String interpolation and URI.parse error? - ruby

Question

I have four arguments taken from user input in the script. All other string interpolation arguments work fine except for URI.parse.
Snippets from the code are:
require 'net/http'
#ARGVs:
prompt = 'test: '
url = ARGV[0]
user = ARGV[1]
pass = ARGV[2]
xml_user = ARGV[3]
# User supplied input:
puts "Whats the URL?"
print prompt
url = STDIN.gets.chomp()
# HTTP connection
uri = URI.parse('#{url}')
req = Net::HTTP.new(uri.hostname, uri.port)
# Header: Creds to get a session
user_and_pass = "#{user}" + ':' + "#{pass}"
base64user_and_pass = Base64.encode64(user_and_pass)
# POST method
res = req.post(uri.path, xml_data, {'Content-Type' => 'text/xml', 'Content-Length' => xml_data.length.to_s,
'Authorization' => "Basic #{base64user_and_pass}", "Connection" => "keep-alive" })
puts res.body
Error:
Ruby200-x64/lib/ruby/2.0.0/uri/common.rb:176:in `split': bad URI(is not URI?): #{url} (URI::InvalidURIError)
A point in the right direction would be appreciated.

Answer 1

uri = URI.parse('#{url}')
should be:
uri = URI.parse(url)

Answer 2

Here's a bit more idiomatic-Ruby version of the code:
require 'net/http'
PROMPT = 'test: '
# ARGVs:
url, user, pass, xml_user = ARGV[0, 4]
# User supplied input:
puts "Whats the URL?"
print PROMPT
url = STDIN.gets.chomp()
# HTTP connection
uri = URI.parse(url)
req = Net::HTTP.new(uri.hostname, uri.port)
# Header: Creds to get a session
base64user_and_pass = Base64.encode64("#{ user }:#{ pass }")
# POST method
res = req.post(
uri.path,
xml_data,
{
'Content-Type' => 'text/xml',
'Content-Length' => xml_data.length.to_s,
'Authorization' => "Basic #{ base64user_and_pass }",
"Connection" => "keep-alive"
}
)
puts res.body
Don't do things like:
user_and_pass = "#{user}" + ':' + "#{pass}"
and:
uri = URI.parse('#{url}')
user, pass and url are already strings, so sticking them inside a string and interpolating their values is a waste of CPU. As developers we need to be aware of our data-types.
It could be written as one of these:
user_and_pass = user + ':' + pass
user_and_pass = '%s:%s' % [user, pass]
user_and_pass = [user, pass].join(':')
But it's more idiomatic to see it how I wrote it above.