strptime.c revision 195015 
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#include <sys/cdefs.h>
55#ifndef lint
56#ifndef NOID
57static char copyright[] __unused =
58"@(#) Copyright (c) 1994 Powerdog Industries.  All rights reserved.";
59static char sccsid[] __unused = "@(#)strptime.c	0.1 (Powerdog) 94/03/27";
60#endif /* !defined NOID */
61#endif /* not lint */
62__FBSDID("$FreeBSD: head/lib/libc/stdtime/strptime.c 195015 2009-06-25 23:59:23Z delphij $");
63
64#include "namespace.h"
65#include <time.h>
66#include <ctype.h>
67#include <errno.h>
68#include <stdlib.h>
69#include <string.h>
70#include <pthread.h>
71#include "un-namespace.h"
72#include "libc_private.h"
73#include "timelocal.h"
74
75static char * _strptime(const char *, const char *, struct tm *, int *);
76
77#define asizeof(a)	(sizeof (a) / sizeof ((a)[0]))
78
79static char *
80_strptime(const char *buf, const char *fmt, struct tm *tm, int *GMTp)
81{
82	char	c;
83	const char *ptr;
84	int	i,
85		len;
86	int Ealternative, Oalternative;
87	struct lc_time_T *tptr = __get_current_time_locale();
88
89	ptr = fmt;
90	while (*ptr != 0) {
91		if (*buf == 0)
92			break;
93
94		c = *ptr++;
95
96		if (c != '%') {
97			if (isspace((unsigned char)c))
98				while (*buf != 0 && isspace((unsigned char)*buf))
99					buf++;
100			else if (c != *buf++)
101				return 0;
102			continue;
103		}
104
105		Ealternative = 0;
106		Oalternative = 0;
107label:
108		c = *ptr++;
109		switch (c) {
110		case 0:
111		case '%':
112			if (*buf++ != '%')
113				return 0;
114			break;
115
116		case '+':
117			buf = _strptime(buf, tptr->date_fmt, tm, GMTp);
118			if (buf == 0)
119				return 0;
120			break;
121
122		case 'C':
123			if (!isdigit((unsigned char)*buf))
124				return 0;
125
126			/* XXX This will break for 3-digit centuries. */
127			len = 2;
128			for (i = 0; len && *buf != 0 && isdigit((unsigned char)*buf); buf++) {
129				i *= 10;
130				i += *buf - '0';
131				len--;
132			}
133			if (i < 19)
134				return 0;
135
136			tm->tm_year = i * 100 - 1900;
137			break;
138
139		case 'c':
140			buf = _strptime(buf, tptr->c_fmt, tm, GMTp);
141			if (buf == 0)
142				return 0;
143			break;
144
145		case 'D':
146			buf = _strptime(buf, "%m/%d/%y", tm, GMTp);
147			if (buf == 0)
148				return 0;
149			break;
150
151		case 'E':
152			if (Ealternative || Oalternative)
153				break;
154			Ealternative++;
155			goto label;
156
157		case 'O':
158			if (Ealternative || Oalternative)
159				break;
160			Oalternative++;
161			goto label;
162
163		case 'F':
164			buf = _strptime(buf, "%Y-%m-%d", tm, GMTp);
165			if (buf == 0)
166				return 0;
167			break;
168
169		case 'R':
170			buf = _strptime(buf, "%H:%M", tm, GMTp);
171			if (buf == 0)
172				return 0;
173			break;
174
175		case 'r':
176			buf = _strptime(buf, tptr->ampm_fmt, tm, GMTp);
177			if (buf == 0)
178				return 0;
179			break;
180
181		case 'T':
182			buf = _strptime(buf, "%H:%M:%S", tm, GMTp);
183			if (buf == 0)
184				return 0;
185			break;
186
187		case 'X':
188			buf = _strptime(buf, tptr->X_fmt, tm, GMTp);
189			if (buf == 0)
190				return 0;
191			break;
192
193		case 'x':
194			buf = _strptime(buf, tptr->x_fmt, tm, GMTp);
195			if (buf == 0)
196				return 0;
197			break;
198
199		case 'j':
200			if (!isdigit((unsigned char)*buf))
201				return 0;
202
203			len = 3;
204			for (i = 0; len && *buf != 0 && isdigit((unsigned char)*buf); buf++) {
205				i *= 10;
206				i += *buf - '0';
207				len--;
208			}
209			if (i < 1 || i > 366)
210				return 0;
211
212			tm->tm_yday = i - 1;
213			break;
214
215		case 'M':
216		case 'S':
217			if (*buf == 0 || isspace((unsigned char)*buf))
218				break;
219
220			if (!isdigit((unsigned char)*buf))
221				return 0;
222
223			len = 2;
224			for (i = 0; len && *buf != 0 && isdigit((unsigned char)*buf); buf++) {
225				i *= 10;
226				i += *buf - '0';
227				len--;
228			}
229
230			if (c == 'M') {
231				if (i > 59)
232					return 0;
233				tm->tm_min = i;
234			} else {
235				if (i > 60)
236					return 0;
237				tm->tm_sec = i;
238			}
239
240			if (*buf != 0 && isspace((unsigned char)*buf))
241				while (*ptr != 0 && !isspace((unsigned char)*ptr))
242					ptr++;
243			break;
244
245		case 'H':
246		case 'I':
247		case 'k':
248		case 'l':
249			/*
250			 * Of these, %l is the only specifier explicitly
251			 * documented as not being zero-padded.  However,
252			 * there is no harm in allowing zero-padding.
253			 *
254			 * XXX The %l specifier may gobble one too many
255			 * digits if used incorrectly.
256			 */
257			if (!isdigit((unsigned char)*buf))
258				return 0;
259
260			len = 2;
261			for (i = 0; len && *buf != 0 && isdigit((unsigned char)*buf); buf++) {
262				i *= 10;
263				i += *buf - '0';
264				len--;
265			}
266			if (c == 'H' || c == 'k') {
267				if (i > 23)
268					return 0;
269			} else if (i > 12)
270				return 0;
271
272			tm->tm_hour = i;
273
274			if (*buf != 0 && isspace((unsigned char)*buf))
275				while (*ptr != 0 && !isspace((unsigned char)*ptr))
276					ptr++;
277			break;
278
279		case 'p':
280			/*
281			 * XXX This is bogus if parsed before hour-related
282			 * specifiers.
283			 */
284			len = strlen(tptr->am);
285			if (strncasecmp(buf, tptr->am, len) == 0) {
286				if (tm->tm_hour > 12)
287					return 0;
288				if (tm->tm_hour == 12)
289					tm->tm_hour = 0;
290				buf += len;
291				break;
292			}
293
294			len = strlen(tptr->pm);
295			if (strncasecmp(buf, tptr->pm, len) == 0) {
296				if (tm->tm_hour > 12)
297					return 0;
298				if (tm->tm_hour != 12)
299					tm->tm_hour += 12;
300				buf += len;
301				break;
302			}
303
304			return 0;
305
306		case 'A':
307		case 'a':
308			for (i = 0; i < asizeof(tptr->weekday); i++) {
309				len = strlen(tptr->weekday[i]);
310				if (strncasecmp(buf, tptr->weekday[i],
311						len) == 0)
312					break;
313				len = strlen(tptr->wday[i]);
314				if (strncasecmp(buf, tptr->wday[i],
315						len) == 0)
316					break;
317			}
318			if (i == asizeof(tptr->weekday))
319				return 0;
320
321			tm->tm_wday = i;
322			buf += len;
323			break;
324
325		case 'U':
326		case 'W':
327			/*
328			 * XXX This is bogus, as we can not assume any valid
329			 * information present in the tm structure at this
330			 * point to calculate a real value, so just check the
331			 * range for now.
332			 */
333			if (!isdigit((unsigned char)*buf))
334				return 0;
335
336			len = 2;
337			for (i = 0; len && *buf != 0 && isdigit((unsigned char)*buf); buf++) {
338				i *= 10;
339				i += *buf - '0';
340				len--;
341			}
342			if (i > 53)
343				return 0;
344
345			if (*buf != 0 && isspace((unsigned char)*buf))
346				while (*ptr != 0 && !isspace((unsigned char)*ptr))
347					ptr++;
348			break;
349
350		case 'w':
351			if (!isdigit((unsigned char)*buf))
352				return 0;
353
354			i = *buf - '0';
355			if (i > 6)
356				return 0;
357
358			tm->tm_wday = i;
359
360			if (*buf != 0 && isspace((unsigned char)*buf))
361				while (*ptr != 0 && !isspace((unsigned char)*ptr))
362					ptr++;
363			break;
364
365		case 'd':
366		case 'e':
367			/*
368			 * The %e specifier is explicitly documented as not
369			 * being zero-padded but there is no harm in allowing
370			 * such padding.
371			 *
372			 * XXX The %e specifier may gobble one too many
373			 * digits if used incorrectly.
374			 */
375			if (!isdigit((unsigned char)*buf))
376				return 0;
377
378			len = 2;
379			for (i = 0; len && *buf != 0 && isdigit((unsigned char)*buf); buf++) {
380				i *= 10;
381				i += *buf - '0';
382				len--;
383			}
384			if (i > 31)
385				return 0;
386
387			tm->tm_mday = i;
388
389			if (*buf != 0 && isspace((unsigned char)*buf))
390				while (*ptr != 0 && !isspace((unsigned char)*ptr))
391					ptr++;
392			break;
393
394		case 'B':
395		case 'b':
396		case 'h':
397			for (i = 0; i < asizeof(tptr->month); i++) {
398				if (Oalternative) {
399					if (c == 'B') {
400						len = strlen(tptr->alt_month[i]);
401						if (strncasecmp(buf,
402								tptr->alt_month[i],
403								len) == 0)
404							break;
405					}
406				} else {
407					len = strlen(tptr->month[i]);
408					if (strncasecmp(buf, tptr->month[i],
409							len) == 0)
410						break;
411					len = strlen(tptr->mon[i]);
412					if (strncasecmp(buf, tptr->mon[i],
413							len) == 0)
414						break;
415				}
416			}
417			if (i == asizeof(tptr->month))
418				return 0;
419
420			tm->tm_mon = i;
421			buf += len;
422			break;
423
424		case 'm':
425			if (!isdigit((unsigned char)*buf))
426				return 0;
427
428			len = 2;
429			for (i = 0; len && *buf != 0 && isdigit((unsigned char)*buf); buf++) {
430				i *= 10;
431				i += *buf - '0';
432				len--;
433			}
434			if (i < 1 || i > 12)
435				return 0;
436
437			tm->tm_mon = i - 1;
438
439			if (*buf != 0 && isspace((unsigned char)*buf))
440				while (*ptr != 0 && !isspace((unsigned char)*ptr))
441					ptr++;
442			break;
443
444		case 's':
445			{
446			char *cp;
447			int sverrno;
448			long n;
449			time_t t;
450
451			sverrno = errno;
452			errno = 0;
453			n = strtol(buf, &cp, 10);
454			if (errno == ERANGE || (long)(t = n) != n) {
455				errno = sverrno;
456				return 0;
457			}
458			errno = sverrno;
459			buf = cp;
460			gmtime_r(&t, tm);
461			*GMTp = 1;
462			}
463			break;
464
465		case 'Y':
466		case 'y':
467			if (*buf == 0 || isspace((unsigned char)*buf))
468				break;
469
470			if (!isdigit((unsigned char)*buf))
471				return 0;
472
473			len = (c == 'Y') ? 4 : 2;
474			for (i = 0; len && *buf != 0 && isdigit((unsigned char)*buf); buf++) {
475				i *= 10;
476				i += *buf - '0';
477				len--;
478			}
479			if (c == 'Y')
480				i -= 1900;
481			if (c == 'y' && i < 69)
482				i += 100;
483			if (i < 0)
484				return 0;
485
486			tm->tm_year = i;
487
488			if (*buf != 0 && isspace((unsigned char)*buf))
489				while (*ptr != 0 && !isspace((unsigned char)*ptr))
490					ptr++;
491			break;
492
493		case 'Z':
494			{
495			const char *cp;
496			char *zonestr;
497
498			for (cp = buf; *cp && isupper((unsigned char)*cp); ++cp) {/*empty*/}
499			if (cp - buf) {
500				zonestr = alloca(cp - buf + 1);
501				strncpy(zonestr, buf, cp - buf);
502				zonestr[cp - buf] = '\0';
503				tzset();
504				if (0 == strcmp(zonestr, "GMT")) {
505				    *GMTp = 1;
506				} else if (0 == strcmp(zonestr, tzname[0])) {
507				    tm->tm_isdst = 0;
508				} else if (0 == strcmp(zonestr, tzname[1])) {
509				    tm->tm_isdst = 1;
510				} else {
511				    return 0;
512				}
513				buf += cp - buf;
514			}
515			}
516			break;
517
518		case 'z':
519			{
520			int sign = 1;
521
522			if (*buf != '+') {
523				if (*buf == '-')
524					sign = -1;
525				else
526					return 0;
527			}
528
529			buf++;
530			i = 0;
531			for (len = 4; len > 0; len--) {
532				if (isdigit((int)*buf)) {
533					i *= 10;
534					i += *buf - '0';
535					buf++;
536				} else
537					return 0;
538			}
539
540			tm->tm_hour -= sign * (i / 100);
541			tm->tm_min  -= sign * (i % 100);
542			*GMTp = 1;
543			}
544			break;
545		}
546	}
547	return (char *)buf;
548}
549
550
551char *
552strptime(const char * __restrict buf, const char * __restrict fmt,
553    struct tm * __restrict tm)
554{
555	char *ret;
556	int gmt;
557
558	gmt = 0;
559	ret = _strptime(buf, fmt, tm, &gmt);
560	if (ret && gmt) {
561		time_t t = timegm(tm);
562		localtime_r(&t, tm);
563	}
564
565	return (ret);
566}
567