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GETTIMEOFDAY(2)                                                GETTIMEOFDAY(2)



NAME
       gettimeofday, settimeofday - get/set date and time

SYNOPSIS
       #include <&lt;sys/time.h>&gt;

       gettimeofday(tp, tzp)
       struct timeval *tp;
       struct timezone *tzp;

       settimeofday(tp, tzp)
       struct timeval *tp;
       struct timezone *tzp;

DESCRIPTION
       Gettimeofday  returns the system's notion of the current Greenwich time
       and the current time zone.  Time returned is expressed relative in sec-
       onds and microseconds since midnight January 1, 1970.

       The structures pointed to by tp and tzp are defined in &lt;sys/time.h&gt; as:

              struct timeval {
                   u_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 min-
       utes of time westward from Greenwich), and a  flag  that,  if  nonzero,
       indicates  that  Daylight Saving time applies locally during the appro-
       priate part of the year.

       Only the super-user may set the time of day.

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), ctime(3)

BUGS
       Time  is never correct enough to believe the microsecond values.  There
       should a mechanism by which, at least, local clusters of systems  might
       synchronize their clocks to millisecond granularity.



4th Berkeley Distribution        27 July 1983                  GETTIMEOFDAY(2)