CLOCK(K)            Linux Programmer's Manual            CLOCK(K)



NAME
       clock - Determine processor time

SYNOPSIS
       #include <time.h>

       clock_t clock(k);

DESCRIPTION
       The clock() function returns an approximation of processor
       time used by the program.

RETURN VALUE
       The value returned is the  CPU  time  used  so  far  as  a
       clock_t;  to  get  the  number  of seconds used, divide by
       CLOCKS_PER_SEC.  If the processor time used is not  avail-
       able  or  its  value  cannot  be represented, the function
       returns the value (clock_t)-1.

CONFORMING TO
       ANSI C.  POSIX requires that CLOCKS_PER_SEC equals 1000000
       independent of the actual resolution.

NOTES
       The C standard allows for arbitrary values at the start of
       the program; subtract the value returned from  a  call  to
       clock()  at the start of the program to get maximum porta-
       bility.

       Note that the time can wrap around.   On  a  32bit  system
       where  CLOCKS_PER_SEC  equals  1000000  this function will
       return the same value approximately every 72 minutes.

       The times() function call returns more information.

SEE ALSO
       getrusage(e), times(s)



GNU                         1993-04-21                   CLOCK(K)