$ gem install recode 

$ recode --help Code Refactoring Utility Usage: recode OLD [to] NEW [in] EXTENSIONS... [options] recode (-h|--help) Options: -a --apply Apply changes -p --prompt Apply changes interactively -h --help Show this help Parameters: OLD Old string, singular and capitalized NEW New string, singular and capitalized EXTENSIONS Space delimited file extensions Examples: recode Member User rb recode Member to User in rb js recode Member to User in rb js --apply recode Member to User in rb js -p