Gets the current value of the system-wide clock.

    Format

      #include  <timers.h>

      int getclock  (int clktyp, struct timespec *tp);

1 - Arguments

 clktyp

    The type of system-wide clock.

 tp

    Pointer to a timespec structure space where the current value of
    the system-wide clock is stored.

2 - Description

    This function sets the current value of the clock specified by
    clktyp into the location pointed to by tp.

    The clktyp argument is given as a symbolic constant name,
    as defined in the <timers.h> header file. Only the TIMEOFDAY
    symbolic constant, which specifies the normal time-of-day clock
    to access for system-wide time, is supported.

    For the clock specified by TIMEOFDAY, the value returned by
    this function is the elapsed time since the Epoch. The Epoch
    is referenced to 00:00:00 UTC (Coordinated Universal Time)
    1 Jan 1970.

    The getclock function returns a timespec structure, which is
    defined in the <timers.h> header file as follows:

     struct  timespec {
      unsigned long tv_sec   /* Elapsed time in seconds since the Epoch*/
      long          tv_nsec  /* Elapsed time as a fraction of a second */
                             /* since the Epoch (in nanoseconds)       */
     };

3 - Return Values

    0                  Indicates success.
    -1                 Indicates an error; errno is set to one of the
                       following values:

                       o  EINVAL - The clktyp argument does not
                          specify a known system-wide clock.

                          Or, the value of SYS$TIMEZONE_DIFFERENTIAL
                          logical is wrong.

                       o  EIO - An error occurred when the system-
                          wide clock specified by the clktyp argument
                          was accessed.