module Mixlib::ShellOut::Windows::Utils

def self.should_run_under_cmd?(command)

https://github.com/ruby/ruby/blob/9073db5cb1d3173aff62be5b48d00f0fb2890991/win32/win32.c#L1437
This parser is based on

this method should return true.
If there are special characters parsable by cmd.exe (such as file redirection), then
api: semi-private 
def self.should_run_under_cmd?(command)
  return true if command =~ /^@/
  quote = nil
  env = false
  env_first_char = false
  command.dup.each_char do |c|
    case c
    when "'", '"'
      if (!quote)
        quote = c
      elsif quote == c
        quote = nil
      end
      next
    when '>', '<', '|', '&', "\n"
      return true unless quote
    when '%'
      return true if env
      env = env_first_char = true
      next
    else
      next unless env
      if env_first_char
        env_first_char = false
        env = false and next if c !~ /[A-Za-z_]/
      end
      env = false if c !~ /[A-Za-z1-9_]/
    end
  end
  return false
end