Understand Bash Environment Variables With This Deep Dive

[@matman1975]

Only you can make learning so much fun, the only reason I started on Linux was watching your videos. Thanks Andrew for taking the time to help so many people who want to learn.

[@theurbanpenguin]

Thanks Matthew

[@Perciwell]

You strike exactly the point of my current interest. I am currently reading and searching for information about the different variables in Linux, their scope and about the differences between environment variables and shell variables and the differences between commands like set and env. Many authors write or say that there are two types of variables: shell variables and environment variables. One author writes that there are three types of variables in Linux: environment variables, shell variables and local variables. I try to understand all those facts thoroughly. Thanks for your video! It's very good.

[@theurbanpenguin]

Thank you

[@Perciwell]

@@theurbanpenguin It's not a comment on your teaching. But I wonder why I have currently difficulties to understand all differences or kinds of variables, although I knew some programming languages and their concepts. IMO those difficulties to understand have to do with the fact that most authors mention that there are different variable types and than dive into the handling of commands like set, env, printenv, export or output of variables with echo etc. But to really get it I personally need first a clear overview. I need to know the available boxes very clear, before the book or teacher dives in one of those boxes and rummages in edges of one box. This is not about your teaching style, in the current moment I only try to understand why the heck it takes so long for me to understand such simple things. I guess, it's because before I really get the whole picture from a bird's-eye view the teacher or book is -- or I am -- in details about particular commands and situations, so that I never memorize a clear view of the whole and every time get lost in details.

[@harunwagura4727]

Best instructor I've come across!!!

[@saheedadebayo8063]

What an excellent teacher you are Andrew!

[@theurbanpenguin]

That is so kind, thank you

[@woesdiary263]

Thank you Mr. Mallett!

[@TyroneHillsmbw]

Sir, You are a Master of your trade!!! Thank God for teachers like you. Shalom from Israel💯🦁🗣

[@Somabilbooks]

you are the Best how to explain is easy and Highly Recommended

[@theurbanpenguin]

Thank you 🙏

[@anssimakela]

Nice vid! could you do a presentation "how to make dynamic names for variables" and how to call those in script...

[@srb1855]

This was excellent 👍. Is any of this material actually documented in the MAN pages or any other official Linux documentation - where does a new user go to learn these details in the absence of nice videos like this one?

[@theurbanpenguin]

The bash man page does help but it is a long read linux.die.net/man/1/bash

[@omparikh4426]

how about more deep overview of env and path variables?pam_environment, xserver, etc

[@santoshkulkarni6871]

Wonderful @urbanpenguin

[@theurbanpenguin]

Thank you

[@enoughmuskspam2490]

Dude you're a legend !

[@theurbanpenguin]

Thanks

[@marwanalturky]

that was an excellent video, thank you very much for your time to make this video.

[@ahsanhabibsonar7059]

Great video. Thank you very much.

[@wesg01]

Awesome stuff as usual. Thank you!

[@graybri]

Fantastic content

[@theurbanpenguin]

Thanks

[@lazellekeith8025]

I see you changed the Logo for the Urban Penguin. Did somebody complain? If so, I kinda figured it would be only a matter of time. That's unfortunate. I liked it..! I didn't find it offensive at all as a person of color. Cheers! btw. great videos!

[@turtlewax3849]

Thank you sir, hope there will be more soon!

[@theurbanpenguin]

You bet!

[@MrYerak5]

The compiler should show a warning since you need to return int but you return void

[@theurbanpenguin]

But it didn't

[@theurbanpenguin]

add -Wall to see all warnings

[@guilherme5094]

Thanks!

[@theurbanpenguin]

Welcome!

[@SlideRSB]

You set your drink environment variable incorrectly. It should be drink=coffee

[@theurbanpenguin]

Of course, I let myself down

[@SlideRSB]

@@theurbanpenguin great video, by the way. I learned a lot.

[@ajaykumark107]

Esc+. a good trick learnt

[@theurbanpenguin]

Thank you

[@SpojlerSSJ]

Hello, you done a great job I've learn a lot from you. I got a question about static IP address on ubuntu, I try to install newest Ubuntu Server after few years and i stuck with new manager, I try look for answers on your video about configuring static IP on ubuntu 12.10 it's little outdated :( Can we expected updated version on newest distro? :)

[@theurbanpenguin]

Thanks 20.04 and 18.04 use netplan for their ip configuration

[@itaco8066]

Awesome

[@theurbanpenguin]

Thank you

[@GauravMehtaShwetaMehta]

Very nice. Thanks

[@theurbanpenguin]

So nice of you

[@FrankTheile]

Now `CROSS_COMPILE=arm-linux- make` makes sense... 😲

[@theurbanpenguin]

For sure, TBH I have never tried the cross compile. I have heard of it but never done it. Now is the time to try and run on my RPi. Thank you

[@MichaelSalo]

It seems like variables are available to subshells in this form. (echo $drink)

[@theurbanpenguin]

Only environment variables. Those that have been exported

[@MichaelSalo]

@@theurbanpenguin This seems to be a case of a subshell accessing a regular variable: drink=tea echo $drink # same shell, gives 'tea' (echo $drink) # subshell, gives 'tea'

[@theurbanpenguin]

drink=tea echo $drink bash echo $drink Drink is not available unless it is exported or set in the bashrc file.

[@MichaelSalo]

@@theurbanpenguin I guess there are different kinds of subshell. Some would say parentheses are a form of subshell.

[@theurbanpenguin]

@@MichaelSalo parentheses evaluate the output of a command a feed it into a temporary or unnamed variable. The command is executed in the current shell hence your local variable works