GETTIMEOFDAY(2)           386BSD Programmer's Manual           GETTIMEOFDAY(2)

NAME
     gettimeofday, settimeofday - get/set date and time

SYNOPSIS
     #include <sys/time.h>

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

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

DESCRIPTION
     Note: timezone is no longer used; this information is kept outside the
     kernel.   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 system clock is hardware dependent, and the time may be updated
     continuously or in ``ticks.''  If tp or tzp is NULL, the associated time
     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)

HISTORY
     The gettimeofday function call appeared in 4.2BSD.

4th Berkeley Distribution       March 10, 1991                               1