Bash Scripting on Linux (The Complete Guide) Class 03 - Variables

Welcome to LearnLinuxTV's brand new complete course on Bash Scripting! In this 18 episode series, you'll learn everything you need to know in order to start writing Bash scripts. Each video builds on the previous one, with additional concepts added as the series progresses. Examples will start off easy with shorter scripts, and by the end of the series you'll be able to write more complex scripts that will actually come in handy while maintaining Linxu servers. In this episode, we'll take a look at variables.
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Time Codes
00:00 - Intro
00:52 - Declaring a variable in Bash
01:45 - How to reference a variable in Bash
06:25 - Using variables within Bash Scripts
16:44 - How to use the output of a command within a Bash Script
22:23 - How to view the environment variables within your Linux session
OTHER BASH SCRIPTING SERIES EPISODES
- Class 01 ➜ Introduction: linux.video/bash1
- Class 02 ➜ Hello World: linux.video/bash2
- Class 03 ➜ Variables: linux.video/bash3
- Class 04 ➜ Math Functions: linux.video/bash4
- Class 05 ➜ If Statements: linux.video/bash5
- Class 06 ➜ Exit Codes: linux.video/bash6
- Class 07 ➜ While Loops: linux.video/bash7
- Class 08 ➜ Universal Update Script: linux.video/bash8
- Class 09 ➜ For Loops: linux.video/bash9
- Class 10 ➜ Where To Store Your Scripts: linux.video/bash10
- Class 11 ➜ Data Streams: linux.video/bash11
- Class 12 ➜ Functions: linux.video/bash12
- Class 13 ➜ Case Statements: linux.video/bash13
- Class 14 ➜ Scheduling Jobs (Part 1): linux.video/bash14
- Class 15 ➜ Scheduling Jobs (Part 2): linux.video/bash15
- Class 16 ➜ Arguments: linux.video/bash16
- Class 17 ➜ Building a Backup Script: linux.video/bash17
- Class 18 ➜ Closing: linux.video/bash18
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• Systemd Deep Dive ➜ linux.video/systemd
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Learn Linux TV provides technical content that will hopefully be helpful to you and teach you something new. However, this content is provided without any warranty (expressed or implied). Learn Linux TV is not responsible for any damages that may arise from any use of this content. The person viewing Learn Linux TV's content is expected to follow their best judgement and to make their best decisions while working with any related technology. Always make sure you have written permission before working with any infrastructure. Also, be sure that you're compliant with all company rules, change control procedures, and local laws.
#linuxtutorial #linux #ubuntu

[@brave.circassian77]

best linux teacher on youtube

[@p5eudo883]

Great series. The intro is longer than my ADHD can cope with, so I skip ahead right away. But the presentation is fantastic.

[@Akahatoo]

Awesome content, quite calming and with hands-on examples

[@alonkadosh400]

This series is so easy to understand and is perfect for beginners. Thank you!

[@jessetello7033]

thank you so much for this series! its been so helpful for my class at university. I am excited to continue learning!

[@davey820051]

Excellent series. You've done a good job of making each installment easily digestible in terms of concepts covered and running time. Thank you.

[@071asadahbar4]

Excellent series, this is the best shell scripting tutorial I can find across the internet.Thank you so much ! You are an excellent teacher

[@sridhartn83]

This is the best shell scripting tutorial I can find across the internet. well paced, explanation of every single term and concept and not just vaguely using it without an explanation to back it, thanks a lot for putting this together, I really appreciate for doing this.

[@Elclaapo]

Great series! Really well done. The fact it is free is pure gold. Thanks a million Jay :)

[@Naposta77]

This is a wonderful resource for linux beginners. Excellent!

[@vincentlivera2948]

You are the best, Buddy. Thanks

[@cristian.adragna]

Bravo! Un corso ben organizzato! Well done!

[@patrob3885]

Thank you so much ! You are an excellent teacher ! I have learnt so much

[@g-jalil6961]

Brilliant series!

[@logger00]

very nice explotnation ,thanks bro best sireis of this topic

[@faradhamadi]

Great work sir thanks for your useful information

[@jonc5373]

Brilliant video. Thank you!

[@RajkoRuza]

Great series!

[@HerrDerDrucker]

You are best teacher ! Thank u so much homie !

[@fabiobianchi3104]

thanks for the class!!!

[@DevOps691]

thanks for this class.

[@jojobobbubble5688]

This helped my wright much DRYer code. Thanks much!

[@AlbandAquino]

I was about to leave a comment about the quotes (and how double quotes allows for variables replacement and single quote don't), but I'm glad I waited 👍🏼
Excellent video, as usual. Your channel is my Linux "cheat sheet" 😁

[@rzbappy7213]

awsome tutorial man

[@simonkalu]

This is refreshing. thanks

[@samiramir91samor78]

Sir thank you really great work

[@chesterbelle]

ty for the lesson your a great teacher

[@rreuter18]

Awesome Series.

[@barkhadibraahim1023]

thanks so much

[@cavenmasetla8740]

When I heard your sad background story I knew this is the guy I have been looking for. I'm going to chill here until Im a senior Linux engineer. Thanks a million Sir

[@fadidib8516]

from this video, i noticed that you follow patterns, a professional.

[@Wespodcastz]

This guy is the best teacher alive..

[@Rithishrayen03]

Great sir

[@JinSheng1990]

very cool!

[@peterjansen4826]

Some people might wonder how you could use the $-sign in the echo command given that the $-sign is used to call a variable. Use the escape-character \ in front of it. This applies in general if you struggle to use a character in a command, like the space or slash.

[@aKa55]

like SHELL was also a regular variable from the system. I wil have my Linux Essentials next week, so thank you very much for ur videos. sub!

[@franciscoromogaray3076]

another banger ma dude

[@CorporateDrone]

amazing!

[@vj1980]

Thank you so much

[@codewithlamin]

Great lecture

[@allahdadkhan8498]

great job.

[@hamadej]

super useful tutorial

[@nazimzhonmullabaev6622]

Thx you man

[@kainaatmakhani6550]

informative lecture

[@burstfireno1617]

Subbed! very cool channel

[@doucesides3805]

appreciate it

[@josephchamness9915]

Nice video series.
I find scope vexing. I used to try updating my $PATH in a bash script and run into problems. Or creating a variable in 1 script and using it in a different 1.😅

[@rickgrimes47]

Damn! You are the best teacher!

[@prateekbhardwaj9943]

your workstation is interesting

[@TechRebel2008]

i use kali linux... btw nice explanation bro

[@haltutor8014]

thanks for this series. not sure why you had quotes around the age variable, tho. isn't that a number and not requiring quotes?

[@leonel_carrizo]

thanks!

[@_nathan978]

Another way to determine variables predefined in bash: Type the dollar sign ($) in the terminal and press tab

[@guilherme5094]

👍Nice!

[@anass_lm9awd_bzf]

3tak lah sa7a habibi

[@seshuyudansh7208]

Thanks alot Jay seems im going to master the scripting which I never get interest to learn

[@silentnight4618]

"A single quote may not occur between single quotes, even when preceded by a backslash." - bash manual

[@TheNotSoSecretUser]

Can you tell us what font you are using here? 😮

[@manomite3544]

I have two questions...
1) Can we camel case method to create variable names like myUsername instead of myUsername.
2) Is it possible to escape the single quote using back slash... Like
'I\'m jude $USER'

[@chrisrodriguez8026]

can you make a new file and instead of reusing the old one. It makes it easier to look back at what you have done.

[@hootiebubbabuddhabelly]

SOLVED! So, how does one restore bash, once one has trashed it somehow?
I accidentally figured out how to reinstall bash, which, apparently, you can't do WITHOUT bash, ROFL, which is EXTREMELY annoying! BUT - you CAN log into the folder with the reinstall scripts AS ROOT, in nemo or, maybe some other file managers as well - not sur - THEN leave the file manager open as root and reinstall with the package manager GUI.
I intended to switch the offending file from bash to sh and then change it back but when I went to change it back after FINALLY getting bash to reinstall with Synaptic, I discovered I'd failed to save the changes so, the only other thing it could have been was the fact that I was logged into the folder in the file manager as root. SOOO - got my terminal back, got bash, got everything updated, everything's working and I can go back to playing with bash scripts! I still don't know how I broke it in the first place so I reckon I'll find out, in pretty short order. But since reinstalling bash is so easy now, who cares?!?! WHEEEE!
If you ever want to know how dependent you are on bash, just break it. I was over a week with no terminal and it 'bout drove me nuts. I couldn't even make a bootable flash drive without it! Couldn't update, install or reinstall anything and, of course, no terminal - though I did get an sh terminal at one point, but that didn't survive my attempts to repair bash so I was totally terminal-less. Thought I was going to have to reinstall and reharden everything which is precisely what I wanted a bash script for - "auto-hardening".

[@lance_c1323]

My Bookmark

[@lance_c1323]

04-08-23 @ 1205AM 10:40

[@anjanbora7943]

Bash command==> 💋

[@hasanferoz2364]

For New Bash Scripters:
do not leave spaces between myname="Jay"
in linux if you wrote myname = "Jay" linux will think it as a command and display unknown command error...

[@Alpha_Sadigh]

☯🙏

[@Mitology]

Thank you! Please subscribe and like the video, free education is AWESOME!