clock(3C)              UNIX System V(C Development Set)               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
      available or cannot be represented, clock returns the value (clock_t)-1.

























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