ls — list directory contents

💬 "ls command"

• Concept: The most basic command that lists files and folders in a directory. It is the first thing you type when you connect to a server.
• Output structure: When run without options, it only lists names, so you cannot see type, permissions, or size.
• Recommended output in practice: Using ls -al organizes permissions, owner, size, and modification time on one line. Add -h to make the size easier to read.
• Left column: file type and permissions (e.g. <code>drwxr-xr-x</code>), link count, and owner and group are displayed.
• Right column: file size, last modification time, and file name are printed.

3 Essential Command Combinations

• ls — Quickly check only the names in the current folder
• ls -l — Check permissions, size, and time in detail
• ls -al — Check all files, including hidden files (starting with .)

Here are some useful options worth knowing.

• -h — Display sizes in easy-to-read KB/MB/GB units
• -t — Sort by most recently modified files first

💬 "Show me how to solve a problem using this"

Scenario: Checking that files have been uploaded correctly to the deployment folder.

Step 1: Check the full list

Check the list including hidden files.

ls -al /var/www/app

Step 2: View recently modified files first

The file you just deployed appears at the top.

ls -lt /var/www/app | head

Step 3: Make the size easy to read

Check again in units that are easier for people to read.

ls -lh /var/www/app

Actual execution screen

An example screen of checking folder contents with ls -al and ls -lh.

!ls command output: permissions, size, modification time and file name

A real production server

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