#!/usr/bin/ruby -w

puts "* one way child2parent pipe"
rd, wr = IO.pipe
if fork
  # parent
  wr.close
  puts "parent: got <#{rd.read}>"
  rd.close
  Process.wait
else
  # child
  rd.close
  wr.write "hi parent"
  wr.close
  exit
end

puts "* two-way paren2child and child2parent pipe"
parent2child_rd, parent2child_wr = IO.pipe
child2parent_rd, child2parent_wr = IO.pipe

if fork
  # parent
  child2parent_wr.close
  parent2child_wr.print "hi child"
  parent2child_wr.close
  puts "parent: got <#{child2parent_rd.read}>"
  child2parent_rd.close
  Process.wait
else
  # child
  parent2child_wr.close
  puts "child: got <#{parent2child_rd.gets}>"
  parent2child_rd.close
  child2parent_wr.write "hi parent"
  child2parent_wr.close
  exit
end

print "parent exit\n"