clock

Purpose

     Reports CPU time used.

Library

     Standard C Library (libc.a)

Syntax

     long clock ( )

Description

     The clock subroutine  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 system times
     of the calling process and its terminated child processes
     for which it has executed a  wait system call or a system
     subroutine.   The  nominal  resolution of  the  clock  is
     16.667  milliseconds if  the process  is being  profiled;
     otherwise,  it is  100 milliseconds.   See "monitor"  and
     "profil" for information about profiling a process.

     Note:   The value  returned  by the  clock subroutine  is
     defined  in microseconds  for compatibility  with systems
     that  have  CPU  clocks   with  much  higher  resolution.
     Because of  this, the  value returned wraps  around after
     accumulating  approximately  2147  seconds  of  CPU  time
     (about 36 minutes).

Related Information

     In this book:   "system," "times," and "wait."