Description

   The getitimer function returns the current value for the timer
   specified by the which argument in the structure pointed to by
   value.

   A timer value is defined by the itimerval structure:

          struct itimerval {
                  struct  timeval it_interval;
                  struct  timeval it_value;
          };

   The following table lists the values for the itimerval structure
   members:

   itimerval Member
   Value              Meaning

   it_interval = 0    Disables a timer after its next expiration and
                      assumes it_value is nonzero.
   it_interval =      Specifies a value used in reloading it_value
   nonzero            when the timer expires.
   it_value = 0       Disables a timer.
   it_value =         Indicates the time to the next timer
   nonzero            expiration.

   Time values smaller than the resolution of the system clock are
   rounded up to this resolution.

   The C RTL provides each process with one interval timer,
   defined in the <time.h> header file as ITIMER_REAL. This timer
   decrements in real time and delivers a SIGALRM signal when the
   timer expires.