strptime.c revision 54316 
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 54316 1999-12-08 15:49:10Z 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			/* XXX This will break for 3-digit centuries. */
133			len = 2;
134			for (i = 0; len && *buf != 0 && isdigit((unsigned char)*buf); buf++) {
135				i *= 10;
136				i += *buf - '0';
137				len--;
138			}
139			if (i < 19)
140				return 0;
141
142			tm->tm_year = i * 100 - 1900;
143			break;
144
145		case 'c':
146			buf = _strptime(buf, Locale->c_fmt, tm);
147			if (buf == 0)
148				return 0;
149			break;
150
151		case 'D':
152			buf = _strptime(buf, "%m/%d/%y", tm);
153			if (buf == 0)
154				return 0;
155			break;
156
157		case 'E':
158			if (Ealternative || Oalternative)
159				break;
160			Ealternative++;
161			goto label;
162
163		case 'O':
164			if (Ealternative || Oalternative)
165				break;
166			Oalternative++;
167			goto label;
168
169		case 'F':
170		case 'f':
171			if (!Ealternative)
172				break;
173			buf = _strptime(buf, (c == 'f') ? Locale->Ef_fmt : Locale->EF_fmt, tm);
174			if (buf == 0)
175				return 0;
176			break;
177
178		case 'R':
179			buf = _strptime(buf, "%H:%M", tm);
180			if (buf == 0)
181				return 0;
182			break;
183
184		case 'r':
185			buf = _strptime(buf, "%I:%M:%S %p", tm);
186			if (buf == 0)
187				return 0;
188			break;
189
190		case 'T':
191			buf = _strptime(buf, "%H:%M:%S", tm);
192			if (buf == 0)
193				return 0;
194			break;
195
196		case 'X':
197			buf = _strptime(buf, Locale->X_fmt, tm);
198			if (buf == 0)
199				return 0;
200			break;
201
202		case 'x':
203			buf = _strptime(buf, Locale->x_fmt, tm);
204			if (buf == 0)
205				return 0;
206			break;
207
208		case 'j':
209			if (!isdigit((unsigned char)*buf))
210				return 0;
211
212			len = 3;
213			for (i = 0; len && *buf != 0 && isdigit((unsigned char)*buf); buf++) {
214				i *= 10;
215				i += *buf - '0';
216				len--;
217			}
218			if (i < 1 || i > 366)
219				return 0;
220
221			tm->tm_yday = i - 1;
222			break;
223
224		case 'M':
225		case 'S':
226			if (*buf == 0 || isspace((unsigned char)*buf))
227				break;
228
229			if (!isdigit((unsigned char)*buf))
230				return 0;
231
232			len = 2;
233			for (i = 0; len && *buf != 0 && isdigit((unsigned char)*buf); buf++) {
234				i *= 10;
235				i += *buf - '0';
236				len--;
237			}
238
239			if (c == 'M') {
240				if (i > 59)
241					return 0;
242				tm->tm_min = i;
243			} else {
244				if (i > 60)
245					return 0;
246				tm->tm_sec = i;
247			}
248
249			if (*buf != 0 && isspace((unsigned char)*buf))
250				while (*ptr != 0 && !isspace((unsigned char)*ptr))
251					ptr++;
252			break;
253
254		case 'H':
255		case 'I':
256		case 'k':
257		case 'l':
258			/*
259			 * Of these, %l is the only specifier explicitly
260			 * documented as not being zero-padded.  However,
261			 * there is no harm in allowing zero-padding.
262			 *
263			 * XXX The %l specifier may gobble one too many
264			 * digits if used incorrectly.
265			 */
266			if (!isdigit((unsigned char)*buf))
267				return 0;
268
269			len = 2;
270			for (i = 0; len && *buf != 0 && isdigit((unsigned char)*buf); buf++) {
271				i *= 10;
272				i += *buf - '0';
273				len--;
274			}
275			if (c == 'H' || c == 'k') {
276				if (i > 23)
277					return 0;
278			} else if (i > 12)
279				return 0;
280
281			tm->tm_hour = i;
282
283			if (*buf != 0 && isspace((unsigned char)*buf))
284				while (*ptr != 0 && !isspace((unsigned char)*ptr))
285					ptr++;
286			break;
287
288		case 'p':
289			/*
290			 * XXX This is bogus if parsed before hour-related
291			 * specifiers.
292			 */
293			len = strlen(Locale->am);
294			if (strncasecmp(buf, Locale->am, len) == 0) {
295				if (tm->tm_hour > 12)
296					return 0;
297				if (tm->tm_hour == 12)
298					tm->tm_hour = 0;
299				buf += len;
300				break;
301			}
302
303			len = strlen(Locale->pm);
304			if (strncasecmp(buf, Locale->pm, len) == 0) {
305				if (tm->tm_hour > 12)
306					return 0;
307				if (tm->tm_hour != 12)
308					tm->tm_hour += 12;
309				buf += len;
310				break;
311			}
312
313			return 0;
314
315		case 'A':
316		case 'a':
317			for (i = 0; i < asizeof(Locale->weekday); i++) {
318				if (c == 'A') {
319					len = strlen(Locale->weekday[i]);
320					if (strncasecmp(buf,
321							Locale->weekday[i],
322							len) == 0)
323						break;
324				} else {
325					len = strlen(Locale->wday[i]);
326					if (strncasecmp(buf,
327							Locale->wday[i],
328							len) == 0)
329						break;
330				}
331			}
332			if (i == asizeof(Locale->weekday))
333				return 0;
334
335			tm->tm_wday = i;
336			buf += len;
337			break;
338
339		case 'U':
340		case 'W':
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 (!isdigit((unsigned char)*buf))
348				return 0;
349
350			len = 2;
351			for (i = 0; len && *buf != 0 && isdigit((unsigned char)*buf); buf++) {
352				i *= 10;
353				i += *buf - '0';
354				len--;
355			}
356			if (i > 53)
357				return 0;
358
359			if (*buf != 0 && isspace((unsigned char)*buf))
360				while (*ptr != 0 && !isspace((unsigned char)*ptr))
361					ptr++;
362			break;
363
364		case 'w':
365			if (!isdigit((unsigned char)*buf))
366				return 0;
367
368			i = *buf - '0';
369			if (i > 6)
370				return 0;
371
372			tm->tm_wday = i;
373
374			if (*buf != 0 && isspace((unsigned char)*buf))
375				while (*ptr != 0 && !isspace((unsigned char)*ptr))
376					ptr++;
377			break;
378
379		case 'd':
380		case 'e':
381			/*
382			 * The %e specifier is explicitly documented as not
383			 * being zero-padded but there is no harm in allowing
384			 * such padding.
385			 *
386			 * XXX The %e specifier may gobble one too many
387			 * digits if used incorrectly.
388			 */
389			if (!isdigit((unsigned char)*buf))
390				return 0;
391
392			len = 2;
393			for (i = 0; len && *buf != 0 && isdigit((unsigned char)*buf); buf++) {
394				i *= 10;
395				i += *buf - '0';
396				len--;
397			}
398			if (i > 31)
399				return 0;
400
401			tm->tm_mday = i;
402
403			if (*buf != 0 && isspace((unsigned char)*buf))
404				while (*ptr != 0 && !isspace((unsigned char)*ptr))
405					ptr++;
406			break;
407
408		case 'B':
409		case 'b':
410		case 'h':
411			for (i = 0; i < asizeof(Locale->month); i++) {
412				if (Oalternative) {
413					if (c == 'B') {
414						len = strlen(Locale->alt_month[i]);
415						if (strncasecmp(buf,
416								Locale->alt_month[i],
417								len) == 0)
418							break;
419					}
420				} else {
421					if (c == 'B') {
422						len = strlen(Locale->month[i]);
423						if (strncasecmp(buf,
424								Locale->month[i],
425								len) == 0)
426							break;
427					} else {
428						len = strlen(Locale->mon[i]);
429						if (strncasecmp(buf,
430								Locale->mon[i],
431								len) == 0)
432							break;
433					}
434				}
435			}
436			if (i == asizeof(Locale->month))
437				return 0;
438
439			tm->tm_mon = i;
440			buf += len;
441			break;
442
443		case 'm':
444			if (!isdigit((unsigned char)*buf))
445				return 0;
446
447			len = 2;
448			for (i = 0; len && *buf != 0 && isdigit((unsigned char)*buf); buf++) {
449				i *= 10;
450				i += *buf - '0';
451				len--;
452			}
453			if (i < 1 || i > 12)
454				return 0;
455
456			tm->tm_mon = i - 1;
457
458			if (*buf != 0 && isspace((unsigned char)*buf))
459				while (*ptr != 0 && !isspace((unsigned char)*ptr))
460					ptr++;
461			break;
462
463		case 'Y':
464		case 'y':
465			if (*buf == 0 || isspace((unsigned char)*buf))
466				break;
467
468			if (!isdigit((unsigned char)*buf))
469				return 0;
470
471			len = (c == 'Y') ? 4 : 2;
472			for (i = 0; len && *buf != 0 && isdigit((unsigned char)*buf); buf++) {
473				i *= 10;
474				i += *buf - '0';
475				len--;
476			}
477			if (c == 'Y')
478				i -= 1900;
479			if (c == 'y' && i < 69)
480				i += 100;
481			if (i < 0)
482				return 0;
483
484			tm->tm_year = i;
485
486			if (*buf != 0 && isspace((unsigned char)*buf))
487				while (*ptr != 0 && !isspace((unsigned char)*ptr))
488					ptr++;
489			break;
490
491		case 'Z':
492			{
493			const char *cp;
494			char *zonestr;
495
496			for (cp = buf; *cp && isupper((unsigned char)*cp); ++cp) {/*empty*/}
497			if (cp - buf) {
498				zonestr = alloca(cp - buf + 1);
499				strncpy(zonestr, buf, cp - buf);
500				zonestr[cp - buf] = '\0';
501				tzset();
502				if (0 == strcmp(zonestr, "GMT")) {
503				    got_GMT = 1;
504				} else if (0 == strcmp(zonestr, tzname[0])) {
505				    tm->tm_isdst = 0;
506				} else if (0 == strcmp(zonestr, tzname[1])) {
507				    tm->tm_isdst = 1;
508				} else {
509				    return 0;
510				}
511				buf += cp - buf;
512			}
513			}
514			break;
515		}
516	}
517	return (char *)buf;
518}
519
520
521char *
522strptime(const char *buf, const char *fmt, struct tm *tm)
523{
524	char *ret;
525
526#ifdef	_THREAD_SAFE
527	pthread_mutex_lock(&gotgmt_mutex);
528#endif
529
530	got_GMT = 0;
531	ret = _strptime(buf, fmt, tm);
532	if (ret && got_GMT) {
533		time_t t = timegm(tm);
534	    localtime_r(&t, tm);
535		got_GMT = 0;
536	}
537
538#ifdef	_THREAD_SAFE
539	pthread_mutex_unlock(&gotgmt_mutex);
540#endif
541
542	return ret;
543}
544