Master the Linux ls Command: 15 Essential Options Explained

The ls command is one of the most frequently used commands in Linux. This article discusses basic ls usage and covers a wide range of options.

1. List files without any options

Running ls without options lists files and directories bare, without showing file type, size, modification date, permissions, or links.

2. List files with the -l option

ls -l

(the letter "l", not the number "1") shows whether each entry is a file or directory, its size, modification date and time, name, owner, and permissions.

3. Show hidden files

Use ls -a to list all files, including those whose names start with a dot.

4. Human‑readable sizes with -lh

Combine -l and -h to display sizes in a human‑readable format.

5. Append a slash to directories with -F

The -F option adds a trailing "/" to directory names.

6. Reverse order with -r

ls -r

displays files and directories in reverse order.

7. Recursive listing with -R

ls -R

lists a full directory tree recursively.

8. Sort by modification time (newest first) with -lt or -ltr

The -lt (or -ltr for reverse) option sorts entries by latest modification time.

9. Sort by file size with -lS

The -lS option lists files from largest to smallest.

10. Show inode numbers with -i

Adding -i displays the inode number of each file or directory.

11. Show the ls version

Use ls --version to view the command’s version information.

12. Display the help page

Run ls --help to list all available options and their descriptions.

13. List directory information

ls -l /tmp

lists files in /tmp; adding -d shows only the directory entry itself.

14. Show UID and GID with -n

ls -n

displays numeric user IDs (UID) and group IDs (GID) for files and directories.

15. Create an alias for ls

Define an alias such as alias ls='ls -l' so that invoking ls automatically uses the -l option.

Use alias without arguments to list all current aliases, and unalias to remove an alias.