clock - report CPU time used
long clock ( )
clock() returns the amount of CPU time (in microseconds) used since the
first call to clock. The time reported is the sum of the user and sys-
tem times of the calling process and its terminated child processes for
which it has executed wait(2V) or system(3).
The resolution of the clock is 16.667 milliseconds.
wait(2V), system(3), times(3V)
The value returned by clock() is defined in microseconds for compati-
bility with systems that have CPU clocks with much higher resolution.
Because of this, the value returned will wrap around after accumulating
only 2147 seconds of CPU time (about 36 minutes).
6 October 1987 CLOCK(3C)