Learning Named Pipe

np-main.sh

#!/usr/bin/env bash

root=$(cd $(dirname $0); pwd)

pipe="/tmp/np-$$"
mkfifo $pipe
echo "np-main: pipe created: $pipe"

"$root/np-sub.sh" "$pipe" "$@" &
echo "np-main: from sub: $(cat $pipe)"
echo "np-main: exit code: $?"

rm -f $pipe
echo "np-main: pipe deleted"

np-sub.sh

#!/usr/bin/env bash

if [[ ! -z $2 ]]; then
  echo "" >$1
  echo "np-sub: error" >&2
  exit 1
fi

echo "np-sub: named pipe!" >$1

echo "np-sub: success"