Basics of using the Linux Command Line / SSH

This is a short sequence of videos discussing some basics of using the Linux command line (the Terminal.) Aimed at users new to the Linux command line this sequence of tutorials gives advice and information for using the Linux command line after connecting to the terminal or via SSH.

• You'll need to be connected via SSH or on the terminal of Linux server / machine.

Prints the current working directory (will show you what directory you are in.):

pwd

List the files in the directory you are in:

ls

Change the directory you are in:

cd

Change to the directory above the one you are in (the parent directory):

cd ..

Read the contents of a file:

cat

Text editor to edit the contents of a file:

vi

Move (cut) a file to another location:

mv

Installs nano on a Redhat / Centos system:

yum install nano

Install nano text editor on Ubuntu / Debian:

apt-get install nano

Download a file from the World Wide Web:

wget

Read the contents of a file and search it for something in this case the word searchterm:

cat filename.txt | grep searchterm

Create a file:

touch

Create a directory:

mkdir

List files in the directory showing permissions, sizes (human readable) last modified times an :

ls -laSh

Updates software repository and if successful upgrades installed software on the system (For CentOS and Red-Hat based distributions):

yum update && yum upgrade

Updates software repository and if successful upgrades installed software on the system (For Ubuntu / Debian based distributions):

apt-get update && apt-get upgrade

View space available on the server in a human readable format:

df -h

list disks, partitions and volumes for the server:

lsblk

Details of server CPUs:

lscpu

View live system usage information:

top

View available and used memory:

free

Connect via SSH from one Linux machine to another (in this case connect to the root user account for myserver.serverdown.co.uk):

ssh [email protected]

List processes listening on TCP along with their port numbers:

ss -plnt

Set the hostname on a CentOS system:

hostnamectl set-hostname chosenhostname.serverdown.co.uk

Check the hostname of the system:

hostnamectl status