Am new to this app and my stream is mechanical engineering and i am interested in learning about unix and its command's

Question

so which lessons should I select ?

Answer 1

1) command "man" is your best friend. It represents manual(s) for the shell. It displays manual pages based on the given argument you give it. For example "man ls" will display the manual for the ls command.

2) "man -k 1" is your next best friend. It displays all user commands in the shell. There are others like kernel calls and what not, but you'll use the user functions more than others.

3) commands/functions have a general setup in the shell: [command] [options] [arguments]
commands are the command(s) you're calling.
options are self-explanatory in that they setup the function call in a given way. Some are optional, others are required. Manual pages will usually tell you.

4) the shell is case sensitive.

5) Be careful when giving arguments that contain special characters. The shell first checks the command you give it before passing it to the function. So for example if you use \n, the shell interprets the backslash as "ignore the next character after backslash". You can see this if you type this "echo \s" the shell will display just "s", but try using "echo \\s". You'll notice it displays the \s. You can prevent the shell from actively interpreting these by wrapping your arguments in double quotations "echo "\s" ".

6) CTRL+C is your friend, and kills the current process. Very helpful for when some functions go in an infinite loop, or if you want to exit while it's actively doing something.

There are many tutorials out that approach learning how to use the shell. Most go into scripting right away. I was taught in university by learning functions and mixing them up, and understanding them before going right into that. But to each their own. Here's a tutorial I just googled. There are plenty more out there:

https://www.howtogeek.com/67469/the-beginners-guide-to-shell-scripting-the-basics/

As for what courses on sololearn. I would learn Python or ruby to understand the basic fundamentals, then move into a language that fits your field.