ri is a documentation viewer for Ruby.
Command line interface to ri
ri v1.0.1 - 20041108 Usage: ri [options] [names...] Display information on Ruby classes, modules, and methods. Give the names of classes or methods to see their documentation. Partial names may be given: if the names match more than one entity, a list will be shown, otherwise details on that entity will be displayed. Nested classes and modules can be specified using the normal Name::Name notation, and instance methods can be distinguished from class methods using "." (or "#") instead of "::". For example: ri File ri File.new ri F.n ri zip Note that shell quoting may be required for method names containing punctuation: ri 'Array.' ri compact\! By default ri searches for documentation in the following directories: /usr/local/share/ri/1.8/system /usr/local/share/ri/1.8/site /Users/wincent/.rdoc /usr/local/lib/ruby/gems/1.8/doc/*/ri Specifying the --system, --site, --home, --gems or --doc-dir options will limit ri to searching only the specified directories. Options: --help, -h you're looking at it --classes, -c Display the names of classes and modules we know about --doc-dir, -d <dirname> A directory to search for documentation. If not specified, we search the standard rdoc/ri directories. May be repeated. --system Include documentation from Ruby's standard library: /usr/local/share/ri/1.8/system --site Include documentation from libraries installed in site_lib: /usr/local/share/ri/1.8/site --home Include documentation stored in ~/.rdoc: /Users/wincent/.rdoc --gems Include documentation from Rubygems: /usr/local/lib/ruby/gems/1.8/doc/*/ri --format, -f <name> Format to use when displaying output: ansi, bs, html, plain, simple Use 'bs' (backspace) with most pager programs. To use ANSI, either also use the -T option, or tell your pager to allow control characters (for example using the -R option to less) --list-names, -l List all the names known to RDoc, one per line --no-pager, -T Send output directly to stdout. --width, -w output width Set the width of the output --version, -v Display the version of ri Options may also be passed in the 'RI' environment variable