Get Ubuntu Set Up
Try multipass from the folks who make ubuntu. This allows us to "Get an instant Ubuntu VM with a single command".
- download that
- "open" the app
- this doesn't really "open" anything visible for me other than a toolbar icon
- the toolbar icon has a dropdown when clicked - open the dropdown and then click the
Open Shelloption - THIS is the beginning of the shell and Linux :)
If you
The Shell, the REPL, and the FS
A Repl
A REPL is a Read-Evaluate-Print-Loop cycle.
This REPL cycle is what is "happening" in the terminal/shell/command prompt.
The terminal's "job" is to Read, then Evaluate, then Print, then Loop. The content the terminal is REP-ing is the text that gets entered in the terminal.
A Shell
The shell, and particularly the Bourne Again Shell (bash) interprets the command-line UI. Bash is also a scripting language.
Mac now comes with zsh, a different type of shell.
Windows come with PowerShell, another type of shell.
A FileSystem
The shell is always "in" a folder - just like the "finder" on a mac or the file explorer on a windows machine.
Sometimes files are referred to as directories,dir, or files. Directories or dir work better as descriptors than "files" - files are often used to describe documents.
the "present working directory" is the current directory that the shell is "in" or "at".
The shell can be used to "navigate" or browser around files/directories through the "file system" - the "system" of files.
Each directory and file "lives" at a file system "path". The path looks like a bunch of words, directory names, separated by / slashes.
A path could be something like /Users/Jake/Desktop/projects/linux-blog/interacting-with-ubuntu.md.
FS commands
pwd: where am I
pwd shows the "present working directory" path.
Typing pwd and pressing <Enter> will tell the terminal to Read the input, evaluate the direction, and print the result.
In a ubuntu environment, the default "location" of the shell is at /home/ubuntu and the pwd command should return that!
The current directory represents the ubuntu user in the home directory.
Every user gets a directory && the default user is the ubuntu user - hence home/ubuntu.
ls: show me a list
ls is like show me a list of files in the pwd.
Typing ls in the terminal should show 2 things that look like Home snap.
The ls is like looking around a "room" noticing all of the directories in the room and printing everything visible.
cd: changing directory
cd is short for change directory.
cd .. will "back out" of the current directory. "back out" is a phrase used to represent moving the terminals location "up" one directory...
With the pwd at /home/ubuntu the ubuntu directory is "in" the home directory, hierarchically. Maybe like putting a paper folder inside another paper folder.
backing out
typing cd .. will "move" the terminal to be "in" the home directory.
With the terminal at the home directory, typing ls will show the ubuntu directory that the shell was just in before typing cd ...
going down
typing cd ubuntu will "move" the terminal "down" into the ubuntu directory.
So,
cd .. can be used to go "back" or "out" or "up" one directory.
ls can be used to show all contents in the current directory.
cd <a-nested-directory> can be used to go "into" a directory at the same "level" as the terminal.
getting specific
cd can be used to go several directories "down" and several directories "back".
cd can be given more specific directories to change into && out of:
with the pwd at /home, typing cd ubuntu/snap/multipass-sshfs/ will change "down" 3 directories.
Here, typing pwd will show /home/ubuntu/snap/multipass-sshfs.
cd can also be given more specific "backing out" instructions -
with the pwd at /home/ubuntu/snap/multipass-sshfs, typing cd ../../../ will "back out" into the /home directory.
Here, typing pwd will show /home.