Slop
Slop is a simple option parser with an easy to remember syntax and friendly API. API Documentation is available here.
Usage
opts = Slop.parse do
'Usage: foo.rb [options]'
on 'name=', 'Your name'
on 'p', 'password', 'An optional password', argument: :optional
on 'v', 'verbose', 'Enable verbose mode'
end
# if ARGV is `--name Lee -v`
opts.verbose? #=> true
opts.password? #=> false
opts[:name] #=> 'lee'
opts.to_hash #=> {:name=>"Lee", :password=>nil, :verbose=>true}
Installation
gem install slop
Printing Help
Slop attempts to build a good looking help string to print to your users. You
can see this by calling opts.help
or simply puts opts
.
Configuration Options
All of these options can be sent to Slop.new
or Slop.parse
in Hash form.
Option | Description | Default/Example |
---|---|---|
strict | Enable strict mode. Slop will raise an InvalidOptionError for unkown options. |
false |
help | Automatically add the --help option. |
false |
banner | Set the help banner text. | nil |
ignore_case | When enabled, -A will look for the -a option if -A does not exist. |
false |
autocreate | Autocreate options on the fly. | false |
arguments | Force all options to expect arguments. | false |
optional_arguments | Force all options to accept optional arguments. | false |
multiple_switches | When disabled, Slop will parse -abc as the option a with the argument bc rather than 3 separate options. |
true |
Lists
opts = Slop.parse do
on :list=, as: Array
end
# ruby run.rb --list one,two
opts[:list] #=> ["one", "two"]
# ruby run.rb --list one,two --list three
opts[:list] #=> ["one", "two", "three"]
You can also specify a delimiter and limit.
opts = Slop.parse do
on :list=, as: Array, delimiter: ':', limit: 2
end
# ruby run.rb --list one:two:three
opts[:list] #=> ["one", "two:three"]
Ranges
opts = Slop.parse do
on :range=, as: Range
end
# ruby run.rb --range 1..10
opts[:range] #=> 1..10
# ruby run.rb --range 1...10
opts[:range] #=> 1...10
# ruby run.rb --range 1-10
opts[:range] #=> 1..10
# ruby run.rb --range 1,10
opts[:range] #=> 1..10
Autocreate
Slop has an 'autocreate' feature. This feature is intended to create options on the fly, without having to specify them yourself. In some case, using this code could be all you need in your application:
# ruby run.rb --foo bar --baz --name lee
opts = Slop.parse(autocreate: true)
opts.to_hash #=> {:foo=>"bar", :baz=>true, :name=>"lee"}
opts.fetch_option(:name).expects_argument? #=> true
Commands
Slop supports git style sub-commands, like so:
opts = Slop.parse do
on '-v', 'Print the version' do
puts "Version 1.0"
end
command 'add' do
on :v, :verbose, 'Enable verbose mode'
on :name=, 'Your name'
run do |opts, args|
puts "You ran 'add' with options #{opts.to_hash} and args: #{args.inspect}"
end
end
end
# ruby run.rb -v
#=> Version 1.0
# ruby run.rb add -v foo --name Lee
#=> You ran 'add' with options {:verbose=>true,:name=>"Lee"} and args ["foo"]
opts.to_hash(true) # Pass true to tell Slop to merge sub-command option values.
# => { :v => nil, :add => { :v => true, :name => "Lee" } }
Remaining arguments
The parse! method will remove any options and option arguments from the original Array:
# restarguments.rb
opts = Slop.parse! do
on :foo
end
Example:
ruby restarguments.rb --foo bar
opts.to_hash = { :foo => true }
ARGV #=> ["bar"]
Woah woah, why you hating on OptionParser?
I'm not, honestly! I love OptionParser. I really do, it's a fantastic library. So why did I build Slop? Well, I find myself using OptionParser to simply gather a bunch of key/value options, usually you would do something like this:
require 'optparse'
things = {}
opt = OptionParser.new do |opt|
opt.on('-n', '--name NAME', 'Your name') do |name|
things[:name] = name
end
opt.on('-a', '--age AGE', 'Your age') do |age|
things[:age] = age.to_i
end
# you get the point
end
opt.parse
things #=> { :name => 'lee', :age => 105 }
Which is all great and stuff, but it can lead to some repetition. The same thing in Slop:
require 'slop'
opts = Slop.parse do
on :n, :name=, 'Your name'
on :a, :age=, 'Your age', as: Integer
end
opts.to_hash #=> { :name => 'lee', :age => 105 }