async repl

$ julia
               _
   _       _ _(_)_     |  A fresh approach to technical computing
  (_)     | (_) (_)    |  Documentation: http://docs.julialang.org
   _ _   _| |_  __ _   |  Type "help()" for help.
  | | | | | | |/ _` |  |
  | | |_| | | | (_| |  |  Version 0.4.0-dev+1148 (2014-10-20 05:03 UTC)
 _/ |\__'_|_|_|\__'_|  |  Commit 6290d34* (0 days old master)
|__/                   |  x86_64-apple-darwin13.4.0

julia> (stdout,stdin,process) = readandwrite(`cat`)
(Pipe(active, 0 bytes waiting),Pipe(open, 0 bytes waiting),Process(`cat`, ProcessRunning))

julia> write(stdin, "a\n"); nothing

julia> const StatusClosed = 6
6

julia> @async while StatusClosed != stdout.status
         line = readline(stdout)
         println("STDOUT: ", line)
       end
STDOUT: a
Task (queued) @0x00007fd888812a00


julia> write(stdin, "b\n"); nothing

julia> b

julia> write(stdin, "c\n"); nothing

julia> STDOUT: c
julia>
julia>

julia> write(stdin, "d\n"); nothing

julia> STDOUT: d
julia>
julia>

julia> close(stdin)

julia>
julia>

julia> stdin
Pipe(closed, 0 bytes waiting)

julia> stdout
Pipe(closed, 0 bytes waiting)

async.jl

(stdout,stdin,process) = readandwrite(`cat`)

write(stdin, "a\n")

const StatusClosed = 6
@async while StatusClosed != stdout.status
  line = readline(stdout)
  println("STDOUT: ", line)
end

write(stdin, "b\n")
write(stdin, "c\n")