Curb - Libcurl bindings for Ruby

• rubyforge rdoc
• rubyforge project
• github project

Curb (probably CUrl-RuBy or something) provides Ruby-language bindings for the libcurl(3), a fully-featured client-side URL transfer library. cURL and libcurl live at http://curl.haxx.se/ .

Curb is a work-in-progress, and currently only supports libcurl's 'easy' and 'multi' modes.

License

Curb is copyright (c)2006 Ross Bamford, and released under the terms of the Ruby license. See the LICENSE file for the gory details.

You will need

• A working Ruby installation (1.8+, tested with 1.8.5, 1.8.6, 1.8.7, and 1.9.1)
• A working (lib)curl installation, with development stuff (7.5+, tested with 7.15)
• A sane build environment

Installation...

... will usually be as simple as:

$ gem install curb

Or, if you downloaded the archive:

$ rake install 

If you have a wierd setup, you might need extconf options. In this case, pass them like so:

$ rake install EXTCONF_OPTS='--with-curl-dir=/path/to/libcurl --prefix=/what/ever'

Currently, Curb is tested only on GNU/Linux x86 - YMMV on other platforms. If you do use another platform and experience problems, or if you can expand on the above instructions, please get in touch via the mailing list on Curb's Rubyforge page.

Curb has fairly extensive RDoc comments in the source. You can build the documentation with:

$ rake doc

Examples

Simple fetch via HTTP:

c = Curl::Easy.perform("http://www.google.co.uk")
puts c.body_str

Same thing, more manual:

c = Curl::Easy.new("http://www.google.co.uk")
c.perform
puts c.body_str

Additional config:

Curl::Easy.perform("http://www.google.co.uk") do |curl| 
  curl.headers["User-Agent"] = "myapp-0.0"
  curl.verbose = true
end

Same thing, more manual:

c = Curl::Easy.new("http://www.google.co.uk") do |curl| 
  curl.headers["User-Agent"] = "myapp-0.0"
  curl.verbose = true
end

c.perform

Supplying custom handlers:

c = Curl::Easy.new("http://www.google.co.uk")

c.on_body { |data| print(data) }
c.on_header { |data| print(data) }

c.perform

Reusing Curls:

c = Curl::Easy.new

["http://www.google.co.uk", "http://www.ruby-lang.org/"].map do |url|
  c.url = url
  c.perform
  c.body_str
end

HTTP POST form:

c = Curl::Easy.http_post("http://my.rails.box/thing/create",
                         Curl::PostField.content('thing[name]', 'box',
                         Curl::PostField.content('thing[type]', 'storage')

HTTP POST file upload:

c = Curl::Easy.new("http://my.rails.box/files/upload")
c.multipart_form_post = true
c.http_post(Curl::PostField.file('myfile.rb'))

Multi Interface (Basic):

# make multiple GET requests
easy_options = {:follow_location => true}
multi_options = {:pipeline => true}

Curl::Multi.get('url1','url2','url3','url4','url5', easy_options, multi_options) do|easy|
  # do something interesting with the easy response
  puts easy.last_effective_url
end

# make multiple POST requests
easy_options = {:follow_location => true, :multipart_form_post => true}
multi_options = {:pipeline => true}

url_fields = [
  { :url => 'url1', :post_fields => {'f1' => 'v1'} },
  { :url => 'url2', :post_fields => {'f1' => 'v1'} },
  { :url => 'url3', :post_fields => {'f1' => 'v1'} }
]

Curl::Multi.post(url_fields, easy_options, multi_options) do|easy|
  # do something interesting with the easy response
  puts easy.last_effective_url
end

Multi Interface (Advanced):

responses = {}
requests = ["http://www.google.co.uk/", "http://www.ruby-lang.org/"]
m = Curl::Multi.new
# add a few easy handles
requests.each do |url|
  responses[url] = ""
  c = Curl::Easy.new(url) do|curl|
    curl.follow_location = true
    curl.on_body{|data| responses[url] << data; data.size }
  end
  m.add(c)
end

m.perform do
  puts "idling... can do some work here, including add new requests"
end

requests.each do|url|
  puts responses[url]
end