Is there an Expect equivalent gem for Ruby?

Question

Is there an Expect equivalent gem for Ruby?

I tried searching on code.google and rubygems.org, but sadly it did not show up.

FYI: Expect is a Unix automation

Answer 1

I recently spent quite a bit of time struggling with this issue (I am stuck with 1.8.7). I found this question, this blog post and this forum thread really useful.

At the end this is my application code if anyone is interested in a little example (pass the password to rpm when signing packages):

def run_interactive command, password, promt
  output   = ''
  begin
    r, w, pid = PTY.spawn(command)
    puts r.expect(promt)
    sleep(0.5)
    w.puts(password)
    begin
      r.each { |l| output += l } 
    rescue Errno::EIO
    end
    $?.exitstatus
    Process.wait(pid)
  rescue PTY::ChildExited => e
    $stderr.puts "The child process #{e} exited! #{$!.status.exitstatus}"
  end 
  output
end

password = "mypassword"
command  = "rpm --define '_signature gpg' --define '_gpg_name #{key_id}' --addsign #{package}"
promt    = %r{.*: }
expected = %r{good}
output = run_interactive(command, password, promt)
if output.match(expected)
  puts output
else
  abort "Error: expected: '#{expected}' got '#{output}'"
end 

It has little error checking but it was all I needed.

Edit: Update the code with Process.wait(pid) to make sure it finishes before continuing and add comment about this being for 1.8.7.