Linux Tips For Beginners

Linux Tips that you regret not knowing earlier...

Configure Linux password-less login

Add your public key to ~/.ssh/authorized_keys.

To get a public key, simply execute the ssh-keygen command, then you'll find your public key and private key in ~/.ssh

The public key is used to encrypt your data, and only the corresponding private key can decrypt that data.

Save printed text

There're two ways to accomplish this.

Use the tee command

The tee command redirects stdout to a given file as well as print those text to the screen. usage:

ls | tee <path/to/output/file>

The | symbol is used to redirect the output of the command before it to the command after it.

Use the > or >> symbol to redirect output

usage:

ls > out.txt

> overwrites existing file, while >> append new content to existing file.

Refresh command every 1 second

Let's say you want to refresh the nvidia-smi command every second, you can simply type

watch -n 1 nvidia-smi

You can also change 1 to any number to increase or decrease refreshing frequency.

Release network port on Debian

First, install iptables.

sudo apt install iptables

Let's say you want to release the 8888 port, you can simply type

iptables -I INPUT -p tcp --dport 8888 -j ACCEPT

Then save the rule that you just set.

iptables-save

Now the changes are taking effect. However, it will lost after a reboot, to actually make the changes to be persistent, you have to install iptables-persistent

sudo apt install iptables-persistent

Then save the rules persistently

netfilter-persistent save
netfilter-persistent reload

Now the port is released forever.

Check how much disk space is free

Simply type

df -h

Enable mouse support for vim

Enter :set mouse=a in vim command mode.

This will expire after the current session is terminated.

To enable that by default, add

set mouse=a

to the ~/.vimrc file.