I'm trying to figure out why the following code chunk fails to edit my
file in-place:

$-i = '.foo'                   # set in-place edit mode
mf = File.open('Makefile', 'r+')
mf.each_line do |line|
  line.sub!(/-l\$\(RUBY_INSTALL_NAME\) /, "")
end
mf.close


Any ideas?

Ian
-- 
Ian Macdonald               | Life is like an onion: you peel off layer
ian / caliban.org             | after layer and then you find there is
                            | nothing in it.   -- James Huneker 
                            | 
                            |