profile ?-commands? ?-eval? on

     profile off arrayVar
          This command is used to collect a  performance  profile
          of a Tcl script.  It collects data at the Tcl procedure
          level. The number of calls  to  a  procedure,  and  the
          amount  of real and CPU time is collected. Time is also
          collected for the global context.  The  procedure  data
          is  collected  by  bucketing  it based on the procedure
          call stack, this allows determination of how much  time
          is spent in a particular procedure in each of it's cal-
          ling contexts.

          The on option enables profile data collection.  If  the
          -commands  option  is  specified,  data on all commands
          within a procedure is collected as well  a  procedures.
          Multiple  occurrences  of  a command within a procedure
          are not distinguished, but this data may still be  use-
          ful for analysis.

          The off option turns off profiling and moves  the  data
          collected  to the array arrayVar.  The array is address
          by a list containing the procedure call stack.  Element
          zero  is  the  top of the stack, the procedure that the
          data is for.  The data in each entry is a list consist-
          ing  of  the procedure call count and the real time and
          CPU time in milliseconds spent in  the  procedure  (but
          not  any  procedures it calls). The list is in the form
          {count real cpu}.

          Normally, the variable scope stack is used in reporting
          where  time  is spent.  Thus upleveled code is reported
          in the context that it was executed in, not the context
          that the uplevel was called in.  If the -eval option is
          specified, the procedure  evaluation  (call)  stack  is
          used  instead  of the procedure scope stack.  Upleveled
          code is reported in the context of the  procedure  that
          did the uplevel.

          A Tcl procedure profrep is supplied  for  reducing  the
          data and producing a report.

          On Windows 95/NT, profile command only reports  elasped
          real time, CPU time is not available and is reported as
          zero.

          This command is provided by Extended Tcl.