Bash allows us to reuse parameters or even whole command. It seams to be nothing, but in reality it helps a lot. Let’s start with examples.

Suppose, you have command like this:

apt-get --purge remove nginx

Command won’t work. You need admin privileges. Instead of typing sudo and whole command again, you can just type:

# Short way - use previous command as parameter
sudo !!

# Long - just for comparision
sudo apt-get --purge remove nginx

# Problem with connection? - try again whole last command
!!

Which do you prefer?

But it’s not only sudo case

# Create file and reuse its path
touch /home/user_name/documents/very/obscure/path/to/new/document/new_document_with_obscure_path.md
vim !$

# Or do hard work twice
touch /home/user_name/documents/very/obscure/path/to/new/document/new_document_with_obscure_path.md
vim /home/user_name/documents/very/obscure/path/to/new/document/new_document_with_obscure_path.md

Docs

Not every option works with each BASH version. Just check what works in your environment.

!!    # run / reuse full command
!$    # run as a command / reuse last parameter
!^    # run as a command / reuse first parameter
!*    # run as a command / reuse all parameters
!:0   # run as a command / reuse previous command name
!:n   # run as a command / reuse n'th parameter
!:n-m # run as a command / reuse parameters form n to m
!:^-$ # run as a command / reuse all parameters
https://stackoverflow.com/questions/3371294/how-can-i-recall-the-argument-of-the-previous-bash-command https://ss64.com/bash/bang.html
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