
410			buf += len;
411			break;
412
413		case 'm':
414			if (!isdigit((unsigned char)*buf))
415				return 0;
416
417			for (i = 0; *buf != 0 && isdigit((unsigned char)*buf); buf++) {
418				i *= 10;
419				i += *buf - '0';
420			}
421			if (i < 1 || i > 12)
422				return 0;
423
424			tm->tm_mon = i - 1;
425
426			if (*buf != 0 && isspace((unsigned char)*buf))
427				while (*ptr != 0 && !isspace((unsigned char)*ptr))
428					ptr++;
429			break;
430
431		case 'Y':
432		case 'y':
433			if (*buf == 0 || isspace((unsigned char)*buf))
434				break;
435
436			if (!isdigit((unsigned char)*buf))
437				return 0;
438
439			for (i = 0; *buf != 0 && isdigit((unsigned char)*buf); buf++) {
440				i *= 10;
441				i += *buf - '0';
442			}
443			if (c == 'Y')
444				i -= 1900;
445			if (c == 'y' && i < 69)
446				i += 100;
447			if (i < 0)
448				return 0;
449
450			tm->tm_year = i;
451
452			if (*buf != 0 && isspace((unsigned char)*buf))
453				while (*ptr != 0 && !isspace((unsigned char)*ptr))
454					ptr++;
455			break;
456
457		case 'Z':
458			{
459			const char *cp;
460			char *zonestr;
461
462			for (cp = buf; *cp && isupper((unsigned char)*cp); ++cp) {/*empty*/}
463			if (cp - buf) {
464				zonestr = alloca(cp - buf + 1);
465				strncpy(zonestr, buf, cp - buf);
466				zonestr[cp - buf] = '\0';
467				tzset();
468				if (0 == strcmp(zonestr, "GMT")) {
469				    got_GMT = 1;
470				} else if (0 == strcmp(zonestr, tzname[0])) {
471				    tm->tm_isdst = 0;
472				} else if (0 == strcmp(zonestr, tzname[1])) {
473				    tm->tm_isdst = 1;
474				} else {
475				    return 0;
476				}
477				buf += cp - buf;
478			}
479			}
480			break;
481		}
482	}
483	return (char *)buf;
484}
485
486
487char *
488strptime(const char *buf, const char *fmt, struct tm *tm)
489{
490	char *ret;
491
492#ifdef	_THREAD_SAFE
493	pthread_mutex_lock(&gotgmt_mutex);
494#endif
495
496	got_GMT = 0;
497	ret = _strptime(buf, fmt, tm);
498	if (ret && got_GMT) {
499		time_t t = timegm(tm);
500	    localtime_r(&t, tm);
501		got_GMT = 0;
502	}
503
504#ifdef	_THREAD_SAFE
505	pthread_mutex_unlock(&gotgmt_mutex);
506#endif
507
508	return ret;
509}
510