strptime.c revision 74412 
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 74412 2001-03-18 11:58:15Z ache $";
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 "namespace.h"
68#include <time.h>
69#include <ctype.h>
70#include <string.h>
71#include <pthread.h>
72#include "un-namespace.h"
73#include "libc_private.h"
74#include "timelocal.h"
75
76static char * _strptime(const char *, const char *, struct tm *);
77
78static pthread_mutex_t	gotgmt_mutex = PTHREAD_MUTEX_INITIALIZER;
79static int got_GMT;
80
81#define asizeof(a)	(sizeof (a) / sizeof ((a)[0]))
82
83static char *
84_strptime(const char *buf, const char *fmt, struct tm *tm)
85{
86	char	c;
87	const char *ptr;
88	int	i,
89		len;
90	int Ealternative, Oalternative;
91	struct lc_time_T *tptr = __get_current_time_locale();
92
93	ptr = fmt;
94	while (*ptr != 0) {
95		if (*buf == 0)
96			break;
97
98		c = *ptr++;
99
100		if (c != '%') {
101			if (isspace((unsigned char)c))
102				while (*buf != 0 && isspace((unsigned char)*buf))
103					buf++;
104			else if (c != *buf++)
105				return 0;
106			continue;
107		}
108
109		Ealternative = 0;
110		Oalternative = 0;
111label:
112		c = *ptr++;
113		switch (c) {
114		case 0:
115		case '%':
116			if (*buf++ != '%')
117				return 0;
118			break;
119
120		case '+':
121			buf = _strptime(buf, tptr->date_fmt, tm);
122			if (buf == 0)
123				return 0;
124			break;
125
126		case 'C':
127			if (!isdigit((unsigned char)*buf))
128				return 0;
129
130			/* XXX This will break for 3-digit centuries. */
131			len = 2;
132			for (i = 0; len && *buf != 0 && isdigit((unsigned char)*buf); buf++) {
133				i *= 10;
134				i += *buf - '0';
135				len--;
136			}
137			if (i < 19)
138				return 0;
139
140			tm->tm_year = i * 100 - 1900;
141			break;
142
143		case 'c':
144			buf = _strptime(buf, tptr->c_fmt, tm);
145			if (buf == 0)
146				return 0;
147			break;
148
149		case 'D':
150			buf = _strptime(buf, "%m/%d/%y", tm);
151			if (buf == 0)
152				return 0;
153			break;
154
155		case 'E':
156			if (Ealternative || Oalternative)
157				break;
158			Ealternative++;
159			goto label;
160
161		case 'O':
162			if (Ealternative || Oalternative)
163				break;
164			Oalternative++;
165			goto label;
166
167		case 'F':
168			if (!Ealternative)
169				buf = _strptime(buf, "%Y-%m-%d", tm);
170			else
171				buf = _strptime(buf,
172						*(tptr->md_order) == 'd' ?
173						"%e %B" : "%B %e", tm);
174			if (buf == 0)
175				return 0;
176			break;
177
178		case 'f':
179			if (!Ealternative)
180				break;
181			buf = _strptime(buf,
182				 *(tptr->md_order) == 'd' ? "%e %b" : "%b %e",
183				 tm);
184			if (buf == 0)
185				return 0;
186			break;
187
188		case 'R':
189			buf = _strptime(buf, "%H:%M", tm);
190			if (buf == 0)
191				return 0;
192			break;
193
194		case 'r':
195			buf = _strptime(buf, tptr->ampm_fmt, tm);
196			if (buf == 0)
197				return 0;
198			break;
199
200		case 'T':
201			buf = _strptime(buf, "%H:%M:%S", tm);
202			if (buf == 0)
203				return 0;
204			break;
205
206		case 'X':
207			buf = _strptime(buf, tptr->X_fmt, tm);
208			if (buf == 0)
209				return 0;
210			break;
211
212		case 'x':
213			buf = _strptime(buf, tptr->x_fmt, tm);
214			if (buf == 0)
215				return 0;
216			break;
217
218		case 'j':
219			if (!isdigit((unsigned char)*buf))
220				return 0;
221
222			len = 3;
223			for (i = 0; len && *buf != 0 && isdigit((unsigned char)*buf); buf++) {
224				i *= 10;
225				i += *buf - '0';
226				len--;
227			}
228			if (i < 1 || i > 366)
229				return 0;
230
231			tm->tm_yday = i - 1;
232			break;
233
234		case 'M':
235		case 'S':
236			if (*buf == 0 || isspace((unsigned char)*buf))
237				break;
238
239			if (!isdigit((unsigned char)*buf))
240				return 0;
241
242			len = 2;
243			for (i = 0; len && *buf != 0 && isdigit((unsigned char)*buf); buf++) {
244				i *= 10;
245				i += *buf - '0';
246				len--;
247			}
248
249			if (c == 'M') {
250				if (i > 59)
251					return 0;
252				tm->tm_min = i;
253			} else {
254				if (i > 60)
255					return 0;
256				tm->tm_sec = i;
257			}
258
259			if (*buf != 0 && isspace((unsigned char)*buf))
260				while (*ptr != 0 && !isspace((unsigned char)*ptr))
261					ptr++;
262			break;
263
264		case 'H':
265		case 'I':
266		case 'k':
267		case 'l':
268			/*
269			 * Of these, %l is the only specifier explicitly
270			 * documented as not being zero-padded.  However,
271			 * there is no harm in allowing zero-padding.
272			 *
273			 * XXX The %l specifier may gobble one too many
274			 * digits if used incorrectly.
275			 */
276			if (!isdigit((unsigned char)*buf))
277				return 0;
278
279			len = 2;
280			for (i = 0; len && *buf != 0 && isdigit((unsigned char)*buf); buf++) {
281				i *= 10;
282				i += *buf - '0';
283				len--;
284			}
285			if (c == 'H' || c == 'k') {
286				if (i > 23)
287					return 0;
288			} else if (i > 12)
289				return 0;
290
291			tm->tm_hour = i;
292
293			if (*buf != 0 && isspace((unsigned char)*buf))
294				while (*ptr != 0 && !isspace((unsigned char)*ptr))
295					ptr++;
296			break;
297
298		case 'p':
299			/*
300			 * XXX This is bogus if parsed before hour-related
301			 * specifiers.
302			 */
303			len = strlen(tptr->am);
304			if (strncasecmp(buf, tptr->am, len) == 0) {
305				if (tm->tm_hour > 12)
306					return 0;
307				if (tm->tm_hour == 12)
308					tm->tm_hour = 0;
309				buf += len;
310				break;
311			}
312
313			len = strlen(tptr->pm);
314			if (strncasecmp(buf, tptr->pm, len) == 0) {
315				if (tm->tm_hour > 12)
316					return 0;
317				if (tm->tm_hour != 12)
318					tm->tm_hour += 12;
319				buf += len;
320				break;
321			}
322
323			return 0;
324
325		case 'A':
326		case 'a':
327			for (i = 0; i < asizeof(tptr->weekday); i++) {
328				len = strlen(tptr->weekday[i]);
329				if (strncasecmp(buf, tptr->weekday[i],
330						len) == 0)
331					break;
332				len = strlen(tptr->wday[i]);
333				if (strncasecmp(buf, tptr->wday[i],
334						len) == 0)
335					break;
336			}
337			if (i == asizeof(tptr->weekday))
338				return 0;
339
340			tm->tm_wday = i;
341			buf += len;
342			break;
343
344		case 'U':
345		case 'W':
346			/*
347			 * XXX This is bogus, as we can not assume any valid
348			 * information present in the tm structure at this
349			 * point to calculate a real value, so just check the
350			 * range for now.
351			 */
352			if (!isdigit((unsigned char)*buf))
353				return 0;
354
355			len = 2;
356			for (i = 0; len && *buf != 0 && isdigit((unsigned char)*buf); buf++) {
357				i *= 10;
358				i += *buf - '0';
359				len--;
360			}
361			if (i > 53)
362				return 0;
363
364			if (*buf != 0 && isspace((unsigned char)*buf))
365				while (*ptr != 0 && !isspace((unsigned char)*ptr))
366					ptr++;
367			break;
368
369		case 'w':
370			if (!isdigit((unsigned char)*buf))
371				return 0;
372
373			i = *buf - '0';
374			if (i > 6)
375				return 0;
376
377			tm->tm_wday = i;
378
379			if (*buf != 0 && isspace((unsigned char)*buf))
380				while (*ptr != 0 && !isspace((unsigned char)*ptr))
381					ptr++;
382			break;
383
384		case 'd':
385		case 'e':
386			/*
387			 * The %e specifier is explicitly documented as not
388			 * being zero-padded but there is no harm in allowing
389			 * such padding.
390			 *
391			 * XXX The %e specifier may gobble one too many
392			 * digits if used incorrectly.
393			 */
394			if (!isdigit((unsigned char)*buf))
395				return 0;
396
397			len = 2;
398			for (i = 0; len && *buf != 0 && isdigit((unsigned char)*buf); buf++) {
399				i *= 10;
400				i += *buf - '0';
401				len--;
402			}
403			if (i > 31)
404				return 0;
405
406			tm->tm_mday = i;
407
408			if (*buf != 0 && isspace((unsigned char)*buf))
409				while (*ptr != 0 && !isspace((unsigned char)*ptr))
410					ptr++;
411			break;
412
413		case 'B':
414		case 'b':
415		case 'h':
416			for (i = 0; i < asizeof(tptr->month); i++) {
417				if (Oalternative) {
418					if (c == 'B') {
419						len = strlen(tptr->alt_month[i]);
420						if (strncasecmp(buf,
421								tptr->alt_month[i],
422								len) == 0)
423							break;
424					}
425				} else {
426					len = strlen(tptr->month[i]);
427					if (strncasecmp(buf, tptr->month[i],
428							len) == 0)
429						break;
430					len = strlen(tptr->mon[i]);
431					if (strncasecmp(buf, tptr->mon[i],
432							len) == 0)
433						break;
434				}
435			}
436			if (i == asizeof(tptr->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	if (__isthreaded)
527		_pthread_mutex_lock(&gotgmt_mutex);
528
529	got_GMT = 0;
530	ret = _strptime(buf, fmt, tm);
531	if (ret && got_GMT) {
532		time_t t = timegm(tm);
533		localtime_r(&t, tm);
534		got_GMT = 0;
535	}
536
537	if (__isthreaded)
538		_pthread_mutex_unlock(&gotgmt_mutex);
539
540	return ret;
541}
542