Basic UNIX commands

Lately, I started learning commands lines. I mean, I used npm install or gulp, but no more.

So I started using commands lines and I have to say that I like it. A lot.

I wanted to share with you what I learned.

cd

The cd command is used to change the current directory.

cd stand for change directory

cd path/of/directory

To move up by one directory you can hit cd .. Source

ls

The ls command list all files of a type other than directory, found in the current directory.

ls stand for list segments

ls

man

The man command display the online manual pages. We can specify a section as parameter. The section is normally the command, function or file name.

man stand for manual.

man name_of_command

To exit the manual you can hit q, :q, Q, :Q or ZZ.

mkdir

The mkdir command is used to create a new directory. The directory would be create in the current directory.

mkdir stand for make directories.

mkdir name_of_directory

rmdir

The rmdir command is used to remove an empty directory.

rmdir stand for remove directories.

rmdir name_of_directory

We can pass an -p option. In this case each directory argument will be treated as a single path and will be removed if they are empty.

rmdir -p name/of/directory

mv

The mv command is used to move a file into a given directory.

mv stand for move.

mv name_of_file name/of/directory/destination/

open

The open command is used to open a file or a directory

open name_of_file

I know, it's very basic, but you have to start somewhere. 😅

I created a Gist where I add what I learn.

And you, what are your favorite commands?

Comments

[Moritz Schramm]

I really do love tar -xfv test.tar and ls -lisa

[Jérémy Levron]

If I understand correctly, you can chain options? -xfv means -x, then -f, then -v, is it correct?

[David Woodward]

This is correct (of most commands)! Some more complex ones can't be chained.

For example, you can't chain --this-is-an-arg and --this-too-is-an-arg but individual letters are usually fine.

[Carl Schelin]

I typically use ls -lart :) (the a isn't necessary but it is appropriate ;) )

[Ben Sinclair]

I understand why you do that and it spoils it a little to add a letter - but my only common use case apart from a normal ls is ls -larth.

[michaeltd]

If you find your self puzzled by the various archive extensions then this is for you. Linux CLI unpack unification script.

pastebin.com/wNCP166T

(Excuse the shameless plug btw)

[Jérémy Levron]

Oh yeah, good to know, thanks!

[David Woodward]

If you're finding yourself attacking those annoying commands often, consider setting an alias for them!

Instead of typing ls -AbcClhoG, you could alias all that into ll.

First thing's first, assuming you're using bash/sh and not zsh or variants (use which $SHELL to figure that out!), run nano ~/.bashrc to start editing your config for the shell.

You'll then want to add an alias at the bottom now, using alias ll="ls -AbcClhoG". Easy!

Ctrl + C, Y, Y to save and exit nano, and you'll want to source ~/.bashrc or make a new tab in Terminal to reload your settings.

---

You can run any commands and name them however you want - even chaining them as you go.

command & command will run them concurrently, whilst command && command will run each individually assuming the last command succeeds. command & will leave the task running indefinitely, so be careful (you can always Ctrl + C out of it).

[Can Nuhlar]

Or you can press Ctrl + Z after you do command & to run it as a background job.

[Andrew Chou]

I think cat and which are extremely useful

[Jérémy Levron]

Oh which command is very useful indeed, especially on macOS where paths are hidden. Thanks, I discovered!

[Ian Kirker]

Using open like that is an OS X/macOS thing -- the FreeDesktop.org standard most Linux distributions adhere to is to use xdg-open.

On Linux, the open command handles virtual terminals.

[Jérémy Levron]

Oh thank you, I didn't know. I note it

[Can Nuhlar]

Nice post! Just a note though, open command is a little different between Mac OS and Linux distributions. Linux equivalent is xdg-open.

Edit: You guys already noticed it :(

[Douglas R Andreani]

The find command is one of the most useful on your toolkit

find . -exec cp {} . \;
(Recusevely find all files in a path and copy to the root)

[jD91mZM2]

Although you should really be using fd

[Cary Reams]

save yourself.
unlearn rmdir.
now.

[Jérémy Levron]

There's something wrong with rmdir?

[Cary Reams]

nope, nothing at all

my bad

I saw "rmdir" and read "rm -rf"

[Promise Akpan]

rm -rf does incredible and irreparable damage except you have backups handy.

[Andrej Naumovski]

You can't restore a backup if you rm -rf /.

[Promise Akpan]

Exactly. You just wiped out the entire system..
Well except if you have an external backup of some sort. 😏

[krishraghuram]

grep is awesome way to search for stuff.

Particularly when combined with | operator to chain stuff.

For example, ls | grep my_file.txt

[Promise Akpan]

Awesome start Jeremy. When I played with Unix terminal for the first time, I made a major mistake which was not going over the basics.

Add these especially if you are in a directory

cd .. takes you back
cd - takes you to the previous directory

ls -sh lists the files/directories with their sizes
ls -l lists the details including permissions.

There are lots more, but add these to yours

Have fun in your journey!