50 lines
1.3 KiB
C
50 lines
1.3 KiB
C
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/* datetime.c - Module for common datetime function. */
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/*
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* GRUB -- GRand Unified Bootloader
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* Copyright (C) 2008 Free Software Foundation, Inc.
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*
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* GRUB is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* GRUB is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with GRUB. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <grub/lib/datetime.h>
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static char *grub_weekday_names[] =
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{
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"Sunday",
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"Monday",
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"Tuesday",
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"Wednesday",
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"Thursday",
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"Friday",
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"Saturday",
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};
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int
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grub_get_weekday (struct grub_datetime *datetime)
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{
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int a, y, m;
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a = (14 - datetime->month) / 12;
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y = datetime->year - a;
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m = datetime->month + 12 * a - 2;
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return (datetime->day + y + y / 4 - y / 100 + y / 400 + (31 * m / 12)) % 7;
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}
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char *
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grub_get_weekday_name (struct grub_datetime *datetime)
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{
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return grub_weekday_names[grub_get_weekday (datetime)];
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}
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