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-rw-r--r--bin/date/vary.c506
1 files changed, 506 insertions, 0 deletions
diff --git a/bin/date/vary.c b/bin/date/vary.c
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--- /dev/null
+++ b/bin/date/vary.c
@@ -0,0 +1,506 @@
+/*-
+ * 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("$FreeBSD$");
+
+#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;
+ }
+}
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