From: Brett Williams <brett_williams@...>
Date: 2005-04-23T02:09:32+09:00
Subject: ruby tk: ruby 1.8.2 bug in TclTkIp with "exit 0" ... ?

I have a little wrapper around TclTkIp to do tcl interpreting with a 
ruby program.  It's super useful and has worked great -- until 1.8.2.

Now, it appears that calling the 'exit' command in tcl with an argument 
raises an exception for some reason.  You can call 'exit', just not 
'exit 0' or 'exit 1'.

Has something changed that makes this the desired behavior, or is this a 
bug?  The tcltk that was built against handles 'exit 0' just fine.

Here are the details:

#!/usr/bin/env ruby

require 'tcltklib'

###
# The TclInterp class wraps up a few useful calls to the tcl interp
###########################################################################
class TclInterp
   class TclError < RuntimeError
   end

   ########   I N S T A N C E   M E T H O D S   ########

   def initialize(name = 'default')
     @interp = TclTkIp.new(name, nil) #nil disables tk
   end

   def get(varname)
     val = self.raw_get(varname)
     return val
   end

   def set(varname, val)
     val = self.eval("set #{varname} #{val}")
     return val
   end

   def eval(str)
     begin
       val = @interp._eval(str)
     rescue => exc
       raise TclError, exc.message + "\n" + self.get('errorInfo')
     end
     return val
   end

   def source(filename)
     return self.eval("source #{filename}")
   end

   def raw_get(varname)
     val = @interp._eval("set __ruby_dummy_var $#{varname}")
     @interp._eval("unset __ruby_dummy_var")
     return val
   end
end

interp = TclInterp.new
interp.eval("exit 0")



Both of these are compiled against tcltk 8.3, linux/i386 (RHEL).

In Ruby 1.8.1:
darkshore:/tmp> ruby -v
ruby 1.8.1 (2003-12-25) [i386-linux]
darkshore:/tmp> ruby t.rb
darkshore:/tmp> echo $?
0

This works as expected.  However, with Ruby 1.8.2, this fails (even 
though the interpreter works for everything else I can find):

darkshore:/tmp> ruby -v
ruby 1.8.2 (2004-12-25) [i386-linux]
darkshore:/tmp> ruby t.rb
t.rb:32:in `eval':  (TclInterp::TclError)

     while executing
"exit 0"        from t.rb:49
darkshore:/tmp> echo $?
1