Parse ~/.netrc in Crystal

netrc.cr

require "string_scanner"

# A partial parser of the netrc format
# No support for default, account, or macdef)
class Netrc
  def self.parse
    file = File.read(File.expand_path("~/.netrc", home: true))
    s = StringScanner.new(file)
    machines = {} of String => Hash(String, String)
    machine = ""

    until s.eos?
      if s.scan(/(default|macdef)\s*/)
        raise "Unsupported token '#{s[1]}' in .netrc"
      end

      if s.scan(/machine\s+(\S+)/)
        machine = s[1]
        machines[machine] = {} of String => String
      end

      if s.scan(/(\S+)\s+(\S+)/)
        raise "Unexpected token '#{s[1]}' in .netrc, expected machine" if machine == ""
        machines[machine][s[1]] = s[2]
      end

      s.scan(/\s*/)
    end

    machines
  end
end