README.md

Common linux commands

• Author: Pedric Kng
• Updated: 04 Dec 2019

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Tail linux system blogs

tail -f /var/log/syslog

SSH Installation

sudo apt install openssh-server
sudo systemctl status ssh
sudo ufw allow ssh

Dotnet SDK Installation

wget -q https://packages.microsoft.com/config/ubuntu/18.04/packages-microsoft-prod.deb -O packages-microsoft-prod.deb
sudo apt-get install apt-transport-https
sudo apt-get update
sudo apt-get install dotnet-sdk-2.1

wget https://download.visualstudio.microsoft.com/download/pr/e5eef3df-d2e3-429b-8204-f58372eb6263/20c825ddcc6062e93ff0c60e8354d3af/dotnet-sdk-2.1.500-linux-x64.tar.gz
sudo mkdir -p /opt/dotnet && sudo tar zxf dotnet-sdk-2.1.500-linux-x64.tar.gz -C /opt/dotnet
sudo ln -s /opt/dotnet/dotnet /usr/local/bin
dotnet --info

Remove Dotnet

apt-get remove dotnet-host

Openjdk 8 installation

sudo apt-get install openjdk-8-jdk
java -version

Create/Edit Systemctl (Systemd) Service

List all services

sudo systemctl

sudo systemctl list-units --type=service
sudo systemctl --type=service

If service already exists, you need to stop the service.

sudo systemctl stop <service name>

# Optional to delete the service
sudo systemctl disable <service name>

Create/Extend new service file

# Create new service file
sudo vim /etc/systemd/system/<servicename>.service

# Edit existing service file
sudo systemctl edit <servicename>

Refer to [2] for service file editing

Add service to systemctl

# Reload the service configuration
sudo systemctl daemon-reload

# Manual reload
sudo systemctl reload <servicename>

# Add service to systemctl
sudo systemctl enable <servicename>.service
sudo systemctl start <servicename>
sudo systemctl status <servicename>

Remove service from systemctl

# Reload the service configuration
sudo systemctl stop <servicename>
sudo systemctl disable <servicename>
rm /etc/systemd/system/<servicename>.service
systemctl daemon-reload
systemctl reset-failed

References

Introduction to Systemctl [1]
Working with unit files [2]