xref: /freebsd/lib/libc/stdtime/strptime.c (revision 4cf49a43559ed9fdad601bdcccd2c55963008675)
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
55 static const char rcsid[] =
56   "$FreeBSD$";
57 #endif
58 
59 #ifndef lint
60 #ifndef NOID
61 static char copyright[] =
62 "@(#) Copyright (c) 1994 Powerdog Industries.  All rights reserved.";
63 static 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 
76 static char * _strptime(const char *, const char *, struct tm *);
77 
78 #ifdef	_THREAD_SAFE
79 static struct pthread_mutex	_gotgmt_mutexd = PTHREAD_MUTEX_STATIC_INITIALIZER;
80 static pthread_mutex_t		gotgmt_mutex   = &_gotgmt_mutexd;
81 #endif
82 static int got_GMT;
83 
84 #define asizeof(a)	(sizeof (a) / sizeof ((a)[0]))
85 
86 static 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 
94 	ptr = fmt;
95 	while (*ptr != 0) {
96 		if (*buf == 0)
97 			break;
98 
99 		c = *ptr++;
100 
101 		if (c != '%') {
102 			if (isspace((unsigned char)c))
103 				while (*buf != 0 && isspace((unsigned char)*buf))
104 					buf++;
105 			else if (c != *buf++)
106 				return 0;
107 			continue;
108 		}
109 
110 		c = *ptr++;
111 		switch (c) {
112 		case 0:
113 		case '%':
114 			if (*buf++ != '%')
115 				return 0;
116 			break;
117 
118 		case 'C':
119 			buf = _strptime(buf, Locale->date_fmt, tm);
120 			if (buf == 0)
121 				return 0;
122 			break;
123 
124 		case 'c':
125 			buf = _strptime(buf, "%x %X", tm);
126 			if (buf == 0)
127 				return 0;
128 			break;
129 
130 		case 'D':
131 			buf = _strptime(buf, "%m/%d/%y", tm);
132 			if (buf == 0)
133 				return 0;
134 			break;
135 
136 		case 'R':
137 			buf = _strptime(buf, "%H:%M", tm);
138 			if (buf == 0)
139 				return 0;
140 			break;
141 
142 		case 'r':
143 			buf = _strptime(buf, "%I:%M:%S %p", tm);
144 			if (buf == 0)
145 				return 0;
146 			break;
147 
148 		case 'T':
149 			buf = _strptime(buf, "%H:%M:%S", tm);
150 			if (buf == 0)
151 				return 0;
152 			break;
153 
154 		case 'X':
155 			buf = _strptime(buf, Locale->X_fmt, tm);
156 			if (buf == 0)
157 				return 0;
158 			break;
159 
160 		case 'x':
161 			buf = _strptime(buf, Locale->x_fmt, tm);
162 			if (buf == 0)
163 				return 0;
164 			break;
165 
166 		case 'j':
167 			if (!isdigit((unsigned char)*buf))
168 				return 0;
169 
170 			for (i = 0; *buf != 0 && isdigit((unsigned char)*buf); buf++) {
171 				i *= 10;
172 				i += *buf - '0';
173 			}
174 			if (i > 365)
175 				return 0;
176 
177 			tm->tm_yday = i;
178 			break;
179 
180 		case 'M':
181 		case 'S':
182 			if (*buf == 0 || isspace((unsigned char)*buf))
183 				break;
184 
185 			if (!isdigit((unsigned char)*buf))
186 				return 0;
187 
188 			for (i = 0; *buf != 0 && isdigit((unsigned char)*buf); buf++) {
189 				i *= 10;
190 				i += *buf - '0';
191 			}
192 			if (i > 59)
193 				return 0;
194 
195 			if (c == 'M')
196 				tm->tm_min = i;
197 			else
198 				tm->tm_sec = i;
199 
200 			if (*buf != 0 && isspace((unsigned char)*buf))
201 				while (*ptr != 0 && !isspace((unsigned char)*ptr))
202 					ptr++;
203 			break;
204 
205 		case 'H':
206 		case 'I':
207 		case 'k':
208 		case 'l':
209 			if (!isdigit((unsigned char)*buf))
210 				return 0;
211 
212 			for (i = 0; *buf != 0 && isdigit((unsigned char)*buf); buf++) {
213 				i *= 10;
214 				i += *buf - '0';
215 			}
216 			if (c == 'H' || c == 'k') {
217 				if (i > 23)
218 					return 0;
219 			} else if (i > 11)
220 				return 0;
221 
222 			tm->tm_hour = i;
223 
224 			if (*buf != 0 && isspace((unsigned char)*buf))
225 				while (*ptr != 0 && !isspace((unsigned char)*ptr))
226 					ptr++;
227 			break;
228 
229 		case 'p':
230 			len = strlen(Locale->am);
231 			if (strncasecmp(buf, Locale->am, len) == 0) {
232 				if (tm->tm_hour > 12)
233 					return 0;
234 				if (tm->tm_hour == 12)
235 					tm->tm_hour = 0;
236 				buf += len;
237 				break;
238 			}
239 
240 			len = strlen(Locale->pm);
241 			if (strncasecmp(buf, Locale->pm, len) == 0) {
242 				if (tm->tm_hour > 12)
243 					return 0;
244 				if (tm->tm_hour != 12)
245 					tm->tm_hour += 12;
246 				buf += len;
247 				break;
248 			}
249 
250 			return 0;
251 
252 		case 'A':
253 		case 'a':
254 			for (i = 0; i < asizeof(Locale->weekday); i++) {
255 				len = strlen(Locale->weekday[i]);
256 				if (strncasecmp(buf,
257 						Locale->weekday[i],
258 						len) == 0)
259 					break;
260 
261 				len = strlen(Locale->wday[i]);
262 				if (strncasecmp(buf,
263 						Locale->wday[i],
264 						len) == 0)
265 					break;
266 			}
267 			if (i == asizeof(Locale->weekday))
268 				return 0;
269 
270 			tm->tm_wday = i;
271 			buf += len;
272 			break;
273 
274 		case 'd':
275 		case 'e':
276 			if (!isdigit((unsigned char)*buf))
277 				return 0;
278 
279 			for (i = 0; *buf != 0 && isdigit((unsigned char)*buf); buf++) {
280 				i *= 10;
281 				i += *buf - '0';
282 			}
283 			if (i > 31)
284 				return 0;
285 
286 			tm->tm_mday = i;
287 
288 			if (*buf != 0 && isspace((unsigned char)*buf))
289 				while (*ptr != 0 && !isspace((unsigned char)*ptr))
290 					ptr++;
291 			break;
292 
293 		case 'B':
294 		case 'b':
295 		case 'h':
296 			for (i = 0; i < asizeof(Locale->month); i++) {
297 				len = strlen(Locale->month[i]);
298 				if (strncasecmp(buf,
299 						Locale->month[i],
300 						len) == 0)
301 					break;
302 
303 				len = strlen(Locale->mon[i]);
304 				if (strncasecmp(buf,
305 						Locale->mon[i],
306 						len) == 0)
307 					break;
308 			}
309 			if (i == asizeof(Locale->month))
310 				return 0;
311 
312 			tm->tm_mon = i;
313 			buf += len;
314 			break;
315 
316 		case 'm':
317 			if (!isdigit((unsigned char)*buf))
318 				return 0;
319 
320 			for (i = 0; *buf != 0 && isdigit((unsigned char)*buf); buf++) {
321 				i *= 10;
322 				i += *buf - '0';
323 			}
324 			if (i < 1 || i > 12)
325 				return 0;
326 
327 			tm->tm_mon = i - 1;
328 
329 			if (*buf != 0 && isspace((unsigned char)*buf))
330 				while (*ptr != 0 && !isspace((unsigned char)*ptr))
331 					ptr++;
332 			break;
333 
334 		case 'Y':
335 		case 'y':
336 			if (*buf == 0 || isspace((unsigned char)*buf))
337 				break;
338 
339 			if (!isdigit((unsigned char)*buf))
340 				return 0;
341 
342 			for (i = 0; *buf != 0 && isdigit((unsigned char)*buf); buf++) {
343 				i *= 10;
344 				i += *buf - '0';
345 			}
346 			if (c == 'Y')
347 				i -= 1900;
348 			if (c == 'y' && i < 69)
349 				i += 100;
350 			if (i < 0)
351 				return 0;
352 
353 			tm->tm_year = i;
354 
355 			if (*buf != 0 && isspace((unsigned char)*buf))
356 				while (*ptr != 0 && !isspace((unsigned char)*ptr))
357 					ptr++;
358 			break;
359 
360 		case 'Z':
361 			{
362 			const char *cp;
363 			char *zonestr;
364 
365 			for (cp = buf; *cp && isupper(*cp); ++cp) {/*empty*/}
366 			if (cp - buf) {
367 				zonestr = alloca(cp - buf + 1);
368 				strncpy(zonestr, buf, cp - buf);
369 				zonestr[cp - buf] = '\0';
370 				tzset();
371 				if (0 == strcmp(zonestr, "GMT")) {
372 				    got_GMT = 1;
373 				} else if (0 == strcmp(zonestr, tzname[0])) {
374 				    tm->tm_isdst = 0;
375 				} else if (0 == strcmp(zonestr, tzname[1])) {
376 				    tm->tm_isdst = 1;
377 				} else {
378 				    return 0;
379 				}
380 				buf += cp - buf;
381 			}
382 			}
383 			break;
384 		}
385 	}
386 	return (char *)buf;
387 }
388 
389 
390 char *
391 strptime(const char *buf, const char *fmt, struct tm *tm)
392 {
393 	char *ret;
394 
395 #ifdef	_THREAD_SAFE
396 	pthread_mutex_lock(&gotgmt_mutex);
397 #endif
398 
399 	got_GMT = 0;
400 	ret = _strptime(buf, fmt, tm);
401 	if (ret && got_GMT) {
402 		time_t t = timegm(tm);
403 	    localtime_r(&t, tm);
404 		got_GMT = 0;
405 	}
406 
407 #ifdef	_THREAD_SAFE
408 	pthread_mutex_unlock(&gotgmt_mutex);
409 #endif
410 
411 	return ret;
412 }
413