mplayer.rb

#!/usr/bin/env ruby

pid = fork do
  Process.setsid # get immune to our parent's TTY signals
  Signal.trap("CLD") { exit } # mplayer died
  IO.popen(['mplayer', *ARGV], :err => [:child, :out]) do |io|
    begin
      loop do
        begin
          IO.copy_stream(io, STDOUT)
        rescue Errno::EIO # STDOUT is gone, but we still need to pump the input
        end
      end
    rescue EOFError # mplayer died
      exit
    rescue Interrupt # parent wants us to go away
      exit # this kills mplayer with us with a SIGPIPE
    end
  end
end

loop do
  begin
    Process.wait(pid)
  rescue Interrupt
    Process.kill('INT', pid)
    # we still need to wait for mplayer to die
    # otherwise, the shell prints its prompt before mplayer has died
  rescue Errno::ECHILD
    exit
  end
end