README

hsbt · hsbt · commit bcc1b5f551e3 · 2020-07-22T18:13:31.000+09:00
diff --git a/README.md b/README.md
@@ -1,8 +1,18 @@
-# Optparse
+# OptionParser
 
-Welcome to your new gem! In this directory, you'll find the files you need to be able to package up your Ruby library into a gem. Put your Ruby code in the file `lib/optparse`. To experiment with that code, run `bin/console` for an interactive prompt.
+OptionParser is a class for command-line option analysis.  It is much more
+advanced, yet also easier to use, than GetoptLong, and is a more Ruby-oriented
+solution.
 
-TODO: Delete this and the text above, and describe your gem
+## Features
+
+1. The argument specification and the code to handle it are written in the
+   same place.
+2. It can output an option summary; you don't need to maintain this string
+   separately.
+3. Optional and mandatory arguments are specified very gracefully.
+4. Arguments can be automatically converted to a specified class.
+5. Arguments can be restricted to a certain set.
 
 ## Installation
 
@@ -22,7 +32,21 @@ Or install it yourself as:
 
 ## Usage
 
-TODO: Write usage instructions here
+```ruby
+require 'optparse'
+
+options = {}
+OptionParser.new do |opts|
+  opts.banner = "Usage: example.rb [options]"
+
+  opts.on("-v", "--[no-]verbose", "Run verbosely") do |v|
+    options[:verbose] = v
+  end
+end.parse!
+
+p options
+p ARGV
+```
 
 ## Development
 
@@ -32,5 +56,5 @@ To install this gem onto your local machine, run `bundle exec rake install`. To
 
 ## Contributing
 
-Bug reports and pull requests are welcome on GitHub at https://github.com/hsbt/optparse.
+Bug reports and pull requests are welcome on GitHub at https://github.com/ruby/optparse.
 
