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settimeofday(3ucb) [opensolaris man page]

gettimeofday(3UCB)				     SunOS/BSD Compatibility Library Functions					gettimeofday(3UCB)

NAME
gettimeofday, settimeofday - get or set the date and time SYNOPSIS
/usr/ucb/cc [ flag ... ] file ... #include <sys/time.h> int gettimeofday(tp, tzp) struct timeval *tzp; struct timezone *tzp; int settimeofday(tp, tzp) struct timeval *tzp; struct timezone *tzp; DESCRIPTION
The system's notion of the current Greenwich time is obtained with the gettimeofday() call, and set with the settimeofday() call. The cur- rent time is expressed in elapsed seconds and microseconds since 00:00 GMT, January 1, 1970 (zero hour). The resolution of the system clock is hardware dependent; the time may be updated continuously, or in clock ticks. long tv_sec; /* seconds since Jan. 1, 1970 */ long tv_usec; /* and microseconds */ tp points to a timeval structure, which includes the following members: If tp is a NULL pointer, the current time information is not returned or set. tzp is an obsolete pointer formerly used to get and set timezone information. tzp is now ignored. Timezone information is now handled using the TZ environment variable; see TIMEZONE(4). Only the privileged user may set the time of day. RETURN VALUES
A -1 return value indicates an error occurred; in this case an error code is stored in the global variable errno. ERRORS
The following error codes may be set in errno: EINVAL tp specifies an invalid time. EPERM A user other than the privileged user attempted to set the time. SEE ALSO
cc(1B), adjtime(2), ctime(3C), gettimeofday(3C), TIMEZONE(4) NOTES
Use of these interfaces should be restricted to only applications written on BSD platforms. Use of these interfaces with any of the system libraries or in multi-thread applications is unsupported. tzp is ignored in SunOS 5.X releases. tv_usec is always 0. SunOS 5.11 30 Oct 2007 gettimeofday(3UCB)

Check Out this Related Man Page

GETTIMEOFDAY(2) 						System Calls Manual						   GETTIMEOFDAY(2)

NAME
gettimeofday, settimeofday - get/set date and time SYNOPSIS
#include <sys/time.h> gettimeofday(tp, tzp) struct timeval *tp; struct timezone *tzp; settimeofday(tp, tzp) struct timeval *tp; 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 set- timeofday call. The time is expressed in seconds and microseconds since midnight (0 hour), January 1, 1970. The resolution of the system clock is hardware dependent, and the time may be updated continuously or in ``ticks.'' If tzp is zero, the time zone information will not be returned or set. The structures pointed to by tp and tzp are defined in <sys/time.h> as: struct timeval { long tv_sec; /* seconds since Jan. 1, 1970 */ long tv_usec; /* and microseconds */ }; struct timezone { int tz_minuteswest; /* of Greenwich */ int tz_dsttime; /* type of dst correction to apply */ }; 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. 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. SEE ALSO
date(1), adjtime(2), ctime(3), timed(8) 4th Berkeley Distribution May 14, 1986 GETTIMEOFDAY(2)
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