

          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 current
               Extended Tcl version, represented by $ver, is included
               in the default file name 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.)

          The Tcl default file is searched for using the following
          algorithm:

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

                    - A global default file, which is usually either
                    /etc/default/tcl$ver or
                    /usr/local/lib/tcldefault$ver.  (Tcl may be
                    compiled to use a different directory if desired).

               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 libraries, 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
               Extended Tcl procedures and variables.
