redis-nc.sh

#!/usr/bin/env bash

set -e
set -x

path=$(mktemp -d)
rd=$path/rd
wr=$path/wr

mkfifo $rd
mkfifo $wr

nc $@ < $rd | grep --line-buffered "^+PONG" > $wr &

(
  # Wait for PONG in the background
  (
    read foo
  ) < $wr &

  # Send stdin and sentinel PING
  cat
  printf "PING\r\n"

  # Wait for PONG (before closing $rd, which terminates `nc`)
  wait
) > $rd

# Clean up
rm -rf $path