adjtime(2)                 DG/UX 4.30                  adjtime(2)



     NAME
          adjtime - correct the time to allow synchronization of the
          system clock

     SYNOPSIS
          #include <sys/time.h>

          adjtime(delta, olddelta)
          struct timeval *delta;
          struct timeval *olddelta;

     DESCRIPTION
          Adjtime makes small adjustments to the system time, as
          returned by gettimeofday(2), advancing or retarding it by
          the amount of time specified by the struct timeval pointed
          to by delta.  The adjustment is gradual.  If *delta
          represents a negative adjustment, the clock is slowed down
          by incrementing it more slowly than normal until the
          correction is complete.  If *delta represents a positive
          adjustment, the correction is achieved by using a larger
          than normal increment.

          Specify a positive adjustment by placing a non-negative
          number of seconds in delta->tv_sec and a number of
          microseconds between 0 and 999999 (inclusive) in
          delta->tv_usec.  Specify a negative adjustment by placing a
          negative number of seconds in delta->tv_sec and a number of
          microseconds between 0 and 999999 (inclusive) in
          delta->tv_usec.  Note that the number of microseconds must
          always be non-negative and always acts to widen an
          advancement or to shorten a delay.  For instance, to
          indicate a delay of 0.7 seconds, place -1 into delta->tv_sec
          and 300000 into delta->tv_usec.  To indicate an advancement
          of 7.22 seconds, place 7 into delta->tv_sec and 220000 into
          delta->tv_usec.

          A time correction from an earlier call to adjtime may not be
          finished when adjtime is called again.  In this case, the
          previous time correction is aborted.  Further, if olddelta
          is not NULL, then the struct timeval it points to will
          contain, upon return, the number of microseconds which were
          still to be corrected from the earlier call.

          Note also that setting the time of day does not cancel any
          time adjustments in progress.

          This call may be used by time servers that synchronize the
          clocks of computers in a local area network.  Such time
          servers would slow down the clocks of some machines and
          speed up the clocks of others to bring them to the average
          network time.




     Licensed material--property of copyright holder(s)         Page 1

     adjtime(2)                 DG/UX 4.30                  adjtime(2)



     ACCESS CONTROL
          The effective user id of the calling process must be
          superuser.

     RETURN VALUE
          A return value of 0 indicates that the call succeeded.  A
          return value of -1 indicates that an error occurred, and in
          this case an error code is stored in the global variable
          errno.

     ERRORS
          The following error codes may be set in errno:

          [EFAULT]       An argument points outside the process's
                         allocated address space.

          [EPERM]        The process's effective user id is not that
                         of the super-user.

     SEE ALSO
          date(1), gettimeofday(2).


































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