Shell out from ruby while setting an environment variable

Question

I need to shell out to a process while setting an environment variable for it. I tried this one-liner:

system \"RBENV_VERSION=system ruby extconf.rb\"
         


        

Answer 1

Using your same approach, but wrapped up as a block method that temporarily modifies the environment (like the block form of Dir.chdir):

def with_environment(variables={})
  if block_given?
    old_values = variables.map{ |k,v| [k,ENV[k]] }
    begin
       variables.each{ |k,v| ENV[k] = v }
       result = yield
    ensure
      old_values.each{ |k,v| ENV[k] = v }
    end
    result
  else
    variables.each{ |k,v| ENV[k] = v }
  end
end

with_environment 'RBENV_VERSION'=>'system' do
  `ruby extconf.rb`
end