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/*
* Copyright (c) 2023-2025 Ian Marco Moffett and the Osmora Team.
* 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.
* 3. Neither the name of Hyra nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT OWNER 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/time.h>
#include <sys/cdefs.h>
#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#define MONTHS_PER_YEAR 12
#define DAYS_PER_WEEK 7
/* Months of the year */
static const char *montab[] = {
"Jan", "Feb", "Mar",
"Apr", "May", "Jun",
"Jul", "Aug", "Sep",
"Oct", "Nov", "Dec"
};
/* Days of the week */
static const char *daytab[] = {
"Sat", "Sun", "Mon",
"Tue", "Wed", "Thu",
"Fri"
};
int
main(void)
{
const char *day, *month;
char date_str[32];
struct date d;
int rtc_fd;
if ((rtc_fd = open("/dev/rtc", O_RDONLY)) < 0) {
return rtc_fd;
}
read(rtc_fd, &d, sizeof(d));
close(rtc_fd);
/* This should not happen */
if (__unlikely(d.month > MONTHS_PER_YEAR)) {
printf("got bad month %d from RTC\n", d.month);
return -1;
}
if (__unlikely(d.month == 0 || d.day == 0)) {
printf("got zero month/day from RTC\n");
return -1;
}
day = daytab[d.day % DAYS_PER_WEEK];
month = montab[d.month - 1];
snprintf(date_str, sizeof(date_str), "%s %s %d %02d:%02d:%02d\n",
day, month, d.day, d.hour, d.min, d.sec);
fputs(date_str, stdout);
return 0;
}
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