I’ve been working for some time with Linux and I feel that sharing some scripts and also tools I frequently use can be helpful.

Search History

history | grep seach_string

or Ctrl+R.

Show File and Folder Size

To analyze file size, there are several ways.

ls -alh 
-rw-r--r--  1 amir amir 270K May 20  2023 Arial.ttf
-rw-r--r--  1 root root   72 Sep 20 21:10 Untitled5.ipynb
-rw-r--r--  1 amir amir 1.2M May 26  2023 exp12.mp4
-rw-r--r--  1 amir amir 4.7M May 26  2023 exp13.mp4
-rw-r--r--  1 amir amir 654M May 22  2023 exp4.avi
-rw-r--r--  1 amir amir   68 Dec 28  2022 kaggle.json
drwxr-xr-x 17 amir amir 4.0K Dec 28  2022 miniconda3
drwxr-xr-x  2 amir amir 4.0K May 26  2023 mp4

You can see from the above output that this only shows file sizes properly.

On folders, I use:

du -h --max-depth=1

(Optional) To sort it:

du -h --max-depth=1 | sort -hr

Of course, this is when I do not have access to sudo. In case of sudo access, I will pretty much always install ncdu via:

sudo apt install ncdu

This way, I would be able to easily navigate between folders and find out which folder is taking the most space.

Test Access to a Server or Service

This is especially the case in big companies when you should request access for a server. They may give the network access to you but not SSH access. Or you may just want to troubleshoot your network and what not.

ping ip
telnet ip port
nc -v ip port

for example:

telnet 22
nc -v 22

Show Network Ports Already being Used

This is especially useful for docker images when you want to spin up a docker image and you want to specify a new port to it.

netstat -nlpt 
(Not all processes could be identified, non-owned process info
 will not be shown, you would have to be root to see it all.)
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name
tcp        0      0    *               LISTEN      -
tcp        0      0  *               LISTEN      -
tcp        0      0  *               LISTEN      -
tcp        0      0  *               LISTEN      -
tcp        0      0  *               LISTEN      -
tcp        0      0  *               LISTEN      -
tcp        0      0 *               LISTEN      -
tcp6       0      0 :::22                   :::*                    LISTEN      -
tcp6       0      0 :::8017                 :::*                    LISTEN      -
tcp6       0      0 :::8019                 :::*                    LISTEN      -

Get Server Information

Logged in users:


IP Address:

ifconfig -a | grep inet


cat /etc/hostname

Linux Kernel:

uname -a

Disk Space:

df -h

Memory and CPU usage:


or maybe just install Neofetch.

Useful Terminal Tools to install

Watch Network Usage

sudo apt install iftop

Enable SSH Access to system

sudo apt install openssh-server

This way you can access your laptop (or server) via SSH easily.

Find Documentation for a command

Let’s say you want to read documentation for a command like find. You might do man find or find --help but none of them are easy to read. We can do better.

sudo apt install tldr
tldr --update

Install tldr (too long didn’t read) and then use tldr find. This way you would find a much better and easy to follow documentation. Just take a look at it. Isn’t that better? (+ / +)

Or, If you don’t want to install anything, you can just use cheat.sh like this:

curl cht.sh/tar
curl cheat.sh/tar

Also, see GitHub - jlevy/the-art-of-command-line: Master the command line, in one page.

A list of Great Tools to install