pipe() public

Creates a pair of pipe endpoints (connected to each other) and returns them as a two-element array of IO objects: [ read_file, write_file ]. Not available on all platforms.

In the example below, the two processes close the ends of the pipe that they are not using. This is not just a cosmetic nicety. The read end of a pipe will not generate an end of file condition if there are any writers with the pipe still open. In the case of the parent process, the rd.read will never return if it does not first issue a wr.close. 

   rd, wr = IO.pipe

   if fork
     wr.close
     puts "Parent got: <#{rd.read}>"
     rd.close
     Process.wait
   else
     rd.close
     puts "Sending message to parent"
     wr.write "Hi Dad"
     wr.close
   end

produces: 

   Sending message to parent
   Parent got: <Hi Dad>
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