Exploring the 'ls' Command in Linux: Options and Examples

Summary

The "ls" command in Linux is one of the most commonly used commands for listing the contents of directories

Detailed information about files and directories

The "ls" command provides a wealth of options to customize the output and gather more detailed information about files and directories. In this article, we’ll explore several commonly used options for the ls command, complete with examples to help you better understand their usage.

Basic Syntax

The basic syntax for the "ls" command is the following (If no directory is specified, "ls" lists the contents of the current working directory.)

ls [options] [directory]

1. Listing Files and Directories

By default, the ls command lists files and directories in a simple format. The following example shows the results after executing the "ls" command in a WordPress folder installation

$ ls
index.php           wp-comments-post.php  wp-load.php
license.txt         wp-config-sample.php  wp-login.php
readme.html         wp-config.php         wp-mail.php
 wp-content/           wp-settings.php
wp-activate.php     wp-cron.php           wp-signup.php
wp-admin/           wp-includes/          wp-trackback.php
wp-blog-header.php  wp-links-opml.php     xmlrpc.php

2. Displaying Hidden Files

Hidden files in Linux start with a "." and are not displayed by default. Use the "-a" option to include hidden files in the output:

$ ls -a
./                           wp-config.php      wp-login.php
../          wp-activate.php       wp-content/        wp-mail.php
.htaccess    wp-admin/             wp-cron.php        wp-settings.php
index.php    wp-blog-header.php    wp-includes/       wp-signup.php
license.txt  wp-comments-post.php  wp-links-opml.php  wp-trackback.php
readme.html  wp-config-sample.php  wp-load.php        xmlrpc.php

3. Long Format Listing

The "-l" option displays detailed information about files and directories, including permissions, ownership, size, and modification date:

$ ls -l
total 350
-rw-r--r-- 1 DELL 197121   405 Jan  3 09:00 index.php
-rw-r--r-- 1 DELL 197121 19915 Jan  3 09:00 license.txt
-rw-r--r-- 1 DELL 197121  7409 Jan  3 09:00 readme.html
-rw-r--r-- 1 DELL 197121  7387 Jan  3 09:00 wp-activate.php
drwxr-xr-x 1 DELL 197121     0 Jan  3 09:06 wp-admin/
-rw-r--r-- 1 DELL 197121   351 Jan  3 09:00 wp-blog-header.php
-rw-r--r-- 1 DELL 197121  2323 Jan  3 09:00 wp-comments-post.php
-rw-r--r-- 1 DELL 197121  3336 Jan  3 09:00 wp-config-sample.php
-rw-r--r-- 1 DELL 197121  3597 Jan  3 09:09 wp-config.php
....

4. Sorting by Modification Time

To sort files by their last modification time, use the "-t" option:

$ ls -lt
total 350
drwxr-xr-x 1 DELL 197121     0 Jan  3 09:10 wp-content/
-rw-r--r-- 1 DELL 197121  3597 Jan  3 09:09 wp-config.php
drwxr-xr-x 1 DELL 197121     0 Jan  3 09:07 wp-includes/
drwxr-xr-x 1 DELL 197121     0 Jan  3 09:06 wp-admin/
-rw-r--r-- 1 DELL 197121  2323 Jan  3 09:00 wp-comments-post.php
-rw-r--r-- 1 DELL 197121  5102 Jan  3 09:00 wp-trackback.php
-rw-r--r-- 1 DELL 197121  7387 Jan  3 09:00 wp-activate.php
-rw-r--r-- 1 DELL 197121  3937 Jan  3 09:00 wp-load.php
-rw-r--r-- 1 DELL 197121  2502 Jan  3 09:00 wp-links-opml.php
-rw-r--r-- 1 DELL 197121  8543 Jan  3 09:00 wp-mail.php
-rw-r--r-- 1 DELL 197121 19915 Jan  3 09:00 license.txt
-rw-r--r-- 1 DELL 197121 29032 Jan  3 09:00 wp-settings.php
-rw-r--r-- 1 DELL 197121 51367 Jan  3 09:00 wp-login.php
-rw-r--r-- 1 DELL 197121  3336 Jan  3 09:00 wp-config-sample.php
....

5. Recursively Listing Subdirectories

The "-R" option allows you to list all files and directories recursively. (Find below a sample of the generated output of the command)

$ ls -R wp-content
wp-content:
index.php  plugins/  themes/  uploads/

wp-content/plugins:
akismet/  hello.php  index.php

wp-content/plugins/akismet:
LICENSE.txt    class.akismet-admin.php     class.akismet.php  wrapper.php
_inc/          class.akismet-cli.php       index.php
akismet.php    class.akismet-rest-api.php  readme.txt
changelog.txt  class.akismet-widget.php    views/
....

6. Human-Readable File Sizes

When combined with the -l option, the -h option displays file sizes in a human-readable format (e.g., KB, MB):

$ ls -lh
total 350K
-rw-r--r-- 1 DELL 197121  405 Jan  3 09:00 index.php
-rw-r--r-- 1 DELL 197121  20K Jan  3 09:00 license.txt
-rw-r--r-- 1 DELL 197121 7.3K Jan  3 09:00 readme.html
-rw-r--r-- 1 DELL 197121 7.3K Jan  3 09:00 wp-activate.php
drwxr-xr-x 1 DELL 197121    0 Jan  3 09:06 wp-admin/
-rw-r--r-- 1 DELL 197121  351 Jan  3 09:00 wp-blog-header.php
-rw-r--r-- 1 DELL 197121 2.3K Jan  3 09:00 wp-comments-post.php
-rw-r--r-- 1 DELL 197121 3.3K Jan  3 09:00 wp-config-sample.php
-rw-r--r-- 1 DELL 197121 3.6K Jan  3 09:09 wp-config.php
...

7. Combining Options

You can combine multiple options for more detailed output. For instance, to display hidden files in a long format with human-readable file sizes, please refer to the following command.

$ ls -alh
total 363K
drwxr-xr-x 1 DELL 197121    0 Jan  7 17:32 ./
drwxr-xr-x 1 DELL 197121    0 Jan  3 08:59 ../
-rw-r--r-- 1 DELL 197121  529 Jan  3 09:10 .htaccess
-rw-r--r-- 1 DELL 197121  405 Jan  3 09:00 index.php
-rw-r--r-- 1 DELL 197121  20K Jan  3 09:00 license.txt
-rw-r--r-- 1 DELL 197121 7.3K Jan  3 09:00 readme.html
-rw-r--r-- 1 DELL 197121 7.3K Jan  3 09:00 wp-activate.php
drwxr-xr-x 1 DELL 197121    0 Jan  3 09:06 wp-admin/
-rw-r--r-- 1 DELL 197121  351 Jan  3 09:00 wp-blog-header.php
-rw-r--r-- 1 DELL 197121 2.3K Jan  3 09:00 wp-comments-post.php
-rw-r--r-- 1 DELL 197121 3.3K Jan  3 09:00 wp-config-sample.php
...

8. Classifying File Types

The "-F" option appends a character to each file name indicating its type:

- / for directories

- * for executables

- @ for symbolic links

$ ls -F
index.php        wp-blog-header.php    wp-cron.php        wp-mail.php
license.txt      wp-comments-post.php  wp-includes/       wp-settings.php
readme.html      wp-config-sample.php  wp-links-opml.php  wp-signup.php
wp-activate.php  wp-config.php         wp-load.php        wp-trackback.php
wp-admin/        wp-content/           wp-login.php       xmlrpc.php

9. Reverse Sorting

To reverse the order of the output, use the "-r" option.

$ ls -lr
total 350
-rw-r--r-- 1 DELL 197121  3246 Jan  3 09:00 xmlrpc.php
-rw-r--r-- 1 DELL 197121  5102 Jan  3 09:00 wp-trackback.php
-rw-r--r-- 1 DELL 197121 34385 Jan  3 09:00 wp-signup.php
-rw-r--r-- 1 DELL 197121 29032 Jan  3 09:00 wp-settings.php
-rw-r--r-- 1 DELL 197121  8543 Jan  3 09:00 wp-mail.php
-rw-r--r-- 1 DELL 197121 51367 Jan  3 09:00 wp-login.php
-rw-r--r-- 1 DELL 197121  3937 Jan  3 09:00 wp-load.php
-rw-r--r-- 1 DELL 197121  2502 Jan  3 09:00 wp-links-opml.php
drwxr-xr-x 1 DELL 197121     0 Jan  3 09:07 wp-includes/
-rw-r--r-- 1 DELL 197121  5617 Jan  3 09:00 wp-cron.php
drwxr-xr-x 1 DELL 197121     0 Jan  3 09:10 wp-content/
...

10. Listing Files by Size

The "-S" option sorts files by size (largest to smallest)

$ ls -lS
total 350
-rw-r--r-- 1 DELL 197121 51367 Jan  3 09:00 wp-login.php
-rw-r--r-- 1 DELL 197121 34385 Jan  3 09:00 wp-signup.php
-rw-r--r-- 1 DELL 197121 29032 Jan  3 09:00 wp-settings.php
-rw-r--r-- 1 DELL 197121 19915 Jan  3 09:00 license.txt
-rw-r--r-- 1 DELL 197121  8543 Jan  3 09:00 wp-mail.php
-rw-r--r-- 1 DELL 197121  7409 Jan  3 09:00 readme.html
-rw-r--r-- 1 DELL 197121  7387 Jan  3 09:00 wp-activate.php
-rw-r--r-- 1 DELL 197121  5617 Jan  3 09:00 wp-cron.php
-rw-r--r-- 1 DELL 197121  5102 Jan  3 09:00 wp-trackback.php
-rw-r--r-- 1 DELL 197121  3937 Jan  3 09:00 wp-load.php
-rw-r--r-- 1 DELL 197121  3597 Jan  3 09:09 wp-config.php

An essential tool

The "ls" command is an essential tool for navigating and managing files in Linux. By mastering its various options, you can tailor its output to suit your specific needs and make file management more efficient. Experiment with these options to become more proficient in using this versatile command.