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 (2.1+)
- A working (lib)curl installation, with development stuff (7.5+, tested with 7.19.x)
- A sane build environment (e.g. gcc, make)
Installation...
... will usually be as simple as:
$ gem install curb
On Windows, make sure you're using the DevKit and the development version of libcurl. Unzip, then run this in your command line (alter paths to your curl location, but remember to use forward slashes):
gem install curb --platform=ruby -- --with-curl-lib=C:/curl-7.39.0-devel-mingw32/lib --with-curl-include=C:/curl-7.39.0-devel-mingw32/include
Or, if you downloaded the archive:
$ rake compile && rake install
If you have a weird setup, you might need extconf options. In this case, pass them like so:
$ rake compile EXTCONF_OPTS='--with-curl-dir=/path/to/libcurl --prefix=/what/ever' && rake install
Curb is tested only on GNU/Linux x86 and Mac OSX - YMMV on other platforms. If you do use another platform and experience problems, or if you can expand on the above instructions, please report the issue at http://github.com/taf2/curb/issues
On Ubuntu, the dependencies can be satisfied by installing the following packages:
$ sudo apt-get install libcurl3 libcurl3-gnutls libcurl4-openssl-dev
On RedHat:
$ sudo yum install ruby-devel libcurl-devel openssl-devel
Curb has fairly extensive RDoc comments in the source. You can build the documentation with:
$ rake doc
Usage & examples
Curb provides two classes:
-
Curl::Easy
- simple API, for day-to-day tasks. -
Curl::Multi
- more advanced API, for operating on multiple URLs simultaneously.
To use either, you will need to require the curb gem:
require 'curb'
Super simple API (less typing)
http = Curl.get("http://www.google.com/")
puts http.body_str
http = Curl.post("http://www.google.com/", {:foo => "bar"})
puts http.body_str
http = Curl.get("http://www.google.com/") do |http|
http.headers['Cookie'] = 'foo=1;bar=2'
end
puts http.body_str
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
HTTP basic authentication:
c = Curl::Easy.new("http://github.com/")
c.http_auth_types = :basic
c.username = 'foo'
c.password = 'bar'
c.perform
HTTP "insecure" SSL connections (like curl -k, --insecure) to avoid Curl::Err::SSLCACertificateError:
c = Curl::Easy.new("https://github.com/")
c.ssl_verify_peer = false
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('thing[file]', 'myfile.rb'))
Using HTTP/2
c = Curl::Easy.new("https://http2.akamai.com")
c.set(:HTTP_VERSION, Curl::HTTP_2_0)
c.perform
puts (c.body_str.include? "You are using HTTP/2 right now!") ? "HTTP/2" : "HTTP/1.x"
Multi Interface (Basic HTTP GET):
# make multiple GET requests
easy_options = {:follow_location => true}
# Use Curl::CURLPIPE_MULTIPLEX for HTTP/2 multiplexing
multi_options = {:pipeline => Curl::CURLPIPE_HTTP1}
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
Multi Interface (Basic HTTP POST):
# make multiple POST requests
easy_options = {:follow_location => true, :multipart_form_post => true}
multi_options = {:pipeline => Curl::CURLPIPE_HTTP1}
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 }
curl.on_success {|easy| puts "success, add more easy handles" }
end
m.add(c)
end
m.perform do
puts "idling... can do some work here"
end
requests.each do|url|
puts responses[url]
end
Easy Callbacks
-
on_success
is called when the response code is 2xx -
on_redirect
is called when the response code is 3xx -
on_missing
is called when the response code is 4xx -
on_failure
is called when the response code is 5xx -
on_complete
is called in all cases.