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(libc.info)Processor Time

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Processor Time Inquiry
----------------------

   The `times' function returns information about a process'
consumption of processor time in a `struct tms' object, in addition to
the process' CPU time.  Note: Time Basics.  You should include the
header file `sys/times.h' to use this facility.

 - Data Type: struct tms
     The `tms' structure is used to return information about process
     times.  It contains at least the following members:

    `clock_t tms_utime'
          This is the total processor time the calling process has used
          in executing the instructions of its program.

    `clock_t tms_stime'
          This is the processor time the system has used on behalf of
          the calling process.

    `clock_t tms_cutime'
          This is the sum of the `tms_utime' values and the `tms_cutime'
          values of all terminated child processes of the calling
          process, whose status has been reported to the parent process
          by `wait' or `waitpid'; see Note: Process Completion.  In
          other words, it represents the total processor time used in
          executing the instructions of all the terminated child
          processes of the calling process, excluding child processes
          which have not yet been reported by `wait' or `waitpid'.

    `clock_t tms_cstime'
          This is similar to `tms_cutime', but represents the total
          processor time system has used on behalf of all the
          terminated child processes of the calling process.

     All of the times are given in numbers of clock ticks.  Unlike CPU
     time, these are the actual amounts of time; not relative to any
     event.  Note: Creating a Process.

 - Function: clock_t times (struct tms *BUFFER)
     The `times' function stores the processor time information for the
     calling process in BUFFER.

     The return value is the calling process' CPU time (the same value
     you get from `clock()'.  `times' returns `(clock_t)(-1)' to
     indicate failure.

   *Portability Note:* The `clock' function described in Note: CPU
Time is specified by the ISO C standard.  The `times' function is a
feature of POSIX.1.  In the GNU system, the CPU time is defined to be
equivalent to the sum of the `tms_utime' and `tms_stime' fields
returned by `times'.