ssh / scp / rsync

Connect to a remote host via SSH.

ssh username@hostname

Connect using a specific port.

ssh -p port username@hostname

Run a remote command and exit.

ssh username@hostname "command"

Copy a file from local to remote (scp).

scp localfile username@hostname:remotepath

Copy a file from remote to local (scp).

scp username@hostname:remotefile localpath

Sync from local to remote (rsync).

rsync -avz localdir/ username@hostname:remotedir/

Command / Option	Description
ssh user@host	Connects to the specified host via SSH.
ssh -p port	Specifies the connection port (default is 22).
ssh -i keyfile	Specifies the private key file to use.
ssh -L localport:dest:port	Sets up local SSH port forwarding.
scp file user@host:path	Copies a file over SSH.
scp -r directory	Recursively copies a directory.
scp -P port	Specifies the port for scp (uppercase P).
rsync -a	Syncs in archive mode, preserving permissions and timestamps.
rsync -v	Syncs with verbose output.
rsync -z	Compresses data during transfer.
rsync --delete	Deletes files at the destination that no longer exist at the source.
rsync --dry-run	Simulates the transfer without making any changes.
rsync -e "ssh -p port"	Specifies the SSH port used by rsync.

The following examples use this SSH connection configuration.

~/.ssh/config

Host myserver
    HostName 192.168.1.100
    User deploy
    Port 2222
    IdentityFile ~/.ssh/id_rsa

Connect via SSH using an alias. Defining entries in ~/.ssh/config keeps your commands short and simple.

ssh myserver

Run a command on the remote host and retrieve the output locally.

ssh myserver "df -h /"
Filesystem      Size  Used Avail Use% Mounted on
/dev/sda1        50G   23G   25G  48% /

Upload a local file to the server using scp.

scp -P 2222 ./config.json deploy@192.168.1.100:/var/www/app/

Recursively copy a directory.

scp -r ./dist/ deploy@192.168.1.100:/var/www/html/

Deploy with rsync. It is good practice to run --dry-run first to preview the changes before applying them.

rsync -avz --delete --dry-run ./dist/ deploy@192.168.1.100:/var/www/html/
sending incremental file list
./
index.html
css/style.min.css
js/common.min.js
deleting old-page.html

sent 234 bytes  received 45 bytes  186.00 bytes/sec
total size is 1,234,567  speedup is 4,426.69 (DRY RUN)

If the dry-run output looks correct, remove --dry-run to perform the actual sync.

rsync -avz --delete ./dist/ deploy@192.168.1.100:/var/www/html/
sending incremental file list
./
index.html
css/style.min.css
js/common.min.js

sent 45,678 bytes  received 92 bytes  18,308.00 bytes/sec
total size is 1,234,567  speedup is 26.99

Sync a backup into a date-stamped directory.

backup_sync.sh

date_dir=$(date +%Y%m%d)
rsync -az /var/www/html/ /backup/$date_dir/

bash backup_sync.sh

Use SSH port forwarding to tunnel local port 8080 to port 80 on the remote host.

ssh -L 8080:localhost:80 myserver

For deployments, rsync -avz --delete is the standard choice. The --delete flag removes files at the destination that have been deleted at the source. Always verify with --dry-run before applying changes to production.

Storing your SSH connection details in ~/.ssh/config simplifies your commands and makes them easier to manage. Make sure your private key has the correct permissions (chmod 600).