summaryrefslogtreecommitdiffstats
path: root/meta/recipes-extended/at/at/posixtm.c
blob: 5514ba4fe26d80181a42debf4d2064b62fa53a6b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
/* Parse dates for touch and date.

   Copyright (C) 1989, 1990, 1991, 1998, 2000, 2001, 2002, 2003, 2004,
   2005, 2006, 2007 Free Software Foundation Inc.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2, or (at your option)
   any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software Foundation,
   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */

/* Yacc-based version written by Jim Kingdon and David MacKenzie.
   Rewritten by Jim Meyering.  */

#include <config.h>

#include "posixtm.h"

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <string.h>

#if USE_UNLOCKED_IO
# include "unlocked-io.h"
#endif

/* ISDIGIT differs from isdigit, as follows:
   - Its arg may be any int or unsigned int; it need not be an unsigned char
     or EOF.
   - It's typically faster.
   POSIX says that only '0' through '9' are digits.  Prefer ISDIGIT to
   isdigit unless it's important to use the locale's definition
   of `digit' even when the host does not conform to POSIX.  */
#define ISDIGIT(c) ((unsigned int) (c) - '0' <= 9)

time_t mktime ();

/*
  POSIX requires:

  touch -t [[CC]YY]mmddhhmm[.ss] FILE...
    8, 10, or 12 digits, followed by optional .ss
    (PDS_LEADING_YEAR | PDS_CENTURY | PDS_SECONDS)

  touch mmddhhmm[YY] FILE... (obsoleted by POSIX 1003.1-2001)
    8 or 10 digits, YY (if present) must be in the range 69-99
    (PDS_TRAILING_YEAR | PDS_PRE_2000)

  date mmddhhmm[[CC]YY]
    8, 10, or 12 digits
    (PDS_TRAILING_YEAR | PDS_CENTURY)

*/

static int
year (struct tm *tm, const int *digit_pair, size_t n, unsigned int syntax_bits)
{
  switch (n)
    {
    case 1:
      tm->tm_year = *digit_pair;
      /* Deduce the century based on the year.
	 POSIX requires that 00-68 be interpreted as 2000-2068,
	 and that 69-99 be interpreted as 1969-1999.  */
      if (digit_pair[0] <= 68)
	{
	  if (syntax_bits & PDS_PRE_2000)
	    return 1;
	  tm->tm_year += 100;
	}
      break;

    case 2:
      if (! (syntax_bits & PDS_CENTURY))
	return 1;
      tm->tm_year = digit_pair[0] * 100 + digit_pair[1] - 1900;
      break;

    case 0:
      {
	time_t now;
	struct tm *tmp;

	/* Use current year.  */
	time (&now);
	tmp = localtime (&now);
	if (! tmp)
	  return 1;
	tm->tm_year = tmp->tm_year;
      }
      break;

    default:
      abort ();
    }

  return 0;
}

static int
posix_time_parse (struct tm *tm, const char *s, unsigned int syntax_bits)
{
  const char *dot = NULL;
  int pair[6];
  int *p;
  size_t i;

  size_t s_len = strlen (s);
  size_t len = (((syntax_bits & PDS_SECONDS) && (dot = strchr (s, '.')))
		? (size_t) (dot - s)
		: s_len);

  if (len != 8 && len != 10 && len != 12)
    return 1;

  if (dot)
    {
      if (!(syntax_bits & PDS_SECONDS))
	return 1;

      if (s_len - len != 3)
	return 1;
    }

  for (i = 0; i < len; i++)
    if (!ISDIGIT (s[i]))
      return 1;

  len /= 2;
  for (i = 0; i < len; i++)
    pair[i] = 10 * (s[2*i] - '0') + s[2*i + 1] - '0';

  p = pair;
  if (syntax_bits & PDS_LEADING_YEAR)
    {
      if (year (tm, p, len - 4, syntax_bits))
	return 1;
      p += len - 4;
      len = 4;
    }

  /* Handle 8 digits worth of `MMDDhhmm'.  */
  tm->tm_mon = *p++ - 1;
  tm->tm_mday = *p++;
  tm->tm_hour = *p++;
  tm->tm_min = *p++;
  len -= 4;

  /* Handle any trailing year.  */
  if (syntax_bits & PDS_TRAILING_YEAR)
    {
      if (year (tm, p, len, syntax_bits))
	return 1;
    }

  /* Handle seconds.  */
  if (!dot)
    {
      tm->tm_sec = 0;
    }
  else
    {
      int seconds;

      ++dot;
      if (!ISDIGIT (dot[0]) || !ISDIGIT (dot[1]))
	return 1;
      seconds = 10 * (dot[0] - '0') + dot[1] - '0';

      tm->tm_sec = seconds;
    }

  return 0;
}

/* Parse a POSIX-style date, returning true if successful.  */

bool
posixtime (time_t *p, const char *s, unsigned int syntax_bits)
{
  struct tm tm0
#ifdef lint
  /* Placate gcc-4's -Wuninitialized.
     posix_time_parse fails to set all of tm0 only when it returns
     nonzero (due to year() returning nonzero), and in that case,
     this code doesn't use the tm0 at all.  */
    = { 0, }
#endif
    ;
  struct tm tm1;
  struct tm const *tm;
  time_t t;

  if (posix_time_parse (&tm0, s, syntax_bits))
    return false;

  tm1 = tm0;
  tm1.tm_isdst = -1;
  t = mktime (&tm1);

  if (t != (time_t) -1)
    tm = &tm1;
  else
    {
      /* mktime returns -1 for errors, but -1 is also a valid time_t
	 value.  Check whether an error really occurred.  */
      tm = localtime (&t);
      if (! tm)
	return false;
    }

  /* Reject dates like "September 31" and times like "25:61".  */
  if ((tm0.tm_year ^ tm->tm_year)
      | (tm0.tm_mon ^ tm->tm_mon)
      | (tm0.tm_mday ^ tm->tm_mday)
      | (tm0.tm_hour ^ tm->tm_hour)
      | (tm0.tm_min ^ tm->tm_min)
      | (tm0.tm_sec ^ tm->tm_sec))
    return false;

  *p = t;
  return true;
}

#ifdef TEST_POSIXTIME
/*
    Test mainly with syntax_bits == 13
    (aka: (PDS_LEADING_YEAR | PDS_CENTURY | PDS_SECONDS))

    This test data assumes Universal Time, e.g., TZ="UTC0".

    This test data also assumes that time_t is signed and is at least
    39 bits wide, so that it can represent all years from 0000 through
    9999.  A host with 32-bit signed time_t can represent only time
    stamps in the range 1901-12-13 20:45:52 through 2038-01-18
    03:14:07 UTC, assuming POSIX time_t with no leap seconds, so test
    cases outside this range will not work on such a host.

    Also, the first two lines of test data assume that the current
    year is 2002.

BEGIN-DATA
12131415.16     13   1039788916 Fri Dec 13 14:15:16 2002
12131415.16     13   1039788916 Fri Dec 13 14:15:16 2002
000001010000.00 13 -62167132800 Sun Jan  1 00:00:00 0000
190112132045.52 13  -2147483648 Fri Dec 13 20:45:52 1901
190112132045.53 13  -2147483647 Fri Dec 13 20:45:53 1901
190112132046.52 13  -2147483588 Fri Dec 13 20:46:52 1901
190112132145.52 13  -2147480048 Fri Dec 13 21:45:52 1901
190112142045.52 13  -2147397248 Sat Dec 14 20:45:52 1901
190201132045.52 13  -2144805248 Mon Jan 13 20:45:52 1902
196912312359.59 13           -1 Wed Dec 31 23:59:59 1969
197001010000.00 13            0 Thu Jan  1 00:00:00 1970
197001010000.01 13            1 Thu Jan  1 00:00:01 1970
197001010001.00 13           60 Thu Jan  1 00:01:00 1970
197001010100.00 13         3600 Thu Jan  1 01:00:00 1970
197001020000.00 13        86400 Fri Jan  2 00:00:00 1970
197002010000.00 13      2678400 Sun Feb  1 00:00:00 1970
197101010000.00 13     31536000 Fri Jan  1 00:00:00 1971
197001000000.00 13            * *
197000010000.00 13            * *
197001010000.60 13            * *
197001010060.00 13            * *
197001012400.00 13            * *
197001320000.00 13            * *
197013010000.00 13            * *
203801190314.06 13   2147483646 Tue Jan 19 03:14:06 2038
203801190314.07 13   2147483647 Tue Jan 19 03:14:07 2038
203801190314.08 13   2147483648 Tue Jan 19 03:14:08 2038
999912312359.59 13 253402300799 Fri Dec 31 23:59:59 9999
1112131415      13   1323785700 Tue Dec 13 14:15:00 2011
1112131415.16   13   1323785716 Tue Dec 13 14:15:16 2011
201112131415.16 13   1323785716 Tue Dec 13 14:15:16 2011
191112131415.16 13  -1831974284 Wed Dec 13 14:15:16 1911
203712131415.16 13   2144326516 Sun Dec 13 14:15:16 2037
3712131415.16   13   2144326516 Sun Dec 13 14:15:16 2037
6812131415.16   13   3122633716 Thu Dec 13 14:15:16 2068
6912131415.16   13     -1590284 Sat Dec 13 14:15:16 1969
7012131415.16   13     29945716 Sun Dec 13 14:15:16 1970
1213141599       2    945094500 Mon Dec 13 14:15:00 1999
1213141500       2    976716900 Wed Dec 13 14:15:00 2000
END-DATA

*/

# define MAX_BUFF_LEN 1024

int
main (void)
{
  char buff[MAX_BUFF_LEN + 1];

  buff[MAX_BUFF_LEN] = 0;
  while (fgets (buff, MAX_BUFF_LEN, stdin) && buff[0])
    {
      char time_str[MAX_BUFF_LEN];
      unsigned int syntax_bits;
      time_t t;
      if (sscanf (buff, "%s %u", time_str, &syntax_bits) != 2)
	printf ("*\n");
      else
	{
	  printf ("%-15s %2u ", time_str, syntax_bits);
	  if (posixtime (&t, time_str, syntax_bits))
	    printf ("%12ld %s", (long int) t, ctime (&t));
	  else
	    printf ("%12s %s", "*", "*\n");
	}
    }
  exit (0);

}
#endif

/*
Local Variables:
compile-command: "gcc -DTEST_POSIXTIME -g -O -Wall -W posixtm.c"
End:
*/