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The ls command

The ls command lets you see the files and directories inside a specific directory (current working directory by default). It normally lists the files and directories in ascending alphabetical order.

Examples:

  1. To show the files inside your current working directory:
ls
  1. To show the files and directory inside a specific Directory:
ls {Directory_Path}

Syntax:

ls [-OPTION] [DIRECTORY_PATH]

Interactive training

In this interactive tutorial, you will learn the different ways to use the ls command:

The ls command by Tony

Additional Flags and their Functionalities:

Short Flag Long Flag Description
-l - Show results in long format
-S - Sort results by file size
-t - Sort results by modification time
-r --reverse Show files and directories in reverse order (descending alphabetical order)
-a --all Show all files, including hidden files (file names which begin with a period .)
-la - Show long format files and directories including hidden files
-lh - list long format files and directories with readable size
-A --almost-all Shows all like -a but without showing .(current working directory) and .. (parent directory)
-d --directory Instead of listing the files and directories inside the directory, it shows any information about the directory itself, it can be used with -l to show long formatted information
-F --classify Appends an indicator character to the end of each listed name, as an example: / character is appended after each directory name listed
-h --human-readable like -l but displays file size in human-readable unit not in bytes

SELinux Support on Red Hat-Based Systems:

On Red Hat-based distributions (RHEL, CentOS, Fedora, Rocky Linux, AlmaLinux) that use SELinux, the ls command provides additional options to display SELinux security context information:

Short Flag Long Flag Description
-Z --context Display SELinux security context for files and directories
-lZ - Show long format with SELinux security context

Example Output:

ls -Z
unconfined_u:object_r:user_home_t:s0 file.txt
unconfined_u:object_r:user_home_t:s0 directory
ls -lZ
-rw-rw-r--. 1 user user unconfined_u:object_r:user_home_t:s0 1234 Jan 15 10:30 file.txt
drwxrwxr-x. 2 user user unconfined_u:object_r:user_home_t:s0 4096 Jan 15 10:25 directory

The SELinux context format is: user:role:type:level

Note: The -Z option is only functional on systems with SELinux enabled. On non-SELinux systems, this option may not be available or will show no additional information.

Setting Persistent Options:

Customizing command behavior in Linux is easy using the alias command. To make these changes permanent, follow these steps:

  1. Create the Alias: Define your alias with the desired options. For example, to enhance the ls command:

    alias ls="ls --color=auto -lh"

  2. Persistence: This alias is effective only for the current session. To make it permanent, add the alias to your shell's configuration file:

    • Bash: Append the alias to ~/.bashrc:

      echo 'alias ls="ls --color=auto -lh"' >> ~/.bashrc
source ~/.bashrc

  3. Verification: Open a new terminal session, and the ls command will display files as configured.