BrainDump

SSH to a server with port and public key:
ssh -p 1234 -i pubkey.file username@example.com

Create a tar.gz file from a folder:
tar czf /path/to/output/folder/filename.tar.gz /path/to/folder

Copy a file from a remote server to localhost:
scp -P 1234 -i pubkey.file username@example.com:filename.tar.gz /home/sgergely/folder/