I'm using docker, I want to use tree command, but I get error: # tree -L 1 /bin/sh: 52: tree: not found # whereis tree tree: # apt install tree Reading package lists... Done Building dependency tree Reading state information... Done E: Unable to locate package tree # pip install tree Requirement already satisfied: tree in /usr/local/lib/python3.8/site-packages (0.2.4) Requirement already satisfied: Pillow in /usr/local/lib/python3.8/site-packages (from tree) (10.0.1) Requirement already satisfied: svgwrite in /usr/local/lib/python3.8/site-packages (from tree) (1.4.3) Requirement already satisfied: setuptools in /usr/local/lib/python3.8/site-packages (from tree) (57.0.0) Requirement already satisfied: click in /usr/local/lib/python3.8/site-packages (from tree) (8.1.7) WARNING: Running pip as the 'root' user can result in broken permissions and conflicting behaviour with the system package manager. It is recommended to use a virtual environment instead: https://pip.pypa.io/warnings/venv # tree -L 1 /bin/sh: 56: tree: not found # How should I do? Continue reading...