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todr(9) [netbsd man page]

TODR(9) 						   BSD Kernel Developer's Manual						   TODR(9)

todr_attach, todr_gettime, todr_settime, clock_ymdhms_to_secs, clock_secs_to_ymdhms -- time-of-day clock support SYNOPSIS
#include <dev/clock_subr.h> void todr_attach(todr_chip_handle_t); int todr_gettime(todr_chip_handle_t, struct timeval *); int todr_settime(todr_chip_handle_t, struct timeval *); void clock_secs_to_ymdhms(int, struct clock_ymdhms *); time_t clock_ymdhms_to_secs(struct clock_ymdhms *); DESCRIPTION
The todr_*() functions provide an interface to read, set and control 'time-of-day' devices. A driver for a 'time-of-day' device registers its todr_chip_handle_t with machine-dependent code using the todr_attach() function. Alternatively, a machine-dependent front-end to a 'time-of-day' device driver may obtain the todr_chip_handle_t directly. The todr_gettime() retrieves the current data and time from the TODR device and returns it in the struct timeval storage provided by the caller. todr_settime() sets the date and time in the TODR device represented by todr_chip_handle_t according to the struct timeval argument. The utilities clock_secs_to_ymdhms() and clock_ymdhms_to_secs() are provided to convert a time value in seconds to and from a structure rep- resenting the date and time as a <year,month,day,weekday,hour,minute,seconds> tuple. This structure is defined as follows: struct clock_ymdhms { u_short dt_year; /* Year */ u_char dt_mon; /* Month (1-12) */ u_char dt_day; /* Day (1-31) */ u_char dt_wday; /* Day of week (0-6) */ u_char dt_hour; /* Hour (0-23) */ u_char dt_min; /* Minute (0-59) */ u_char dt_sec; /* Second (0-59) */ }; Note: leap years are recognised by these conversion routines. RETURN VALUES
The todr_*() functions return 0 if the requested operation was successful; otherwise an error code from <sys/errno.h> shall be returned. However, behaviour is undefined if an invalid todr_chip_handle_t is passed to any of these functions. The clock_ymdhms_to_secs() function returns -1 if the time in seconds would be less that zero or too large to fit in a time_t. The clock_secs_to_ymdhms() function never fails. SEE ALSO
intersil7170(4), mk48txx(4), inittodr(9), resettodr(9), time_second(9) BSD
September 6, 2006 BSD

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GETTIMEOFDAY(2) 					      BSD System Calls Manual						   GETTIMEOFDAY(2)

gettimeofday, settimeofday -- get/set date and time SYNOPSIS
#include <sys/time.h> int gettimeofday(struct timeval *restrict tp, void *restrict tzp); int settimeofday(const struct timeval *tp, const struct timezone *tzp); DESCRIPTION
The system's notion of the current Greenwich time and the current time zone is obtained with the gettimeofday() call, and set with the settimeofday() call. The time is expressed in seconds and microseconds since midnight (0 hour), January 1, 1970. The resolution of the sys- tem clock is hardware dependent, and the time may be updated continuously or in ``ticks.'' If tp is NULL and tzp is non-NULL, gettimeofday() will populate the timezone struct in tzp. If tp is non-NULL and tzp is NULL, then only the timeval struct in tp is populated. If both tp and tzp are NULL, nothing is returned. The structures pointed to by tp and tzp are defined in <sys/time.h> as: struct timeval { time_t tv_sec; /* seconds since Jan. 1, 1970 */ suseconds_t tv_usec; /* and microseconds */ }; struct timezone { int tz_minuteswest; /* of Greenwich */ int tz_dsttime; /* type of dst correction to apply */ }; The timeval structure specifies a time value in seconds and microseconds. The values in timeval are opaque types whose length may vary on different machines; depending on them to have any given length may lead to errors. The timezone structure indicates the local time zone (measured in minutes of time westward from Greenwich), and a flag that, if nonzero, indicates that Daylight Saving time applies locally during the appropriate part of the year. Only the super-user may set the time of day or time zone. If the system securelevel is greater than 1 (see launchd(8) ), the time may only be advanced. This limitation is imposed to prevent a malicious super-user from setting arbitrary time stamps on files. The system time can still be adjusted backwards using the adjtime(2) system call even when the system is secure. RETURN
A 0 return value indicates that the call succeeded. A -1 return value indicates an error occurred, and in this case an error code is stored into the global variable errno. ERRORS
The following error codes may be set in errno: [EFAULT] An argument address referenced invalid memory. [EPERM] A user other than the super-user attempted to set the time. LEGACY SYNOPSIS
#include <sys/time.h> int gettimeofday(struct timeval *tp, struct timezone *tzp); The type of tzp has changed. SEE ALSO
date(1), adjtime(2), ctime(3), compat(5), timed(8) HISTORY
The gettimeofday() function call appeared in 4.2BSD. 4th Berkeley Distribution August 5, 2008 4th Berkeley Distribution
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