
   task.exec

   A special macro to be executed before constructing the job command.
   The macro is defined by commands following the 'task.exec' command,
   ending with the word 'end'.  If the exit status of the task.exec
   macro is FALSE, then the job is NOT constructed.  This allows the
   construction of a job to be conditional on other, external
   quantites.  (Note: the exit status of the macro is false if 'break'
   is called).  The task command may be defined within the task.exec
   macro, in which case the command is constructed only when the exec
   macro is run, every job construction interval.  Thus, the command
   arguments may depend on the result of the exec macro operation.

   See also:
   task
   task.command
