1. ctrl-o open source file. 2. ctrl-h open 'Replace' dialog: set 'Replace with pattern' to: 3. Click 'Replace', done! Explanation: function replace($match,'A-Za-z','a-zA-Z',2) will make a mapping from A-Z to a-z, and a-z to A-Z, the last parameter "2" means make letter-to-letter mapping instead of str replace. |