settimeofday(2) [hpux man page]

settimeofday(2) 						System Calls Manual						   settimeofday(2)

NAME

       settimeofday - set the date and time

SYNOPSIS


DESCRIPTION

       The function sets the current time, expressed as seconds and microseconds since Epoch, and passed as the structure pointed to by tp.

       The resolution of the system clock is one microsecond.

   Security Restrictions
       Setting	the  time of day requires the privilege (SYSATTR).  Processes owned by the superuser will have this privilege.	Processes owned by
       other users may have this privilege, depending on system configuration.

       See privileges(5) for more information about privileged access on systems that support fine-grained privileges.

PARAMETERS

       tp   A pointer to a structure in which the current time is returned.

	    The structure includes the following members:

       tzp  If this parameter is not a null pointer, it is interpreted as a pointer to a structure under HP-UX.  The structure has  the  following
	    fields:

	    tz_minuteswest The number of minutes that the local time zone is west of Coordinated Universal Time (UTC) or Epoch.

	    tz_dsttime	   A  flag that, if nonzero, indicates that Daylight Savings Time (DST) applies locally during the appropriate part of the
			   year.

RETURN VALUE

       returns the following values under HP-UX:

	      Successful completion.

	      Failure.
		     is set to indicate the error.

ERRORS

       If fails, is set to the following value under HP-UX:

	      An argument address referenced invalid memory.

	      The	     member of the tp parameter to was less than zero or greater than 2^31.

	      A user lacking appropriate privileges attempted to
			     set the time.

WARNINGS

       Relying on a granularity of one microsecond may result in code that is not portable to other platforms.

AUTHOR

       was developed by the University of California, Berkeley, and HP.

SEE ALSO

       date(1), ftime(2), gettimeofday(2), stime(2), time(2), ctime(3C), privileges(5).

																   settimeofday(2)

gettimeofday(3C)					   Standard C Library Functions 					  gettimeofday(3C)

NAME

       gettimeofday, settimeofday - get or set the date and time

SYNOPSIS

       #include <sys/time.h>

       int gettimeofday(struct timeval *tp, void *tzp);

       int settimeofday(struct timeval *tp, void *tzp);

DESCRIPTION

       The  gettimeofday()  function  gets  and  the  settimeofday()  function	sets  the system's notion of the current time. The current time is
       expressed in elapsed seconds and microseconds since 00:00 Universal Coordinated Time, January 1, 1970. The resolution of the  system  clock
       is hardware dependent; the time may be updated continuously or in clock ticks.

       The tp argument points to a timeval structure, which includes the following members:

       long    tv_sec;	  /* seconds since Jan. 1, 1970 */
       long    tv_usec;   /* and microseconds */

       If tp is a null pointer, the current time information is not returned or set.

       The TZ environment variable holds time zone information. See TIMEZONE(4).

       The tzp argument to gettimeofday() and settimeofday() is ignored.

       Only privileged processes can set the time of day.

RETURN VALUES

       Upon successful completion, 0 is returned.  Otherwise, -1 is returned and errno is set to indicate the error.

ERRORS

       The settimeofday() function will fail if:

       EINVAL	       The structure pointed to by tp specifies an invalid time.

       EPERM	       The {PRIV_SYS_TIME} privilege was not asserted in the effective set of the calling process.

       The gettimeofday() function will fail for 32-bit interfaces if:

       EOVERFLOW       The system time has progressed beyond 2038, thus the size of the tv_sec member of the timeval structure pointed to by tp is
		       insufficient to hold the current time in seconds.

USAGE

       If the tv_usec member of tp is > 500000, settimeofday() rounds the seconds upward. If the time needs to be set with better than one  second
       accuracy, call settimeofday() for the seconds and then adjtime(2) for finer accuracy.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |gettimeofday() is Standard.  |
       +-----------------------------+-----------------------------+
       |MT-Level		     |MT-Safe			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       adjtime(2), ctime(3C), gethrtime(3C), TIMEZONE(4), attributes(5), privileges(5), standards(5)

SunOS 5.10							    1 Aug 2003							  gettimeofday(3C)