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101 Bash Commands and Tips for Beginners to Experts

Andrew (he/him) on January 13, 2019

Update 25 Sep 2019: This article is now available in Japanese, thanks to the hard work of ラナ・クアール. Please check out their work by following the li...

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Ben Halpern • Jan 14 '19

Holy cow!

Andrew (he/him) • Jan 14 '19

My Markdown editor started choking near the end of writing this. RIP Simplenote.

Joe Hobot • Jan 15 '19 • Edited

That's what s..... ah nevermind 😛

Andrea Giammarchi • Jan 15 '19

this is an awesome post but I've no idea how could anyone use a shell that looks like a pipe operator all the time ... some command with pipe reads very badly, why not removing all the starting parts of your snippets, adding a classic $ like any other shell, instead of 17:40 | andrew@pc01 ~ | ?

Phil Ashby • Jan 14 '19

Fabulous readable reference, thanks Andrew!

Minor niggle - almost all of these are not bash commands, but command line tools that work the same from any shell - it would be nice to know what are bash built-ins that might go pop in another shell, and what aren't :)

Long-running advanced voodoo:

disown (bash built-in): disconnects background processes from your terminal such that they stay running after you log off.
screen (cli tool): opens a new terminal (tty/pty), such that anything you run in that terminal stays running when you disconnect from it / log off. You can also reconnect (screen -r) when you log back in.

I prefer screen over using disown, because of the reconnection ability.

David J Eddy • Jan 16 '19

I'd like to add tmux to this list of helpful tools. Does similar thing as screen.

Andrew (he/him) • Jan 14 '19

Thanks, Phil! I'll have to do some more research.

Watch out for the "unabridged" version of this in the future.

xhiena • Jan 15 '19

Yes, I was missing those on the SSH section, @andrew really awesome post

Solomon Ucko • Jan 15 '19

FWIW, most of these aren't actually bash commands (only the builtins are); they're Unix/Posix/whatever commands.
Also, the prompt you use confuses me: it looks like there's an extra command (such as the ex command) at the start of the pipeline.

Bilus • Jan 14 '19

Great reference, I would suggest changing the format of your prompt. Having the | symbol dividing the time and username is confusing on first look.

Venkatesh-Prasad Ranganath • Jan 15 '19

Great list!! I would have added "type" and "tmux" to the list :)

For folks interested in useful Unix tricks, Unix Power Tools book is a great source.

Kyle R. Conway • Jan 14 '19

Impressive post! I remember when I found ncdu it was an amazing day. It's by far my favorite tool to find what's taking up my disk space! I really hope more people use it as a result of your excellent post!

Andrew (he/him) • Jan 14 '19

ncdu is great, it's what du should have been. Writing this post, I found a few other commands and flags that I forgot about / never learned about. One of my favourite ones is the -p flag to mkdir, which will create all missing intermediate directories! Small things like that can save you lots of time.

Robin Kretzschmar • Jan 16 '19

I think it's really awesome that you tought of the reader and added a "Back to TOC" after each topic for easy navigation!
And of course the content is very well explained with just enough words but much information in it :)

Janne Kujanpää • Jan 17 '19

Cool article but there are few things I need to disagree.

Environment variable creation

Using format foo=bar stores environment variable only current command. To keep environment variable loaded in your running bash process you need to export it with export foo=bar. This behaviour can be checked with commands env, printenv or by echoing environment variable.

source vs sh

Results of source and sh commands might look identical but they are not. Source command executes script in running bash and all exported envirenment variables are part of the running bash shell. sh invokes a new shell and exported variables are not usable in the calling shell. Also working directory of calling bash shell might be changed when using source command.

Please note that sh usually is linked to posh or some other lightweight shell which does not have all bash features.

Janne Kujanpää • Jan 18 '19

More about source

In some systems source and . are interchangeable command. (POSIX compatibility is swamp)

Anyway source command is good if you need (temporary) setup your environment: e.g. load environment variables, aliases and even request passwords from user with read -s <variable_name> or to load functions from external libraries.

Usually source is used in scripts(1) but I'm sure that users can find use cases when to use source to setup environment for running shell.

Bryn Smith • Jan 15 '19

Good post! Do not run kill -9, but rather use just plain kill, or kill -15 if that doesn't work.
Kill and kill -15 end a process somewhat gracefully, so that the os is at least notified that the process is killed. -9 just causes it to vanish with no notice. It's akin to just hitting the power button, on a process level, without doing any sort of shutdown routine.
Also, ag (Silversurfer) is my team's grep replacement, give it a look.

Michael Tharrington • Jan 14 '19

Exactly what I need right now...

Actually, more than I need, but in the best way, haha. Thx! 😄

Marcelo Xavier • Sep 19 '23

Great article!! Thank you so much for the contribution!👏👏

Btw, the exercise about nohup yes just almost broke my PC by creating a file of 40GB in less than a min!!🫣😱
This is because nohup created a log file called nohup.out appending all output values spit by the command. So in very little time I had a HUGE file with 'y' on each line.

I advise you to change this exercise before brake others computer storage : )

Thomas Melville • Jan 22 '19

A great resource, thanks.

If the file you're looking for is not found with locate, you can run updatedb to update the list of files for locate.

letsfindcourse • Nov 3 '19

This tutorial means that this is a brief introductory guide to SED that will help give beginners a solid foundation about concrete tasks.
letsfindcourse.com/tutorials/sed-t...

Heiko Müller • Jan 15 '19

Thank you for your impressive post!
And for mac users: If you want to use the very convenient ncdu command, there's a version available for Homebrew:

brew install ncdu

Aaron Ross • Jan 15 '19

rm -rf is commonly referred to as "rimraf" or "rimraf-ing".

Looking back it seems intutuitive but I didn't make that connection for the longest time.

Great article :)

Katie • Jan 14 '19 • Edited

Great post!

BTW, A similarly "for beginners" tutorial that I enjoyed, in book form, is M.G. Venkateshmurthy's "Introduction to Unix and Shell Programming," if anyone is still looking for additional material. (It gives fun "why" context to all of its "how" -- for example, it points out that the commands/flags of command-line interfaces are short and hard to remember because back when the only way to interact with your computer was a command line interface and only specialists used computers, the last thing programmers wanted to do was type a lot, so they just made up a bunch of cryptic short commands.)

Paul Rennix • Oct 12 '19 • Edited

WELL DONE!

set -x is a favorite of mine for debugging.

#!/bin/bash
set -x

this turns on line-by-line logic/command flow output and is great for debugging. It can be used inside a script or on the command line. If using on the command line, you'll want to turn it off at the end of the line. When used in a script, it's activity ends when the script does, or when unset with set -x

~ prennix$ set -x; for number in $(seq 1 3); \
do echo "Number ${number}"; done; \
if [ "${number}" == "3" ]; then echo "it's three"; \
else echo "this text is never printed"; fi; set +x

++ seq 1 3
+ for number in '$(seq 1 3)'
+ echo 'Number 1'
Number 1
+ for number in '$(seq 1 3)'
+ echo 'Number 2'
Number 2
+ for number in '$(seq 1 3)'
+ echo 'Number 3'
Number 3
+ '[' 3 == 3 ']'
+ echo 'it'\''s three'
it's three
+ set +x

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Karuna Sehgal • Jan 15 '19

Thank you for writing this post!

Andrew (he/him) • Jan 25 '19

Hi everyone!

Thanks for the amazing response to this article! I've updated the command prompt so it's a bit less confusing. I hope to post an updated / revised / expanded version of this in the future, where I'll take everyone's suggestions below into consideration.

Thanks again!

Amr • Jan 19 '19

the picture associated with the xdg-open command appears to be from a Windows machine! how would it be possible?

Andrew (he/him) • Jan 25 '19

Hi Amr,

Because I'm sshing into an Ubuntu machine from Windows using MobaXTerm. xdg-open (at least in this case) is using the default window styling from Windows.

readyready15728 • Jan 15 '19

Good article. Should have mentioned ipython and trash-cli though. (Also probably in most contexts, for the Python 3 version to run, one has to enter in "python3", "ipython3", "pip3" etc.)

Uday Vunnam • Jan 15 '19

This is so good. I can use many of these.
Thanks for sharing!!

Md.Atiqul Haque • Jan 15 '19

Very useful article. Thanks Andrew for this article.

Lasha Kakhidze • Feb 28 '19

Awesome post!!! Thanks Andrew.

Aidas Bendoraitis • Jan 16 '19 • Edited

Really remarkable article!

But it seems that top uses the capital -U for the username. At least on Mac OS and FreeBSD.

Ben Sinclair • Apr 2 '19

df takes a --max-depth=N

You meant du there, I think.

Andrew (he/him) • Apr 2 '19

I did, thanks! It's fixed now.

Janne Kujanpää • Feb 7 '19

Bonus tip for date command: date +%s prints unix time (in seconds)

Derek Rosenzweig • Jan 14 '19

Nice reference, thanks!

Gilang A. Ramadan • Jan 14 '19

Wohoo awesome, thanks!

Di Wu • Jan 15 '19

sick post! need these

Vignesh D • Jan 15 '19

Great. But that Pipe operator as prompt in the command snippet seems very confusing.

Jochem Stoel • Jan 15 '19

Epic.

Sung M. Kim • Jan 15 '19

Thank you, Andrew.

A great article written at the perfect time (I started using Ubuntu recently) 👍

Nilesh Kevlani • Jan 14 '19

Amazing article, got to learn many new thing :)

John Demian • Jan 15 '19

Sweet Jesus, this is awesome!
I took note of some of these, can't wait to show off in front of my peeps back at the office.

Jaime González García • Jan 14 '19

WoW

Nava • Sep 7 '19

This post is a great effort to cover most cli commands.It can help many to get started with command line.

Alexander Lazaris • Apr 8 '19

Awesome stuff Andrew! Funnily enough I missed the title (and the URL ...) and was pleasantly suprised by how many different commands you listed. Nice work

Prathap Rathod • Jan 14 '19

Thanks Andrew

Jesse M. Holmes • Jan 14 '19

I will use this, thanks! Now, if posts a similar article for PowerShell, I'll be done. lol

Chris Bertrand • Jan 14 '19

That's a monster post!

elliotd123 • Jan 16 '19

This is an awesome list - but it should be noted that most of these are not bash commands. They are just common programs. Many of them are therefore usable in any shell, not just bash.