Aliases (PowerShell users, skip this section)

Since we saw that rm is a wrecking ball, we should temper it using the -i flag. For safety, we would like rm to always ask us about deletion. We can instruct bash or zsh to do this for us by creating an alias.

alias rm="rm -i"

After executing this, any time we use rm, our shell will instead execute rm -i, thereby keeping us out of trouble.

Another useful alias, often implemented by default, is to make ls list things more prettily.

For macOS:

alias ls="ls -FG"

For Linux:

alias ls="ls -F --color"

The -F flag makes ls put a slash at the end of directories. This helps us tell the difference between files and directories. The -G or --color flag enables coloring of the output, also useful for differentiating file types.

Furthermore, if you decide to use rsync, you may want to alias rsync -avzP to rsync:

alias rsync="rsync -avzP"

Aliases will usually be forgotten when you close the current terminal. To make them persistent, add the command to ~/.bashrc (on most Linux or old macOS) or ~/.zshrc (on macOS). If these files do not exist, you can create them.

Copyright note: In addition to the copyright shown below, this recitation was developed based on materials from Axel Müller.