#!/usr/bin/env bash
set -euo pipefail
ROOT="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")/../.." && pwd)"
WORK="$ROOT/outputs/linux/linux-permissions"
mkdir -p -- "$WORK"
old_umask="$(umask)"
trap 'umask "$old_umask"' EXIT
umask 027
printf '%s\n' 'permission demo' > "$WORK/private.txt"
chmod 640 -- "$WORK/private.txt"
printf 'owner uid: '; id -u
printf 'mode: '; stat -c '%a' "$WORK/private.txt"
unset LOCAL_LABEL
LOCAL_LABEL='course'
bash -c 'printf "before export: %s\n" "${LOCAL_LABEL-unset}"'
export LOCAL_LABEL
bash -c 'printf "after export: %s\n" "$LOCAL_LABEL"'