So I have been daily driving Linux systems on my PCs for a year now, but I still haven’t “learn Linux” systematicly yet, so here I decided to take a course on this, and here are my notes.

Basic Navigations

When we open up a terminal emulator or TTY, we are usually in our home directory by default.

To see the where we are currently, use:

pwd

To See My Username

whoami

or

echo $USER

List File and Directories

Now let’s see what’s in current (or any) directory:

ls <directory>

  • to see hiddent permissons,timestamps and more info of them, add -l flag:

    ls -l

  • some distribution may have preconfigured alias for it as:

    ll

  • to list hidden files, add -a flag:

    ls -la

  • to list contents of directory and its sub-directories, use -R to list recursively:

    ls -laR

alternatives to ls:

  • exa https://github.com/ogham/exa written in Rust

    exa is a modern replacement for the venerable file-listing command-line program ls that ships with Unix and Linux operating systems, giving it more features and better defaults. It uses colours to distinguish file types and metadata. It knows about symlinks, extended attributes, and Git.

  • lsd https://github.com/Peltoche/lsd written in Rust

    This project is a rewrite of GNU ls with lot of added features like colors, icons, tree-view, more formatting options etc.

Change Directory

To change to a different directory:

cd <directory path>

In Linux/Unix or macOS, directory/file path can be:

  • Exact location

    cd /home/user0/Documents

  • Absolute location

    # Assume that I am in user0's home directory already
cd Documents

    . is the current directory, this following command is the same as above

    cd ./Documents

    if I am in /home/user0/Documents/notes, use .. to go up a directory

    cd ..

  • This ~ tilde sign represent current user’s home directory

    cd ~/Documents

Now that covers the basics of navigation, of course there are more ways such as tree, but let’s move on for now.