SSH

Make sure ssh-agent starts automatically and keys persist across reboots.

# Add these lines to ~/.bashrc
eval "$(ssh-agent -s)"
ssh-add -k ~/.ssh/*

# Check keys added to ssh-agent
ssh-add -l
ssh-add -L

SSH into a host machine:

# -i = pass in a private key (identity) file.
# IP = ip of the host machine
ssh -i ~/.ssh/id_rsa username@192.168.1.45
# Specify port
ssh <user>@<hostname> -p 8090

Kill a frozen SSH terminal:

# Key sequence = Enter, shift + ~, period

Copy file from remote to local machine desktop folder:

scp username@192.168.1.45:~/files/test.txt ./Desktop

Run bash commands on remote machine over SSH:

ssh username@192.168.1.45 "ls -la ~/files"
ssh username@192.168.1.45 "ls -la ~/files; cd /; ifconfig"	# Multiple commands.

Adding SSH keys:

# Start SSH agent. This wipes all existing keys from the agent.
eval "$(ssh-agent -s)"
# Add the key.
ssh-add ~/.ssh/id_ed25519
# List existing keys registered with the agent.
ssh-add -l

Generate Public SSH Key from Private Key:

ssh-keygen -y -f ~/.ssh/id_rsa > ~/.ssh/id_rsa.pub