1 /* Parse dates for touch and date.
2
3 Copyright (C) 1989, 1990, 1991, 1998, 2000, 2001, 2002, 2003, 2004,
4 2005, 2006, 2007 Free Software Foundation Inc.
5
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
9 any later version.
10
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software Foundation,
18 Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
19
20 /* Yacc-based version written by Jim Kingdon and David MacKenzie.
21 Rewritten by Jim Meyering. */
22
23 #include "config.h"
24
25 #include "posixtm.h"
26
27 #include <stdio.h>
28 #include <stdlib.h>
29 #include <sys/types.h>
30 #include <string.h>
31
32 #if USE_UNLOCKED_IO
33 # include "unlocked-io.h"
34 #endif
35
36 /* ISDIGIT differs from isdigit, as follows:
37 - Its arg may be any int or unsigned int; it need not be an unsigned char
38 or EOF.
39 - It's typically faster.
40 POSIX says that only '0' through '9' are digits. Prefer ISDIGIT to
41 isdigit unless it's important to use the locale's definition
42 of `digit' even when the host does not conform to POSIX. */
43 #define ISDIGIT(c) ((unsigned int) (c) - '0' <= 9)
44
45 /*
46 POSIX requires:
47
48 touch -t [[CC]YY]mmddhhmm[.ss] FILE...
49 8, 10, or 12 digits, followed by optional .ss
50 (PDS_LEADING_YEAR | PDS_CENTURY | PDS_SECONDS)
51
52 touch mmddhhmm[YY] FILE... (obsoleted by POSIX 1003.1-2001)
53 8 or 10 digits, YY (if present) must be in the range 69-99
54 (PDS_TRAILING_YEAR | PDS_PRE_2000)
55
56 date mmddhhmm[[CC]YY]
57 8, 10, or 12 digits
58 (PDS_TRAILING_YEAR | PDS_CENTURY)
59
60 */
61
62 static int
year(struct tm * tm,const int * digit_pair,size_t n,unsigned int syntax_bits)63 year (struct tm *tm, const int *digit_pair, size_t n, unsigned int syntax_bits)
64 {
65 switch (n)
66 {
67 case 1:
68 tm->tm_year = *digit_pair;
69 /* Deduce the century based on the year.
70 POSIX requires that 00-68 be interpreted as 2000-2068,
71 and that 69-99 be interpreted as 1969-1999. */
72 if (digit_pair[0] <= 68)
73 {
74 if (syntax_bits & PDS_PRE_2000)
75 return 1;
76 tm->tm_year += 100;
77 }
78 break;
79
80 case 2:
81 if (! (syntax_bits & PDS_CENTURY))
82 return 1;
83 tm->tm_year = digit_pair[0] * 100 + digit_pair[1] - 1900;
84 break;
85
86 case 0:
87 {
88 time_t now;
89 struct tm *tmp;
90
91 /* Use current year. */
92 time (&now);
93 tmp = localtime (&now);
94 if (! tmp)
95 return 1;
96 tm->tm_year = tmp->tm_year;
97 }
98 break;
99
100 default:
101 abort ();
102 }
103
104 return 0;
105 }
106
107 static int
posix_time_parse(struct tm * tm,const char * s,unsigned int syntax_bits)108 posix_time_parse (struct tm *tm, const char *s, unsigned int syntax_bits)
109 {
110 const char *dot = NULL;
111 int pair[6];
112 int *p;
113 size_t i;
114
115 size_t s_len = strlen (s);
116 size_t len = (((syntax_bits & PDS_SECONDS) && (dot = strchr (s, '.')))
117 ? (size_t) (dot - s)
118 : s_len);
119
120 if (len != 8 && len != 10 && len != 12)
121 return 1;
122
123 if (dot)
124 {
125 if (!(syntax_bits & PDS_SECONDS))
126 return 1;
127
128 if (s_len - len != 3)
129 return 1;
130 }
131
132 for (i = 0; i < len; i++)
133 if (!ISDIGIT (s[i]))
134 return 1;
135
136 len /= 2;
137 for (i = 0; i < len; i++)
138 pair[i] = 10 * (s[2*i] - '0') + s[2*i + 1] - '0';
139
140 p = pair;
141 if (syntax_bits & PDS_LEADING_YEAR)
142 {
143 if (year (tm, p, len - 4, syntax_bits))
144 return 1;
145 p += len - 4;
146 len = 4;
147 }
148
149 /* Handle 8 digits worth of `MMDDhhmm'. */
150 tm->tm_mon = *p++ - 1;
151 tm->tm_mday = *p++;
152 tm->tm_hour = *p++;
153 tm->tm_min = *p++;
154 len -= 4;
155
156 /* Handle any trailing year. */
157 if (syntax_bits & PDS_TRAILING_YEAR)
158 {
159 if (year (tm, p, len, syntax_bits))
160 return 1;
161 }
162
163 /* Handle seconds. */
164 if (!dot)
165 {
166 tm->tm_sec = 0;
167 }
168 else
169 {
170 int seconds;
171
172 ++dot;
173 if (!ISDIGIT (dot[0]) || !ISDIGIT (dot[1]))
174 return 1;
175 seconds = 10 * (dot[0] - '0') + dot[1] - '0';
176
177 tm->tm_sec = seconds;
178 }
179
180 return 0;
181 }
182
183 /* Parse a POSIX-style date, returning true if successful. */
184
185 bool
posixtime(time_t * p,const char * s,unsigned int syntax_bits)186 posixtime (time_t *p, const char *s, unsigned int syntax_bits)
187 {
188 struct tm tm0
189 #ifdef lint
190 /* Placate gcc-4's -Wuninitialized.
191 posix_time_parse fails to set all of tm0 only when it returns
192 nonzero (due to year() returning nonzero), and in that case,
193 this code doesn't use the tm0 at all. */
194 = { 0, }
195 #endif
196 ;
197 struct tm tm1;
198 struct tm const *tm;
199 time_t t;
200
201 if (posix_time_parse (&tm0, s, syntax_bits))
202 return false;
203
204 tm1 = tm0;
205 tm1.tm_isdst = -1;
206 t = mktime (&tm1);
207
208 if (t != (time_t) -1)
209 tm = &tm1;
210 else
211 {
212 /* mktime returns -1 for errors, but -1 is also a valid time_t
213 value. Check whether an error really occurred. */
214 tm = localtime (&t);
215 if (! tm)
216 return false;
217 }
218
219 /* Reject dates like "September 31" and times like "25:61". */
220 if ((tm0.tm_year ^ tm->tm_year)
221 | (tm0.tm_mon ^ tm->tm_mon)
222 | (tm0.tm_mday ^ tm->tm_mday)
223 | (tm0.tm_hour ^ tm->tm_hour)
224 | (tm0.tm_min ^ tm->tm_min)
225 | (tm0.tm_sec ^ tm->tm_sec))
226 return false;
227
228 *p = t;
229 return true;
230 }
231
232 #ifdef TEST_POSIXTIME
233 /*
234 Test mainly with syntax_bits == 13
235 (aka: (PDS_LEADING_YEAR | PDS_CENTURY | PDS_SECONDS))
236
237 This test data assumes Universal Time, e.g., TZ="UTC0".
238
239 This test data also assumes that time_t is signed and is at least
240 39 bits wide, so that it can represent all years from 0000 through
241 9999. A host with 32-bit signed time_t can represent only time
242 stamps in the range 1901-12-13 20:45:52 through 2038-01-18
243 03:14:07 UTC, assuming POSIX time_t with no leap seconds, so test
244 cases outside this range will not work on such a host.
245
246 Also, the first two lines of test data assume that the current
247 year is 2002.
248
249 BEGIN-DATA
250 12131415.16 13 1039788916 Fri Dec 13 14:15:16 2002
251 12131415.16 13 1039788916 Fri Dec 13 14:15:16 2002
252 000001010000.00 13 -62167132800 Sun Jan 1 00:00:00 0000
253 190112132045.52 13 -2147483648 Fri Dec 13 20:45:52 1901
254 190112132045.53 13 -2147483647 Fri Dec 13 20:45:53 1901
255 190112132046.52 13 -2147483588 Fri Dec 13 20:46:52 1901
256 190112132145.52 13 -2147480048 Fri Dec 13 21:45:52 1901
257 190112142045.52 13 -2147397248 Sat Dec 14 20:45:52 1901
258 190201132045.52 13 -2144805248 Mon Jan 13 20:45:52 1902
259 196912312359.59 13 -1 Wed Dec 31 23:59:59 1969
260 197001010000.00 13 0 Thu Jan 1 00:00:00 1970
261 197001010000.01 13 1 Thu Jan 1 00:00:01 1970
262 197001010001.00 13 60 Thu Jan 1 00:01:00 1970
263 197001010100.00 13 3600 Thu Jan 1 01:00:00 1970
264 197001020000.00 13 86400 Fri Jan 2 00:00:00 1970
265 197002010000.00 13 2678400 Sun Feb 1 00:00:00 1970
266 197101010000.00 13 31536000 Fri Jan 1 00:00:00 1971
267 197001000000.00 13 * *
268 197000010000.00 13 * *
269 197001010000.60 13 * *
270 197001010060.00 13 * *
271 197001012400.00 13 * *
272 197001320000.00 13 * *
273 197013010000.00 13 * *
274 203801190314.06 13 2147483646 Tue Jan 19 03:14:06 2038
275 203801190314.07 13 2147483647 Tue Jan 19 03:14:07 2038
276 203801190314.08 13 2147483648 Tue Jan 19 03:14:08 2038
277 999912312359.59 13 253402300799 Fri Dec 31 23:59:59 9999
278 1112131415 13 1323785700 Tue Dec 13 14:15:00 2011
279 1112131415.16 13 1323785716 Tue Dec 13 14:15:16 2011
280 201112131415.16 13 1323785716 Tue Dec 13 14:15:16 2011
281 191112131415.16 13 -1831974284 Wed Dec 13 14:15:16 1911
282 203712131415.16 13 2144326516 Sun Dec 13 14:15:16 2037
283 3712131415.16 13 2144326516 Sun Dec 13 14:15:16 2037
284 6812131415.16 13 3122633716 Thu Dec 13 14:15:16 2068
285 6912131415.16 13 -1590284 Sat Dec 13 14:15:16 1969
286 7012131415.16 13 29945716 Sun Dec 13 14:15:16 1970
287 1213141599 2 945094500 Mon Dec 13 14:15:00 1999
288 1213141500 2 976716900 Wed Dec 13 14:15:00 2000
289 END-DATA
290
291 */
292
293 # define MAX_BUFF_LEN 1024
294
295 int
main(void)296 main (void)
297 {
298 char buff[MAX_BUFF_LEN + 1];
299
300 buff[MAX_BUFF_LEN] = 0;
301 while (fgets (buff, MAX_BUFF_LEN, stdin) && buff[0])
302 {
303 char time_str[MAX_BUFF_LEN];
304 unsigned int syntax_bits;
305 time_t t;
306 if (sscanf (buff, "%s %u", time_str, &syntax_bits) != 2)
307 printf ("*\n");
308 else
309 {
310 printf ("%-15s %2u ", time_str, syntax_bits);
311 if (posixtime (&t, time_str, syntax_bits))
312 printf ("%12ld %s", (long int) t, ctime (&t));
313 else
314 printf ("%12s %s", "*", "*\n");
315 }
316 }
317 exit (0);
318
319 }
320 #endif
321
322 /*
323 Local Variables:
324 compile-command: "gcc -DTEST_POSIXTIME -g -O -Wall -W posixtm.c"
325 End:
326 */
327