gistfile1.rb

#!/usr/bin/ruby

require 'rubygems'
require 'open4'

# catch SIGCHLD (child process terminated) signals and handle them
trap("CHLD") do
  begin
    Process.wait(-1, Process::WNOHANG)
  rescue Object
    # catch exceptions, but don't do anything with them
  end
end

input_data = File.read("test_file.csv")

# I want to pope the input data first through sort, then through my custom binary

# sort using regular popen
Open4.popen4("sort") do |pid, i, o, e|
  i << input_data   # does this complete, or does sort begin to block?
  
  # now spawn the next item in the chain -- timeouts are optional
  Open4.spawn "/path/to/binary", :stdin => o, :stdout => STDOUT, :stderr => STDERR, :stdin_timeout => 30.0
end