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/* vi: set sw=4 ts=4:
*
* date.c - set/get the date
*
* Copyright 2012 Andre Renaud <andre@bluewatersys.com>
*
* See http://pubs.opengroup.org/onlinepubs/9699919799/utilities/date.html
USE_DATE(NEWTOY(date, "r:u", TOYFLAG_BIN))
config DATE
bool "date"
default y
help
usage: date [-u] [+format] | mmddhhmm[[cc]yy]
Set/get the current date/time
*/
#include "toys.h"
/* Convert a string of decimal numbers to their integer equivalent */
static int fromdec(const char *buf, int len)
{
int result = 0;
while (len--) result=result * 10 + (*buf++ - '0');
return result;
}
void date_main(void)
{
const char *format_string = "%a %b %e %H:%M:%S %Z %Y";
/* Check if we should be displaying the date */
if (!toys.optargs[0] || toys.optargs[0][0] == '+') {
time_t now = time(NULL);
struct tm *tm;
if (toys.optargs[0]) format_string = toys.optargs[0]+1;
if (toys.optflags) tm = gmtime(&now);
else tm = localtime(&now);
if (!tm) perror_msg("Unable to retrieve current time");
if (!strftime(toybuf, sizeof(toybuf), format_string, tm))
perror_msg("bad format `%s'", format_string);
puts(toybuf);
} else {
int len = strlen(toys.optargs[0]);
struct tm tm;
struct timeval tv;
if (len < 8 || len > 12 || len & 1)
error_msg("bad date `%s'", toys.optargs[0]);
memset(&tm, 0, sizeof(tm));
/* Date format: mmddhhmm[[cc]yy] */
tm.tm_mon = fromdec(toys.optargs[0], 2) - 1;
tm.tm_mday = fromdec(&toys.optargs[0][2], 2);
tm.tm_hour = fromdec(&toys.optargs[0][4], 2);
tm.tm_min = fromdec(&toys.optargs[0][6], 2);
if (len == 12) tm.tm_year = fromdec(&toys.optargs[0][8], 4) - 1900;
else if (len == 10) {
tm.tm_year = fromdec(&toys.optargs[0][8], 2);
/* 69-99 = 1969-1999, 0 - 68 = 2000-2068 */
if (tm.tm_year < 69) tm.tm_year += 100;
} else {
/* Year not specified, so retrieve current year */
time_t now = time(NULL);
struct tm *now_tm = localtime(&now);
if (!now_tm) perror_msg("Unable to retrieve current time");
tm.tm_year = now_tm->tm_year;
}
if (!toys.optflags) tv.tv_sec = mktime(&tm);
else {
/* Get the UTC version of a struct tm */
char *tz = NULL;
tz = getenv("TZ");
setenv("TZ", "", 1);
tzset();
tv.tv_sec = mktime(&tm);
if (tz) setenv("TZ", tz, 1);
else unsetenv("TZ");
tzset();
}
if (tv.tv_sec == (time_t)-1)
error_msg("bad `%s'", toys.optargs[0]);
tv.tv_usec = 0;
if (!strftime(toybuf, sizeof(toybuf), format_string, &tm))
perror_msg("bad format `%s'", format_string);
puts(toybuf);
if (settimeofday(&tv, NULL) < 0) perror_msg("cannot set date");
}
}
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