

          The standard Tcl shell initialization consists of the
          following steps:

               Search for a default file.  The default file is a Tcl
               script that is executed to set important Tcl variables
               that govern startup, such as TCLPATH.  The Tcl default
               file is searched for using the following algorithm:
               The current Extended Tcl version, represented by $ver,
               is included in the default file naming to allow
               multiple Tcl versions to exists on a system.  Note that
               the Extended Tcl version is the standard Tcl version
               number with an alphabetic character added to indicated
               the version of Extended Tcl.  The infox version command
               will return this version number.

                    - An environment variable, TCLDEFAULT, is checked
                    for.  If present, it is used as the name of the
                    default file.

                    - A file, TCLDEFAULT, is looked for in the current
                    directory.

                    - A global default file with is usually either
                    /etc/default/tcl$ver or
                    /usr/local/lib/tcldefault$ver.  (Tcl may be
                    compiled to use a different directory on some
                    systems).

               First, Tcl executes the default file.  This file
               normally sets at least two Tcl variables: TCLPATH,
               which contains a list of directories that contain tcl
               source files, and TCLINIT, the full pathname of the Tcl
               source file that performs Tcl initialization.  Other
               site-specific variables may also be set in this file.

               Next, tcl executes the initialization file specified by
               the Tcl variable TCLINIT.  This is normally the
               TclInit.Tcl file distributed with Tcl.  This file
               defines the Tcl environment, including standard Tcl
               procs and variables.
