Purpose: describe the various methods available within Tcl for code reuse.


   Cut/copy and paste:   user maintains a series of text files containing tcl code and then just copies the text when needed.

   source:   tcl has a command called '''source''' which reads a file, treating the contents just as if they were a part of the original file.

   load:   tcl has a command called '''load''' which is used to attach a dynamically loadable object extension to the current library.

   unknown:   tcl has a command called '''unknown''' which is invoked whenever the tcl interpreter is unable to determine a particular command.  unknown does some processing and can provide dynamic sourcing of functions.  Details go here.

   exec:   '''exec''' is a tcl command used to invoke a stand alone command.  This command can be written in any language supported by the system.

   pipe:   tcl supports, in the '''open''' command, the ability to open an input and/or output pipeline to another process, which is started in a manner similar to the exec command.


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I hope people stopping by this page will update the above descriptions to fill in a lot of the details (where does pkgIndex, tclIndex come in - what other options are available, etc.).