This information is provided for the Ubuntu/Debian editions of Linux used in the CS Department. Other Linux versions may vary.

In Linux, you can use the Secure File Transfer Protocol (SSH File Transfer Protocol) (SFTP) from the command line (CLI) (the sftp command) to securely copy files and directories between remote hosts.

In most cases, SFTP is preferable to FTP because of its underlying security features and ability to piggy-back on an SSH connection. FTP is an insecure protocol that should only be used in limited cases or on trusted networks. FTP is NOT available on CS Department computers.

You can establish a SFTP connection by issuing the following command:

sftp [options] remote_username@remote_host

You will connect the the remote system and your prompt will change to an SFTP prompt.

• Name of the account on the host computer (remote_username)
• Hostname (i.e. FQDN) of the computer on which the source file resides (remote_host)

Options can include things like [-oPort=custom_port] if not connecting to the standard SSH port 22.

Once connected to the remote host, you can navigate around the remote file system with commands similar to the Unix/Linux Shell.

• pwd: show remote working directory.
• ls: view contents of the current remote directory.
• cd: change remote directory.

You can direct commands towards the local file system by preceding them with an “l” for local.

• lpwd: show local working directory.
• lls: view contents of the current local directory.
• lcd: change local directory.

Transferring files from the remote system is accomplished by using the appropriately named “get” command:

To download a file from the remote host.

get remote_filename

To download a file from the remote host and rename.

get remote_filename new_local_filename

To download a directory and it's contents.

get -r remote_directory

To preserve full file permissions and access times during the copy, use the -p flag.

get -p remote_filename

Transferring files to the remote system is accomplished by using the appropriately named “put” command:

To upload a file to the remote host.

put local_filename

To upload an entire local directory to the remote host.

put -r local_directory

To quit a SFTP session use the exit command

exit

SFTP has a help command. This gives you access to a summary of the SFTP help. You can call it by typing either of these in the prompt:

help

?

This will display a list of the available commands:

You can find more information on Ubuntu SFTP in the Ubuntu man pages