Question

I have some simple shell scripting tasks that I want to do

For example: Selecting a file in the working directory from a list of the files matching some regular expression.

I know that I can do this sort of thing using standard bash and grep but I would be nice to be able to hack quick scripts that will work in windows and linux without me having to memorize a heap of command line programs and flags etc.

I tried to get this going but ended up getting confused about where I should be getting information such as a reference to the current directory

So the question is what parts of the Ruby libraries do I need to know to write ruby shell scripts?

Answer 1

By default, you already have access to Dir and File, which are pretty useful by themselves.

Dir['*.rb'] #basic globs Dir['**/*.rb'] #** == any depth of directory, including current dir. #=> array of relative names  File.expand_path('~/file.txt') #=> '/User/mat/file.txt' File.dirname('dir/file.txt') #=> 'dir' File.basename('dir/file.txt') #=> 'file.txt' File.join('a', 'bunch', 'of', 'strings') #=> 'a/bunch/of/strings'  __FILE__ #=> the name of the current file 

Also useful from the stdlib is FileUtils

require 'fileutils' #I know, no underscore is not ruby-like include FileUtils # Gives you access (without prepending by 'FileUtils.') to cd(dir, options) cd(dir, options) {|dir| .... } pwd() mkdir(dir, options) mkdir(list, options) mkdir_p(dir, options) mkdir_p(list, options) rmdir(dir, options) rmdir(list, options) ln(old, new, options) ln(list, destdir, options) ln_s(old, new, options) ln_s(list, destdir, options) ln_sf(src, dest, options) cp(src, dest, options) cp(list, dir, options) cp_r(src, dest, options) cp_r(list, dir, options) mv(src, dest, options) mv(list, dir, options) rm(list, options) rm_r(list, options) rm_rf(list, options) install(src, dest, mode = <src's>, options) chmod(mode, list, options) chmod_R(mode, list, options) chown(user, group, list, options) chown_R(user, group, list, options) touch(list, options) 

Which is pretty nice