Making HEAD request in Ruby

Question

I am kind of new to ruby and from a python background I want to make a head request to a URL and check some information like if the file exists on the server and timestamp, etag etc.,I am not able to get this done in RUBY. In Python: ``` import httplib2 print httplib2.Http().request('url.com/file.xml','HEAD') ``` In Ruby: I tried this and throwing some error ``` require 'net/http' Net::HTTP.start('url.com'){|http| response = http.head('/file.xml') } puts response SocketError: getaddrinfo: nodename nor servname provided, or not known from /Users/comcast/.rvm/rubies/ruby-2.0.0-p0/lib/ruby/2.0.0/net/http.rb:877:in `initialize' from /Users/comcast/.rvm/rubies/ruby-2.0.0-p0/lib/ruby/2.0.0/net/http.rb:877:in `open' from /Users/comcast/.rvm/rubies/ruby-2.0.0-p0/lib/ruby/2.0.0/net/http.rb:877:in `block in connect' from /Users/comcast/.rvm/rubies/ruby-2.0.0-p0/lib/ruby/2.0.0/timeout.rb:51:in `timeout' from /Users/comcast/.rvm/rubies/ruby-2.0.0-p0/lib/ruby/2.0.0/net/http.rb:876:in `connect' fro…

Accepted Answer

I don't think that passing in a string to :start is enough; in the docs it looks like it requires a URI object's host and port for a correct address:

```
uri = URI('http://example.com/some_path?query=string')

Net::HTTP.start(uri.host, uri.port) do |http|
  request = Net::HTTP::Get.new uri

response = http.request request # Net::HTTPResponse object
end
```

You can try this:

```
require 'net/http'

url = URI('yoururl.com')

Net::HTTP.start(url.host, url.port){|http|
   response = http.head('/file.xml')
   puts response
}
```

One thing I noticed - your `puts response` needs to be inside the block! Otherwise, the variable `response` is not in scope.

Edit: You can also treat the response as a hash to get the values of the headers:

```
response.each_value { |value| puts value }
```

Making HEAD request in Ruby

Solution

Problem