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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:54:16 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:54:16 +0000
commit485f6ecd453d8a2fd8b9b9fadea03159d8b50797 (patch)
tree32451fa3cdd9321fb2591fada9891b2cb70a9cd1 /grub-core/lib/datetime.c
parentInitial commit. (diff)
downloadgrub2-485f6ecd453d8a2fd8b9b9fadea03159d8b50797.tar.xz
grub2-485f6ecd453d8a2fd8b9b9fadea03159d8b50797.zip
Adding upstream version 2.06.upstream/2.06upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'grub-core/lib/datetime.c')
-rw-r--r--grub-core/lib/datetime.c117
1 files changed, 117 insertions, 0 deletions
diff --git a/grub-core/lib/datetime.c b/grub-core/lib/datetime.c
new file mode 100644
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--- /dev/null
+++ b/grub-core/lib/datetime.c
@@ -0,0 +1,117 @@
+/* datetime.c - Module for common datetime function. */
+/*
+ * GRUB -- GRand Unified Bootloader
+ * Copyright (C) 2008 Free Software Foundation, Inc.
+ *
+ * GRUB 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 3 of the License, or
+ * (at your option) any later version.
+ *
+ * GRUB 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 GRUB. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <grub/datetime.h>
+#include <grub/i18n.h>
+#include <grub/misc.h>
+#include <grub/mm.h>
+
+static const char *const grub_weekday_names[] =
+{
+ N_("Sunday"),
+ N_("Monday"),
+ N_("Tuesday"),
+ N_("Wednesday"),
+ N_("Thursday"),
+ N_("Friday"),
+ N_("Saturday"),
+};
+
+int
+grub_get_weekday (struct grub_datetime *datetime)
+{
+ unsigned a, y, m;
+
+ if (datetime->month <= 2)
+ a = 1;
+ else
+ a = 0;
+ y = datetime->year - a;
+ m = datetime->month + 12 * a - 2;
+
+ return (datetime->day + y + y / 4 - y / 100 + y / 400 + (31 * m / 12)) % 7;
+}
+
+const char *
+grub_get_weekday_name (struct grub_datetime *datetime)
+{
+ return _ (grub_weekday_names[grub_get_weekday (datetime)]);
+}
+
+#define SECPERMIN 60
+#define SECPERHOUR (60*SECPERMIN)
+#define SECPERDAY (24*SECPERHOUR)
+#define DAYSPERYEAR 365
+#define DAYSPER4YEARS (4*DAYSPERYEAR+1)
+
+
+void
+grub_unixtime2datetime (grub_int64_t nix, struct grub_datetime *datetime)
+{
+ int i;
+ grub_uint8_t months[12] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
+ /* In the period of validity of unixtime all years divisible by 4
+ are bissextile*/
+ /* Convenience: let's have 3 consecutive non-bissextile years
+ at the beginning of the counting date. So count from 1901. */
+ int days_epoch;
+ /* Number of days since 1st Januar, 1901. */
+ unsigned days;
+ /* Seconds into current day. */
+ unsigned secs_in_day;
+
+ /* Transform C divisions and modulos to mathematical ones */
+ if (nix < 0)
+ /*
+ * The result of division here shouldn't be larger than GRUB_INT_MAX.
+ * So, it's safe to store the result back in an int.
+ */
+ days_epoch = -(grub_divmod64 (((grub_int64_t) (SECPERDAY) - nix - 1), SECPERDAY, NULL));
+ else
+ days_epoch = grub_divmod64 (nix, SECPERDAY, NULL);
+
+ secs_in_day = nix - days_epoch * SECPERDAY;
+ days = days_epoch + 69 * DAYSPERYEAR + 17;
+
+ datetime->year = 1901 + 4 * (days / DAYSPER4YEARS);
+ days %= DAYSPER4YEARS;
+ /* On 31st December of bissextile years 365 days from the beginning
+ of the year elapsed but year isn't finished yet */
+ if (days / DAYSPERYEAR == 4)
+ {
+ datetime->year += 3;
+ days -= 3*DAYSPERYEAR;
+ }
+ else
+ {
+ datetime->year += days / DAYSPERYEAR;
+ days %= DAYSPERYEAR;
+ }
+ for (i = 0; i < 12
+ && days >= (i==1 && datetime->year % 4 == 0
+ ? 29 : months[i]); i++)
+ days -= (i==1 && datetime->year % 4 == 0
+ ? 29 : months[i]);
+ datetime->month = i + 1;
+ datetime->day = 1 + days;
+ datetime->hour = (secs_in_day / SECPERHOUR);
+ secs_in_day %= SECPERHOUR;
+ datetime->minute = secs_in_day / SECPERMIN;
+ datetime->second = secs_in_day % SECPERMIN;
+}