11.7. How do I get a Canvas to output PostScript(c)? 
 
 Many thanks to Tom Oelke <tpo9617@rit.edu> for providing this question,
 answer & snippet of code: 
 
  The following section of code gets the postscript code for the section of
  canvas that's top-left corner is at $min_x, $min_y, and has a width and
  height equivalent to the displayed region. This ps code is then piped out
  to lpr to be printed. 
 
     my $ps = $canvas->postscript( '-x' => $min_x,
                                   '-y' => $min_y,
                                   -width => $canv->Width,
                                  -height => $canv->Height);
     open (PS, "| lpr"); # customize with -Pname e.g. 
     print PS $ps;
     close (PS);
 
 Whereas you would use something like: 
 
     open (PS, ">file.ps"); # to output to a file
     print PS $ps;
     close (PS);

##</code><code>##

% lpr file.ps