In message "[ruby-talk:00578] trace_var doesn't work with $< ???"
    on 99/08/06, clemens.hintze / alcatel.de <clemens.hintze / alcatel.de> writes:

|I try do do the following...
|
|	p :$<
|	p "$<".intern
|
|	trace_var :$<, proc { p "New file" }
|
|	while gets
|	   p "#{$.}(#{$<}): #{$_}"
|	end

|But I didn't get the lines with the `****' remark! What do I wrong?

Because opening new file, does not assign $<, but just change the
state of $< object.  You will know it by following script:

	trace_var :$<, proc { p "New file" }

	while gets
	  p "#{$.}(#{$<};#{$<.id}): #{$_}"
	end

The $<.id is unchanged.
                                                        matz.