bin/date/vary.c

/*-
 * Copyright (c) 1997 Brian Somers <brian@Awfulhak.org>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD: stable/9/bin/date/vary.c 133381 2004-08-09 13:43:39Z yar $");

#include <err.h>
#include <time.h>
#include <string.h>
#include <stdlib.h>
#include "vary.h"

struct trans {
  int val;
  const char *str;
};

static struct trans trans_mon[] = {
  { 1, "january" }, { 2, "february" }, { 3, "march" }, { 4, "april" },
  { 5, "may"}, { 6, "june" }, { 7, "july" }, { 8, "august" },
  { 9, "september" }, { 10, "october" }, { 11, "november" }, { 12, "december" },
  { -1, NULL }
};

static struct trans trans_wday[] = {
  { 0, "sunday" }, { 1, "monday" }, { 2, "tuesday" }, { 3, "wednesday" },
  { 4, "thursday" }, { 5, "friday" }, { 6, "saturday" },
  { -1, NULL }
};

static char digits[] = "0123456789";
static int adjhour(struct tm *, char, int, int);

static int
domktime(struct tm *t, char type)
{
  time_t ret;

  while ((ret = mktime(t)) == -1 && t->tm_year > 68 && t->tm_year < 138)
    /* While mktime() fails, adjust by an hour */
    adjhour(t, type == '-' ? type : '+', 1, 0);

  return ret;
}

static int
trans(const struct trans t[], const char *arg)
{
  int f;

  for (f = 0; t[f].val != -1; f++)
    if (!strncasecmp(t[f].str, arg, 3) ||
        !strncasecmp(t[f].str, arg, strlen(t[f].str)))
      return t[f].val;

  return -1;
}

struct vary *
vary_append(struct vary *v, char *arg)
{
  struct vary *result, **nextp;

  if (v) {
    result = v;
    while (v->next)
      v = v->next;
    nextp = &v->next;
  } else
    nextp = &result;

  if ((*nextp = (struct vary *)malloc(sizeof(struct vary))) == NULL)
    err(1, "malloc");
  (*nextp)->arg = arg;
  (*nextp)->next = NULL;
  return result;
}

static int mdays[12] = { 31, 0, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };

static int
daysinmonth(const struct tm *t)
{
  int year;

  year = t->tm_year + 1900;

  if (t->tm_mon == 1)
    if (!(year % 400))
      return 29;
    else if (!(year % 100))
      return 28;
    else if (!(year % 4))
      return 29;
    else
      return 28;
  else if (t->tm_mon >= 0 && t->tm_mon < 12)
    return mdays[t->tm_mon];

  return 0;
}


static int
adjyear(struct tm *t, char type, int val, int mk)
{
  switch (type) {
    case '+':
      t->tm_year += val;
      break;
    case '-':
      t->tm_year -= val;
      break;
    default:
      t->tm_year = val;
      if (t->tm_year < 69)
        t->tm_year += 100;              /* as per date.c */
      else if (t->tm_year > 1900)
        t->tm_year -= 1900;             /* struct tm holds years since 1900 */
      break;
  }
  return !mk || domktime(t, type) != -1;
}

static int
adjmon(struct tm *t, char type, int val, int istext, int mk)
{
  int lmdays;

  if (val < 0)
    return 0;

  switch (type) {
    case '+':
      if (istext) {
        if (val <= t->tm_mon)
          val += 11 - t->tm_mon;        /* early next year */
        else
          val -= t->tm_mon + 1;         /* later this year */
      }
      if (val) {
        if (!adjyear(t, '+', (t->tm_mon + val) / 12, 0))
          return 0;
        val %= 12;
        t->tm_mon += val;
        if (t->tm_mon > 11)
          t->tm_mon -= 12;
      }
      break;

    case '-':
      if (istext) {
        if (val-1 > t->tm_mon)
          val = 13 - val + t->tm_mon;   /* later last year */
        else
          val = t->tm_mon - val + 1;    /* early this year */
      }
      if (val) {
        if (!adjyear(t, '-', val / 12, 0))
          return 0;
        val %= 12;
        if (val > t->tm_mon) {
          if (!adjyear(t, '-', 1, 0))
            return 0;
          val -= 12;
        }
        t->tm_mon -= val;
      }
      break;

    default:
      if (val > 12 || val < 1)
        return 0;
      t->tm_mon = --val;
  }

  /* e.g., -v-1m on March, 31 is the last day of February in common sense */
  lmdays = daysinmonth(t);
  if (t->tm_mday > lmdays)
    t->tm_mday = lmdays;

  return !mk || domktime(t, type) != -1;
}

static int
adjday(struct tm *t, char type, int val, int mk)
{
  int lmdays;

  switch (type) {
    case '+':
      while (val) {
        lmdays = daysinmonth(t);
        if (val > lmdays - t->tm_mday) {
          val -= lmdays - t->tm_mday + 1;
          t->tm_mday = 1;
          if (!adjmon(t, '+', 1, 0, 0))
            return 0;
        } else {
          t->tm_mday += val;
          val = 0;
        }
      }
      break;
    case '-':
      while (val)
        if (val >= t->tm_mday) {
          val -= t->tm_mday;
          t->tm_mday = 1;
          if (!adjmon(t, '-', 1, 0, 0))
            return 0;
          t->tm_mday = daysinmonth(t);
        } else {
          t->tm_mday -= val;
          val = 0;
        }
      break;
    default:
      if (val > 0 && val <= daysinmonth(t))
        t->tm_mday = val;
      else
        return 0;
      break;
  }

  return !mk || domktime(t, type) != -1;
}

static int
adjwday(struct tm *t, char type, int val, int istext, int mk)
{
  if (val < 0)
    return 0;

  switch (type) {
    case '+':
      if (istext)
        if (val < t->tm_wday)
          val = 7 - t->tm_wday + val;  /* early next week */
        else
          val -= t->tm_wday;           /* later this week */
      else
        val *= 7;                      /* "-v+5w" == "5 weeks in the future" */
      return !val || adjday(t, '+', val, mk);
    case '-':
      if (istext) {
        if (val > t->tm_wday)
          val = 7 - val + t->tm_wday;  /* later last week */
        else
          val = t->tm_wday - val;      /* early this week */
      } else
        val *= 7;                      /* "-v-5w" == "5 weeks ago" */
      return !val || adjday(t, '-', val, mk);
    default:
      if (val < t->tm_wday)
        return adjday(t, '-', t->tm_wday - val, mk);
      else if (val > 6)
        return 0;
      else if (val > t->tm_wday)
        return adjday(t, '+', val - t->tm_wday, mk);
  }
  return 1;
}

static int
adjhour(struct tm *t, char type, int val, int mk)
{
  if (val < 0)
    return 0;

  switch (type) {
    case '+':
      if (val) {
        int days;

        days = (t->tm_hour + val) / 24;
        val %= 24;
        t->tm_hour += val;
        t->tm_hour %= 24;
        if (!adjday(t, '+', days, 0))
          return 0;
      }
      break;

    case '-':
      if (val) {
        int days;

        days = val / 24;
        val %= 24;
        if (val > t->tm_hour) {
          days++;
          val -= 24;
        }
        t->tm_hour -= val;
        if (!adjday(t, '-', days, 0))
          return 0;
      }
      break;

    default:
      if (val > 23)
        return 0;
      t->tm_hour = val;
  }

  return !mk || domktime(t, type) != -1;
}

static int
adjmin(struct tm *t, char type, int val, int mk)
{
  if (val < 0)
    return 0;

  switch (type) {
    case '+':
      if (val) {
        if (!adjhour(t, '+', (t->tm_min + val) / 60, 0))
          return 0;
        val %= 60;
        t->tm_min += val;
        if (t->tm_min > 59)
          t->tm_min -= 60;
      }
      break;

    case '-':
      if (val) {
        if (!adjhour(t, '-', val / 60, 0))
          return 0;
        val %= 60;
        if (val > t->tm_min) {
          if (!adjhour(t, '-', 1, 0))
            return 0;
          val -= 60;
        }
        t->tm_min -= val;
      }
      break;

    default:
      if (val > 59)
        return 0;
      t->tm_min = val;
  }

  return !mk || domktime(t, type) != -1;
}

static int
adjsec(struct tm *t, char type, int val, int mk)
{
  if (val < 0)
    return 0;

  switch (type) {
    case '+':
      if (val) {
        if (!adjmin(t, '+', (t->tm_sec + val) / 60, 0))
          return 0;
        val %= 60;
        t->tm_sec += val;
        if (t->tm_sec > 59)
          t->tm_sec -= 60;
      }
      break;

    case '-':
      if (val) {
        if (!adjmin(t, '-', val / 60, 0))
          return 0;
        val %= 60;
        if (val > t->tm_sec) {
          if (!adjmin(t, '-', 1, 0))
            return 0;
          val -= 60;
        }
        t->tm_sec -= val;
      }
      break;

    default:
      if (val > 59)
        return 0;
      t->tm_sec = val;
  }

  return !mk || domktime(t, type) != -1;
}

const struct vary *
vary_apply(const struct vary *v, struct tm *t)
{
  char type;
  char which;
  char *arg;
  size_t len;
  int val;

  for (; v; v = v->next) {
    type = *v->arg;
    arg = v->arg;
    if (type == '+' || type == '-')
      arg++;
    else
      type = '\0';
    len = strlen(arg);
    if (len < 2)
      return v;

    if (type == '\0')
      t->tm_isdst = -1;

    if (strspn(arg, digits) != len-1) {
      val = trans(trans_wday, arg);
      if (val != -1) {
          if (!adjwday(t, type, val, 1, 1))
            return v;
      } else {
        val = trans(trans_mon, arg);
        if (val != -1) {
          if (!adjmon(t, type, val, 1, 1))
            return v;
        } else
          return v;
      }
    } else {
      val = atoi(arg);
      which = arg[len-1];
      
      switch (which) {
        case 'S':
          if (!adjsec(t, type, val, 1))
            return v;
          break;
        case 'M':
          if (!adjmin(t, type, val, 1))
            return v;
          break;
        case 'H':
          if (!adjhour(t, type, val, 1))
            return v;
          break;
        case 'd':
          t->tm_isdst = -1;
          if (!adjday(t, type, val, 1))
            return v;
          break;
        case 'w':
          t->tm_isdst = -1;
          if (!adjwday(t, type, val, 0, 1))
            return v;
          break;
        case 'm':
          t->tm_isdst = -1;
          if (!adjmon(t, type, val, 0, 1))
            return v;
          break;
        case 'y':
          t->tm_isdst = -1;
          if (!adjyear(t, type, val, 1))
            return v;
          break;
        default:
          return v;
      }
    }
  }
  return 0;
}

void
vary_destroy(struct vary *v)
{
  struct vary *n;

  while (v) {
    n = v->next;
    free(v);
    v = n;
  }
}
Revision:	9664
Committed:	Sun Oct 22 23:20:00 2017 UTC (6 years, 6 months ago) by laffer1
Content type:	text/plain
File size:	11236 byte(s)
Log Message:	tag freebsd rev 9.r249549
#	Content
1	/*-
2	* Copyright (c) 1997 Brian Somers <brian@Awfulhak.org>
3	* All rights reserved.
4	*
5	* Redistribution and use in source and binary forms, with or without
6	* modification, are permitted provided that the following conditions
7	* are met:
8	* 1. Redistributions of source code must retain the above copyright
9	* notice, this list of conditions and the following disclaimer.
10	* 2. Redistributions in binary form must reproduce the above copyright
11	* notice, this list of conditions and the following disclaimer in the
12	* documentation and/or other materials provided with the distribution.
13	*
14	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17	* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24	* SUCH DAMAGE.
25	*/
26
27	#include <sys/cdefs.h>
28	__FBSDID("$FreeBSD: stable/9/bin/date/vary.c 133381 2004-08-09 13:43:39Z yar $");
29
30	#include <err.h>
31	#include <time.h>
32	#include <string.h>
33	#include <stdlib.h>
34	#include "vary.h"
35
36	struct trans {
37	int val;
38	const char *str;
39	};
40
41	static struct trans trans_mon[] = {
42	{ 1, "january" }, { 2, "february" }, { 3, "march" }, { 4, "april" },
43	{ 5, "may"}, { 6, "june" }, { 7, "july" }, { 8, "august" },
44	{ 9, "september" }, { 10, "october" }, { 11, "november" }, { 12, "december" },
45	{ -1, NULL }
46	};
47
48	static struct trans trans_wday[] = {
49	{ 0, "sunday" }, { 1, "monday" }, { 2, "tuesday" }, { 3, "wednesday" },
50	{ 4, "thursday" }, { 5, "friday" }, { 6, "saturday" },
51	{ -1, NULL }
52	};
53
54	static char digits[] = "0123456789";
55	static int adjhour(struct tm *, char, int, int);
56
57	static int
58	domktime(struct tm *t, char type)
59	{
60	time_t ret;
61
62	while ((ret = mktime(t)) == -1 && t->tm_year > 68 && t->tm_year < 138)
63	/* While mktime() fails, adjust by an hour */
64	adjhour(t, type == '-' ? type : '+', 1, 0);
65
66	return ret;
67	}
68
69	static int
70	trans(const struct trans t[], const char *arg)
71	{
72	int f;
73
74	for (f = 0; t[f].val != -1; f++)
75	if (!strncasecmp(t[f].str, arg, 3) \|\|
76	!strncasecmp(t[f].str, arg, strlen(t[f].str)))
77	return t[f].val;
78
79	return -1;
80	}
81
82	struct vary *
83	vary_append(struct vary v, char arg)
84	{
85	struct vary result, *nextp;
86
87	if (v) {
88	result = v;
89	while (v->next)
90	v = v->next;
91	nextp = &v->next;
92	} else
93	nextp = &result;
94
95	if ((nextp = (struct vary )malloc(sizeof(struct vary))) == NULL)
96	err(1, "malloc");
97	(*nextp)->arg = arg;
98	(*nextp)->next = NULL;
99	return result;
100	}
101
102	static int mdays[12] = { 31, 0, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
103
104	static int
105	daysinmonth(const struct tm *t)
106	{
107	int year;
108
109	year = t->tm_year + 1900;
110
111	if (t->tm_mon == 1)
112	if (!(year % 400))
113	return 29;
114	else if (!(year % 100))
115	return 28;
116	else if (!(year % 4))
117	return 29;
118	else
119	return 28;
120	else if (t->tm_mon >= 0 && t->tm_mon < 12)
121	return mdays[t->tm_mon];
122
123	return 0;
124	}
125
126
127	static int
128	adjyear(struct tm *t, char type, int val, int mk)
129	{
130	switch (type) {
131	case '+':
132	t->tm_year += val;
133	break;
134	case '-':
135	t->tm_year -= val;
136	break;
137	default:
138	t->tm_year = val;
139	if (t->tm_year < 69)
140	t->tm_year += 100; /* as per date.c */
141	else if (t->tm_year > 1900)
142	t->tm_year -= 1900; /* struct tm holds years since 1900 */
143	break;
144	}
145	return !mk \|\| domktime(t, type) != -1;
146	}
147
148	static int
149	adjmon(struct tm *t, char type, int val, int istext, int mk)
150	{
151	int lmdays;
152
153	if (val < 0)
154	return 0;
155
156	switch (type) {
157	case '+':
158	if (istext) {
159	if (val <= t->tm_mon)
160	val += 11 - t->tm_mon; /* early next year */
161	else
162	val -= t->tm_mon + 1; /* later this year */
163	}
164	if (val) {
165	if (!adjyear(t, '+', (t->tm_mon + val) / 12, 0))
166	return 0;
167	val %= 12;
168	t->tm_mon += val;
169	if (t->tm_mon > 11)
170	t->tm_mon -= 12;
171	}
172	break;
173
174	case '-':
175	if (istext) {
176	if (val-1 > t->tm_mon)
177	val = 13 - val + t->tm_mon; /* later last year */
178	else
179	val = t->tm_mon - val + 1; /* early this year */
180	}
181	if (val) {
182	if (!adjyear(t, '-', val / 12, 0))
183	return 0;
184	val %= 12;
185	if (val > t->tm_mon) {
186	if (!adjyear(t, '-', 1, 0))
187	return 0;
188	val -= 12;
189	}
190	t->tm_mon -= val;
191	}
192	break;
193
194	default:
195	if (val > 12 \|\| val < 1)
196	return 0;
197	t->tm_mon = --val;
198	}
199
200	/* e.g., -v-1m on March, 31 is the last day of February in common sense */
201	lmdays = daysinmonth(t);
202	if (t->tm_mday > lmdays)
203	t->tm_mday = lmdays;
204
205	return !mk \|\| domktime(t, type) != -1;
206	}
207
208	static int
209	adjday(struct tm *t, char type, int val, int mk)
210	{
211	int lmdays;
212
213	switch (type) {
214	case '+':
215	while (val) {
216	lmdays = daysinmonth(t);
217	if (val > lmdays - t->tm_mday) {
218	val -= lmdays - t->tm_mday + 1;
219	t->tm_mday = 1;
220	if (!adjmon(t, '+', 1, 0, 0))
221	return 0;
222	} else {
223	t->tm_mday += val;
224	val = 0;
225	}
226	}
227	break;
228	case '-':
229	while (val)
230	if (val >= t->tm_mday) {
231	val -= t->tm_mday;
232	t->tm_mday = 1;
233	if (!adjmon(t, '-', 1, 0, 0))
234	return 0;
235	t->tm_mday = daysinmonth(t);
236	} else {
237	t->tm_mday -= val;
238	val = 0;
239	}
240	break;
241	default:
242	if (val > 0 && val <= daysinmonth(t))
243	t->tm_mday = val;
244	else
245	return 0;
246	break;
247	}
248
249	return !mk \|\| domktime(t, type) != -1;
250	}
251
252	static int
253	adjwday(struct tm *t, char type, int val, int istext, int mk)
254	{
255	if (val < 0)
256	return 0;
257
258	switch (type) {
259	case '+':
260	if (istext)
261	if (val < t->tm_wday)
262	val = 7 - t->tm_wday + val; /* early next week */
263	else
264	val -= t->tm_wday; /* later this week */
265	else
266	val = 7; / "-v+5w" == "5 weeks in the future" */
267	return !val \|\| adjday(t, '+', val, mk);
268	case '-':
269	if (istext) {
270	if (val > t->tm_wday)
271	val = 7 - val + t->tm_wday; /* later last week */
272	else
273	val = t->tm_wday - val; /* early this week */
274	} else
275	val = 7; / "-v-5w" == "5 weeks ago" */
276	return !val \|\| adjday(t, '-', val, mk);
277	default:
278	if (val < t->tm_wday)
279	return adjday(t, '-', t->tm_wday - val, mk);
280	else if (val > 6)
281	return 0;
282	else if (val > t->tm_wday)
283	return adjday(t, '+', val - t->tm_wday, mk);
284	}
285	return 1;
286	}
287
288	static int
289	adjhour(struct tm *t, char type, int val, int mk)
290	{
291	if (val < 0)
292	return 0;
293
294	switch (type) {
295	case '+':
296	if (val) {
297	int days;
298
299	days = (t->tm_hour + val) / 24;
300	val %= 24;
301	t->tm_hour += val;
302	t->tm_hour %= 24;
303	if (!adjday(t, '+', days, 0))
304	return 0;
305	}
306	break;
307
308	case '-':
309	if (val) {
310	int days;
311
312	days = val / 24;
313	val %= 24;
314	if (val > t->tm_hour) {
315	days++;
316	val -= 24;
317	}
318	t->tm_hour -= val;
319	if (!adjday(t, '-', days, 0))
320	return 0;
321	}
322	break;
323
324	default:
325	if (val > 23)
326	return 0;
327	t->tm_hour = val;
328	}
329
330	return !mk \|\| domktime(t, type) != -1;
331	}
332
333	static int
334	adjmin(struct tm *t, char type, int val, int mk)
335	{
336	if (val < 0)
337	return 0;
338
339	switch (type) {
340	case '+':
341	if (val) {
342	if (!adjhour(t, '+', (t->tm_min + val) / 60, 0))
343	return 0;
344	val %= 60;
345	t->tm_min += val;
346	if (t->tm_min > 59)
347	t->tm_min -= 60;
348	}
349	break;
350
351	case '-':
352	if (val) {
353	if (!adjhour(t, '-', val / 60, 0))
354	return 0;
355	val %= 60;
356	if (val > t->tm_min) {
357	if (!adjhour(t, '-', 1, 0))
358	return 0;
359	val -= 60;
360	}
361	t->tm_min -= val;
362	}
363	break;
364
365	default:
366	if (val > 59)
367	return 0;
368	t->tm_min = val;
369	}
370
371	return !mk \|\| domktime(t, type) != -1;
372	}
373
374	static int
375	adjsec(struct tm *t, char type, int val, int mk)
376	{
377	if (val < 0)
378	return 0;
379
380	switch (type) {
381	case '+':
382	if (val) {
383	if (!adjmin(t, '+', (t->tm_sec + val) / 60, 0))
384	return 0;
385	val %= 60;
386	t->tm_sec += val;
387	if (t->tm_sec > 59)
388	t->tm_sec -= 60;
389	}
390	break;
391
392	case '-':
393	if (val) {
394	if (!adjmin(t, '-', val / 60, 0))
395	return 0;
396	val %= 60;
397	if (val > t->tm_sec) {
398	if (!adjmin(t, '-', 1, 0))
399	return 0;
400	val -= 60;
401	}
402	t->tm_sec -= val;
403	}
404	break;
405
406	default:
407	if (val > 59)
408	return 0;
409	t->tm_sec = val;
410	}
411
412	return !mk \|\| domktime(t, type) != -1;
413	}
414
415	const struct vary *
416	vary_apply(const struct vary v, struct tm t)
417	{
418	char type;
419	char which;
420	char *arg;
421	size_t len;
422	int val;
423
424	for (; v; v = v->next) {
425	type = *v->arg;
426	arg = v->arg;
427	if (type == '+' \|\| type == '-')
428	arg++;
429	else
430	type = '\0';
431	len = strlen(arg);
432	if (len < 2)
433	return v;
434
435	if (type == '\0')
436	t->tm_isdst = -1;
437
438	if (strspn(arg, digits) != len-1) {
439	val = trans(trans_wday, arg);
440	if (val != -1) {
441	if (!adjwday(t, type, val, 1, 1))
442	return v;
443	} else {
444	val = trans(trans_mon, arg);
445	if (val != -1) {
446	if (!adjmon(t, type, val, 1, 1))
447	return v;
448	} else
449	return v;
450	}
451	} else {
452	val = atoi(arg);
453	which = arg[len-1];
454
455	switch (which) {
456	case 'S':
457	if (!adjsec(t, type, val, 1))
458	return v;
459	break;
460	case 'M':
461	if (!adjmin(t, type, val, 1))
462	return v;
463	break;
464	case 'H':
465	if (!adjhour(t, type, val, 1))
466	return v;
467	break;
468	case 'd':
469	t->tm_isdst = -1;
470	if (!adjday(t, type, val, 1))
471	return v;
472	break;
473	case 'w':
474	t->tm_isdst = -1;
475	if (!adjwday(t, type, val, 0, 1))
476	return v;
477	break;
478	case 'm':
479	t->tm_isdst = -1;
480	if (!adjmon(t, type, val, 0, 1))
481	return v;
482	break;
483	case 'y':
484	t->tm_isdst = -1;
485	if (!adjyear(t, type, val, 1))
486	return v;
487	break;
488	default:
489	return v;
490	}
491	}
492	}
493	return 0;
494	}
495
496	void
497	vary_destroy(struct vary *v)
498	{
499	struct vary *n;
500
501	while (v) {
502	n = v->next;
503	free(v);
504	v = n;
505	}
506	}