clock(3C)               LIBRARY FUNCTIONS               clock(3C)



NAME
     clock - report CPU time used

SYNOPSIS
     #include <time.h>

     clock_t clock (void);

DESCRIPTION
     clock returns the amount of CPU time (in microseconds)  used
     since  the  first call to clock in the calling process.  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 the wait system call, the  pclose  function,
     or the system function.

     Dividing  the  value  returned  by  clock  by  the  constant
     CLOCKS_PER_SEC, defined in the time.h header file, will give
     the time in seconds.

     The resolution of the clock is 10 milliseconds  on  AT&T  3B
     computers.

SEE ALSO
     times(2), wait(2), popen(3S), system(3S).

NOTES
     The value returned by clock is defined in  microseconds  for
     compatibility  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).  If the process time used is not  avail-
     able  or  cannot  be  represented,  clock  returns the value
     (clock_t)-1.





















                                                                1