tk4.2 User Commands - tkvars






NAME

     tkvars - Variables used or set by Tk





DESCRIPTION

     The following Tcl variables are either set or used by Tk  at
     various times in its execution:

     tk_library     This variable  holds  the  file  name  for  a
                    directory containing a library of Tcl scripts
                    related to Tk.  These scripts include an ini-
                    tialization  file  that is normally processed
                    whenever a Tk  application  starts  up,  plus
                    other files containing procedures that imple-
                    ment default behaviors for widgets.  The ini-
                    tial  value  of tcl_library is set when Tk is
                    added to an interpreter;   this  is  done  by
                    searching several different directories until
                    one is found that contains an appropriate  Tk
                    startup  script.   If the TK_LIBRARY environ-
                    ment variable exists, then the  directory  it
                    names  is checked first.  If TK_LIBRARY isn't
                    set or doesn't refer to an appropriate direc-
                    tory,  then  Tk  checks  several other direc-
                    tories based on a compiled-in  default  loca-
                    tion,  the location of the Tcl library direc-
                    tory, the location of the  binary  containing
                    the  application,  and  the  current  working
                    directory.  The variable can be  modified  by
                    an  application  to  switch  to  a  different
                    library.

     tk_patchLevel  Contains a decimal integer giving the current
                    patch  level  for  Tk.   The  patch  level is
                    incremented for each new  release  or  patch,
                    and  it  uniquely identifies an official ver-
                    sion of Tk.

     tkPriv         This variable is an array containing  several
                    pieces of information that are private to Tk.
                    The elements of tkPriv are used by Tk library
                    procedures and default bindings.  They should
                    not be accessed by any code outside Tk.

     tk_strictMotif This variable is set to zero by default.   If
                    an  application  sets  it  to  one,  then  Tk
                    attempts to adhere as closely as possible  to
                    Motif  look-and-feel standards.  For example,
                    active elements such as buttons and scrollbar
                    sliders   will  not  change  color  when  the
                    pointer passes over them.

     tk_version     Tk sets this variable in the interpreter  for
                    each  application.   The  variable  holds the
                    current version number of the Tk  library  in
                    the  form  major.minor.   Major and minor are
                    integers.  The major version number increases
                    in  any Tk release that includes changes that
                    are not backward  compatible  (i.e.  whenever
                    existing Tk applications and scripts may have
                    to change to work with the new release).  The
                    minor  version number increases with each new
                    release of Tk, except that it resets to  zero
                    whenever the major version number changes.



KEYWORDS

     variables, version