Description

   The value returned by the clock function must be divided by the
   value of the CLK_TCK, as defined in the standard header file
   <time.h>, to obtain the time in seconds.

   The type clock_t is defined in the <time.h> header file as
   follows:

   typedef long int clock_t;

   Only the accumulated times for child processes running a C main
   program or a program that calls VAXC$CRTL_INIT or DECC$CRTL_INIT
   are included.

   A typical usage of the clock function is to call it after a
   program does its initial setup, and then again after the program
   executes the code to be timed. Then subtract the two values to
   give elapsed CPU time.