Overview
alias is a powerful feature that helps you use commands more efficiently in the shell. You can use it to simplify complex commands, correct typos, or ensure specific options are always included.
Key Features
- Command Shorthand: Replace long, frequently used commands with shorter names.
- Typo Correction: Automatically correct common command typos.
- Default Option Setting: Ensure specific commands always run with certain options.
Key Options
The alias command itself has a few usage patterns.
Alias Management
Generated command:
Try combining the commands.
Description:
`alias` Executes the command.
Combine the above options to virtually execute commands with AI.
Usage Examples
Define a new alias
alias ll='ls -alF'Shorthand the frequently used 'ls -alF' command to 'll'.
View all currently set aliases
aliasCheck the list of all aliases defined in the current shell session.
Check the definition of a specific alias
alias llVerify which command a specific alias (e.g., 'll') is defined for.
Remove an alias
unalias llDelete an alias (e.g., 'll') that is no longer needed. (Use the unalias command)
Override an existing command
alias rm='rm -i'Set an alias for the rm command to always run in interactive mode (-i) to prevent accidental file deletion.
Tips & Precautions
Tips and points to consider for effective alias usage.
Setting Permanent Aliases
Aliases are only valid for the current shell session and disappear when the shell is closed. For permanent use, add the `alias` command to one of the following files and restart your shell or apply it using the `source` command.
- Bash: `~/.bashrc` or `~/.bash_profile`
- Zsh: `~/.zshrc`
Using Quotes
When defining an alias, if the command contains spaces, it must be enclosed in single quotes (') or double quotes ("). Single quotes prevent variable expansion, while double quotes allow it.
- Example (no variable expansion): `alias myip='ip a | grep inet'`
- Example (with variable expansion): `alias mydir="ls -l $HOME/Documents"`
Overriding Existing Commands
You can override existing commands with aliases, such as `alias rm='rm -i'`. While this can be useful for safety, it can also lead to unexpected behavior, so exercise caution.
- To execute a command with an alias as the original command, prepend a backslash (`\`) before the command (`\ls`) or use the `command` keyword (`command ls`).