Ruby Programming/Reference/Objects/IO/File

File The file class is typically used for opening and closing files, as well as a few methods like deleting them and stat'ing them. If you want to manipulate a file, not open it, also check out the Pathname class, as well as the FileUtils class. To create a directory you'll need to use the Dir.mkdir method. File#chmod Here's how to do the equivalent of "chmod u+x filename" File.class_eval do def self.addmod(flags, filename) themode=stat(filename).mode | flags chmod(themode, filename) end end Although there's no error checking and the return value could probably be something better (like themode). So after defining that, your 'u+w' would be: @File.addmod(0200, 'filename')@ from http://www.ruby-forum.com/topic/196999#new File#grep This is actually Enumerable#grep, and I believe it just works piece-wise, like File.each_line{|l|yield l if l=~ /whatever/ } File.join This is useful for combining objects that aren't (or might not be) strings into a path. See here.