#!/usr/bin/env bash

pipe1=/tmp/pipe1
pipe2=/tmp/pipe2
src=/usr/share/dict/words

# Create the diversions
mkfifo $pipe1
mkfifo $pipe2

# Run the plumbing
cat $src | tee $pipe1 | grep "foo" | tee $pipe2 > foo.txt &
cat $pipe1 | grep "bar" > bar.txt &
cat $pipe2 | grep "bar" > foobar.txt

rm $pipe1 $pipe2