Команды, пути и файловая система

tmp=$(mktemp -d)
mkdir -p "$tmp/real/sub"
ln -s "$tmp/real" "$tmp/link"
cd "$tmp/link/sub"
printf '%s\n' "$PWD"
pwd -P

base=/var/tmp/app
name='../logs/run.log'
printf '%s\n' "$base/$name"
realpath -m "$base/$name"

tmp=$(mktemp -d)
mkdir -p "$tmp/src" "$tmp/dst"
printf x > "$tmp/src/.env"
printf y > "$tmp/src/app"
cp -a "$tmp/src/." "$tmp/dst/"
printf '%s\n' "$(find "$tmp/dst" -mindepth 1 -maxdepth 1 -printf '%f ' | sort)"

target=${1:-}
if [[ -n $target && $target == /var/tmp/app/* ]]; then
  printf 'delete:%q\n' "$target"
else
  printf 'refuse\n'
fi

start=$PWD
cd /tmp
work=$(mktemp -d)
cd "$work"
rm -rf "$work"
cd "$start"

root=/srv/app
file=/etc/passwd
printf '%s\n' "$root/$file"

src=/data/report.csv
dst=/archive/report.csv
mv "$src" "$dst"
printf 'moved\n'

dir=${WORKDIR:-}
rm -rf "$dir"/*

old=$PWD
cd "$target" || exit 1
run_task
cd "$old"

root=/srv/uploads
path=$1
case $path in
  /*) target=$root$path ;;
  *)  target=$root/$path ;;
esac

cp -r "$source" "$target"
rm -rf "$source"

target=$1
[[ $target == "$root"/* ]] || exit 2
rm -rf -- "$target"