NAME
       tk - Manipulate Tk internal state

SYNOPSIS
       tk option ?arg arg ...?


DESCRIPTION
       The  tk  command provides access to miscellaneous elements
       of Tk's internal state.  Most of the  information  manipu-
       lated  by  this  command  pertains to the application as a
       whole, or to a screen or display, rather than to a partic-
       ular window.  The command can take any of a number of dif-
       ferent forms depending on the option argument.  The  legal
       forms are:

       tk appname ?newName?
              If  newName  isn't  specified, this command returns
              the name of the application (the name that  may  be
              used  in  send  commands  to  communicate  with the
              application).  If newName is  specified,  then  the
              name  of the application is changed to newName.  If
              the given name is already in use, then a suffix  of
              the form `` #2'' or `` #3'' is appended in order to
              make the name unique.  The command's result is  the
              name  actually  chosen.   newName  should not start
              with a capital letter.  This  will  interfere  with
              option  processing, since names starting with capi-
              tals are assumed to be classes;  as  a  result,  Tk
              may not be able to find some options for the appli-
              cation.  If sends have been  disabled  by  deleting
              the  send  command, this command will reenable them
              and recreate the send command.

       tk scaling ?-displayof window? ?number?
              Sets and queries the current scaling factor used by
              Tk  to convert between physical units (for example,
              points, inches, or millimeters)  and  pixels.   The
              number  argument  is  a  floating point number that
              specifies the number of pixels per  point  on  win-
              dow's  display.  If the window argument is omitted,
              it defaults to the  main  window.   If  the  number
              argument is omitted, the current value of the scal-
              ing factor is returned.

              A ``point'' is a unit of measurement equal to  1/72
              inch.   A  scaling  factor  of 1.0 corresponds to 1
              pixel per point, which is equivalent to a  standard
              72  dpi  monitor.   A  scaling factor of 1.25 would
              mean 1.25 pixels per point, which  is  the  setting
              for a 90 dpi monitor; setting the scaling factor to
              1.25 on a 72 dpi monitor would cause everything  in
              the application to be displayed 1.25 times as large
              as normal.   The  initial  value  for  the  scaling
              factor is set when the application starts, based on
              properties of the installed monitor, but it can  be
              changed  at  any time.  Measurements made after the
              scaling factor is changed will use the new  scaling
              factor,  but  it is undefined whether existing wid-
              gets will resize themselves dynamically to  accomo-
              date the new scaling factor.

KEYWORDS
       application name, send
