diff options
Diffstat (limited to 'usr.bin/date/date.c')
-rw-r--r-- | usr.bin/date/date.c | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/usr.bin/date/date.c b/usr.bin/date/date.c new file mode 100644 index 0000000..a47e3eb --- /dev/null +++ b/usr.bin/date/date.c @@ -0,0 +1,86 @@ +/* + * 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; +} |