tree — Visualize Directory Structure

💬 "tree command"

tree shows the directory structure in a hierarchical shape. It is faster to understand the structure than running ls multiple times.

Use it to quickly check the structure of directories where logs accumulate or deployment artifacts.

• Concept: Outputs subdirectories and files in a tree format starting from the specified path.
• Left side: Represents hierarchy with connector lines like ├──, └──.
• Last line: Summarizes the number of directories and files.
• Depth: You can limit how many levels to view with the -L option.

Commonly Used Options

3 Essential Command Combinations

• tree -L 2 /var/www/html — Check the web root structure up to 2 levels only
• tree -d -L 2 /opt/app — View only directories to understand the structure
• tree --du -h /var/log | head -30 — Check size by log directory

💬 "Which options should be used together to reduce mistakes?"

Here are situations commonly encountered on a live server, organized in order.

Step 1 · View the Structure at a Glance

Limit the depth to understand the overall layout.

tree -L 2 /var/www/html

Step 2 · View with Sizes

Check which subfolders are large.

tree --du -h -L 2 /var/log

Step 3 · Save as Documentation

Save the structure to a file for review or handover.

tree -L 3 /opt/app > /tmp/app-structure.txt

How This Is Used in Practice

1. Verify Deployment Structure

Situation — You unpacked a release archive, but the file layout is different from expected.

tree -L 2 /opt/app/releases/20261018

Result — If public/ should be at the top level but a subfolder goes one level deeper, it is an archive path issue.

Point — The habit of checking with tree after deployment helps you quickly find the cause of 404/500 errors.

2. Identify Where Log Data Accumulates

Situation — The disk is full, so you check which log directory is large.

tree --du -h -L 2 /var/log | sort -k2 -h | tail

Result — Identify the large subdirectories and decide what to rotate.

Point — Because tree's --du shows recursive totals, it is convenient for judging at the folder level.

Things to Keep in Mind

• If you run tree without options in a directory with tens of thousands of files, the output explodes. Limit it with -L.
• tree is not always installed by default, so if the tree command is missing, you need to install the package.
• If the output is long, trim it with head/tail.

Actual Execution Screen

This is the result of checking the two-level structure of the web root.

!tree command execution result: directory tree structure

A live production server

Source (HTML): https://games.aidebatehub.com/programs/linux/filesystem/tree.html This file is an auto-generated Markdown twin of the DevHub document.