alias command in Linux

The Linux alias command allows users to create custom shortcuts for frequently used commands. By using aliases, users can save time and increase productivity by simplifying complex or lengthy commands into shorter, more memorable ones. Aliases can be set up for specific users or system-wide, making it a versatile tool for customizing the command line experience. With the alias command, users can define new commands, override existing ones, or add options to existing commands. This flexibility empowers users to tailor their command line interface to suit their specific needs and preferences.

alias Syntax:

alias [name]='command'

Linux alias Options:

Option	Description
-p	Print all defined aliases in a format that can be reused as input.
-r	Remove specified alias.

alias Parameters:

Parameter	Description
name	The alias name to be defined or modified.
command	The command or sequence of commands to be aliased.

Caution

Caution: Be careful when using aliases as they can potentially override existing commands or cause confusion for other users. Make sure aliases do not conflict with existing commands before setting them.

How to use alias command:

Create a simple alias

alias ll='ls -alF'

Creates a new alias named “ll” which will execute the “ls -alF” command when used.

List all existing aliases

alias

Displays a list of all currently defined aliases.

Remove an alias

unalias ll

Removes the alias named “ll” from the system.

Create an alias with arguments

alias lsd='ls -l | grep "^d"'

Creates an alias named “lsd” which lists only directories.

Temporarily override an alias

\ls

Temporarily overrides an alias (in this case, “ls”) and executes the original command.

Persisting aliases

echo "alias update='sudo apt update && sudo apt upgrade -y'" >> ~/.bashrc

Adds a new alias named “update” to the ~/.bashrc file for persistent use.

Display details of a specific alias

alias ll

Displays the definition of the alias named “ll”.

Create a chained alias

alias lf="ls -l | grep -E '^\-\|'"

Creates an alias named “lf” which lists only regular files.

Tip

Always remember to use single quotes when creating an alias with parameters to prevent unexpected behavior due to variable expansion.

How do I use alias in Linux?

To use the alias command in Linux, execute the following command:

alias --option <value>

How do I create a new alias in bash?

To create a new alias in bash, use the following command syntax:

alias new_alias='command_to_alias'

How do I list all existing aliases in bash?

To list all existing aliases in bash, run the following command:

alias

How do I remove an alias in Linux?

To remove an alias in Linux, use the unalias command followed by the alias name. Here is an example:

unalias alias_name

How do I make an alias permanent in bash?

To make an alias permanent in bash, add the alias command to your ~/.bashrc or ~/.bash_profile file. It will automatically load every time you start a new shell.

How can I temporarily disable an alias in bash?

To temporarily disable an alias in bash, use the command unalias followed by the alias name. Here is an example:

unalias alias_name

How do I show the alias definition for a specific alias in bash?

To display the definition of a specific alias in bash, use the alias command followed by the alias name. Here is an example:

alias alias_name

Can I use an alias name that is the same as a built-in command in bash?

Yes, you can create an alias with the same name as a built-in command in bash. The alias will take precedence over the built-in command when you run it.

How do I export an alias to be available in subshells in bash?

To export an alias to be available in subshells in bash, use the following command:

export -f alias_name

Applications of the alias Command

• Creating custom shortcuts for frequently used commands
• Shortening long or complex command syntax
• Adding default options or flags to commands
• Improving productivity by saving time on typing repetitive commands