Making HTTP HEAD request with timeout in Ruby

问题:

In a Rails app, I'd like to make a HTTP HEAD request for a resource (a user-provided URL), to make sure that it exists. I'd also like a timeout, to ensure that the method fails after spending a reasonable period of time waiting. What is the most straightforward way to accomplish this (using the standard library, if possible)?

回答1:

Try this snippet:

require 'net/http'

Net::HTTP.start('www.some_site.com') do |http|
  http.open_timeout = 2
  http.read_timeout = 2
  req = Net::HTTP::Head.new('/')
  http.request(req).each { |k, v| puts "#{k}: #{v}" }
end

Hope this is what you're looking for.

UPDATE

Because there is head method that looks like

def head(path, initheader = nil)
  request(Head.new(path, initheader))
end

You can also use this snippet:

require 'net/http'

Net::HTTP.start('www.rubyinside.com') do |http|
  http.open_timeout = 2
  http.read_timeout = 2
  http.head('/').each { |k, v| puts "#{k}: #{v}" }
end