From: Oddly Zen <mark.coates@...>
Date: 2009-12-15T05:16:08+09:00
Subject: Re: Working with a command-line application on a remote server via 	Net::SSH

On Dec 14, 12:23 pm, Oddly Zen <mark.coa...@gmail.com> wrote:

> How do I send the data once the application is invoked on the remote
> machine, wait for the response (checking that against possible
> responses), then send more data, and repeat until all the options are
> sent, until I get the final output from the application?

Well, I'll answer my own question for historical purposes. I found
that Net::SSH::Connection::Session#open_channel to do exactly what I
need. I can then pass in a block and use the #on_data callback to
interact with my remote command-line application. The code now looks
somewhat like:

    Net::SSH.start(@server, @user, :password => @pass) do |ssh|
      ssh.open_channel do |channel|
        channel.exec "./solve -iy -c /path/to/config/file" do |ch,
success|
          abort "Could not execute command!" unless success
          channel.on_data do |ch, data|
            puts "got stdout: #{data}"
            channel.send_data "li\n"
            puts "got stdout: #{data}"
            channel.send_data "etc.\n"
            ...
          end
        end
      end
    #ssh.loop -- bleck!
    end

I am sure that I can clean this up now by queueing up the data to be
sent and waiting on the response rather than just cycling through all
this in a loop like it does now.  Any suggestions for this pattern?