Too heavy - if you're looking for expect-like functionality but much simpler - look at empty (worst name in the world and impossible to search for - but great code): http://empty.sourceforge.net/
1. http://ruby-doc.org/stdlib-2.2.2/libdoc/pty/rdoc/PTY.html 2. http://ruby-doc.org/stdlib-2.1.0/libdoc/pty/rdoc/IO.html
Read this first: phttp://www.osnews.com/story.php?news_id=10929
Source code: ftp://ftp.tw.freebsd.org/pub/ports/distfiles/empty-0.6.18b.tgz