CLOCK(3C-SVR4)      RISC/os Reference Manual       CLOCK(3C-SVR4)



NAME
     clock - report CPU time used

SYNOPSIS
     #include <time.h>

     clockt 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.

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.
























                        Printed 11/19/92                   Page 1