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tree

a directory, drawn

tree lists a directory recursively and draws the nesting with lines, so the shape of a project is visible at a glance. It is not installed by default on most systems — one package away.

ls shows one level; tree shows how the levels fit together.

Shows

Nested layout

directories and files

Limit depth

-L NUM

or large trees scroll for ever

Ends with

A count

directories and files

Install

apt install tree

or dnf install tree

At the terminal

Read the session first, then the notes: each numbered line in the output is answered by the note with the same number.

user@netflow — bashtree

$ tree -L 2 project

1project

├── README.md

2├── src

│ ├── app.py

3│ └── db

└── tests

└── test_app.py

43 directories, 3 files

Illustrative session · names, sizes and dates are examples, and every address is from a documentation or private range

Reading the output

What the numbered lines are telling you

The starting directory

Everything below is drawn relative to it. With no argument, tree starts from the current directory.

A branch is a directory

Entries drawn beneath src and indented are inside it. The vertical line shows that more entries of the parent follow.

-L 2 stopped here

db is a directory, but its contents are a third level and were not shown.

The summary line

The starting directory itself is not counted: src, db and tests are the three.

Switches

A switch changes how the command behaves. These are the ones used day to day; man tree lists the rest. Single-letter switches can usually be joined, so -l -a may be written -la.

-L NUM: Descend only NUM levels deep.
-a: All: include hidden entries.
-d: List directories only.
-h: Print each file’s size in readable units.
-f: Print the full path of each entry.
-I PATTERN: Leave out entries matching the pattern.

Variations worth knowing

The same tool, pointed at a narrower question. These four cover most of what it is reached for day to day.

tree -a

Includes hidden entries, whose names begin with a dot.

tree -d

Shows directories only, leaving the files out.

tree -h --du

Adds sizes, with each directory showing the total of its contents.

tree -I "node_modules|.git"

Leaves out anything matching a pattern.

In cybersecurity

A drawn tree is the fastest way to notice what should not be there.

Review before publishing

Running tree -a on a web root or a repository shows stray .git directories, backups and .env files before someone else finds them.

Hidden is only hidden from ls

Without -a, dot files are left out. An audit that skips them skips where secrets usually are.

Pasting output

A tree of a home directory or server reveals user names, software and layout. Trim it before posting it in a public question.

Filed under

Navigation

Read alongside

lsLists the contents of a directory — names, and with -l the type, permissions, owner, size and date of each entry.findWalks a directory tree and prints every entry that passes the tests you give it — by name, age, size, owner or permissions.