strptime.c revision 48550 
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	"$Id: strptime.c,v 1.6 1999/04/25 07:28:39 wes Exp $";
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#include "timelocal.h"
71
72#define asizeof(a)	(sizeof (a) / sizeof ((a)[0]))
73
74static int got_GMT = 0;
75
76char *
77strptime(const char *buf, const char *fmt, struct tm *tm)
78{
79	char	c;
80	const char *ptr;
81	int	i,
82		len;
83
84	ptr = fmt;
85	while (*ptr != 0) {
86		if (*buf == 0)
87			break;
88
89		c = *ptr++;
90
91		if (c != '%') {
92			if (isspace((unsigned char)c))
93				while (*buf != 0 && isspace((unsigned char)*buf))
94					buf++;
95			else if (c != *buf++)
96				return 0;
97			continue;
98		}
99
100		c = *ptr++;
101		switch (c) {
102		case 0:
103		case '%':
104			if (*buf++ != '%')
105				return 0;
106			break;
107
108		case 'C':
109			buf = strptime(buf, Locale->date_fmt, tm);
110			if (buf == 0)
111				return 0;
112			break;
113
114		case 'c':
115			buf = strptime(buf, "%x %X", tm);
116			if (buf == 0)
117				return 0;
118			break;
119
120		case 'D':
121			buf = strptime(buf, "%m/%d/%y", tm);
122			if (buf == 0)
123				return 0;
124			break;
125
126		case 'R':
127			buf = strptime(buf, "%H:%M", tm);
128			if (buf == 0)
129				return 0;
130			break;
131
132		case 'r':
133			buf = strptime(buf, "%I:%M:%S %p", tm);
134			if (buf == 0)
135				return 0;
136			break;
137
138		case 'T':
139			buf = strptime(buf, "%H:%M:%S", tm);
140			if (buf == 0)
141				return 0;
142			break;
143
144		case 'X':
145			buf = strptime(buf, Locale->X_fmt, tm);
146			if (buf == 0)
147				return 0;
148			break;
149
150		case 'x':
151			buf = strptime(buf, Locale->x_fmt, tm);
152			if (buf == 0)
153				return 0;
154			break;
155
156		case 'j':
157			if (!isdigit((unsigned char)*buf))
158				return 0;
159
160			for (i = 0; *buf != 0 && isdigit((unsigned char)*buf); buf++) {
161				i *= 10;
162				i += *buf - '0';
163			}
164			if (i > 365)
165				return 0;
166
167			tm->tm_yday = i;
168			break;
169
170		case 'M':
171		case 'S':
172			if (*buf == 0 || isspace((unsigned char)*buf))
173				break;
174
175			if (!isdigit((unsigned char)*buf))
176				return 0;
177
178			for (i = 0; *buf != 0 && isdigit((unsigned char)*buf); buf++) {
179				i *= 10;
180				i += *buf - '0';
181			}
182			if (i > 59)
183				return 0;
184
185			if (c == 'M')
186				tm->tm_min = i;
187			else
188				tm->tm_sec = i;
189
190			if (*buf != 0 && isspace((unsigned char)*buf))
191				while (*ptr != 0 && !isspace((unsigned char)*ptr))
192					ptr++;
193			break;
194
195		case 'H':
196		case 'I':
197		case 'k':
198		case 'l':
199			if (!isdigit((unsigned char)*buf))
200				return 0;
201
202			for (i = 0; *buf != 0 && isdigit((unsigned char)*buf); buf++) {
203				i *= 10;
204				i += *buf - '0';
205			}
206			if (c == 'H' || c == 'k') {
207				if (i > 23)
208					return 0;
209			} else if (i > 11)
210				return 0;
211
212			tm->tm_hour = i;
213
214			if (*buf != 0 && isspace((unsigned char)*buf))
215				while (*ptr != 0 && !isspace((unsigned char)*ptr))
216					ptr++;
217			break;
218
219		case 'p':
220			len = strlen(Locale->am);
221			if (strncasecmp(buf, Locale->am, len) == 0) {
222				if (tm->tm_hour > 12)
223					return 0;
224				if (tm->tm_hour == 12)
225					tm->tm_hour = 0;
226				buf += len;
227				break;
228			}
229
230			len = strlen(Locale->pm);
231			if (strncasecmp(buf, Locale->pm, len) == 0) {
232				if (tm->tm_hour > 12)
233					return 0;
234				if (tm->tm_hour != 12)
235					tm->tm_hour += 12;
236				buf += len;
237				break;
238			}
239
240			return 0;
241
242		case 'A':
243		case 'a':
244			for (i = 0; i < asizeof(Locale->weekday); i++) {
245				len = strlen(Locale->weekday[i]);
246				if (strncasecmp(buf,
247						Locale->weekday[i],
248						len) == 0)
249					break;
250
251				len = strlen(Locale->wday[i]);
252				if (strncasecmp(buf,
253						Locale->wday[i],
254						len) == 0)
255					break;
256			}
257			if (i == asizeof(Locale->weekday))
258				return 0;
259
260			tm->tm_wday = i;
261			buf += len;
262			break;
263
264		case 'd':
265		case 'e':
266			if (!isdigit((unsigned char)*buf))
267				return 0;
268
269			for (i = 0; *buf != 0 && isdigit((unsigned char)*buf); buf++) {
270				i *= 10;
271				i += *buf - '0';
272			}
273			if (i > 31)
274				return 0;
275
276			tm->tm_mday = i;
277
278			if (*buf != 0 && isspace((unsigned char)*buf))
279				while (*ptr != 0 && !isspace((unsigned char)*ptr))
280					ptr++;
281			break;
282
283		case 'B':
284		case 'b':
285		case 'h':
286			for (i = 0; i < asizeof(Locale->month); i++) {
287				len = strlen(Locale->month[i]);
288				if (strncasecmp(buf,
289						Locale->month[i],
290						len) == 0)
291					break;
292
293				len = strlen(Locale->mon[i]);
294				if (strncasecmp(buf,
295						Locale->mon[i],
296						len) == 0)
297					break;
298			}
299			if (i == asizeof(Locale->month))
300				return 0;
301
302			tm->tm_mon = i;
303			buf += len;
304			break;
305
306		case 'm':
307			if (!isdigit((unsigned char)*buf))
308				return 0;
309
310			for (i = 0; *buf != 0 && isdigit((unsigned char)*buf); buf++) {
311				i *= 10;
312				i += *buf - '0';
313			}
314			if (i < 1 || i > 12)
315				return 0;
316
317			tm->tm_mon = i - 1;
318
319			if (*buf != 0 && isspace((unsigned char)*buf))
320				while (*ptr != 0 && !isspace((unsigned char)*ptr))
321					ptr++;
322			break;
323
324		case 'Y':
325		case 'y':
326			if (*buf == 0 || isspace((unsigned char)*buf))
327				break;
328
329			if (!isdigit((unsigned char)*buf))
330				return 0;
331
332			for (i = 0; *buf != 0 && isdigit((unsigned char)*buf); buf++) {
333				i *= 10;
334				i += *buf - '0';
335			}
336			if (c == 'Y')
337				i -= 1900;
338			if (c == 'y' && i < 69)
339				i += 100;
340			if (i < 0)
341				return 0;
342
343			tm->tm_year = i;
344
345			if (*buf != 0 && isspace((unsigned char)*buf))
346				while (*ptr != 0 && !isspace((unsigned char)*ptr))
347					ptr++;
348			break;
349
350		case 'Z':
351			{
352			const char *cp;
353			char *zonestr;
354
355			for (cp = buf; *cp && isupper(*cp); ++cp) {/*empty*/}
356			if (cp - buf) {
357				zonestr = alloca(cp - buf + 1);
358				strncpy(zonestr, buf, cp - buf);
359				zonestr[cp - buf] = '\0';
360				tzset();
361				if (0 == strcmp(zonestr, "GMT")) {
362					got_GMT = 1;
363				} else if (0 == strcmp(zonestr, tzname[0])) {
364					tm->tm_isdst = 0;
365				} else if (0 == strcmp(zonestr, tzname[1])) {
366					tm->tm_isdst = 1;
367				} else {
368					return 0;
369				}
370				buf += cp - buf;
371			}
372			}
373			break;
374		}
375	}
376
377	if (got_GMT) {
378		time_t t = timegm(tm);
379		localtime_r(&t, tm);
380	}
381	return (char *)buf;
382}
383