linux_handy_stuff

Check the display devices

To display the devices the command is

sudo lshw -c

to check the display devices and kernal

inxi -G 

nvidia-smi

This repository contains the important and common to use shell commands for a quick reference.

Copy directory from local to remote

We can use secure copy (scp) with the recursive option (-r):

sudo scp -r /path/to/local/dir user@remotehost:/path/to/remote/dir
sudo scp -r /home/muhay/Documents/scripts remote@1.1.1.1:/home

Copy directory from remote to local

sudo scp -r user@remotehost:/path/to/remote/dir /path/to/local/dir
sudo scp -r remote@1.1.1.1:/home/scripts /home/muhay/Documents

Alternatively rsync because we can resume transfers if the connection breaks, and it intelligently transfers only the differences between files:

rsync -avz -e 'ssh' /path/to/local/dir user@remotehost:/path/to/remote/dir
rsync -avz -e 'ssh' user@remotehost:/path/to/remote/dir /path/to/local/dir 

Copy files by excluding hidden files

rsync -av --exclude=".*" RepoA/ RepoB/

SSH Key Generation

open terminal/cygwin and type

ssh-keygen.exe

press enter for all answers

Copy the public key into the remote system

scp .ssh/id_rsa.pub remote_user@IP:  e.g. (scp .ssh/id_rsa.pub muhayy@192.168.1.1:)

the colon is important

Access the remote system using ssh with follwoing command

ssh remote_user@IP   e.g. (ssh muhayy@192.168.1.1)

Permissions

Command	Meaning
chmod 400 file	To protect a file against accidental overwriting.
chmod 500 directory	To protect yourself from accidentally removing, renaming or moving files from this directory.
chmod 600 file	A private file only changeable by the user who entered this command.
chmod 644 file	A publicly readable file that can only be changed by the issuing user.
chmod 660 file	Users belonging to your group can change this file, others don't have any access to it at all.
chmod 700 file	Protects a file against any access from other users, while the issuing user still has full access.
chmod 755 directory	For files that should be readable and executable by others, but only changeable by the issuing user.
chmod 775 file	Standard file sharing mode for a group.
chmod 777 file	Everybody can do everything to this file.